quick change over

Successful PracticesIn

Manufacturing: Blow Molding Team AchievesQuick Changeover on SIDEL SBO-16

October 1998Villahermosa, Mexico

Blow Molding Team Averages 24 Quick Changeovers Per MonthWhile Meeting Peak Demand Production Levels

Coca-Cola FEMSA, (Femento Económico Mexicano, S.A. de C.V.) in Mexico is one of the anchorbottlers for Latin America. FEMSA has operations in the Valley of Mexico and in the southeasternarea of Mexico. The plant in Villahermosa has one line running REFPET and returnable glass bottlesand another line running PET. Annual physical case production is 10.7 MM cases. The Villahermosasingle stage blow molding operation produces the following packages on a SIDEL SBO-16:

Contour Multi-product



*Ciel Ciel

2 Liter 2 Liter 1 Liter 1 Liter 500 ml 500 ml 500 ml 1.5 Liter*Ciel = FEMSA water product

The blow molding area has adopted self-directed teams. There are four teams that operate two 12-hour shifts – teams work 4 days and rest for 3 days. Teams have established their own work rules,including sanctions for tardiness and absenteeism. They also set their own goals and objectives.Teams meet once a week to review production, maintenance, and other issues. During meetings, theyalso discuss methods for improving processes and changeover speed.

In terms of team continuity, if a replacement for a team member on the blow-molding machine isneeded, the palletizer operator is the first choice. The palletizer operator assists in changeovers byadjusting the air conveyor and works with the blow molding team as needed.

The blow molding team in Villahermosa has improved their changeover technique to the point wheretheir average changeover time is less than 1.5 hours.

The rapid changeovers have been achieved due to the processes the team has developed and to aseries of simple modifications to the machine.

This document discusses their team processes and the modifications made to the SIDEL SBO-16.

Process For Changeover of Blow Molding Machine

One of the keys to success is the process of staging the molds, parts and tools that will be used duringthe changeover. One hour before the scheduled changeover, coordinators and technicians layout themolds, parts and tools near the machine. The diagram shows how the molds and parts are staged.

A complete mold station has all parts that belong to the station numbered – molds, stretch rod,adjustment caps and stoppers.

Note that the molds are staged so that teams access the machine from two sides. A coordinator and atechnician work from each of the two tables where molds are staged. Three molds can be accessedthrough each of the two doors – when six molds have been changed, the technician rotates themachine for the next 6. The mold staging is setup so that as the machine is rotated, each pair ofassociates has the correct molds on their table.

Oven

1,2,3,4,9,10,11,12

5,6,

7,8,

13,1

4,15

,16

SBO-16Access

Access

Table forStretch Rodsand Stoppers

Out-feed StarWheel Staged

Molds Staged

PLAN VIEWOF WORK AREA

ScheduleChangeover

Stage Molds& Parts

Prepare Tools

ExecuteChangeover

Clean & MaintainMolds, Parts &

Tools

Molds Staged at Each Access

Tools Staged

Stretch Rods and Stoppers

Tools Staged

Star Wheel and Out-feed GuidesStaged By Access Door

SIDEL Changeover Timing

T1 Prepare and position molds to the presentation to be changed toPrepare and position tools, screws and boltsPrepare and position preform in-feed and bottle exit star wheel

T2 Machine is stopped – power lock-out for safetyClose and by-pass cold and hot water circuits

T3 Dismount mold safety barsDismount stretch rodsDismount stretch-rod stoppers and mount new onesChange preform-in-feed and starwheelChange bottle exit starwheel and guard rails

T4 Oven adjustmentBottle sensor adjustmentInput new recipe (intensities changed on some lamps – others on or off)

T5 Unfasten screws left side of mold, right side of moldDisconnect water hoses (10)Demagnetize and dismount baseDismount left side of moldDismount right side of moldMount right side of moldMount left side of moldMount base and magnetize

T6 Connect hoses to mold bottom and baseClose mold and connect top mold hosesOpen water circuitsSet and tighten screws and both sides of moldInstall stretch rods

