TekniTekni--FilmsFilms

TroubleshootingTroubleshootingThermoformable Thermoformable PackagingPackaging

Optimizing the thermoformingOptimizing the thermoformingprocess with differing materials.process with differing materials.

TEKNI-FILMSTEKNI-FILMS A Division of

TroubleshootingTroubleshootingThermoformable Thermoformable PackagingPackaging

Optimizing the thermoformingOptimizing the thermoformingprocess with differing materials.process with differing materials.

TEKNI-FILMSTEKNI-FILMSCompanyA

TekniTekni--FilmsFilms

Defining the Manufacturing ProcessDefining the Manufacturing Process

•• All processes contain variables of threeAll processes contain variables of threediffering types:differing types:

–– Design VariablesDesign Variables

–– Production VariablesProduction Variables

–– Manpower VariablesManpower Variables

•• TekniTekni-Films-Films’’ Troubleshooting Guide will Troubleshooting Guide willaddress the design and production variables.address the design and production variables.

TekniTekni--FilmsFilms

Part I - Design VariablesPart I - Design Variables

Variables determined whenVariables determined whenpurchasing blister thermoformingpurchasing blister thermoforming

machinerymachinery

TekniTekni--FilmsFilms

Film Roll Unwind

Film Heating

Blister Cavity Formation

Blister Cavity Filling

Lidstock Sealing

To Cartoning

Blister Machine Process SchematicBlister Machine Process Schematic

TekniTekni--FilmsFilms

Types of Machines and Sealing DevicesTypes of Machines and Sealing Devices

Rotary, continuous web movement

Platen, indexed web movement

Cam, IMA, Cam, IMA, KlocknerKlockner, , NoackNoack, and , and UhlmannUhlmannproduce indexing machinery.produce indexing machinery.

Bosch, IMA produce Bosch, IMA producerotary rotary thermoformersthermoformers

TekniTekni--FilmsFilms

More Machinery VariablesMore Machinery Variables

•• Film Heating - The number and location ofFilm Heating - The number and location ofcontrolled heating zones allows for morecontrolled heating zones allows for morecontrolled and consistent web heating.controlled and consistent web heating.Ideally the heating plates are 3 indexesIdeally the heating plates are 3 indexeslong.long.

•• Blister Cavities can be filled either byBlister Cavities can be filled either byflooding the fill zone with pills, or byflooding the fill zone with pills, or bydedicated filling manifolds.dedicated filling manifolds.

•• Cooling plates after forming and sealing toCooling plates after forming and sealing tobe present.be present.

TekniTekni--FilmsFilms

Thermoforming Mold VariablesThermoforming Mold Variables

•• Molds may be coated with special releasingMolds may be coated with special releasingmaterials to aid in blister separation from thematerials to aid in blister separation from thetooling. Different coatings may aid intooling. Different coatings may aid inseparating one type of film, but may enhanceseparating one type of film, but may enhancethe bond to another.the bond to another.

•• Plug assisted cavities physically Plug assisted cavities physically ““pushpush”” the thematerial prior to itmaterial prior to it’’s final pressurized airs final pressurized airforming.forming.

TekniTekni--FilmsFilms

Part II- Production VariablesPart II- Production Variables

Controlling the process toyield optimal results.

TekniTekni--FilmsFilms

Film Heating StationFilm Heating Station

General Suggestions:

• Use the lowest setting possibleto minimize film shrinkage andcurl, while still forming completecavities.• Make sure platens are flat,parallel in alignment and gap.• Adjust temperature in 5O

increments.• Heating plate length: 3 indexes.

T1 T2 T3

T4 T5 T6

TekniTekni--FilmsFilms

Film Heating StationFilm Heating Station

PVC - Upper and lower platens set to thesame temperature, zones need not beincreased for best thermoforming results.

PCTFE PCTFE or PVdC coating -- Platen facingPCTFE or PVdC coating should be lowerthan that facing PVC. Incremental rise intemperature zones is generally desirable.

Typical Temperature Setting:

T1: 130 O C T2: 135 O C T3: 140 O C

T4: 125 O C T5: 130 O C T6: 135 O C

T1 T2 T3

T4 T5 T6

TekniTekni--FilmsFilms

Blister Cavity FormationBlister Cavity Formation

General Suggestions:

•Always activate plug assist to atleast 50% when available (up to75% ). Plug assist aids in moreuniform cavity thicknessdistribution, and usually resultsin lower platen heat settings.• Air forming pressure of 60-120PSI (4-8 bar) is optimal.• Use matched tooling.

P1

TekniTekni--FilmsFilms

Blister Cavity FormationBlister Cavity Formation

PVC - Almost any cooling conditions andcoatings will form cavities.

PVdC coatings - Require Teflon coatedcavities to lengthen tool life. Cold tools arediscouraged to reduce PVdC cracking.

PCTFEPCTFE -- These materials may bond withTeflon coatings. Mold temperaturesshould be “room temperature”. Plugassist is recommended.

P1

TekniTekni--FilmsFilms

Blister Cavity FillingBlister Cavity Filling

General Suggestions:

•Always insure improperlyoriented solid dosage forms andcrushed product are removedprior to the lidstock lamination.

•A change in film gage will affectproduct fit into the blister cavity.

