increasing profit through improved materials … · non-fibrous materials used by the industry each...
TRANSCRIPT
GG194GUIDE
INCREASING PROFITTHROUGH IMPROVEDMATERIALS ADDITIONS:Management Guide for Paper Mills
GOOD PRACTICE: Proven technology and techniques for profitable environmental improvement
© Crown copyright. First printed June 1999.
This material may be freely reproduced in its original form except for sale or advertising purposes.
Printed on paper containing 75% post-consumer waste.
INCREASING PROFITTHROUGH IMPROVEDMATERIALS ADDITIONS:Management Guide for Paper Mills
This Good Practice Guide was produced by the
Environmental Technology Best Practice Programme
Prepared with assistance from:
Dames & Moore
The Environmental Technology Best Practice Programme is grateful to the many mills thatprovided information during the production of this Guide.
The recovery and re-use of waste fibre from the papermaking process receive considerable attentionin UK paper and board mills. However, lower priority is given to controlling the significant amountsof materials such as fillers, retention aids, biocides, sizes and coatings used by the industry each year.
Poor control of non-fibrous material additions costs money. A 1% reduction in their use would savethe UK paper industry some £4 million/year in the direct cost of the raw materials alone. Thepotential for indirect savings through improved paper quality, increased machine efficiency and lessproduction of broke is substantially higher. In addition, some of the excess non-fibrous materialsend up in effluent, thus increasing effluent treatment and disposal costs. Conservative estimatesput the indirect costs associated with non-fibrous materials at over £5/tonne of paper produced.
This Good Practice Guide aims to help managers understand the cost implications of poor controlof non-fibrous materials and particularly the real cost of broke. Broke is a waste of machine time,energy, labour and materials. It is estimated that better control of non-fibrous material additionscan reduce broke by 5%.
The Guide contains advice to help paper and board mills:
■ assess their current level of non-fibrous material use;
■ identify the cost of waste resulting from poor control of non-fibrous material additions;
■ calculate the real cost of broke;
■ develop a plan for improved management of non-fibrous material additions.
Checklists, benchmarking data and Industry Examples are provided to help mills identify thepotential cost savings and other benefits of improving the control of their non-fibrous materialadditions. These benefits arise from improved control of the papermaking processes and more ‘rightfirst time’ papermaking.
Detailed, practical advice on how to achieve improvements is given in a companion volume, GoodPractice Guide (GG195) Increasing Profit Through Improved Materials Additions: Technical Guide forPaper Mills. GG195 is available free of charge through the Environment and Energy Helpline on0800 585794.
S U M M A R Y
Section Page
1 Introduction 1
1.1 The purpose of this Guide 2
2 Benefits of improved control of non-fibrous material additions 3
2.1 Direct costs 3
2.2 Indirect costs 6
2.3 The real cost of broke 7
3 Measures to improve control of non-fibrous material additions 9
3.1 Raw materials, type and quality of paper product 10
3.2 Chemical selection 10
3.3 Chemical supply and contract conditions 10
3.4 Chemical storage, handling and dosing 11
3.5 Good design and capital investment 11
3.6 Production scheduling 12
3.7 Management approach 12
3.8 Measuring to manage 13
4 Action Plan 14
Appendices
Appendix 1 Checklists 15
Appendix 2 Derivation of the formula for calculating the real cost of broke 20
Appendix 3 Broke reduction logic tree 22
C O N T E N T S
The main constituent of paper is cellulose fibre. However, considerable amounts of water and othermaterials such as fillers, retention aids, biocides, sizes and coatings are used by UK paper and boardmills. Table 1 lists the various types of non-fibrous materials used in papermaking.
Major efforts are made by paper and board mills in the UK to recover and re-use waste fibre fromthe papermaking process. However, lower priority is given to controlling the significant amounts ofnon-fibrous materials used by the industry each year. In 1996, the industry used some 1.1 milliontonnes of non-fibrous materials at a cost of around £400 million. Just a 1% reduction in the use ofnon-fibrous materials would save the UK paper industry £4 million/year in direct costs alone.
Activity Type of chemical
De-inking Acids and alkalis
Flotation soaps
Dispersants/surfactants
Bleaches
Papermaking: process control Deposit/scale control agents, eg biocide
Retention/drainage aids
Defoamers
Cleaning chemicals for machines and fabrics
Papermaking: product performance Fillers for opacity
Sizing agents for water resistance
Dry strength agents
Wet strength agents
Dyes and optical brightening agents (OBAs)
Softening agents
Surface or coating additions Size press additives, eg starch
Coating chemicals, eg mineral pigments and binders
Converting chemicals, eg adhesives
Table 1 Different types of non-fibrous materials used in UK paper and board mills
Non-fibrous materials also affect paper quality, the speed or runability of the machine, and thegeneration of broke. Thus poor control of non-fibrous material additions can lead to significantindirect costs. There is a general view in the industry that, because its fibre content is recovered,broke has a zero cost. This is incorrect. Besides the waste of energy, labour and machine operatingtime used to produce the broke, the value of most of the added chemicals in the broke is lost. Thereal cost of broke is discussed in more detail in Section 2.3. The potential to reduce broke providesthe justification for taking action to improve control of non-fibrous material additions.
Paper mills can also achieve significant cost savings and other benefits by taking action to reducetheir water consumption. Advice on how mills can save money by assessing and improving theirmanagement of water is given in Good Practice Guide (GG111) Practical Water Management inPaper and Board Mills. GG111 is available free of charge through the Environment and EnergyHelpline on 0800 585794.
