wrap large scale hdpe recycling trial report.4328448f.3769

7/27/2019 WRAP Large Scale HDPE Recycling Trial Report.4328448f.3769

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Large Scale HDPE Recycling Trial

Project code: MDP006 ISBN: 1-84405-308-3

Research date: Date: February 2007


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Front cover photograph:

While steps have been taken to ensure accuracy, WRAP cannot accept responsibility or be held liable to any person for any loss or damage arising out of or in connection

with this information being inaccurate, incomplete or misleading. It is the responsibility of the potential user of a material, product or process to consult with the supplier

or manufacturer and ascertain whether a particular product or process will satisfy their specific requirements.

The listing or featuring of a particular product, process or company does not constitute an endorsement by WRAP and WRAP cannot guarantee the performance of

individual products, processes or materials. For more detail, please refer to WRAPs Terms and Conditions on its web site: www.wrap.org.uk

Published by

Waste & Resources The Old Academy Tel: 01295 819 900 Helpline freephone

Action Programme 21 Horse Fair Fax: 01295 819 911 0808 100 2040

Banbury, Oxon E-mail: [email protected]

OX16 0AH


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Large Scale HDPE Recycling Trial 1

Executive summary

The development of world leading UK recycling technology allows post-consumer milk bottles to be recycled back

into food contact milk bottles. Milk bottles with 30% recycled content perform identically as virgin resin bottles,

have been extensively tested and have passed all EU, UK and consumer tests and are currently in production

within UK dairies. The revolutionary technology represents the first time post consumer HDPE Milk bottles have

been recycled back into Milk Bottles with full food contact status. This achievement is a world first.

The process is innovative in the unique separation technology and the decontamination process that it uses. The

sorting process exploits a new sensitivity that can identify the homopolymer used in milk bottles apart from the

balance of the HDPE bottles in the waste stream. The decontamination technology has demonstrated its

efficiency via challenge tests that show it is capable of decontaminating HDPE to a "super-clean" state to

meet food packaging standards.

The resin and bottles have been tested at industrial scale production and have performed in exactly the same

manner as virgin materials and bottles requiring no changes to production equipment beyond the introduction of

blending equipment.

The milk bottles represent worlds best practice in sustainable milk packaging and will save significant amounts of

energy and greenhouses gases and make a major contribution to landfill reduction as the technology spreads

through the milk packaging industry. Consumers have positively endorsed the use of recycled content in food

packaging.


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Contents

1.0 Introduction............................................................................................................................. 42.0 Supply of Baled HDPE............................................................................................................... 43.0 Bottle Washing and Grinding Process ...................................................................................... 4

3.1 Washing and Granulating of HDPE Bottles Process Background.............................................43.2 Balestock Material Differentiation..........................................................................................53.3 Adhesive Contamination Issues in rHDPE......................................................................... ......63.4 Flake Colour Differences (Batch A / Batch B) ...................................... ...................................73.5 Other Key Findings..............................................................................................................93.6 Material Balance for the Washing/Grinding Step at Sorepla ........................................... ........10

4.0 Sorting of rHDPE Flake........................................................................................................... 104.1 Flake Sorting Requirements................................................................................................104.2 Efficiency of Flake Sorting ........................................ ....................................... ................... 124.3 Flake Surface Residue........................................................................................................18

5.0 Extrusion and Decontamination of rHDPE Flake.................................................................... 195.1 Material Extrusion & Decontamination................................................ ................................. 195.2 Visual Analysis of Recycled HDPE pellets ........................................ ..................................... 195.3 Rheological Results .......................................... ........................................... ...................... 205.4 Material Balance after Sorting and Extrusion..................... ........................................ ...........215.5 Overall Material Balance.....................................................................................................21

6.0 Blow Moulding of Milk Bottles................................................................................................ 226.1 Processing of Recycled HDPE Pellets into Milk Bottles ............................................ ...............226.2 Blow Moulding Conclusions ...................................... ........................................... ...............226.3 Nampak Plastics Evaluation of rHDPE resin......................................... ................................. 23

6.3.1 Material A - Nampak Blow Moulding Trial Evaluation: .......................................... .....236.3.2 Material B Nampak Blow Moulding Trial Evaluation................................................236.3.3 Nampak Plastics Blow Moulding Evaluation Summary ....................................... ........24

7.0 Milk Bottle Filling Trials and Tests ......................................................................................... 247.1 Visual Analysis of Milk Filled Bottles ............................................ ........................................ 257.2 Full Scale Commercial Milk Filled Bottles (Chadwell Heath 05-08/12/2006) ............................. 257.3 Full Scale Commercial Milk Filled Bottles (Severnside)...........................................................26

7.3.1 Severnside Audit Trail............................................................................................277.3.2 Summary: ....................................... ........................................ ............................. 28

7.4 Conclusions from Filling Trials ......................................... ............................................... ....298.0 Milk Bottle Decontamination Analysis ................................................................................... 29

8.1 Fraunhofer IVV Material Testing .......................................... ........................................... ....298.2 Screening of HDPE Recyclates for Migration Relevant Compounds ..................................... ....298.3 Screening of rHDPE Milk Bottles for Migration Relevant Compounds.......................................318.4 Determination of the Overall Migration from HDPE Milk Bottles (Fraunhofer IVV) ....................34

8.4.1 Overall Migration Results ........................................ ........................................... ....358.4.2 Food Regulatory Assessment .................................. ....................................... ........35

8.5 Determination of the Specific Migration of Irganox 1076 (Fraunhofer IVV)..............................35 8.5.1 Results of Specific Migration of Irganox 1076 ........................................... ...............358.5.2 Food Regulatory Assessment .................................. ....................................... ........35

8.6 Overall Migration from Milk Bottles (PIRA International Analysis) ........................................... 368.7 Migration Studies on Recycled HDPE to be Used for Milk Packaging - PIRA ............................. 37

8.7.1 Conclusions .................................. ....................................... ................................. 378.8 Recycled HDPE Decontamination Conclusions ..................................... ................................. 378.8.1 Conclusions from Volatile Screening of HDPE Flake, Pellet and Milk Bottle... ...............37

8.8.2 Overall Migration Conclusions.................................................................................388.8.3 Specific Migration Conclusions................................................................................398.8.4 Decontamination of Recycled HDPE Key Findings:.................................................39

9.0 Sensory and Bacteriological Test Results .............................................................................. 399.1 CCFRA Sensory Test Results...............................................................................................39

9.1.1 CCFRA Findings ................................... ....................................... .......................... 409.1.2 Conclusions .................................. ....................................... ................................. 40

9.2 Reading Scientific Services Sensory Test Results ..................................... .......................... 40


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9.2.1 Sensory Evaluation Taint Test: .......................................... ..................................... 409.2.2 Sensory Evaluation Triangle Tests: ......................................... ................................ 419.2.3 Conclusions .................................. ....................................... ................................. 41

9.3 Bacteriological Testing ......................................... ............................................... ...............419.3.1 Conclusions:.........................................................................................................41

9.4 Dairy Crest - RHDPE Bottle Filling and Shelf Life Assessment Report ...................................... 419.4.1 Aims:... ....................................... ........................................ ................................. 419.4.2 Scope: ..................................... ........................................ .................................... 419.4.3 Methodology: ...................................... ....................................... .......................... 429.4.4 Results.................................................................................................................42 9.4.5 Summary ................................. ........................................ .................................... 469.4.6 Conclusion ................................... ....................................... ................................. 46

10.0 Legal Assessment of the EU Food Contact Status for Recycled HDPE Milk Bottles............... 4710.1 Keller and Heckmann Assessment.......................................................................................4710.2 EU Food Contact Status of Recycled Plastic Materials............................................................47

10.2.1 EU Harmonization ....................................... ........................................... ...............4710.2.2 Suitable Purity of Recycled Plastics ........................................ ................................. 4810.2.3 Regulation of Recycled Materials in the EU Member States ....................................... 4810.2.4 Establishing a Suitable Regulatory Status of Nexteks Post-Consumer Recycled HDPEMilk Bottles.......................................................................................................................4810.2.5 Summary of the Food Safety Assessment................................................................50

11.0 Fraunhofer Institute IVV Expert Opinion on rHDPE Milk Bottles Food Contact Safety....... 5011.1 Introduction......................................................................................................................50 11.2 Technical Aspects..............................................................................................................5011.3 Compliance with Food Legislation ........................................... ........................................... .5111.4 Evaluation ..................................... ....................................... ............................................ 52

