Troubleshooting boxmaking machinery takes patience and time. Everyone wants the problem solved immediately. Rather than trying to rush to a solution, it is best to take the time and find the root cause of the problem. Time and patience will solve it.
When a problem is noticed, the operator should look at every stage of the process. First, find at which stage the problem started then find the cause. Here are some hints to help you solve a few common problems. Always remember to keep a log book with the problems and solutions. They'll be easier to solve next time around.
Don't forget to write your original settings down before you begin troubleshooting. Try one thing at a time. If it doesn't work, return to the original settings and try something else.
| Problem | Cause | Solution |
|---|---|---|
| Unexact cutting edges | Wrong knife angle | Knife with cutting angle of 22° and a prefase of 28° |
| Cutters are worn out | Use of sufficiently sharp and exact cutters | |
| Film stacks are too high | Reduce the stacks height: take 10 cm as an approximate height |
| Problem | Cause | Solution |
|---|---|---|
| Poor sheet guiding
(blocking, double-sheet feeding, etc.) | Stock and handling conditions have not been kept | Store film in original packaging; if possible remove packaging 24 hours before handling and store film in printing hall; a relative humidity of at least 55% is recommended |
| Format stacks are too strongly charged | Do not stack more than two pallets on top of each other | |
| No air between sheets | Fan and/or lift up outer sheets before printing | |
| Film sheets stick together/stick to machine due to electrostatic charge | Separate film sheets with ionized air | |
| Printing speed is too high | Reduce printing speed (depends on machine) | |
| Insufficient ink key | Inappropriate ink | Use printing ink which is suitable for polymer type and drying procedure |
| Surface tension is too low | Use pretreated film | |
| Printing ink is not scratch resistant Film sheets stick together after printing Printing ink is passed on to next sheet | Unsuitable printing ink | Use printing ink which is suitable for polymer type and drying procedure |
| Printing ink has not been sufficiently hardened/dried | Evaporate drying: increase amount of air, if necessary, air temperature | |
| UV-drying: optimize/clean UV-heater | ||
| Oxidative drying: use a film with sufficient roughness depth/check composition of fountain solution (ph-value) |
| Problem | Cause | Solution |
|---|---|---|
| Film breaks | Punching tool is damaged | Change punching tool or punching support |
| Film is too cold | Do not process film under a temperature of 15°C | |
| Film is not suficiently impact resistant | Use a film with higher tensile strength |
| Problem | Cause | Solution |
|---|---|---|
| Bond strength of gluing line not strong enough | Unsuitable glue | Use only glue which is recommended for the polymer being used |
| Speed of machine is too high | Adjust speed | |
| Contact pressure or contact time is too low | Raise pressure/speed | |
| Glue line discolors (APET, GAG) | Solvent glue has been used | Use PU-Hotmelt (APET, GAG); if necessary, a glue with slower effect (GAG) |
| Vapor locks generate in the glue line (PU-hotmelt) | Contact pressure is too low | Use suitable glue |
Card lamination is the way of bonding two or more layers of films together under increased temperature and pressure without using adhesives. The process is used mostly for combining PVC layers, but different substrate layers can be used if required.
The lamination properties of vinyl films are highly dependent on the formulation of the film. Additives like acetate-copolymer reduce the softening behavior significantly. ABS additives are used to increase the softening behavior. Here are quick and detailed guides to aid you in the lamination process.