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I N T R O D U C T I O N1
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1
1.1 THE PURPOSE OF THIS GUIDE
This Good Practice Guide is intended to help paper and board mills achieve cost savings and otherbenefits through improving the control of the addition of non-fibrous materials during thepapermaking process.
The Guide provides:
■ benchmarking data on the cost and quantity of non-fibrous materials currently used by UKpaper and board mills;
■ checklists to help you:
– identify how much non-fibrous material your mill uses;
– calculate the efficiency of your papermaking machine;
– calculate how much broke costs your mill.
■ an indication of the range of no-cost and low-cost measures that can be taken to improveperformance;
■ examples of the cost savings already achieved by some mills.
Section 2 explains the benefits of improved management of non-fibrous materials in paper mills,while Section 3 describes the first key steps in improving your control of additions.
Using this Guide, managers should be able to:
■ assess how much non-fibrous material their mill uses and compare it with the average fortheir sector;
■ identify the cost of waste due to poor control of non-fibrous materials;
■ develop an action plan to improve their mill’s management of additions.
Detailed advice on how to implement improvements and achieve cost savings is given in acompanion volume, Good Practice Guide (GG195) Increasing Profit Through Improved MaterialsAdditions: Technical Guide for Paper Mills. Free copies of this volume are available through theEnvironment and Energy Helpline on 0800 585794.
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Poor control of non-fibrous materials costs you money. These costs are estimated to be at least£5/tonne of paper produced. A mill that produces 100 000 tonnes/year of paper could therefore bewasting over £500 000/year unnecessarily. In addition, machine efficiency can fall, leading toreduced output. This Section explains how these costs arise and how to estimate them for your mill.
2.1 DIRECT COSTS
Excess non-fibrous materials leave the mill either as give-away in the paper or in effluent. You arepaying for this loss.
A breakdown of the use of non-fibrous materials by UK paper mills in terms of quantity and cost isshown in Fig 1. Fig 1 shows that the non-fibrous materials used most, ie pigments/fillers/opacifiers,are not those with the highest cost, ie retention aids and sizes. When seeking to reduce direct costs,be aware that the greatest potential for savings may not necessarily be associated with the chemicalthat you use most.
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Fig 1 Use and costs of different types of non-fibrous materials in UK paper mills1
Adhesives
Anti-scale agents
Binders
Biocides
Bleaches
Coating starch and resins
Defoamers
Dispersants
Dry strength agents
Dyes and colours
Felt cleaning
Flotation aids/de-inking chemicals
Optical brightening agents (OBAs)
Others
Pigments/fillers/opacifiers
Retention aids
Sizes (internal)
Sizes (surface)
Softeners and surfactants
System cleaning
Wet strength agents
0 100 000200 000
300 000400 000
500 000800 000
700 000600 000
0 10 20 30 40 50 60 70 80
Quantity (tonnes/year)
Cost (£ million/year)
Use
Cost
BENEFITS OF IMPROVED CONTROL OFNON-FIBROUS MATERIAL ADDITIONS
2
1 Data extrapolated from a survey carried out on behalf of the Environmental Technology Best Practice Programme of millsrepresenting 25% of total UK paper production.
Table 2 shows the range of costs for different types of non-fibrous materials (as delivered, not theactive component).
Type of material Typical cost (£/tonne)
Binder 550 - 1 750
Biocide 1 750 - 9 000
Bleach 750 - 1 000
Brightener 800 - 2 500
Cleaning chemicals 50 - 600
Colour and dyes 1 000 - 6 000
Defoamer 350 - 1 200
Dispersant 800 - 1 000
Dry strength 230 - 550
Filler 10 - 70
Ink dispersant 300 - 500
Opacifier 450 - 1 300
pH control 60 - 160
Retention aid 1 000 - 2 300
Sizes (internal) 15 - 1 300
Sizes (surface) 200 - 1 700
Stabiliser 20 - 40
Stickies control 200 - 300
Wet strength 150 - 250
Table 2 Typical costs for different types of non-fibrous materials (1998 prices)
2.1.1 How does your mill compare with the sector average?
Table 3 shows the average use of non-fibrous materials in kg/tonne of paper produced (gross) bydifferent sectors of the paper industry, together with the average cost in £/tonne of paper produced.At an average industry cost of £60/tonne of production, simply reducing the amount of materialsadded will produce immediate savings.
Sector/products Average use Average cost(kg/tonne produced) (£/tonne produced)
Newsprint 131 62
Printings and writings:- uncoated 232 92- coated 437 72
Corrugated case materials:- corrugated 43 18- liner 2 2
Packaging papers 119 53
Packaging board:- uncoated 17 20- coated 217 70
Household and sanitary 29 36
Industry average 170 60
Table 3 Average use and costs of non-fibrous materials in UK paper mills2
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2 Based on a survey carried out on behalf of the Environmental Technology Best Practice Programme of mills representing25% of total UK paper production.
Use the data given in this Guide to ‘benchmark’ your mill against others in your sector:
■ Use Checklist 1 (see Appendix 1) to assess your mill’s use of non-fibrous materials. Comparethe amount of non-fibrous materials used/tonne of paper produced and the cost of non-fibrous materials/tonne of paper produced with the average for your sector given in Table 3.
■ Fig 2 shows the range of non-fibrous materials used by paper type and Fig 3 the range ofcosts for non-fibrous material additions by paper type. How does your mill’s performancecompare?