12.0 Project Conclusions................................................................................................................ 52Appendix 1 Participant Details........................................................................................................... 55Appendix 2 Screening of HDPE Recyclates for Migration Relevant Compounds................................ 56Appendix 3 Screening of HDPE Milk Bottles for Migration Relevant Compounds.............................. 73Appendix 4 Determination of the Overall Migration from HDPE Milk Bottles.................................... 80Appendix 5 Determination of the Specific Migration of Irganox 1076 .............................................. 83Appendix 6 PIRA Migration Study...................................................................................................... 86Appendix 7 Migration Studies on Recycled HDPE for Milk Packaging (PIRA).................................... 91Appendix 8 Legal Assessment of rHDPE Food Safety in the EU and UK (Keller & Heckmann LLP).. 109Appendix 9 Fraunhofer IVV Expert Opinion ..................................................................................... 116Appendix 9 Milk Taint Test Data ...................................................................................................... 121Appendix 10 Sensory Test Results ................................................................................................... 130Appendix 11 Milk Filling Trial Protocol............................................................................................. 146Appendix 12 Dairy Crest Comparison of Virgin and Recycled Bottles APC Results ......................... 152Appendix 13 Rheological Test Data ................................................................................................. 156Appendix 14 Variations in Balestock Quality ................................................................................... 158Appendix 15 Extrusion Mass Balance............................................................................................... 159


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1.0 IntroductionThis project was initiated by WRAP to demonstrate the feasibility of large scale recycling of milk bottles from

kerbside collection sources into food grade recycled HDPE resin. Recycling of high density polyethylene (HDPE)

milk bottles is highly attractive as it provides a recycled material stream that is rheologically highly consistent with

a fairly consistent MFI (Melt Flow Index) of approximately 0.6 g/10min. Furthermore rHDPE resin derived from

milk bottles is in high demand as it is unpigmented and provides the most consistent recycled HDPE stream.

2.0 Supply of Baled HDPEThe balestock material for the large scale trial was ordered from RECOUP in the UK. The material as ordered was

to be manually pre-sorted HDPE, with the specification being for less than 5% coloured HDPE content. RECOUPhad obtained the balestock (2 truckloads) from two different suppliers. The balestock on the 1st truckload was

primarily made up of milk bottles. It was later discovered that the second truckload was found to contain

significantly high levels of coloured HDPE from HC (household cleaning) containers such as detergent, shampoo,

cleaning agents and fabric softener type bottles. The effects of this difference in supply had significant

consequences for this trial. These are further described in later sections of this report.

Figure 1 Pictures of UK pre-sorted HDPE balestock that was used in this trial.

The balestock material was collected in the UK and shipped to a large bottle recycling facility in France

Sorepla Industrie S.Afor bottle washing and grinding. The process description, a material balance as well as key

findings from the washing and grinding stage are described in the following section of this report.

3.0 Bottle Washing and Grinding Process3.1 Washing and Granulating of HDPE Bottles Process Background

Analysis of balestock at Sorepla revealed that besides milk and juice bottles the HDPE balestock also contained

household cleaning containers such as detergent and cleaning agent type bottles which are manufactured from

copolymer HDPE. This was particularly the case with the 2nd truckload delivery where bale analysis indicated a

10-20% coloured HDPE content. The first truckload of bales was clearly made up of majority milk bottles. These

milk bottles had primarily green, blue and red coloured caps

The washing plant based at Sorepla uses the Sorema washing technology and together with the grinding process

is based upon a typical industrial recycling process for plastic bottles with a production throughput of 2 tonnes/hr.

The bales were broken up using a bale breaker and declumper, passed through vibrating tables and trommels to

remove caps and other contaminants. The bottles also contain residues which need to be removed during the

grinding and washing step. At Sorepla this involved a whole bottle hot wash as well as flake washing. The bottles

were hot-washed and passed through a further trommel to remove labels, caps, fibres and other film type

contamination. The post-consumer HDPE bottles were then visually checked and any PET, PVC and non-PE

bottles were manually removed from the conveyor belt. Where possible coloured-HDPE bottles were also


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removed, however the large percentage (>10%) made it impossible to manually remove these. The balestock

also contained large amounts of 5-20L HDPE containers and these had to be manually removed as they had

caused a number of conveyor blockages.

Aluminium and other tin can contamination was found to be very low and was either manually removed, or

removed in the process through trommels or via the Pellenc optical sorting system which automatically rejected

any metal contamination. Analysis of this system showed that it was also picking up and rejecting large amounts

of milk bottles which contained aluminium foil induction cap seals. At Sorepla the Pellenc sorting system removed

many of these bottles. Overall it was had found that significant number of milk bottles had contained the

aluminium foil induction cap seals.

After visual inspection and manual sorting, the bottles were granulated into flake (5-8mm) and then elutriated to

remove fines and plastic film contamination. The flake was then washed to remove residual labels and adhesives

as well as milk and other bottle residues. The washed flake was then transferred to a sink-float tank to separate

other polymers or contaminants. The flake was then rinsed off, dried and bagged.

Figure 2 Bottle and flake wash chemistry flowchart.

3.2 Balestock Material DifferentiationGiven the differences in balestock supply a decision was made to classify flake from the 1st truckload as Material

A and flake from the 2nd truckload as Material B.

Samples from Material A (1st truckload) had shown that colour content in the final flake product was primarily

around 4-6% (w/w). The main colour content was from caps as the coloured flakes were primarily green, blue,

followed by red and some whites. The percentage of natural-HDPE flakes that still contained attached labels was

found to be as high as 5%. Clean natural HDPE flake was determined to be approximately 90% of the flake

product after the hot wash and grinding process at Sorepla.

Material from the 2nd truckload had also contained milk bottles but also contained a significantly higher level of

household cleaning containers. This was clearly evidenced in flake samples as the coloured HDPE composition

had changed to the following colours; white, yellow, orange, light blue, light green, purple and black. These

colours are not typically used in the dairy industry and as milk bottle caps are primarily a dark green, blue or red

colour. The colour content variation between batch A and batch B is shown in Figures 3 and 4.

Figures 3 Material A Unsorted Flake Figure 4. Material B Unsorted Flake

Figures 3 and 4 These pictures provide a visual comparison of the differences between the supply of Material A

and Material B.

Bottle Wash

Hot Water

Caustic

Flake Wash

Hot Water

Detergent

Antifoaming Agent

Flotation Tanks

Water

Antifoaming Agent

Flake Rinse

Water

Antifoaming Agent


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Some of the following household cleaning bottles and other type bottles were present in the bales:

Bleach, detergent, shampoo and fabric softener bottles

Industrial and automotive cleaning agent bottles

Weed spray bottles

Motor oil bottles

The HDPE balestock, although manually pre-sorted, also contained between 1-3% of other non-PE bottles such

as PET, PVC and PP bottles as well PE film in the form of plastic bags and some Tetra-pak cartons. These bottlesand film were being manually removed at Sorepla at a manual sorting conveyor belt. Testing of final HDPE flake

samples were found to have on average a PET/PVC contamination of approximately 6.75ppm, but certain samples

did show PET/PVC contamination as high as 48ppm.

3.3 Adhesive Contamination Issues in rHDPEHot melt adhesives can cause a number of major problems during recycling of HDPE. For example some rubber

based hot melt adhesives can become blended with HDPE during reprocessing and reduce the mechanical

properties of the rHDPE resin. Furthermore adhesives that are not water soluble cause a number of problems

during further reprocessing stages and cause darkening of the extruded recyclate. During the trial, it was noticed

that specific milk bottles had labels with very strong glues that did not come off during the hot wash. Whilst there

were a variety of labels that stayed on the bottles, the following labels were particularly visually prevalent in this

balestock:

Company & Milk Bottle Details Comments

Somerfield Stores Ltd(www.somerfield.co.uk)Semi-skimmed milk

Green labels on these milk bottles were notcoming off the bottles during hot wash process.

Nisa Todays Holdings Ltd(www.nisa-todays.com)Nisa Todays Heritage Fresh Milk

Green labels on these milk bottles were notcoming off the bottles during hot wash process.

Welsh Milk Bottles had primarily green but also blue labels.Most labels were not coming off and the hot washprocess had problems with removing both green and blue labels.

Kwik Save(www.kwiksave.co.uk)

Bottles had both green and blue labels, which were not coming offthe bottles.