For further information on card production, visit the card product section of the site.
| Temperature Set Point | Heat Time | Cooling Time |
|---|---|---|
| 285 to 300°F | 22 minutes at 125 psi | 18 minutes (125 psi for first 2 minutes; 250 psi at remaining 16 minutes) |
| Temperature Set Point | Heat Time | Cooling Time |
|---|---|---|
| 285 to 300°F | 22 minutes at 125 psi | 18 minutes (125 psi for first 2 minutes; 250 psi at remaining 16 minutes) |
| Temperature set point will vary from lamination press to lamination press | The goal of the heating cycle is to get the middle sheet in any opening to reach a probe temperature of 250°F. | The goal in any cooling cycle is to bring the material down to ambient room temperature. |
| At that point, you want your outside sheets (top sheet in opening & bottom sheet in opening) to be as close to 250°F as possible. | The maximum exit temperature for the material out of the lamination press would be recommended at 100°F. | |
| We would expect the delta between these two locations ideally to be 5 to 7°F & not greater than 10°F. | Higher exit temperatures will lead to card warpage. | |
| Meeting the center temperature will guarantee maximum peel strength & great center core-to-core bonding for split card construction cards. | Some presses have chillers & some don't. If a chiller is available set its exit temperature between 55 to 60°F. | |
| Variation in temperature from the middle to top or bottom sheet in any one opening of greater than 10° would be a concern for yellowing & possible distortion to the outer most sheets. | Elapse time is the time required by the lamination press to bring the exit temperature at or below 100°F. Thus time will vary. With a chiller 18 to 20 minutes would be typical. | |
| Please note that once center temperature in any opening reaches 250°F you can immediately go into the cooling cycle. | Pressure is kept the same as in the heating cycle for the first two minutes of cooling because the center sheet temperature in the middle of each opening are still raising. | |
| The material just needs to see 250°F for an instant to reach maximum benefit. | After two minutes, the pressure is doubled to further ensure that that the layers of PVC materials remain intact during cooling. | |
| It does not have to cook for a period of time at that 250°F. |
Troubleshooting printing machinery takes patience and time. Everyone wants the problem solved immediately. Rather than trying to rush to a solution, it is best to take the time and find the root cause of the problem. Time and patience will solve it.
When a problem is noticed, the operator should look at every stage of the process. First, find at which stage the problem started then find the cause. Here are some hints to help you solve a few common problems. Always remember to keep a log book with the problems and solutions. They'll be easier to solve next time around.
Don't forget to write your original settings down before you begin troubleshooting. Try one thing at a time. If it doesn't work, return to the original settings and try something else.
| Problem | Cause | Solution |
|---|---|---|
| Unexact cutting edges | Wrong knife angle | Knife with cutting angle of 22° and a prefase of 28° |
| Cutters are worn out | Use of sufficiently sharp and exact cutters | |
| Film stacks are too high | Reduce the stacks height: take 10 cm as an approximate height |
| Problem | Cause | Solution |
|---|---|---|
| Poor sheet guiding
(blocking, double-sheet feeding, etc.) | Stock and handling conditions have not been kept | Store film in original packaging; if possible remove packaging 24 hours before handling and store film in printing hall; a relative humidity of at least 55% is recommended |
| Format stacks are too strongly charged | Do not stack more than two pallets on top of each other | |
| No air between sheets | Fan and/or lift up outer sheets before printing | |
| Film sheets stick together/stick to machine due to electrostatic charge | Separate film sheets with ionized air | |
| Printing speed is too high | Reduce printing speed (depends on machine) | |
| Insufficient ink key | Inappropriate ink | Use printing ink which is suitable for polymer type and drying procedure |
| Surface tension is too low | Use pretreated film (Corona) | |
| Printing ink is not scratch resistant Film sheets stick together after printing Printing ink is passed on to next sheet | Unsuitable printing ink | Use printing ink which is suitable for polymer type and drying procedure |
| Printing ink has not been sufficiently hardened/dried | Evaporate drying: increase amount of air, if necessary, air temperature | |
| UV-drying: optimize/clean UV-heater | ||
| Oxidative drying: use a film with sufficient roughness depth/check composition of fountain solution (ph-value) |
| Problem | Cause | Solution |
|---|---|---|
| Film breaks | Punching tool is damaged | Change punching tool or punching support |
| Film is too cold | Do not process film under a temperature of 15°C | |
| Film is not sufficiently impact resistant | Use a film with higher tensile strength |
| Problem | Cause | Solution |
|---|---|---|
| Bond strength of gluing line not strong enough | Unsuitable glue | Use only glue which is recommended for the polymer being used |
| Speed of machine is too high | Adjust speed | |
| Contact pressure or contact time is too low | Raise pressure/speed | |
| Glue line discolors (APET, GAG) | Solvent glue has been used | Use PU-Hotmelt (APET, GAG); if necessary, a glue with slower effect (GAG) |
| Vapor locks generate in the glue line (PU-hotmelt) | Contact pressure is too low | Use suitable glue |
Troubleshooting thermoforming and form/fill/seal machinery takes patience and time. Everyone wants the problem solved immediately. Rather than trying to rush to a solution, it is best to take the time and find the root cause of the problem. Time and patience will solve it.