• Incompletely formed cavitieswill negatively affect fillingperformance

TekniTekni--FilmsFilms

Winding PCTFE OUT

Winding PCTFE IN

Alu Foil LiddingALWAYS SEALS TO THE PVC SIDE

PCTFE on outside of blister

PCTFE Lamination Blister Package

PCTFE Film

PVC

Adhesive

You must specify the winding of the PCTFE side OUT or IN for the slit roll depending on the machine configuration

TEKNIFLEXTEKNIFLEX®® Laminations - Winding Laminations - Winding

TekniTekni--FilmsFilms

Lidstock Lidstock SealingSealing

General Suggestions:

•Lidstocks generally seal verywell to PVC, adequately toPVdC, and poorly to PCTFElayers. Novel lidstocks seal toPCTFE.

•Sealing Temperatures between170-220O C are used for mostPVC coated lidstocks. Universaland Polyolefin lidstocks can berun at 140-200O C.

Note: Curling may occur with PCTFEfilms at higher sealing temperatures.

T1

TekniTekni--FilmsFilms

Part III - TroubleshootingPart III - TroubleshootingSolutionsSolutions

Identifying and correctingIdentifying and correcting

common industry problems.common industry problems.

TekniTekni--FilmsFilms

Types of ProblemsTypes of Problems

•• Film shrinkageFilm shrinkage

•• Film curlFilm curl

•• Film stickingFilm sticking

•• Film Film delaminationdelamination

•• Incomplete blister cavitiesIncomplete blister cavities

•• Poor Poor lidstock lidstock sealingsealing

•• Blister card curlBlister card curl

TekniTekni--FilmsFilms

Film ShrinkageFilm ShrinkageMost Thermoforming films shrink somewhat during the thermoformingprocess. Concern is placed particularly on those films which shrink in

an erratic manner.

PCTFEPCTFE films shrink more than PVC in the trans-machine direction films shrink more than PVC in the trans-machine direction(TD). This shrinking both narrows the web and curls the film.(TD). This shrinking both narrows the web and curls the film.Properly processed film may shrink 3-5% for copolymer and 1-3%Properly processed film may shrink 3-5% for copolymer and 1-3%for for homopolymer homopolymer PCTFE films.PCTFE films.

Note:Note: With all films, tension in the machine direction will result in With all films, tension in the machine direction will result inloss of web width. Lessening the heat or increasing lines speedsloss of web width. Lessening the heat or increasing lines speedswill reduce the TD shrinkage in most films.will reduce the TD shrinkage in most films.

TekniTekni--FilmsFilms

Film CurlFilm Curl

•• Film Curl occurs when two or more films haveFilm Curl occurs when two or more films havedifferent shrinkage rates. This most commonlydifferent shrinkage rates. This most commonlyoccurs with occurs with PCTFE films that are laminated to PVC with films that are laminated to PVC witha PE tie layer.a PE tie layer.

•• Typical solutions to this difficulty are identical toTypical solutions to this difficulty are identical toreducing film shrinkage. Curl can also be reduced byreducing film shrinkage. Curl can also be reduced byduplex laminations and conversion to duplex laminations and conversion to homopolymerhomopolymermaterials.materials.

TekniTekni--FilmsFilms

Film StickingFilm Sticking

• May occur between the heating platens and/or to theforming mold.

• Most common with PVdC/PVC materials (PVdC-coatingrelatively tacky).

• Cleanliness & condition of heating platen surfacesimportant.

• Gap between platens should be uniform over entire area.

• Platens should be replaced or reconditioned periodicallywith a non-stick (e.g., Teflon) surface.

• Additional mold-cooling recommended for PVdC/PVC,but not for PCTFE laminations.

• Sticking may cause MD-stretching and web shrinkage.

TekniTekni--FilmsFilms

Film Film DelaminationDelamination

• PVC/PE/PCTFE - Adhesive is semi-activatedduring lamination, and is fully-activated uponapplication of heat during thermoforming.

• Adhesion strength increases remarkablyduring thermoforming.

TekniTekni--FilmsFilms

Incomplete Blister CavitiesIncomplete Blister Cavities• Normally indicates insufficient heat to film.

• Is sometimes accompanied by milky-white areas withincavities.

• Is also seen with loss of forming air pressure (audibleventing).

• Cavity formation may usually be improved by using moreheat (higher temperatures and/or slower cycle speeds).

• Striations may be caused by excessive heat used onPCTFE laminations.

• The actual temperature of the heating plates needs to becalibrated against the read-out on the controller.

TekniTekni--FilmsFilms

Poor Poor Lidstock Lidstock SealingSealing• Sealing temperature indicates heat applied to

coating on aluminum foil-based lidstock.

• Sealing temperature normally identical for PVC,PVdC/PVC and PCTFE /(PE)/PVC (PVC isgenerally product & lidstock contact layer).

• Sealing to correct side?

• Minimum heat-seal activation temperature.

• Sealing pressure.

• Cleanliness, condition, and pattern of sealingplatens is important.

• Alignment and flatness of platens is important.

TekniTekni--FilmsFilms

Blister Card CurlBlister Card Curl

• Most common with PCTFE laminations (card curlstoward PCTFE side).

• Same phenomenon as film curl.

• Same cause as TD web shrinkage: higher TDshrinkage rate of raw PCTFE film compared to PVCand PE films.

• Curl normally may be decreased by using less heatat heating-platen station (lower temperatures and/orfaster cycle speeds).

• Curl may also be decreased by utilizing duplexPVC/PCTFE construction.

TekniTekni--FilmsFilms

Control of production variablesControl of production variablesis the key to reducing oris the key to reducing or

eliminating faulty packaging.eliminating faulty packaging.

TekniTekni--FilmsFilms Flexible thinking, clear answers.