Iceland Milk(www.iceland.co.uk)

Green labels on milk bottles not coming off the bottles.

Sainsburys BritishSemi-skimmed milk

Green labels on these bottles were occasionally not coming off.These bottles may have slightly more water soluble glues

Table 1 Details of specific labels that were difficult to remove during this particular trial.

The issue with troublesome adhesives and labels will need to be resolved by setting up dialogue about adhesives

with the bottle packaging industry. Tests on the washed flake samples had indicated that approximately 1.5-5.5%

of the natural HDPE flake still contained labels stuck to the flake after the hot-wash process. It was also

discovered that the colours from many of these labels had leached out to a major degree into the wash water,

however the polypropylene (PP) labels themselves still remained attached to the flake due to the strong water

insoluble adhesives used.

Dairy Crest have provided feedback on the labels which were found to be difficult to wash off. These labels were

all exclusively PP, some single ply and some laminated. Many of the dairies have been persuaded that PP givebetter performance in terms of application onto the bottles. The dairy industry requires an adhesive that as very

high tack and will cope with wet bottles and a cold damp environment and for this reason a rubber based hot

melt adhesive. The hot melt rubber based adhesive is permanent and is therefore very difficult to remove. Paper

labels on milk bottles absorb moisture and the washing liquids and as such wash off more easily during the hot-

wash process, which then exposes the underlying adhesive to the hot caustic wash and allows for the adhesive to

be washed off. The PP labels do not absorb any liquid and as such remain firmly stuck to the flakes. Dairy Crest

was advised that the flake sorters would be able to remove the flakes that had stuck labels onto them. Dairy

Crest had previously had discussions with milk label suppliers about their adhesives, but were informed that this


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style of adhesive is an industry standard and that it would be difficult to change this and changing the adhesive

could be costly.

This feedback corresponds well with what was found during the trial. This is why the flake sorter was set up to

specifically remove both coloured flakes as well as flakes with attached colour faded labels. The higher levels of

flakes with attached labels had later resulted in increased material loss during the sorting stage. Analysis of the

labels that were difficult to remove showed that all were PP and primarily laminated, although some were also

single ply.

Figure 5 Examples of difficult to remove labels; aluminium caps and induction seals in caps as well as some

labels with leached ink.

Figure 6 Microscopic analysis of individual flakes. When viewed under a microscope a substantial amount of glue

residue appears coated in green coloured ink.

3.4 Flake Colour Differences (Batch A / Batch B)As described in earlier section of this report an important finding was determined regarding the levels and source

of coloured HDPE within the balestock. This difference had resulted in colour variation within the washed flake


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product.

Bulk bags of flake that contained significantly higher levels of a coloured-HDPE flake of 10-17% after initial

testing of the flake was classified as Material B. All bulk bags classified as Material B were segregated to be

double sorted and extruded separately to Material A. Analysis of Material B flake bulk bags, indicated a more

uniform spread of colours. In particular colours such as white, yellow, orange and light purple were more

dominant than green, blue, black or red colours. The colour variation was therefore more evenly distributed. The

flake also smelled differently and the odour could be described as detergent type smell. However the important

factor was that the surface colour of this flake was significantly cleaner and did not show any of the visible

greenish tinge of Material A. Another factor that may have contributed to the cleaner flake itself may have beenthe washing action of the residual detergent from the household cleaning containers. These bottles were

primarily detergent bottles, bottles containing cleaning products, bleach bottles, shampoo bottles, etc. Due to the

much higher levels and wider spectrum of colours it was decided that it would be necessary to sort this flake

twice.

The bulk bags that had less coloured flake were primarily from milk bottles, and the coloured flakes consisted of

mainly green, blue and red coloured HDPE fragments as would typically be seen on milk bottle caps. Prior to

extrusion and decontamination at Erema, this flake had a typically clear milk bottle based odour. The surface

colour of the Nat-HPDE flakes themselves were noted to have a green tinge. This was visually observed by

comparing the flake surface colour to samples from the previous WRAP trial as well as the flake from Material B in

this trial. Visually there was a visible difference between the samples. This material contained approximately 1-

5% colour content and hence it was decided that bulk bags with this flake would be sorted once only. The

greenish flake surface residue seen in Material A is shown and further discussed in Section 4.2 of this report.

A potential reason why Material A flake exhibits a greenish tinge is due to a combination of adhesive removed

from labels or antifoam and the inks from labels had washed into the water and then deposited as a thin film on

the surface of the flake. The flakes produced from 2nd truckload (Material B) were free of this green tinge possibly

due to lower levels of green labels and or possibly due to the extra washing action of residual detergents and

cleaning agents from the household cleaning bottles.

Whilst the coloured ink from wrap around labels had leached out a lot more easily, many of the single ply or

laminated PP labels, which were primarily green, blue with black print, had also lost the printed colour and been

leached from the label itself during the hot wash of the whole bottles as well as the flake washing at Sorepla. It

may be that the leached colour from the labels may have contaminated the wash water colour and therefore

coated the surface of the HDPE flakes. This may not have happened with the flakes from Material B due to the

presence of residual detergents and cleaning agents. Due to the colour variation between Material A flake and

Material B flake a decision was made to separate the bulk bags for sorting purposes.

Therefore it can be concluded that are two label related issues that will require optimization of washing and

sorting:

Labels with strong glues that do not dissolve in water and did not come off after the hot wash.

Labels where the glue and colour leached out into the hot wash water and built up within the water andcoated the flakes in a thin film of glue and green ink/pigments.

Suggestions for improvements:

Printing inks, particularly those containing heavy metals and pigments that easily leach out need to beavoided.

If stick on labels are needed it is best to use water soluble adhesives instead of hot melt or solventbased adhesives for convenient removal during washing stages

Where possible use wrap around labels or shrink sleeves, as these come off easily during washing andafter granulation. During the trial it was discovered that the wrap around labels were the easiest toremove from the bottles, however these labels do not have stable inks and pigments as these leach out

during the washing stages. The following pictures show how easily the ink from wrap around labels hadleached out. This is clearly shown in Figure 6.


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Figure 7 Examples of leached ink from milk bottle labels after a hot wash process.

3.5 Other Key Findings

None of the laboratory tests on flake samples showed any aluminium content, however it was expected

that the flake product would contain residual aluminium contamination due to the high level ofaluminium foil induction cap seals, as well as aluminium foil caps on some flavoured milk bottles andsmall yoghurt drink bottles. These metal foils would be eventually removed by the extrusion process.

Many of the bottles after the hot wash still contained caps which need to be removed as the caps werecoloured and were approximately 10% (w/w). These caps were not coming off easily during the hot-

wash or during the debaling and trommeling processes.

Detergent bottles and other household cleaning containers, although HDPE are also primarily colouredand as they are made from copolymer HDPE it is preferable that these containers are removed andrecycled separately. Due to the high level of coloured household cleaning type bottles in the 2nd

truckload bales, it was not physically possible to manually remove many of these at Sorepla and as suchthe majority were left in the recyclate stream and would need to be removed using the flake sortingsystem. In an ideal situation an automated bottles sorting system at the recycling plant would have beenable to remove the majority of the coloured HDPE bottles and hence leave a much more pure natural

HPDE stream. The Sorepla plant did not have whole bottle sorting equipment to specifically removecoloured HDPE bottles.

The balestock also contained large amounts of multi-layer yoghurt drink bottles. Removing the whitemulti-layer bottles and flakes is very important as they contain a black coloured barrier middle layer, andthis will significantly darken the final pellets during the extrusion step. Multi-layer flakes were identified

be an issue for the final product quality and as such information was provided to the f lake sortingcompany so that the flake sorter was optimized to removed them. The multi-layer flake seemed to

primarily come from small yoghurt drink bottles and other flavoured milk bottles. These bottles are quitedifficult to remove due to their small size. These bottles did not come out through the trommel screen asthe openings in the screen were not the right size to remove these bottles. The best method ofremoving these materials is to optimise the flake sorting equipment to specifically identify whites andremove these.

During the washing stage it was noticed that the bales also contained occasional black motor oil HDPEcontainers. Where ever possible these were manually removed on the sorting belt, but some may havepassed through. It is essential that these containers are removed as even after intensive hot washing in


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combination with surfactants, there is still some residual oil left over. During reprocessing, the residualoil could result in strong odour and this may limit the use of the recycled resin.

Flake samples were sieved and tested for residual fines and were found to contain up to 0.125% offines.

The majority of the flake was ground to a size of 5-7mm.