When a problem is noticed, the operator should look at every stage of the process. First, find at which stage the problem started then find the cause. Here are some hints to help you solve a few common problems. Always remember to keep a log book with the problems and solutions. They'll be easier to solve next time around.
Don't forget to write your original settings down before you begin troubleshooting. Try one thing at a time. If it doesn't work, return to the original settings and try something else.
THERMOFORMING
| Problem | Cause | Solution |
|---|---|---|
| Appearance of folds, webbing, or wrinkles | Material too hot | Reduce heating time / intensity |
| Stretch of the material too high / sagging | Reduce heating time / intensity; if moulding insufficient change material | |
| Big shrinkage differences over the width or excessive TD growth | Defective material | |
| Irregular heating | Check temperature of radiator (oven)/heating plate. Inspect for bent/damaged heaters, replace |
| Problem | Cause | Solution |
|---|---|---|
| Material tears or blows holes when contacting the tool or during forming | Material too hot | Reduce heating time / intensity |
| Material too cold | Increase heating time / intensity | |
| Compressed air / vacuum too early | Adapt delay | |
| Tooling too cold | Increase temperature of the tool | |
| Edges and corners of the tool are too sharp | Change geometry of the formed part | |
| Tool too rough (material does not slide) | Polish tool surface | |
| Excessive material sag; drags tool on index | Reduce heating time or increase line speed | |
| Too little clearance between tooling components | Adjust tooling for greater distances between male/female | |
| Forming press / plug speed too fast | Adjust speed | |
| Material gauge insufficient for designed draw | Increase material gauge / review tooling draw ratios |
| Problem | Cause | Solution |
|---|---|---|
| Glossy spots | Material too hot | Reduce heating time / intensity |
| Unequal material distribution | Add vacuum holes around this area | |
| Non-uniform tool surface | Bead or polish tool |
| Problem | Cause | Solution |
|---|---|---|
| Walls too thin | Cold or hot areas in heating station | Check radiators / heating plate |
| Not enough space between cavities | Increase space between cavities | |
| Tool close or plug speed too fast | Adjust tool close or plug speed | |
| Material gauge insufficient for designed draw | Increase material gauge / review tooling draw ratios |
| Problem | Cause | Solution |
|---|---|---|
| Bubbles or pit marks on surface of formed part | Material too hot | Reduce heating time / intensity |
| Form ejected too fast | Decrease demoulding speed | |
| Irregular heating | Optimize heat distribution | |
| Heating too intensive | Reduce heating time / intensity | |
| Forming temperature window of material too narrow | Exchange material | |
| Trapped air between sheet and tool | Roughen or sand tool to assist in air escape | |
| Dust, dirt, or small particulate matter on tool | Clean tool | |
| Condensation on tooling / water dripping on sheet | Increase tooling temperature / repair leaks |
| Problem | Cause | Solution |
|---|---|---|
Bad transparency of the formed part; | APET-film too hot (cristallisation) | Reduce film temperature |
| Film temperature too low (whitebreak) | Increase film temperature | |
| Surface of the mould too rough | Polish surface | |
| Tool or plugs too cold | Increase tool or plug temperature | |
| Plug or tool speed too fast | Decrease plug or tool speed | |
| Material surface scratched or abraided | Inspect material transport through machine |
| Problem | Cause | Solution |
|---|---|---|
| Bridges/Webs | Material too hot | Reduce heating time / intensity |
| Insufficient compressed air | Increase air pressure | |
| Tool too hot | Reduce tool temperature | |
| Sagging of material | Reduce heating time / intensity; if moulding insufficient change material | |