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Fig 2 Non-fibrous material use by paper type
Newsprint
Printings andwritings (uncoated)
Printings andwritings (coated)
Corrugated casematerials (corrugated)
Corrugated casematerials (liner)
Packaging papers
Packagingboard (uncoated)
Packagingboard (coated)
Householdand sanitary
0 10 100 1 000Total non-fibrous material used (kg/tonne of production)
Fig 3 Non-fibrous material costs by paper type
Newsprint
Printings andwritings (uncoated)
Printings andwritings (coated)
Corrugated casematerials (corrugated)
Corrugated casematerials (liner)
Packaging papers
Packagingboard (uncoated)
Packagingboard (coated)
Householdand sanitary
0 20 40 60 80 100 120 140 160 180 200Cost of non-fibrous material used (£/tonne of production)
2.2 INDIRECT COSTS
2.2.1 Effluent treatment/disposal
Some of the excess non-fibrous materials will end up in the mill’s effluent, thus adding to the loadon your effluent treatment plant (ETP) and increasing treatment and disposal costs. Many of thechemicals used in papermaking, eg sizes and starches, have a high chemical oxygen demand (COD).Poor control of non-fibrous materials (either losses or excessive additions) can easily increase theeffluent COD by a few hundred mg/litre. Apart from the direct cost of the lost non-fibrous materials,the effluent will either cost more to treat or incur additional trade effluent charges. For a millproducing effluent 24 hours/day at a rate of 100 m3/hour, a 300 mg/litre increase in COD couldincrease trade effluent charges by £45 000 - £150 000/year. The actual increase will depend on themill’s location and the charges imposed by the local water company according to the MogdenFormula.
2.2.2 Machine efficiency
Lower efficiency due to stoppages and ‘out-of-spec’ paper can be partly attributed to inadequate orpoorly controlled additions of non-fibrous materials.
Machine efficiency can be determined by comparing actual saleable production against calculatedgross production (speed x grammage x width x time). Simply comparing gross tonnes (ie woundpaper off the machine) against net tonnes (ie paper sold out of the gate) ignores the closed loopsof broke within the machine and machine downtime. It also ignores materials lost in broke and inthe backwater and other effluent streams from the machine or stock preparation area.
Use Checklist 2 (see Appendix 1) to calculate your machine efficiency. This Checklist includes aworked example to help you. Then ask yourself, where is all this lost production going?
2.2.3 Broke
Poor control of non-fibrous material additions can cause paper to go off-spec, leading to increasedbroke production. Broke is widely accepted as an operational fact within paper mills. However, itis not necessary and is a major factor affecting mill profitability.
Broke is waste. It is not a zero-cost item because only some of the materials - filler and fibre - aresubstantially recoverable. Broke represents a waste of machine operating time, energy, labour andmaterials.
Some materials, eg retention aids and OBAs, are only partly recoverable and, in some cases, requiremore chemicals to quench their effects. For some materials, eg size press starch, little is recoverableand most of the material is lost to effluent. In addition, some of the chemicals in the broke can makethe overall papermaking process inherently less stable. In extreme cases, eg recycling broke of adifferent colour, further out-of-spec paper may be produced.
Apart from the loss of added value in broke, re-use of broke can also generate additional costs suchas higher effluent treatment costs or trade effluent charges.
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Low-cost high-gain idea
Immediate savings can be achieved by interlocking dosing systems to the operation of thepapermaking machinery so that they switch off when the machine stops. Unnecessary dosing iseliminated and machine start-ups are easier.
Simply reducing the amount of material added will yield immediate savings.
Although some mills require recirculation of broke to maintain paper quality, this is usually due toshortcomings in mill design and inadequate capacities. Most mills do not require a high recirculationof broke, if any at all. However, broke production that is 8 - 30% higher than any actual‘requirement’ is often considered acceptable by paper mills. At this level of rework on top ofdowntime, gross production of 100 000 tonnes/year of base paper would result in only 70 000 - 92 000 tonnes/year of saleable paper.
Any reduction in broke not required for quality reasons leads to:
■ more gross tonnes of paper production ending up as saleable tonnes;
■ greater overall efficiency;
■ improved controllability of papermaking operations;
■ reduced waste.
2.3 THE REAL COST OF BROKE
Materials, energy, labour and an attributable proportion of capital investment all add value to thefibre as it proceeds through the papermaking process to give the final paper product. The cost ofbroke depends on where in the process it is generated.3 A significant proportion of broke is finishedpaper that has failed quality control. Consequently, broke contains most of the non-fibrousmaterials used in the papermaking process.
To calculate the real cost of broke in your mill, you need to know:
■ selling price/tonne of product;
■ storage and distribution costs/tonne of product;
■ value of recoverable fibre/tonne of broke;
■ value of recoverable chemicals/tonne of broke;
■ costs associated with broke handling and re-use.
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Cost of redissolved surface additives
A paper mill incorporates 4 - 5% starch weight/weight on its paper and generates 20% broke.The amount of starch in its effluent is therefore approximately 1% weight/weight of paperproduced, ie 10 kg starch/tonne of paper. Assuming an equivalent COD load (ie 1 kg starch isequivalent to 1 kg COD), the redissolved starch present in the effluent will increase trade effluentcharges by approximately £4/tonne of paper produced.
Broke is:
Electricity
Time
Steam
Additions
Water
3 Sources of broke are discussed in more detail in Good Practice Guide (GG195) Increasing Profit Through Improved MaterialsAdditions: Technical Guide for Paper Mills. GG195 is available free of charge through the Environment and Energy Helplineon 0800 585794.
The real cost of broke per tonne of production can be estimated using the following formula:
Use the formula to calculate the cost of broke in your mill. Appendix 2 explains how the formula isderived.
Checklist 3 (see Appendix 1) shows a simple method for estimating the total value lost per tonne ofbroke. The Checklist includes a worked example to help you.