Figure 8 Examples of aluminium contamination.

3.6 Material Balance for the Washing/Grinding Step at SoreplaThe following data on material losses has been provided by Sorepla.

Balestock

Weight

(Kg)

Moisture

in

Balestock

(Kg)

Raw

Material

Input

(Kg)

Heavy

Parts Loss

(Kg)

Waste

(Kg)

Fines,

Paper

(Kg)

Sink

Fraction

(Kg)

Final

Product

(Kg)

34,220 2,750 31,470 800Kg 300Kg 600Kg 800Kg 28,970Kg

8% 100% 2.5% 1.0% 1.9% 2.5% 92.1%

Table 2 Material balance for the washing and granulating of post-consumer HDPE bottles*. (Source: Sorepla)

The above table shows the material balance and associated losses during bottle washing, grinding and flake

washing stage. As the table shows, there was also substantial loss due to moisture/liquid present within the

bottles in the bales. Sorepla have provided us with feedback that they typically find that most bales contain

anywhere between 7-12% moisture/liquid content. During this trial it was found that moisture/liquid within baled

bottles was approximately 8%.The above table shows that actual material loss during bottle washing, grinding

and flake washing is almost 8%.

4.0 Sorting of rHDPE Flake4.1 Flake Sorting RequirementsColoured HDPE recyclate is of concern for blow moulding of unpigmented HDPE bottles. In most operations the

green colour of rHDPE derived from milk bottles is caused by the incorporation of the caps of the milk bottles into

the recycled stream. For this reason it is necessary to utilize colour flake sorters to remove the coloured HDPE

cap material. Apart from sorting out coloured caps because of discolouration of the unpigmented natural HDPE, itis also important to remove coloured HDPE bottles. Recycled HDPE homopolymer from dairy bottles can also be

mixed with clear and coloured HDPE copolymer containers used in the manufacture of detergent and household

cleaning containers, which have a lower melt flow index. It is important to remove the copolymer HDPE bottles

due to potential resin discolouration as well due to the mixed resin potentially resulting in lower modulus of the

recycled milk bottle resin.

The S+S flake sorter system was set up at Erema by the S+S technicians. The initial set-up needed further

optimization as there was a need to remove residual label and film fines from the incoming HDPE flake. Thus a

basic hydrocyclone air separator was set-up to remove the label film flakes. Once installed, this proved to be an


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effective way to remove these residues. A further advantage was that the label film did not build up on the flake

sorter screen and infeed tables due to static friction. The following figure shows the settings of the test unit.

These optimised settings were found to be the most effective at removing the large levels of colour.

Figures 9 and 10 Figures 9 and 10 show incoming flake from materials A and B. Material A clearly exhibits less

colour and the colours shown (green, red and blue) are typical of cap material. Material B shows cap colours but

also shows many other coloured flakes from non-milk bottles.

FLAKE SORTING SET-UP

Product: HDPE

Delay: 9ms

Eject Time: 4ms

Filter: 1mm

Sensitivity: 50%

Vibro Level: 88%

Throughput: 600Kg

S+S Spektrum 1000 sorting unit Material Input, Reject and Output Settings of Test Unit

Figure 11 The S+S Separation and Sorting Technology GmbH, flake sorting set-up.

Figure 9. Material A Unsorted Flake Figure 10. Material B Unsorted Flake


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4.2 Efficiency of Flake SortingAnalysis was performed on a number of samples for Material A and Material B to ascertain the flake sorting

efficiencies at Erema and this data is presented in the following diagrams.

Figure 12 The flake sorting flowchart showing sorting efficiency on Material A flake.

MMaatteerriiaall AA FFllaakkee

Nat-HDPE 91 %Col-HDPE 5.5 %

Labels 3.5 %


11sstt PPaassss RReejjeeccttss

Nat-HDPE 74 %Col-HDPE 21.5 %Labels 4.5 %


11sstt PPaassss AAcccceeppttss

Nat-HDPE 99.8%Col-HDPE 0.1 %

Labels 0.1 %

1stPass

EERREEMMAA

EExxttrruussiioonn

&&

DDeeccoonnttaammiinnaattiioonn

1stRESORT


22nndd PPaassss AAcccceeppttss

Nat-HDPE 99.4 %Col-HDPE 0.3 %

Labels 0.3 %MMaatteerriiaall AA FFllaakkee11sstt RREESSOORRTT RReejjeeccttss

Nat-HDPE 63 %Col-HDPE 34 %Labels 3 %

REJECT STREAMCol-HDPE Flake

rHDPEPellets


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Figure 13 Pictorial schematic for Material A sorting and the final pelletised HDPE resin.

Unsorted Flake (Material A)

1st Pass Rejects from Material A Sorted Flake (Material A)

Final Product after extrusion


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Figure 14 The flake sorting flowchart showing sorting efficiency on Material A flake.

(The WRAP April 2005 HDPE trial flake contained a coloured HDPE content of around 1.4% and the material after

sorting going into the Erema extruder had a colour content of < 100ppm).

The figure of 1.4% coloured HDPE content in previous WRAP trial is extremely low and not typical of industrial

situations as coloured HDPE fragments from caps alone are normally between 5-10% (w/W) of bottles. During

this trial it was found that colour content in manually pre-sorted HDPE balestock can vary from 5% up to 15%,

depending the collection scheme and the manual sorting efficiency at the material recycling plants.

MMaatteerriiaall BB FFllaakkee

Nat-HDPE 80 %Col-HDPE 14.5 %Labels 5.5 %


11sstt PPaassss RReejjeeccttss

Nat-HDPE 52%Col-HDPE 42.5%

Labels 5.5 %


11sstt PPaassss AAcccceeppttss

Nat-HDPE 98.2%Col-HDPE 1%Labels 0.8%

1stPass SORT


22nndd PPaassss RReejjeeccttss



Nat-HDPE 99.63 %Col-HDPE 0.25 %Labels 0.12 %

EERREEMMAA

EExxttrruussiioonn

&&

DDeeccoonnttaammiinnaattiioonn

1stRESORT 2ndPass




Labels 3.2 %




Labels 0.2 %

2NDRESORT


11sstt//22n

ndd RREESSOORRTT

RReejjeeccttss

Nat-HDPE 55.0 %Col-HDPE 38.5 %Labels 6.5 %

REJECT STREAMCol-HDPE Flake

rHDPEPellets


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Figure 15 Pictorial schematic for Material A sorting and the final pelletised HDPE resin.

Unsorted Flake (Material B)

1st Pass Sort of Material BMaterial B 1st Pass Rejects

2nd Pass Sort of Material B

Final product after extrusion.


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The following sorting efficiency data analysis was obtained from the S+S testing laboratory on flake inputs into

the S+S sorter from flake materials A and B. This is shown in Figures 16 and 17.

Figure 16 Laboratory analysis on material A sorting efficiency.

(Source: S+S Separation and Sorting Technology GmbH)


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Figure 17 Laboratory analysis on material B sorting efficiency. (Source: S+S Separation and Sorting Technology

GmbH).


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4.3 Flake Surface ResidueA build up of glue and ink type green residue was noticed on pipes conveying flake to the sorter and the glass

chute window on the sorter itself. The glue and the residue were able to be wiped off with a cloth. Further to

that a greenish angel hair type film formed on a number of pipes. Evidence of this phenomena is shown in the

following pictures.

Figures 18-23 The figures above show examples of the issues created by excessive glues and the leached ink

on the sorting and auxiliary equipment.

Figure 19. Wiping off glue & green ink.

Figure 20. Glue & ink residue wiped from glass Figure 21. Glue & green ink inside air-classifier

Figure 22. Angel hair film removed from pipes. Figure 23. Angel hair film build up in pipes.

Figure 18. Glue & green ink build up on glass.


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5.0 Extrusion and Decontamination of rHDPE Flake5.1 Material Extrusion & Decontamination

At Erema after separately extruding the two batches of flake it was finally determined that there were clearly two

distinctive types of recycled HDPE flake. The greenish surface tinge of Material A flake had resulted in a light

green pellet after extrusion, whereas the extruded HDPE pellets from the cleaner Material B flake had a much

lighter natural colour. During the trial at Erema it was not possible to do a 30% rHDPE/virgin blend to check what

the final colour of the resin for milk bottles would be as there was no available virgin resin.

Figure 24 The Erema two-step process used for the decontamination and extrusion of post-consumer HDPE

flake.