| Space between plug and mould too narrow or wide | Optimize plug and/or ring dimensions | |
| Tool construction | Optimize tool geometry, install technical aid | |
| Cycle time too long / short | Optimize cycle time |
| Problem | Cause | Solution |
|---|---|---|
| Cloudy areas; surface distortion or marks | Tool temperature too low | Increase tool temperature until cloudy areas disappear |
| Too much silicone on surface or film defects | Exchange material |
| Problem | Cause | Solution |
|---|---|---|
| Material tears on the bottom of the formed part or formed cavity too thin | Material too hot | Reduce heating time / intensity |
| Too much pre-stretching | Decrease level of pre-stretching | |
| Upper plug too late / too slow | Optimize timing / speed | |
| Material too thin | Choose thicker material | |
| Uneven thickness profile over width | Check thickness profile over width | |
| Material has inclusions | Check material specification | |
| Vacuum on too early or too much pressure | Adjust vacuum timing or pressure |
| Problem | Cause | Solution |
|---|---|---|
| White stretch (stress) marks | Upper plug too early / too fast | Optimize timing / speed |
| Distance between heating plate and tool too big | Decrease distance | |
| Material difficult to thermoform | Exchange material | |
| Material too cold | Increase heating time / intensity | |
| Ejection air pressure too low | Optimize ejection air pressure | |
| Tool surface too rough | Polish tool surface | |
| Table moves down too quickly | Reduce speed of table-movement | |
| Form press opens too fast | Decrease opening speed |
| Problem | Cause | Solution |
|---|---|---|
| Bad definition at the edges of the forming area | Material too cold | Increase heating time / intensity |
| Ejected part too hot | Reduce temperature of tool; increase cooling time | |
| Downholder | Reflect downholder out | |
| Draught (draft) over the film | Protect machine / film against draught | |
| Not enough space between cavities | Increase space between cavities | |
| Clamping frame too narrow | Enlarge clamping frame | |
| Clamping frame not reflected out | Reflect frame out | |
| Pressure and or vacuum timing not optimized | Modify vacuum and pressure settings | |
| Pin chain rails cooling edges of material | Increase temperature of pin chain rails |
| Problem | Cause | Solution |
|---|---|---|
| Folds on thermoformed part | Material too hot | Reduce heating time / intensity |
| In corners: compressed air / vacuum too early | Optimize delay | |
| On walls / bottom: compressed air / vacuum too late | Optimize delay | |
| Too much pre-stretching | Decrease level of pre-stretching | |
| No evacuation / evacuation holes plugged | Optimize mould / clean evacuation holes | |
| Corners or undercut of the mould too sharp | Adjust geometry of the part | |
| Sagging of material / material touches mould | Reduce heating time / intensity; if moulding insufficient change material; use sag bar or spread chain rails |
| Problem | Cause | Solution |
|---|---|---|
| Formed part sticks to tool | Ejection-air (missing or too low)Zelle | Check pressure of compressed air |
| Edges / corners or undercut of the mould too sharp | Adjust geometry of the part | |
| Surface of the tool too rough (material does not slide) | Polish surface of the tool | |
| Bad demoulding of film/poor mould release | Exchange material / use release agent | |
| Tool too hot | Reduce tool temperature | |
| Material too hot | Reduce heating time/intensity |
| Problem | Cause | Solution |
|---|---|---|
| Part deforms during demoulding | Material ejected too hot | Increase cooling time |
| Tool too hot | Reduce tool temperature (cooling) | |
| Ejection air too high / ejection time too long | Optimize ejection |
| Problem | Cause | Solution |
|---|---|---|
| Parts in the corners too thin | Material too hot | Reduce heating time / intensity |
| Radius of the mould too small | Increase radius/use thicker material | |