2.3.1 The potential for savings from reduced broke
In 1997, saleable paper production in the UK was around 6.5 million tonnes. Assuming average UKbroke levels were 15%, then gross production would have been approximately 7.5 million tonnesand broke production would have been approximately 1.1 million tonnes. Industry opinion suggeststhat improved monitoring and control could reduce broke by 10 - 30%. Even with a conservativefigure of 5% reduction in broke, the opportunities for cost savings and increased profitability acrossthe industry are significant. For a mill with gross production of 100 000 tonnes/year, reducing brokefrom 15% to 14.25% (ie a 5% decrease compared to the original 15% broke production) wouldincrease profits by approximately £500 000/year at the same level of gross production.
Fig 4 shows the increased profit that could be achieved by reducing broke production for a milloperating at 15% broke.
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Real cost of broke (£/tonne) =
Paper selling price – Storage costs – Distribution costs
– Value of recoverable fibre – Value of recoverable chemicals
+ All costs associated with broke re-use, eg handling, storage, quench chemicals, effluent treatment/disposal and waste disposal
Fig 4 Value of 5% broke reduction for a mill operating at 15% broke
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0 2 4 6
5
8 10 12 14 16 18 20 22 24 26 28 30 32 34 36
% reduction of original 15% broke production
Incr
ease
d p
rofi
t (£
mill
ion
/yea
r)
Savings assuming constant gross production(increase in saleable goods)
Savings assuming constant net production(maintaining same volume of saleable goods)
Improved addition and control of non-fibrous materials will help you to reduce broke and thus increase your profits.
The greatest potential opportunity for reducing indirect costs is to reduce broke. Even a smallreduction in broke increases profitability significantly. The main sources of broke production are:
■ losses at start-up and shut-down;
■ on-line breaks;
■ effects of improper application of non-fibrous materials on production parameters.
Losses at start-up and shut-down are a function of run time. This is dictated by production planning.However, dosing of non-fibrous materials during stoppages can lead to undesirable concentrationsof chemicals building up in the system making start-up more difficult and unstable. The frequencyof on-line breaks can also be significantly affected by non-fibrous material application.
Not all quality failures can be blamed on improper addition of non-fibrous materials. Other causesinclude fibre problems and problems during pressing and drying. Once you have identified the realcost of broke, use the logic tree diagram in Appendix 3 to help you analyse why broke occurs andwhether chemical addition is a contributory factor.
Factors that affect the use of non-fibrous materials include:
■ raw materials, type and quality of paper product;
■ chemical selection;
■ chemical supply and contract conditions;
■ chemical storage, handling and dosing;
■ good design and capital investment;
■ production scheduling;
■ management approach.
These factors are considered briefly below and illustrated with Industry Examples. Detailedinformation about how to improve the control of additions of non-fibrous materials is given in GoodPractice Guide (GG195) Increasing Profit Through Improved Materials Additions: Technical Guide forPaper Mills. GG195 is available free of charge through the Environment and Energy Helpline on0800 585794.
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MEASURES TO IMPROVE CONTROL OFNON-FIBROUS MATERIAL ADDITIONS
3
Ignored dosing pump results in more waste
At one mill, the machine operator was supposed to stop the pump adding retention aid whenthe machine was not operating. However, each time the machine shut down, the operator’spre-occupation with getting it started again meant that this seemingly trivial retention aid dosingpump was considered irrelevant. As a result, the stock was overdosed with retention aid andbreaks frequently occurred on start-up. This fact only became known after many years ofoperation.
3.1 RAW MATERIALS, TYPE AND QUALITY OF PAPER PRODUCT
The type of operation at a paper or board mill dictates the use of non-fibrous materials. The end-product and the raw materials (particularly fibre) significantly affect non-fibrous materialconsumption. For example, the need to accommodate the variability of the feed material andcontaminants when using low-grade recovered paper to manufacture paper or board putsconstraints on the manufacturing process.
3.2 CHEMICAL SELECTION
The performance of some chemicals may require conditions that can only be achieved by using otherchemicals, ie ideal conditions are not naturally present in the stock.
3.3 CHEMICAL SUPPLY AND CONTRACT CONDITIONS
It is common practice in the paper industry for a mill to place a contract for a package of serviceswith a chemical supplier. Besides supply of the chemical itself, the contract may include:
■ technical advice;
■ supply of storage and make-up dosing equipment;
■ analytical services;
■ operational services;
■ maintenance services.
Some contracts are based on the amount of material used, some have a fixed fee and others relateto performance, eg fixed or maximum cost per tonne of paper produced. There can be a conflictbetween contract conditions and encouraging minimum chemical use.
Care should be taken when negotiating long-term chemical supply contracts to ensure that there isan incentive for the supplier to monitor and control chemical additions correctly.
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Improved performance through greater use of retention aid
A mill changed from using a retention aid (polyacrylamide) periodically on one machine only tousing it constantly on all three of its papermaking machines. In addition to a significantreduction in fibre loss, use of other non-fibrous materials and waste has also fallen. A smallreduction in broke has also been achieved. Estimated cost savings are £100 000/year comparedwith the total cost of retention aid of £61 500/year (ie 15 tonnes @ £4 100/tonne).
Significant cost savings by changing from acid to neutral sizing
A mill that changed from acid sizing to neutral sizing reduced its use of alum by 2 000 tonnes/year. Estimated cost savings of £150 000/year were achieved through reducedalum consumption and improved quality. Other benefits included reduced loading on theeffluent treatment plant and fewer corrosion problems due to the neutral rather than acid pH ofthe effluent. The cost of the change was minimal as no equipment costs were involved.