MACHINE PARAMETERS OPERATING CONDITIONS

Temp. KT 80-97 C

Vacuum KT 2-4.5 mbar

Aver. dwell time KT 45 min

Temp. Reactor RGAT - VS 120-125 C

Vac. Reactor RGAT - VS 0.5-3 mbarAver. Dwell time RGAT - VS 60 min

Screw speed 150 rpm

Output 275-325 kg/h

Melt temp. 218-221C

Melt pressure 140-170 bar

Screens 150 mesh (~100m)

Back flush interval 80-120 min

Table 3 Process parameters of the Erema two step process used in this study for decontamination of post-

consumer HDPE.

The screw design used by Erema for this trial was based upon a special design which, when compared to the

barrier screw used for the previous WRAP study had the following unique modifications:

Shallower cut in the feed section

Lower compression-ratio

Includes varying screw-pitches to avoid sudden channel reductions / enlargements

5.2 Visual Analysis of Recycled HDPE pelletsA common source of contamination in extruded recycled HDPE pellets is black specs. These are generally small

bits of the polymer or contamination that have been degraded and have become carbonized due to excessive


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temperatures or residence time within the extruder. These black specs usually occur due to hang up spots within

the extruder. Black specs cause major problems when blow moulding natural bottles, where they are visually

undesirable and can potentially reduce the containers mechanical properties. Extruded material was analysed by

compression moulding it into sheets and examined for black specs but none were found.

Flushed material from the Erema filters was analysed and was found to contain some residual PET fines, flakes

and some fibrous materials from paper labels. The rHDPE pellet material was filtered using 150m mesh.

Recycling of PCR (Post Consumer Recyclate) HDPE can also lead to the formation of gels during extrusion due to

cross-linking, when the stabilizing antioxidants become consumed. The cross-linked regions gels can providestress points which can cause blow outs in bottles. Extruded material was compression moulded into sheets and

visually analysed for gel formations, however none were discovered.

5.3 Rheological ResultsThe following rheological results were obtained from extruded HDPE samples. More rheological tests will be

performed on material samples in the near future.

MFI

190C / 2.16Kg

Sample Details

0.61 10:30am 10/07 (Material A) Tested at Erema

0.62 1:30pm 10/07 (Material A) Tested at Erema


0.66 8:00am 11/07 (Material A) Tested at Erema0.61 9:30am 11/07 (Material A) Tested at Erema



0.65 8:00am 13/07 (Material A) Tested at Erema

0.64 Material A (Bag 4) Tested at London Met Uni




0.64 MFI Average for Material A

0.61 8:00am 12/07 (Material B) Tested at Erema

0.50 12:00am 12/07 (Material B) Tested at Erema

0.54 4:00pm 12/07 (Material B) Tested at Erema0.58 Material B (Bag 10) Tested at London Met Uni

0.65 Material B (Bag 11) Tested at London Met Uni






0.59 MFI Average for Material B

(Reference Sample:WRAP trial April 2005 MFI = 0.64)

Table 4 Rheological data of HDPE recycled pellets. (Source: Erema/London Metropolitan University)

Material A was primarily made up of flake that came from milk bottle balestock and hence the MFI results show a

high level of consistency. The MFI average was 0.64 g/10min, this compares favourably with the previous WRAP

trial where the MFI of the material was found to be 0.64 g/10min. Material B shows slightly lower MFI results

and this may be due to the slightly higher levels of clear copolymer HDPE resin. Full rheological study test results

are presented in Appendix D.


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5.4 Material Balance after Sorting and Extrusion

INPUT SORTINGLOSSES

EXTRUSIONLOSSES

OUTPUTS

HDPE Flake

(Kg)

Material

Conveying &

Transfer Losses

(Kg)

Air Classifier

Losses

(Kg)

Melt Filtration

Losses

(Kg)

Coloured

HDPE Flake

(Kg)

HDPE

Pellets

(Kg)

28,970 654 2,100 250 6,713 19,253

Table 5 Mass balance after sorting and extrusion. (Source: Erema)

5.5 Overall Material BalanceThe following data is preliminary data only, which is being cross-checked and will be further updated.

Material Balance (Effic iency & Losses)

Processing Stages Material

Amounts

Step Loss per Stage Cumulative Loss per

Stage(Kg) % %

Balestock input 34,220

Moisture and Liquid Loss 2,750 8%

Baled HDPE Bottle Input 31,470

Loss of Material(washing/grinding)

2,500 8%

Output of Washed Flake 28,970 15%

Sorting - Washed Flake Input 28,970

Material Conveying Losses 654 2%

Air Classifier Losses 2,100 7%

Rejects - Coloured HDPE Flake 6,713 23%Output of Sorted Flake 19,503 33%

Extrusion - Sorted Flake Input 19,503

Melt Filtration Losses 250 1% 1%

Output of Pelletised HDPE

Resin

19,253

Total Cumulative Loss: 44%

Table 6 The overall process mass balance.


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6.0 Blow Moulding of Milk BottlesThe blow moulding of milk bottles took place at Nampak Plastics on the 25th of July. The trial involved blow

moulding of bottles from Material A and B blended with virgin milk bottle HDPE resin on a single head machine

using a 4 pint mould. The bottles were manufactured from a blend of 70% virgin resin / 30% recycled HDPE

resin. Some bottles were also manufactured from 100% recycled HDPE resin, using both batch A and B recycled

HDPE resin. An initial trial was conducted to produce several hundred bottles. These bottles were then supplied to

Dairy Crest for a filling trial and subsequent microbiological and sensory testing.

Figure 25 Blow moulding of milk bottles with 30% of rHDPE content at Nampak Plastics.

6.1 Processing of Recycled HDPE Pellets into Milk BottlesThe blow moulding trials resulted in production of bottles containing 30% recycled HDPE content bottles that had

similar colour characteristics to the reference bottles (100% virgin). The bottles containing 30% recycled HDPE

have also been tested for toploads, brimful capacity, stability, dimensional tests and visual tests and compared to

reference 100% virgin bottles.

As previously mentioned recycled HDPE Material A pellets, had a greener tinge then Material B pellets. However,when blended with 70% virgin, the bottles were visually similar to the 100% virgin bottles. Bottles produced with

a 30% blend of Material B were also visually similar to the 100% virgin reference bottles.

Production of bottles from Material A / virgin blend had experienced occasional problems with contamination

within the resin. This had resulted in a number of bottles showing streaking and some bottles had also contained

small holes or occasionally resulted in blow-outs. The contamination origin is currently being investigated,

however it appears to be possibly related to PET fines/flake residue. The PET fines/flakes contamination is

believed to have likely come from hang-up spots in material conveying equipment. This issue was found to be

related only to the first processed material (e.g. Batch A). There were no bottle processing issues related to the

Material B / virgin resin blend. This blend had processed in a similar manner to 100% virgin resin, with very few

changes to the machine set-up. The bottles produced did not show any visual or other type defects during the

trial production run.

6.2 Blow Moulding ConclusionsBottles were successfully moulded from a 70:30 blend of virgin HDPE to recycled HDPE (Material A and B). The

material blend had rheologically behaved in a similar manner to 100% virgin HDPE and the machine set-up did

not need to be changed. The rHDPE bottles have also passed all Nampak quality tests such as toploads, brimful

capacity, stability and all dimensional and visual tests.


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6.3 Nampak Plastics Evaluation of rHDPE resinThe following section contains an evaluation report from Nampak Plastics, after a four day commercial trial. The

project was run over a four-day period to fully assess the performance of both WRAP grade A and B materials.

The main purpose was to assess the process ability and stability of both grades on a standard Uniloy Recip

machine designed for HDPE material. The machine designated to the trial was Severnsides SB1 - 4 pint HIS, and

was run at a target weight of 41 grams +/- 1.0 with a cycle time of 7.5 seconds. The material was introduced at

30% as per the trial request. The granulator was cleaned down and the machine line was marked up to notify all

that the trial was in progress.

6.3.1 Material A - Nampak Blow Moulding Trial Evaluation:The grade A trial was run over a period of two days (180,000 containers), and the following observations were

made:

A 0.3 0.4-gram weight increase was observed in bottles

Noted a slightly reduced die swell from a standard virgin/regrind mix.

Made no changes to the process from our standard running conditions (timers, air pressures or

hydraulics)

Material was very clean, with little or no contamination evident.