| Tool too hot/cold | Adjust tool temperature (cooling or heating) | |
| Flanks too flat | Redesign part |
| Problem | Cause | Solution |
|---|---|---|
| No demoulding of material - parts do not eject | Temperatutre of tool too high | Reduce tool temperature (cooling) |
| Ejection air too low | Increase pressure of ejection air | |
| Material too sticky | Exchange material |
| Problem | Cause | Solution |
|---|---|---|
| Details too sharp (e.g. vacuum holes visible) | Material too hot | Reduce heating time / intensity |
| Surface of the tool too rough | Clean surface / reduce roughness of the tool | |
| Level of compressed air too high | Reduce pressure | |
| Tool too hot | Reduce tool temperature (cooling) | |
| Vacuum or pressure duration too long | Reduce vacuum or pressure timing |
| Problem | Cause | Solution |
|---|---|---|
| Bad forming; no definition | Closing of tool not sufficientZelle | Check / change sealing ring; check flatness of plates |
| Bad timing of vacuum-/ pressureforming | Adjust timing | |
| Forming pressure not sufficient | Increase pressure | |
| Material too cold | Increase heating time / intensity | |
| Cycle too short | Increase cycle time | |
| Tool too cold | Check/optimize cooling temperature | |
| Vacuum not sufficient | Increase number of vacuum holes | |
| Check vacuum system for leaks | ||
| Trapped air between cavity and film | Check arrangement and number of vacuum holes |
| Problem | Cause | Solution |
|---|---|---|
| Thermoformed part warped | Tool too hot | Reduce tool temperature (cooling) |
| Clamping frame doesn't work properly | Increase closing pressure of clamping frame | |
| Jaws in chain not adjusted properly | Adjust jaws in chain | |
| Vacuum and/or air pressure not syncronized | Adjust forming air timing | |
| Excessive post forming material shrinkage | Mold design - consider oversized molds or re-design |
| Problem | Cause | Solution |
|---|---|---|
| Thin areas | Wrong temperature of material | Optimize profile of heat distribution |
| Material too thin | Use thicker material | |
| Vacuum too fast | Optimize vacuum speed | |
| Cavities too close together | Increase distance between cavities |
| Problem | Cause | Solution |
|---|---|---|
| Tearmarks | Wrong setup of pre-stretching | Use pre-stretch plug made of polished aluminium, coated Teflon® or expanded plastic |
| Problem | Cause | Solution |
|---|---|---|
| Webs or folds in the corners when positive forming | Material too cold | Increase heating time / intensity |
| Pre-stretching sequence too long | Shorten pre-stretching sequence | |
| Form of mould not enough conical | Design form of mould more conical | |
| Edges and corners too sharp | Redesign mould | |
| Walls too vertical/draft angle too steep | Redesign mould allowing greater draft |
| Problem | Cause | Solution |
|---|---|---|
| No contact to the forming tool | Tool does not close properly | Check flatness of tool |
| Problem | Cause | Solution |
|---|---|---|
| Lateral quench marks | Upper plug moves too early or too quickly | Optimize time and speed |
| Tool too cold | Increase tool temperature | |
| Surface of the tool too smooth | Sandblast surface of the tool | |
| Heat distribution | Optimize heat distribution profile | |
| Pre-stretching too low / too short | Increase pre-stretching | |
| Upper plug too cold | Increase temperature |
| Problem | Cause | Solution |
|---|---|---|
| Unequal border (trim) width of the formed parts | Material too hot | Reduce heating time / intensity |
| Pre-stretching too early | Delay pre-stretching | |
| Forming too early | Delay forming | |
| Table moves too quickly | Reduce speed of table-movement | |
| Insufficient closure of tool | Check flatness of tool | |
| Material too thin | Choose thicker material | |
| Shrinkage of material too high | Exchange material |
| Problem | Cause | Solution |
|---|---|---|
| Poor surface of the formed part | Poor tool surface | Polish or abrasive blast tool surface |