T7 Adjust pre-blow and blow camsAdjust pre-blow and blow pressureAdjust mold closing (1 mm.) left side and install and tighten safety bars

T8 Start blower to test recipe (new settings)T9 Bottle QC (wall thickness and burst-strengthT10 Re-start productionT11 Adjustments to bottle quality as necessary

T1 T2 T3

T4

T5 T6 T7 T8 T9 T10 T11

StartChangeover

Timing

StopChangeover

Timing

Change Air Conveyor RailsClean out Pre-form bin - Dump New Pre-forms

The timing of the changeover process assures success. Referring to the previous page, times T1through T11 take place sequentially – with the exception of T4. The oven adjustment (T4) takesplace as molds are being changed.

The palletizer operator changes the air-conveyor rails from the SIDEL out-feed to the palletizer whilemold changes take place.

A team of 1 coordinator, 1 operator and 2 technicians complete the changeover process. Each teammember understands exactly which task to perform.

The team times the changeover based on the read-out display from the SIDEL. The changeovertiming starts when the old preforms stop flowing into the oven and stops when the bottle thicknessand burst test are complete. There are usually some fine tuning adjustments to make certain allquality tests are passed but this time is charged to SIDEL operations, not changeover time. It is feltthat any after-changeover adjustments are the responsibility of the coordinator. Therefore, any T11time is charged to the coordinator for operations. This time averages 11.4 minutes and could betheoretically added to changeover times.

Pneumatic wrenches are used at the machine.Air lines have been installed so that eachcoordinator and technician has an air-operatedwrench to facilitate rapid loosening and tighteningof mold fasteners.

Four air wrenches are available; one set is off thepicture to the left.

Metal bin boxes have been fabricated to attach to theframe of the SIDEL. These bin boxes are sectioned tohold nuts and screws for the changeover as well as toorganize special small tools needed in the changeover.

Pneumatic Wrenches

Metal Bin Box

Oven lamp adjustments have beenspecially tailored to save set-up time.For each package, the team hasdetermined the correct positioning ofheating lamps and sensors. In manycases, rather than move heating lamps,the intensity of lamps is adjusted.

Adjusting the intensity and turning lampson or off cuts well over an hour off theset-up time for the oven. The recipe foreach package has been determined byexperiment and recorded by the team.

Molds and associated parts for each package are colorcoded and numbered for identification. This includes starwheels and out-feed guides. Molds and parts such as stretchrods and stretch-rod stoppers have been numbered so that eachmold station always uses the same associated parts. Thiscompensates for any normal variation in machine tolerances thatmight cause adjustment problems.

The quick-disconnect heating andcooling hoses have been color-coded.The colors identify in-let and out-lethoses for a mold so that they cannot beeasily mis-connected.

Example of ColorCoding on Star Wheel

Changing the supports for the cam activator bars allows more access to more molds. Changingthe location of these supports allows three molds on each side to be accessed without rotating themachine.

On one side, the two vertical supports for thefinal-blow cam activator bar have beenremoved. The picture shows how the supportslooked before removal.

The bar is now supported horizontally from theframe sides. The yellow lines show where thesupports were.

On the other side, the pre-blow cam activator bar had a vertical support. This support has beenmodified at an angle to allow better mold access.

A special tool means mold base adjustments can be done byone person. Prior to designing this tool, it took two teammembers to adjust a mold base. The team designed a lever,which allows one team member to make the adjustment.

A split out-feed rail adjustment saves dismount time.When changing the out-feed rails previously, the air conveyorhad to be dismounted to allow the rails to slip over the top ofthe support posts. The team cut the adjustment bars into twopieces so that they do not have to be placed over the top of thesupport bars – simply clamped to them. Not having todismount the air conveyor at the out-feed saves a considerable amount of time.

Mold bolts have been standardized. Previously, each mold had a combination of allen head andhex head bolts. The team changed them all to hex heads thus save a tool change when mounting anddis-mounting the molds.