Trial reject levels over the total trial period - 2.4%, Nampak reported that the low reject levels could have been

attributed to the high emphasis put on the machine with the correct labour in place. However the low reject

levels was mainly due to the cleanliness of the material. At the initial start Nampak staff did see a small degree of

contamination, which Nampak staff felt was due to the storage of the material (debris on the top of the bag),wooded pallets and the fact that the material was being stored in fabric sacks.

6.3.2 Material B Nampak Blow Moulding Trial EvaluationThe grade B trial was run over a period of 14hours (52,000containers), and the following observations were

made:

A 0.7 1.0-gram weight increase was observed in bottles.

The die swell was slightly decreased again and it was felt that this was due to the material having a

higher density characteristic.

On the commencement of the trial we saw a greater degree of contamination. Whilst it was not enough

to cause holes, we could see gel spots and small contaminants.

During the night shift the operator reported a high percentage of split parisons, and was unable to carry

on processing material. The bag was changed and we saw no further issues. This caused us

approximately 40 minutes of lost production time.

Total trial rejects for the trial period ran at 7.1%.

Figure 26 Commercial blow moulding trials at Nampak Plastics.


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6.3.3 Nampak Plastics Blow Moulding Evaluation SummaryWhilst both material grades processed well, the preferred material would be grade A. Both materials showed

very little issues with trimming, processing or problems with weight control. The weights over the period of the

whole trial (A and B) gave a maximum variation of +/- 0.3 grams. The grade B as previously stated was not

as clean and may be a little more labour demanding (splits parisons).

7.0 Milk Bottle Filling Trials and TestsThe first milk bottle filling trials took place at Dairy Crest from the 26th of July to 28th of July at the Totnes site.

The filling trials involved filling of milk bottles with the following milk types.

Skim Milk (26/07/06)

Full Cream Milk (27/07/06)

Semi-skim Milk (28/07/06)

Bottles containing blends of recycled HDPE from Batch A and Batch B were filled and sent for external sensory

testing. Bottles containing Material A only were filled and set aside for stability/bacteriological testing. A

comprehensive testing regime was developed and is presented in Appendix E. The following photographs show

the rHDPE milk bottles during the milk fill ing process.

Figure 27 Milk bottle filling trials at Dairy Crest.


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7.1 Visual Analysis of Milk Filled BottlesThe milk bottles were filled with several different types of milk to test the effect of milk differences on the visual

colour variation of the end product. This is necessary due to the fact that full cream milk has different opacity and

hues to skim milk or semi-skim milk. Milk filled bottles had clearly demonstrated that there was no visual colour

variation between bottles that contained 30% of recycled HDPE from Batch A or Batch B. The following

photographs show that visually there is no difference between samples, A, B and C (the reference bottles).

Figure 28 Comparison of milk filled recycled bottles.

Filled bottles were then marked and the following tests were commissioned:

Organoleptic sensory tests by Campden & Chorleywood Food Research Association (CCFRA), Consumer

and Sensory Sciences Department

Organoleptic sensory tests by Reading Scientific Services Ltd

Microbiological / bacteriological tests performed by Eclipse Scientific Group

Shelf life testing by Dairy Crest Ltd

7.2 Full Scale Commercial Milk Filled Bottles (Chadwell Heath 05-08/12/2006)A second market trial was carried out in Chadwell Heath on Marks & Spencer (M&S) standard milk which went

into store for a week and was sold out. A total of 78,500 units of 4-pint RHDPE bottles were filled between 4/12

and 8/12 in M&S label (standard English Whole, Semi-skimmed and Skimmed Milk) on a Stork filler at Dairy Crest.

These bottles contained 30% recycled content and were sent into store to fulfil M&S demand in order to

determine the following:

Do the consumers notice any organoleptic difference between milk in an r-HDPE and milk in a virgin

HDPE bottle?

Do standard milk consumers notice any difference in appearance between a virgin and rHDPE bottle

Is there any difference in performance of a recycled bottle through the supply chain for example

leakers or cracked bottles at depot / store or in consumers homes

The trial was monitored via M&S consumer complaints data supplied via feedback from M&S. The following table

provides a comparison of customer complaints during the trial period this year and a comparison to previousyears complaints.

This Years Complaints Last Years Complaints

1 5

The results indicated a 0.6% increase in unit volume and a 80% decrease in complaints.

The trial was successful from a filling perspective, although there needed to be significant adjustments made to

the filler line due to the distinct differences in dimensions and mouldings of bottles blown at the Severnside site.

The dimensional differences from the different sites had resulted in some bottles not being capped and having


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suffered damage to the sealing lip. The production was checked for leaking product approx 1 in every 200 / 250

didnt get capped and suffered damage to the sealing lip. 6 bottles were found in the cold store with mechanical

damage from the filler and one bottle was found with a pinhole. Throughout the trial, it had been necessary to

adjust the filler settings in order to run with minimal issues, the adjustments made however had reduced excess

foaming and damage to the bottle necks stabilised. The dimensional differences between standard Chadwell

blown and Severnside rHDPE blown bottles have proven to be significant, and showed the tight tolerances in the

milk filling operations.

Figure 29 C Severnside bottles were found to be minutely different in size to the Chadwell bottles. Changes to

filler set-up had overcome this slight difference.

Figure 30 Due to this slight difference, there was some initial thread damage to a small number of bottles. This

issue was overcome with an optimised filler set-up.

In conclusion, there are set up changes that needed to be made to the filler at start and end of production. All

the bottles that were damaged under the capping heads didnt actually get capped so were all rejected. If all

bottles supplied to site were from the same moulds then the filler could be engineered to run them successfully

but this could not be done for the trial.

7.3 Full Scale Commercial Milk Filled Bottles (Severnside)The final commercial trial took place at the Dairy Crest Severnside site. The trial used bottles that were blown by

Nampak Severnside site. The bottles were used for M&S Organic (whole, semi-skimmed and skimmed) milk. All

bottles were coded and labelled as containing recycled HDPE (R) and each bottle used for this trial was also

marked at the base of the bottle. This can be clearly seen in the following pictures.


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The trial was very successful in terms of operational filling of the bottles and there were no major issues found

with the rHDPE bottles. The rHDPE bottles performed as well as virgin HDPE bottles in all aspects.

Figure 31 Trials at Dairy Crest Severnside site. The above pictures show the (R) marking on milk bottles sent to

M&S for sale and customer evaluation. Each milk bottle with a 30%recycled HDPE content was also marked with

a punched dot at the base of the bottle.

7.3.1 Severnside Audit TrailProducts were filled and boxed at Severnside. Bottles were checked by the DC CSM team in order that a complete

audit could be carried out.




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Products were also viewed in Nuneaton (Dairy Crest NDC), M&S Gist depot at Faversham and finally at store

overleaf:



The Dairy Crest CSM feedback was found to be invaluable as it allowed DC staff to track the product throughoutthe complete supply chain

Figure 34 rHDPE bottles (in store) (at home) (proof of purchase)

This Years Complaints (DC Severnside) Last Years Complaints (DC Severnside)

0 2

The results indicated an 11% increase in unit volume and a 100% decrease in complaints.

7.3.2 Summary:Three milk bottle filling trials have been carried out by Dairy Crest at Totnes, Chadwell Heath and Severnside

sites. Some operational difficulties were experienced at Chadwell due to slight bottle size differences. but were

overcome by optimising the filling line set up. The finding was that there are very tight tolerances from site to site

both in bottle blow moulding and filler set-ups. All trials have now concluded and have been customer complaint

results have been signed off technically by M&S. R-HDPE performed comparably to virgin bottles in the supply

chain tests.


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7.4 Conclusions from Filling TrialsThe filling trials clearly demonstrated that there were no quality or operational differences when filling milk

bottles with recycled HDPE content and 100% virgin HDPE bottles. During the filling trials, one defective bottle

was found in the input of bottles sent from Nampak Plastics.

The milk bottle filling trials had also clearly demonstrated that there was no significant visual colour variation

between bottles containing 30% recycled HDPE (Batch A & B) when compared to filled 100% virgin HDPE milk

bottles. Bottles containing 30% recycled HDPE filled with different types of milk such as skim; semi-skim and full-

cream milk, did not show any significant colour variation when compared to 100% virgin HDPE milk bottles.

Overall feedback from Dairy Crest has indicated that filling of the rHDPE bottles was successful.