3.4 CHEMICAL STORAGE, HANDLING AND DOSING
The effective use of non-fibrous materials depends on good dosing control. This is a function of thequality of the storage, handling, dosing and control system. This area has the greatest scope forimprovement through low-cost measures.
3.5 GOOD DESIGN AND CAPITAL INVESTMENT
Although it is often not immediately apparent, good design can save money.
The level of investment is an important factor in the quality of control of non-fibrous material use.Because simple, inexpensive dosing systems are achievable (especially as add-on systems), there is atemptation to ‘try and get away’ with the minimum requirement and invest elsewhere in the mill.For example, equipment is provided by a chemical supplier on a trial basis but when the trial ends,the inefficient temporary equipment remains as the permanent installation.
Lack of investment can have knock-on effects. For example, in one mill where the starch cookersare undersized for current production rates, the use of synthetic retention aids has increased. Atanother mill where recovered paper is used as a raw material, the lack of suitable de-inking plantmeans that excessive use of non-fibrous materials is required to ensure suitable product quality andappearance.
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Installation of high-level alarms on bulk storage tanks
The simple fitting of high-level alarms on bulk storage and day tanks, eg holding alum or size,can eliminate overfilling and costly spillages. Linking these alarms to trip switches on the deliverypumps is also recommended. At one mill, a recent example of overfilling and spillage caused alarge quantity of alum to flow into the mill’s effluent treatment plant. This led to the plant failingand put the mill at risk of total shut-down. The potential cost would have been considerablymore than the value of the chemical itself, which in turn was far greater than the cost of fittinghigh-level alarms and trips.
Poor design of backwater collection systems
In a mill with shared backwater drainage and collection and one machine producing high wetstrength paper, the paper on the other machines will absorb additional wet strength material.This is usually unnecessary and leads, in effect, to a giveaway of wet strength - with obvious costpenalties.
Cost savings from installation of bulk storage facilities
Installation of bulk storage facilities for calcium carbonate and a change in the addition point tothe process resulted in reduced waste, labour costs and manual handling at one mill. Estimateddirect savings of 500 tonnes/year (worth £30 000/year at £60/tonne) were achieved through morecontrolled addition. Total savings were at least £40 000/year. Additional benefits included reducedloading to the effluent treatment plant and less primary sludge disposed of to landfill. The capitalcost of the changes was an estimated £30 000, giving a payback period of less than a year.
Thinking laterally about the impact of capital spending is also necessary. For example, minimisingwet end volume will reduce the volume of stock dumped when significant grade changes are made.
3.6 PRODUCTION SCHEDULING
Production scheduling can have an impact on losses of non-fibrous materials due to washdown andbroke at start-up and shut-down. Incorrect scheduling of coloured paper production can lead tounnecessary dumps and inefficient production. For example, changing from white to pastel greento blue to black does not usually require dumps and washout for the colour change. However, ifthe changes are from blue to white to black to pastel green, then two dumps and washouts may benecessary.
It is important to maintain a balance between production scheduling, stock control and just-in-timesupply.
3.7 MANAGEMENT APPROACH
The approach adopted by management may be instrumental in ensuring the careful and efficientuse of non-fibrous materials. Whatever strategy you decide to adopt for your mill, it is essential toconvey your commitment to everyone on site.
Incentive schemes can help to breed a culture of continuous improvement, waste minimisation andincreased awareness. For example, some mills give a bonus to shifts if the production cost per tonneof paper is reduced.
The development of an ownership culture has implications for both management and theworkforce. Careful implementation of an ownership scheme can generate significant savings - asillustrated by the experience at a snack food company in County Durham. For details of itsstructured approach to waste minimisation, see Good Practice Case Study (GC19) WasteMinimisation Pays Major Dividends, available free of charge through the Environment and EnergyHelpline on 0800 585794.4
Increased staff awareness of the issues associated with non-fibrous materials use can reduce wasteand production costs. Awareness can be increased by:
■ specific training sessions;
■ extensive and correct labelling of pumps, pipework and tanks;
■ local labelling and flow indicators (in units not percentages);
■ use of standard operating procedures - these should be easily available for reference.
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Installation of colour measurement and control
One mill reduced its use of dyestuffs and OBAs by around 170 tonnes/year through use ofautomatic measuring and control of colour dosing to the machines. Estimated cost savings of£100 000/year were achieved through reduced raw material use, less waste of product as brokeand shorter grade change times. The capital cost of the equipment was about £80 000, plus£40 000 for pump conversion, giving a payback period of less than 15 months. Costs do notinclude installation.
4 General advice and information on all aspects of waste minimisation are available through the Environment and EnergyHelpline on 0800 585794.
To promote a more standardised and, therefore, efficient dosing regime:
■ provide operating manuals or similar guidance documents;
■ display information, eg graphs, at the point of dosing.
Such measures will help to ensure standardisation across different shifts and over a period of time.
3.8 MEASURING TO MANAGE
Monitoring and recording of non-fibrous materials consumption is often poor. Many mills rely ontheir chemical suppliers for this information or, due to the form of contract between the mill andthe chemical supplier, never collect data on the amounts of non-fibrous materials used.
Incorrect dosing of non-fibrous materials results in problems which may only be recognised sometime later. The time taken for the problem to manifest itself can also vary (see Table 4). Weekly ordaily monitoring may not reveal significant changes in use that could severely affect product qualityand result in the production of broke. Correct dosing is therefore essential.