Notch Fits into BracketFastened on Machine

Support Post

Benchmarks for changeovers with this type of equipment are around 240 minutes. In January1997, the Villahermosa blow-molding operation shifted to self-directed teams. Improvements havebeen steady since that time. In September 1998, the average changeover time was down to 75minutes and the team has already achieved a 55-minute changeover.

In November of 1997, a slight increase is seen. During this month, the team installed a quick-changekit from SIDEL that includes such things as magnetic base mounts. The kit, however, did NOTinclude shell molds. There was a 2-3 month learning curve involved in working with the newconfiguration but in January 1998, times again began to decrease.

480445 450

420

360330

300270

240210 225 210

180150

125 110 100 90 80 7590

0

100

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Feb

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Aug Se

p

Oct

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p

Time in M inutes

1997

1998

Mold Changeover Times SBO 16/16 No. 133

PET Bottle Production For 1998One of the major benefits to reducing changeover times has meant that the Villahermosa plant hasbeen able to meet peak production demands without having to call upon 3rd party sources for PETbottles. Had changeover times been longer, peak production demands would not have been met andthe plant would have incurred increased costs for outside sourcing.

Scrap Rate Chart Typifies What Is Achieved(Figures are in %)

Pack: CC2 MPV2 MPV2 1.5CIEL CC1 MPC1 MPV1 CC1/2 CIEL1/2 Ave %Jan 98

%*0.27 0.18 0.13 0.32 0.07 0.08 0.23 0.06 0 0.167

Feb 98%

0.18 0.09 0.33 0.18 0.34 0.17 0.07 0.06 0.06 0.164

Mar 98%

0.13 0.17 0.12 0.42 0.07 0.07 0.02 0.08 0.08 0.128

*Percentage of scrap vs. total production – includes both preforms and bottles

In addition, the scrap rates (see chart above) and maintenance costs are low. The team, aware ofmaintenance costs, uses special care in handling of molds. For example, all tables where molds arestaged are either wood or covered with rubber padding. The molds are never placed on tables withthe o-ring side facing down.

6,2985,779

9,501 9,78410,381 10,254

9,832

7,786

9,005

0

2000

4000

6000

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10000

12000

Jan Feb Mar Apr May Jun Jul Aug Sep

Bottles

The team is continuing to improve their process. They are considering a modification to the mainaccess doors on the SIDEL so that they open upward – this way the doors would not impedemovement around the machine during changeovers.

Also under consideration is a modification to the stretch rod adjusters. Overtime, the adjustments slipduring normal operation. By burnishing or knurling the rods slightly in the area where the adjustmentclamps contact the rods, it is hoped the slippage can be alleviated.

Finally, they plan to build a stretch rod adjustment jig so that the rods can be placed in the fixture andquickly adjusted without measurements.

References/Contributors

Plant at Villahermosa:Arturo Garcia Fiesco – Manufacturing Manager

Samuel Varela Ayala - CoordinatorIsrael Dueñas Chamorro – Technical MechanicJavier Copó - CoordinatorGustavo Gomez Gobantez - CoordinatorArturo Sanchez Jauregui – Technical MechanicRodrigo Mendez Pech - Coordinator

Coca-Cola FEMSARoberto Mendoza-RalphRio Amazonas 43 – 7 PisoCol. Cuauhtémoc06500 Mexico D. F.Phone: 525-209-5186

525-209-0925

The Coca-Cola CompanyVictor E. GibsonOne Coca-Cola PlazaAtlanta, GA 30313Phone: 404-676-6266Fax: 404-676-7416Email: [email protected]

ASKFAX: 404-676-7416 Phone: 404-676-1014

or mail to: P.O. Drawer 1734, Atlanta, GA 30301Email questions or comments to: [email protected] or call Operations Services at 404-515-8677

Please return form to: Steve Istvan, FAX: 404-676-7416 Phone: 404-676-1014

or mail to: P.O. Drawer 1734, Atlanta, GA 30301Email questions or comments to: [email protected] or call Operations Services at 404-515-8677

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Document Title: Manufacturing: Blow Molding Team Achieves Quick Changeover onSIDEL SBO-16

Document Date: October 1998

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