8.0 Milk Bottle Decontamination Analysis8.1 Fraunhofer IVV Material TestingFraunhofer IVV was commissioned to perform analytical tests on washed flake; super-cleaned extruded pellets,

milk bottles. Samples of washed HDPE flake and corresponding extruded pellets of recycled HDPE in tight lid jars

were sent to Fraunhofer Institute for testing. Samples were received by the Fraunhofer on the 18 th of July. The

testing process has involved headspace screening for volatile compounds as well as extraction of the samples and

GC screening for medium and non volatile compounds. Bottles from Nampak blow moulding trials were sent to

Fraunhofer IVV. All results are compared with virgin HDPE and previous WRAP trial.

The following analytical tests were initiated and are described in detail in the following sections of this report:

Screening of HDPE Recyclates for Migration Relevant Compounds

Screening of rHDPE Milk Bottles for Migration Relevant Compounds

Determination of the Overall Migration from HDPE Milk Bottles

Determination of the Specific Migration of Irganox 1076

8.2 Screening of HDPE Recyclates for Migration Relevant CompoundsThe screening for migration relevant compounds in the post-consumer HDPE material was carried out usingheadspace gas chromatography by the Fraunhofer Institute for process Engineering and Packaging. The followingfigures provide typical results obtained from screening tests for migration relevant compounds in the post-consumer recycled HDPE flake and super-cleaned pellets. A comparison to virgin HDPE and previous WRAP trialresults is also made.

The screening for migration relevant compounds in the post-consumer HDPE materials was carried out usingheadspace gas chromatography. This method detects substances up to a molecular weight of about 250 g mol -1.The detection limit is in the order of about 1 ppm. The following graphs provide a summary of the headspace testresults. Full results of the headspace fingerprints of the investigated recyclate samples are shown in Figure 1 toFigure 37 in Appendix B. Fingerprints of reference samples from the previous study as well as virgin HDPE aregiven in Figure 38 and Figure 39 in Appendix B. Full details of the screening tests as performed by the FraunhoferInstitute are provided in Appendix B.

The evaluation of the results was done only on a qualitative basis. However all samples are analysed in the sameway and the fingerprints were plotted in the same scale so that the headspace gas chromatograms can becompared with each other.


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Figure 35 Typical headspace gas chromatogram of super-clean HDPE pellets. (Sample - previous WRAP trial).

Figure 36 Typical headspace gas chromatogram of washed HDPE flake. (Sample 2a).

Figure 37 Typical headspace gas chromatogram of super-cleaned HDPE pellet. (Sample 2b)


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Figure 38 Typical headspace gas chromatogram of virgin HDPE pellets.

In the flakes samples several polyolefin oligomers could be determined as well as some post-consumercompounds. In the corresponding super-clean pellet samples, the concentrations of these compounds aresignificantly reduced down to levels below the oligomer concentrations in virgin HDPE. For sample 5a higheramounts of suspicious compounds, which are not typical of HDPE have been detected. However in a second sub-sample, these peaks could not be determined. This indicates, that only some individual flakes are contaminatedwith higher amounts of compounds that are not related to HDPE. The level of these compounds will be decreasedby dilution with non-contaminated HDPE flakes down to lower ppm levels. The super-clean decontamination stepfurther decreases the concentrations in the final product.

Due to the fact that most of the detected suspicious compounds are related to flavour and fragrance compounds,

Fraunhofer Institute recommended organoleptic tests with milk bottles manufactured from super-clean recycled

post-consumer HDPE.

8.3 Screening of rHDPE Milk Bottles for Migration Relevant CompoundsThe screening for migration relevant compounds in the milk bottles containing 30% super-clean rHDPE materialwas carried out using headspace gas chromatography by the Fraunhofer Institute for process Engineering andPackaging.

The following figures provide results that were obtained from screening tests for migration relevant compounds inHDPE milk bottles manufactured with 30% super-cleaned recycled HDPE pellets. A comparison is made to 100%virgin HDPE milk bottles and milk bottles previous WRAP study1.

The screening for volatile migration relevant compounds in the investigated HDPE milk bottles was carried outusing headspace gas chromatography. This method detects substances up to a molecular weight of about 250 gmol-1. The detection limit is in the order of about 1 ppm. The headspace fingerprints of the investigated recyclatesamples are shown in Figure 36 and Figure 37. Fingerprints of reference samples are shown in Figure 38 andFigure 39 respectively. Full report of the screening tests as performed by the Fraunhofer Institute are provided in

Appendix C.

Samples tested:

Sample 1: HDPE milk bottles, 4 pint, 30% recyclate, Batch A

Sample 2: HDPE milk bottles, 4 pint, 30% recyclate, Batch B

Sample 3: HDPE milk bottles, 4 pint, 100% virgin HDPE (reference bottle)

Sample 4: HDPE milk bottles, 4 pint, 30% recyclate, WRAP project 2005 (reference bottle)


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Results Obtained:

Figure 39 Headspace gas chromatogram of sample 1 (30% Material A)

Figure 40 Headspace gas chromatogram of sample 2 (30% Material B).

Figure 41 Headspace gas chromatogram of sample 3 (100% virgin HDPE).

Samples 1 to 3 have similar headspace fingerprints. The concentrations of the detected compounds are in thereference sample (sample 3, 100% virgin) slightly higher than in the bottles containing recycled HDPE (samples 1and 2). The bottle from the previous WRAP project (sample 4) has the lowest concentrations, which is however,most probably due to another HDPE virgin pellet quality.


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Figure 42 Headspace gas chromatogram of sample 4 (WRAP Project, 2005).

Figures 43 and 44 show the gas chromatograms of the dichloromethane extract of the investigated HDPE milkbottle samples with 30% recyclate. In gas chromatograms of the reference samples are given in Figure 45 andFigure 46 respectively. The internal standards have retention times of 18.4 min (butyl-hydroxyanisol, BHA) and47.5 min (Tinuvin 234) respectively.

Figure 43 Gas chromatogram of the dichloromethane extract of sample 1 (30% Material A).

Figure 44 Gas chromatogram of the dichloromethane extract of sample 2 (30% Material B).


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Figure 45 Gas chromatogram of the dichloromethane extract of sample 3 (100% virgin HDPE).

Figure 46 Gas chromatogram of the dichloromethane extract of sample 4 (WRAP Project, 2005).

All investigated samples have similar fingerprints. The oligomeric pattern, which was determined in theheadspace screening was also determined in the extracts. In addition, the polymer additives Irfagos 168 as well

as Irganox 1076 were determined. The concentrations of these two additives were in the same concentrationrange than the virgin milk bottle.

Due to the fact that the recyclate containing HDPE milk bottles and the reference bottle manufactured from

100% virgin show no significant differences, it can be expected that also the migration (specific as well as the

overall migration) will be in the same range.

8.4 Determination of the Overall Migration from HDPE Milk Bottles (Fraunhofer IVV)The Fraunhofer Institute for Process Engineering and Packaging had performed tests to determine overallmigration into aqueous food stimulants from milk bottles manufactured using recycled HDPE. The full report is in

Appendix D. The following section of this report gives the results obtained and provides food regulatoryassessment.

The following samples were supplied for analysis:

Sample 1: HDPE milk bottle, 4 pint, 30% recyclate, Batch A Sample 2: HDPE milk bottle, 4 pint, 30% recyclate, Batch B

Sample 3: HDPE milk bottle, 4 pint, 100% virgin material (reference)

The test method used was, European Standard EN 1186-9. The test was performed over a period of 10 days at20C. The stimulants used were 3% acetic acid and 50% ethanol. The test conditions involved total immersionover a contact area/volume of 0.5dm2/100ml.


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8.4.1 Overall Migration ResultsThe following table shows the overall migration test results obtained. The result values given are as mean values.

SAMPLES Overall Migration

3% acetic acid

(mg/dm2)

Overall Migration

50% ethanol

(mg/dm2)

Sample 1 Batch A (0.0, 0.0, 0.0)

Mean Value = 0.0

(0.0, 0.0, 0.1)

Mean Value = 0.0Sample 2 Batch B (0.0,0.0,1.7)

Mean Value = 0.6

(0.0, 0.0,0.0)

Mean Value = 0.0

Sample 3 - Reference (0.0, 0.0)

Mean Value = 0.0

(0.0, 0.4)

Mean Value = 0.2

Table 7 Overall migration test results.

8.4.2 Food Regulatory AssessmentThe overall migration limit is 10 mg/dm2 contact surface or 60 mg/kg food stimulant. The analytical tolerance of

the method used is 2 mg/dm2 for aqueous simulants and for ethanol. Based on the results the Fraunhofer

Institute have found that investigated HDPE milk bottles are in compliance with the requirement of the overallmigration for milk products as well as for aqueous and acidic types of food for long term storage conditions up to

20C.