Problem When identifiable
Error in the dosing of colour or addition of filler Within minutes
Inadequate dosing of retention aids and defoamers Medium term
Inadequate dosing of biocides and pitch control chemicals Long term
Table 4 Possible time taken to identify dosing problems
Obtain data on non-fibrous materials use in your mill and compare your use to the industry averageor, better still, to a similar type of mill. The use and costs of non-fibrous materials by sector are givenin Figs 2 and 3 respectively (see Section 2.1).
Many operators consider checking the use of non-fibrous materials to be mundane. This viewshould be eliminated by education and training. On-line and off-line monitoring of non-fibrousmaterials can provide significant opportunities for reducing waste and achieving cost savings. Withsome substances costing around £6 000/tonne, even a small reduction in use or the repair of aleaking piece of equipment will produce significant direct cost savings without compromising theprocess.
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Operators did not know a dosing pump had failed
The operators at one mill did not notice that a retention aid dosing pump had failed. Apart fromsuggesting that retention aid may not actually be necessary, the incident demonstrated the needfor flow indication and, preferably, no-flow indicators/alarms.
Both local and remote flow indicators should show actual flow and not a 0 - 100% scale.Percentage scales generally convey little information as the true 100% flow is unlikely to beknown and, even if it is, the flow is unlikely to be linear.
Remember:
If you don’t measure it, you can’t manage it.
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A C T I O N P L A N4
If you want to cut costs by improving the control of your non-fibrous materials:
Establish the amount and cost of the non-fibrous materials used by the mill (seeChecklist 1).
Compare your use and costs with the average for your sector (see Section 2.1).
Assess broke production and work out the real cost of broke in your mill (seeSection 2.3 and Checklist 3).
Use this information to convince others of the potential savings from improvingthe control of your non-fibrous material additions, eg by reducing broke.
Make someone responsible for non-fibrous materials on your site.
Identify and evaluate the reasons for unnecessary direct and indirect costs.
Set targets for improvement.
Use the practical advice given in Good Practice Guide (GG195) Increasing ProfitThrough Improved Materials Additions: Technical Guide for Paper Mills to plan andimplement measures to improve your performance.
Monitor performance to assess improvement.
If you want to reduce other operating costs:
Take action to reduce your water consumption. Follow the advice given in:
Good Practice Guide (GG67) Cost-effective Water Saving Devices and Practices;
Environmental Performance Guide (EG69) Water Use in UK Paper and Board Manufacture;
Good Practice Guide (GG111) Practical Water Management in Paper and Board Mills;
Good Practice Guide (GG152) Tracking Water Use to Cut Costs.
Implement a systematic waste minimisation programme. Tools and techniques foridentifying opportunities to reduce waste are described in:
Good Practice Guide (GG25) Saving Money Through Waste Minimisation: Raw Material Use;
Good Practice Guide (GG26) Saving Money Through Waste Minimisation: Reducing Water Use;
Good Practice Guide (GG27) Saving Money Through Waste Minimisation: Teams and Champions.
Seek free advice and information on all aspects of minimising waste and obtaincopies of relevant Environmental Technology Best Practice Programmepublications, including the ones referred to in this Guide, from the Environmentand Energy Helpline on 0800 585794.
Three checklists are provided to help you assess the potential for improving the control of non-fibrous material additions in your mill. Much of the information needed to complete these simplechecklists should be available on-site. If required, the checklists can be photocopied.
The three checklists are:
■ What non-fibrous materials are there on-site? An aid to help you identify:
– which non-fibrous materials are added to the papermaking process;
– how much of each material is used annually;
– the annual cost of each material;
– the potential scope for reduced use.
■ How efficient is your papermaking machine? This Checklist allows you to compare youractual saleable production with your calculated gross production.
■ How much does broke cost you? This Checklist calculates the total value lost in terms ofenergy, labour and non-fibrous materials per tonne of broke.
Worked examples are included in Checklists 2 and 3.
15
appx
A1
C H E C K L I S T SAppendix 1
Useful conversion factors
1 tonne = 1 000 kg
1 tonne = 1 000 000 g
1 kg = 1 000 g
CH
ECK
LIST
1: W
HA
T N
ON
-FIB
RO
US
MA
TER
IALS
AR
E TH
ERE
ON
-SIT
E?
16
Mat
eria
l
De-
inki
ng
Aci
ds
and
alk
alis
:
Flo
tati
on
so
aps:
Dis
per
san
ts/s
urf
acta
nts
:
Ble
ach
es:
Pap
erm
akin
g: p
roce
ss c
on
tro
l
Dep
osi
t/sc
ale
con
tro
l ag
ents
, eg
bio
cid
e:
Ret
enti
on
/dra
inag
e ai
ds:
Def
oam
ers:
Cle
anin
g c
hem
ical
s fo
r m
ach
ines
an
d f
abri
cs:
Ch
emic
alU
nit
co
stA
mo
un
t u
sed
per
yea
rA
mo
un
t u
sed
per
ton
ne
of
pap
erp
rod
uce
d (
gro
ss)
Co
st o
f n
on
-fi
bro
us
mat
eria
lp
er t
on
ne
of
pap
erp
rod
uce
d (
gro
ss)
Pote
nti
al f
or
red
uce
d u
se:
Low
/med
/hig
h
GG194 published by the Environmental Technology Best Practice Programme. Helpline 0800 585794
CH
ECK
LIST
1: W
HA
T N
ON
-FIB
RO
US
MA
TER
IALS
AR
E TH
ERE
ON
-SIT
E?
(co
nti
nu
ed)
17
Mat
eria
l
Tota
l
Pap
erm
akin
g: p
rod
uct
per
form
ance
Fille
rs f
or
op
acit
y:
Sizi
ng
ag
ents
fo
r w
ater
res
ista
nce
:
Dry
str
eng
th a
gen
ts:
Wet
str
eng
th a
gen
ts:
Dye
s an
d o
pti
cal b
rig
hte
nin
g a
gen
ts:
Soft
enin
g a
gen
ts:
Surf
ace
or
coat
ing
ad
dit
ion
s
Size
pre
ss a
dd
itiv
es, e
g s
tarc
h:
Co
atin
g c
hem
ical
s, e
g m
iner
al
pig
men
ts a
nd
bin
der
s:
Co
nve
rtin
g c
hem
ical
s, e
g a
dh
esiv
es:
Ch
emic
alU
nit
co
stA
mo
un
t u
sed
per
yea
rA
mo
un
t u
sed
per
ton
ne
of
pap
erp
rod
uce
d (
gro
ss)
Co
st o
f n
on
-fi
bro
us
mat
eria
lp
er t
on
ne
of
pap
erp
rod
uce
d (
gro
ss)
Pote
nti
al f
or
red
uce
d u
se:
Low
/med
/hig
h
GG194 published by the Environmental Technology Best Practice Programme. Helpline 0800 585794
CH
ECK
LIST
2: H
OW
EFF
ICIE
NT
IS Y
OU
R P
APE
RM
AK
ING
MA
CH
INE?
18
Spee
d
Gra
mm
age
Wid
th
Ho
urs
op
erat
ed/d
ay
Cap
acit
y
Am
ou
nt
of
sale
able
* p
aper
pro
du
ced
Effi
cien
cy
* P
aper
of
adeq
uat
e q
ual
ity
for
the
sub
seq
uen
t p
roce
ss, e
g s
ale,
co
atin
g a
nd
co
nve
rtin
g.
met
res/
min
ute
g/m
2
met
res
ho
urs
ton
nes
/day
ton
nes
/day
%
S G W H C A
= (
S x
60)
x G
x W
x H
1
000
000
= A
x 1
00
C
450
120
2.5
24
= (
450
x 60
) x
120
x 2.
5 x
24
100
000
0=
194
.4
176.
8
= 1
76.8
x 1
00
194.
4=
90.
9%
= ..
......
.... x
100
...
......
...
= ..
......
....%
= (
......
x 6
0) x
....
.. x
......
x ..
....
1
000
000
= ..
......
Un
its
Form
ula
Exam
ple
You
r m
ach
ine
GG194 published by the Environmental Technology Best Practice Programme. Helpline 0800 585794
CH
ECK
LIST
3: H
OW
MU
CH
DO
ES B
RO
KE
CO
ST Y
OU
?
19
Pap
er m
ach
ine'
s g
ross
to
nn
age
cap
acit
y
An
nu
al e
ner
gy
bill
An
nu
al la
bo
ur
bill
No
n-f
ibro
us
mat
eria
ls c
ost
per
to
nn
e o
f p
aper
pro
du
ced
(fr
om
Ch
eckl
ist
1) m
inu
s th
e co
st o
f fi
llers
Tota
l val
ue
lost
/to
nn
e b
roke
5000
0 to
nn
es/y
ear
......
.....
ton
nes
/yea
r
£225
000
0
£120
000
0
£40/
ton
ne
£....
......
.....
£....
......
.....
£....
......
...../
ton
ne
225
000
0 =
45
50
000
120
000
0 =
24
50
000
40 = 4
5 +
24
+ 4
0
= £
109
Val
ue
Co
st (
£/to
nn
e)V
alu
eC
ost
(£/
ton
ne)
Exam
ple
You
r m
ach
ine
= .
......
= .
......
......
...
= .
....
+ .
....
+ .
....
= £
......
....
GG194 published by the Environmental Technology Best Practice Programme. Helpline 0800 585794
Consider a reel of paper that has been produced and is standing by the paper machine waiting forquality control (QC). Regardless of whether the reel is sold or is rejected as broke, production costsfor the reel are the same up to this point. Imagine that a one tonne reel of paper from the machinehas been picked up by a fork-lift truck and that a delivery lorry and the broke pulper are nearby (see Fig A1).
If the one tonne reel of paper is not sold, but is returned to the pulper as broke then:
20
Fig A1 The real cost of broke
Quality Control
Pulper
Lorry to customer
Do we put the reel on the lorryand send it to the customer?
orDo we put the reel in the pulper?
Value of broke in pulper =Value of recoverable fibre in the broke+ Value of recoverable chemicals in the broke– All other production costs– All costs associated with broke re-use, eg handling, storage, quench chemicals, effluent treatment/disposal and waste disposal
Value of saleable product on lorry =Selling price– Storage costs– Distribution costs– All other production costs
Cost of broke =Value of saleable product
– Value of broke
Equation (1)
Cost of broke = Value of saleable product – Value of broke
DERIVATION OF THE FORMULA FORCALCULATING THE REAL COST OF BROKE
Appendix 2
appx
A2
If the cost of a relatively small quantity of broke is being calculated, then it can be assumed that anyvariation in costs due to different characteristics, eg additional pulping requirements of brokecompared to bought-in pulp, can be ignored.
If QC releases the one tonne reel for delivery to the customer then:
However, if QC marks the one tonne reel as unsaleable then:
Inserting equations (2) and (3) in equation (1) for the value of saleable product and value of brokerespectively gives, for a one tonne reel of paper:
If storage costs, distribution costs, the value of recoverable chemicals and the costs associated withbroke re-use are assumed to be low, and fibre recovery is assumed to be high, then equation (5) canbe used as a rough estimate.