8.5 Determination of the Specific Migration of Irganox 1076 (Fraunhofer IVV)The Fraunhofer Institute for Process Engineering and Packaging had performed tests to determine the specificmigration of Irganox 1076 from milk bottles manufactured using recycled HDPE. The full report is in Appendix E.The following section of this report gives the results obtained and provides food regulatory assessment.

The following samples were supplied for analysis:

Sample 1: HDPE milk bottle, 4 pint, 30% recyclate, Batch A

Sample 2: HDPE milk bottle, 4 pint, 30% recyclate, Batch B

Sample 3: HDPE milk bottle, 4 pint, 100% virgin material (reference)

The testing method for migration of Irganox 1076 was European Standard 1186-3. The test uses 0.5dm2 of thesample immersed in 110ml 50% ethanol for 10 days at 20C. Another 0.5dm2 of the sample was immersed in110ml 3% acetic acid for 10 days at 20C. Determination of Irganox 1076 was performed in 95% ethanolicmigration solution. Irganox 1076 was quantified without further sample preparation using HPLC with UV-detection. In the 3% acetic acid migration solution Irganox 1076 was quantified after dilution with ethanol(0.5ml migration solution + 0.5ml ethanol). The calibration was carried out by external standards. Recoveryexperiments were performed by spiking the sample.

8.5.1 Results of Specific Migration of Irganox 1076Irganox 1076 was not detected in the food simulants 95% ethanol and 3% acetic acid. The detection limit for

Irganox 1076 in 3% acetic acid was 0.01mg/dm2 and 0.05mg/kg respectively. The detection limit in 50% ethanol

was 0.02 mg/dm2 and 0.12 mg/kg, respectively.

8.5.2 Food Regulatory AssessmentThe specific migration limit for Irganox 1076 is 6mg/kg octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)-

propionate (Irganox 1076, CAS: 2082-79-3) according to the EU Plastics Directive 2002/72/EC las amended by

Directive 2005/79/EC. Based on the specific migration tests, Fraunhofer Institute have found that the investigated

HDPE milk bottle samples (30% recyclate Batch A, 30% recyclate Batch B and 100% virgin reference) comply

with the specific migration limit of Irganox 1076 for milk products as well as for all aqueous and acidic types of

food at long term storage conditions at up to 20C.


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8.6 Overall Migration from Milk Bottles (PIRA International Analysis)PIRA International were independently commissioned by Nampak to perform an overall migration test on HDPEbottles manufactured from 100% recycled HDPE (Batch A and B) as well as bottles manufactured using 30%recycled HDPE (Batch A and B). Overall migration was tested by filling, into 50%v/v ethanol; exposure conditions10 days at 40C. After exposure to the simulant under conditions specified, test specimens were removed fromcontact; the aqueous extract was transferred to a weighed container and evaporated to dryness and constantweight. EN 1186 - 9 - single side contact by filling.

1) 100% recycled material - Batch A Bottles - Test conditions: 10 days at 40C

Method EN 1186-9

Migration into

(50% v/v ethanol)

l

Replicates mg/kg

1 4.0

2 4.0

3 4.5

Mean result 4.2

Limit 60.0

2) 100% recycled material - Batch B Bottles - Test conditions: 10 days at 40C

Method EN 1186-9Migration into

(50% v/v ethanol)

Replicates mg/kg

1 4.0

2 3.0

3 3.5

Mean result 3.5

Limit 60.0

3) 70% Virgin 30% Batch A recycled resin - Test conditions: 10 days at 40C

Method EN 1186-9

Migration into

(50% v/v ethanol)

Replicates mg/kg

1 3.0

2 1.5

3 2.5

Mean result 2.3

Limit 60.0

4) 70% Virgin 30% Batch B recycled resin - Test conditions: 10 days at 40C

Method EN 1186-9

Migration into(50% v/v ethanol)

Replicates mg/kg

1 1.5

2 0.5

3 1.5

Mean result 1.2

Limit 60.0

The full PIRA report is presented in Appendix F.


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8.7 Migration Studies on Recycled HDPE to be Used for Milk Packaging - PIRAThe full PIRA report on migration studies from recycled HDPE for use in milk bottle packaging is given in

Appendix 7.

In summary, the objective of these experiments was to estimate migration of moderately volatile, unidentified

substances found to be present in recycled HDPE pellets in a previous study (Report 06A11J0412) to enable a

safety assessment to be made.

Migration studies were performed on HDPE bottles made from recycled post consumer stock using the foodstimulant 50% ethanol v/v in water. The test conditions applied were 10 days at 5C, representing refrigerated

storage at 5C or below. Additional tests were also conducted using 50% ethanol and exposure conditions of 2

days at 20C, followed by 5 days at 5C to allow for a worst case situation where milk may be left out of the

fridge at room temperature for a short time. In both cases virgin HDPE control bottles were tested alongside the

recycled bottles for comparison. Currently, water is the designated food stimulant for milk, as given in Directive

85/572/EC. However, it is highly likely that 50% ethanol will replace water in the 4th amendment to Directive

2002/72/EC based on experimental findings that migration of substances into milk and other dairy products can

be significantly higher than water.

The test solutions were extracted with n-heptane and injected for analysis by GCFID. Internal standards wereadded to the 10 day at 5C test solutions, prior to solvent extraction, at levels of 2.69 pg/dm2 and 1.62 pg/dm2(16 ppb and 10 ppb at the EU conventional food packaging ratio of 6dm21kg). The 10 day at 5C test solutionswere also fortified with 0.54 pg/dm2 (3.2 ppb at the EU conventional food packaging ratio of 6dm2/kg).

No peaks larger than the internal standards were seen in the recycled bottle extracts that were not also presentin the control extracts in both sets of migration tests. The conclusion of these studies is that, althoughunidentified contaminants are present in the recycled HDPE, there is no detectable migration of individualcomponents into 50% ethanol with a LOD equating to 10 ppb, or better. Considering only the 10 day at 5Cresults it can also be judged that migration levels of specific substances into 50% ethanol are below 0.54 m/dm2(3.2 ppb at the EU conventional food packaging ratio of 6dm2/kg). This value is below the US FDA threshold ofregulation of 0.5 ppb in the diet, after applying the FDA Consumption Factor of 0.13 for HDPE. Taking intoaccount the headspace GC analysis performed by Fraunhofer Institute and the challenge testing, there is nowsubstantial evidence that the use of this batch of recycled HDPE (WRAP A) for the packaging of milk is unlikely toendanger human health.

8.7.1 ConclusionsThe analytical work in this study provides experimental data showing that there is no detectable migration of

substances into 50% ethanol from bottles made from recycled HDPE, in addition to substances that migrate fromvirgin HDPE. The LOD for the analytical work is judged to be 10 g/kg (ppb) in solution based upon the

responses of three different standards, corresponding to 3 g/kg (ppb) at the conventional EU food packaging

ratio of 6 dm2/kg. Taking into account the headspace GC analysis performed by Fraunhofer Institute and the

challenge testing, there is substantial evidence that the use of this batch of recycled HDPE (WRAP A) for the

packaging of milk is unlikely to endanger human health.

8.8 Recycled HDPE Decontamination Conclusions8.8.1 Conclusions from Volatile Screening of HDPE Flake, Pellet and Milk BottleThe Erema decontamination process was found to have removed a wide number of compounds detected in both

virgin resin and the HDPE flake. The analytical tests performed by Fraunhofer IVV found that flake samples

showed several polyolefin oligomers as well as some post-consumer compounds. When the material input was

largely milk bottles, the pellet had the lowest levels of residual of flavour and fragrance compounds

(e.g. Material A).

The inclusion of household cleaning bottles in the feedstock had resulted in detectable fragrance residues in the

finished flake and pellet (Material B). The primary detectable fragrance compound was found to be l imonene,

however the level of limonene was significantly reduced once the flake had been super-cleaned and extruded by

the Erema process. From all the samples tested there was only one sample of flake that showed other fragrance

based compounds such as (alpha-pinene, camphene, eucalyptol and isobornylacetate), however further sub-

sample tests did not determine these compounds. It can therefore be concluded that only some individual flakes

contain these compounds. These findings clearly demonstrate how essential it is for the sorting process to

eliminate household cleaning bottles/flakes.


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