There are further complications in the calculation if the paper is converted. The value of paper forthe conversion process could be taken as ‘the selling price if the paper were to be sold in reels directfrom the paper machine’. This is equivalent to the cost of substitution by bought-in paper. This costwill be already known - or relatively easy to find out - if paper is occasionally bought-in for conversion.
21
appx
A2
Equation (2)
Value of saleable product = Selling price – Storage costs – Distribution costs
– All other production costs (excluding distribution per net tonne)
Equation (3)
Value of broke = Value of recoverable fibre in the broke + Value of recoverable chemicals in thebroke
– All other production costs (excluding distribution per net tonne)
– All costs associated with broke re-use, eg handling, storage, quenchchemicals, effluent treatment/disposal and waste disposal
Equation (4)
Real cost of broke = Value of saleable product – Value of broke
= Selling price – Storage costs – Distribution costs
– Value of recoverable fibre in the broke
– Value of recoverable chemicals in the broke
+ All costs associated with broke re-use, eg handling, storage, quenchchemicals, effluent treatment/disposal and waste disposal
NB The item ‘All other production costs (excluding distribution per net tonne)’ is eliminated.
Equation (5)
Cost of broke = Selling price per tonne of finished paper – Cost of fibre per tonne of finishedpaper
22
appx
A2
23
Iden
tify
th
e re
al c
ost
of
bro
ke a
nd
bre
aks
Iden
tify
th
e at
trib
ute
sw
hic
h r
esu
lt in
rej
ecti
on
as b
roke
Iden
tify
th
e ca
use
s o
fb
roke
an
d b
reak
s an
d a
ssig
nco
sts
to e
ach
cau
se
Pro
du
ctio
n t
eam
Pro
du
ctio
n r
eco
rds
Lab
ora
tory
rec
ord
sEx
per
ien
ce
Go
od
Pra
ctic
e G
uid
e G
G19
5*C
on
tro
l eq
uip
men
t m
anu
fact
ure
rsO
ther
exp
erie
nce
Co
nsi
der
invo
lvin
gm
anu
fact
ure
rs
Iden
tify
th
e cr
itic
al in
dic
ato
rsw
hic
h s
ho
uld
be
mo
un
ted
to
allo
w t
hes
e ca
use
s to
be
avo
ided
Prio
riti
se li
st o
f at
trib
ute
s,ca
use
s, c
ost
s an
d in
dic
ato
rs
Are
th
ere
any
man
agem
ent,
mo
nit
ori
ng
or
anal
ytic
alsy
stem
s w
ith
wh
ich
to
mo
nit
or
the
ind
icat
or?
Iden
tify
su
itab
lesy
stem
s fo
r ev
alu
atio
n
Info
rmat
ion
Bro
ke a
nd
bre
aks
reco
rds
Cal
cula
ted
co
st o
f b
roke
(usi
ng
th
is G
oo
d P
ract
ice
Gu
ide)
Co
nsi
der
:
Bro
ke/b
reak
s:W
et e
nd
Oth
er-
pap
er m
ach
ine
- o
ff p
aper
mac
hin
e
Cau
ses/
effe
cts:
Man
agem
ent
Ch
emic
al/p
hys
ical
Ind
icat
ors
:In
dic
ativ
eQ
uan
tita
tive
Mo
nit
ori
ng
sys
tem
s:In
dic
ativ
eQ
uan
tita
tive
On
-lin
eO
ff m
ach
ine
Co
ntr
ol s
yste
ms:
Op
erat
or
adju
stm
ent
Feed
fo
rwar
dFe
ed b
ack
Op
en o
r cl
ose
d lo
op
* A
vaila
ble
fre
e o
f ch
arg
e th
rou
gh
th
e En
viro
nm
ent
and
En
erg
y H
elp
line
080
0 58
5794
No
Yes
B R O K E R E D U C T I O N L O G I C T R E E
Appendix 3
Co
uld
th
e m
anag
emen
t,m
on
ito
rin
g o
r an
alyt
ical
syst
em b
e u
sed
to
co
ntr
ol
the
vari
able
s w
hic
haf
fect
th
e id
enti
fied
ind
icat
or?
Is t
his
an
attr
acti
ve p
roje
ct?
Esti
mat
e p
ote
nti
alre
du
ctio
n in
bro
ke a
nd
bre
aks
Esti
mat
ep
roje
ct b
ud
get
Co
st s
avin
gs/
inco
me
fro
m r
edu
ctio
ns
in b
roke
Req
uir
ed p
ayb
ack
Equ
ipm
ent
cost
sEs
tim
ate
cost
of
imp
lem
enta
tio
n
Det
aile
d e
valu
atio
nan
d im
ple
men
tati
on
No
No
Yes
Yes
appx
A3
The Environmental Technology Best Practice Programme is a joint Department of Trade and Industry
and Department of the Environment, Transport and the Regions programme. It is managed by
AEA Technology plc through ETSU and the National Environmental Technology Centre.
The Programme offers free advice and information for UK businesses and promotes
environmental practices that:
■ increase profits for UK industry and commerce;
■ reduce waste and pollution at source.
To find out more about the Programme please call the Environment and Energy Helpline on
freephone 0800 585794. As well as giving information about the Programme, the Helpline has
access to a wide range of environmental information. It offers free advice to UK businesses on
technical matters, environmental legislation, conferences and promotional seminars. For smaller
companies, a free counselling service may be offered at the discretion of the Helpline Manager.
FOR FURTHER INFORMATION, PLEASE CONTACT THE ENVIRONMENT AND ENERGY HELPLINE
0800 585794world wide web: http://www.etsu.com/etbpp/
e-mail address: [email protected]