| Dirty material | Sort material out | |
| Heating plates dirty | Clean heating plates | |
| Surface of upper plug too rough | Polish plug | |
| Dirty mould | Clean mould with applicable cleaner | |
| Inclusions in the material | Check specification |
| Problem | Cause | Solution |
|---|---|---|
| Marks on the bottom of the thermoformed part | Material too hot | Reduce heating time / intensity |
| Vacuum not sufficient | Optimize vacuum | |
| Pre-stretching insufficient | Optimize pre-stretching | |
| Vacuum holes too small / too less | Increase dimensions / number of vacuum holes |
| Problem | Cause | Solution |
|---|---|---|
| Material accumulation in transversal direction | Vacuum too slow | Increase vacuum speed |
| Material too hot | Reduce heating time / intensity | |
| Tool surface too smooth | Sandblast tool surface | |
| Wrong position of vacuum holes | Redesign position of vacuum holes |
| Problem | Cause | Solution |
|---|---|---|
| Air streaks on thermoformed part | Vacuum not sufficient | Optimize vacuum |
| Tool surface too smooth | Sandblast tool surface | |
| Insufficient closure of tool | Check flatness of tool | |
| Vacuum holes too small / too less | Increase dimensions / number of vacuum holes | |
| Material defects | Exchange material |
| Problem | Cause | Solution |
|---|---|---|
| Blister is not (well) stackable; denesting problems | No antiblocking additive (PET) | Exchange material |
| Film too thick | Reduce thickness | |
| Too little release agent between mould and material | Use release agent or silicone coated material | |
| Part design | Add denesting lugs, increase draft angles, or remove undercuts; redesign |
| Problem | Cause | Solution |
|---|---|---|
| Blister is unstable | Material too thin | Change to ticker material |
| No reinforcing ribs | Add reinforcements | |
| Part design | Add chamfeurs or redesign part |
| Problem | Cause | Solution |
|---|---|---|
| Holes in thermoformed part | Cycle time too short | Adjust cycle time |
| Irregular heating | Change defect parts of heating system | |
| Material too cold | Increase temperature / intensity | |
| Material sticks to mould | Change material / use mould with Teflon® coated surface | |
| Vacuum holes too large | Close vacuum holes and redrill smaller holes | |
| Inclusions in the material | Check specification | |
| Ventilation does not work properly when plug moves into the cavity | Check ventilation | |
| Vacuum / Pressure timing not optimized | Adjust vacuum and pressure onset / duration |
| Problem | Cause | Solution |
|---|---|---|
| Angel hair | Knife too blunt | Sharpen knifes, or change for new ones - replace strike plate |
| Material too soft or tensile strength too high | Modify material choice | |
| Cutting depth too low | Increase knife penetration |
| Problem | Cause | Solution |
|---|---|---|
| No cutting | Knife too blunt | Sharpen knifes, or change for new ones |
| Knife has no contact to cutting plate | Adjust position of knife | |
| Punching pressure too low | Optimize punching pressure | |
| Hydraulic system contains air | Close and purge hydraulic system | |
| Punching knife warped | Adjust / renew knife |
| Problem | Cause | Solution |
|---|---|---|
| No continuous cut | Irregular blade | Exchange cutting blade |
| Cutting knife not installed properly | Adjust knife position |
| Problem | Cause | Solution |
|---|---|---|
| Material sticks to knife | Material too hot | Increase cooling |
| Zelle | Knife temperature too high | Reduce knife temperature |
| Zelle | Silicone coated side away from knife | Reverse material at the unwind |
FORM/FILL/SEAL
| Problem | Cause | Solution |
|---|---|---|
| Transport chain or feeding system does not grip or index the film | The transport chain or clipping mechanism pulls on one side only (wear) | Tighten or exchange the transport chain; replace springs or worn clips |
| Bad closing tension | Revise closing tension | |
| Alignment of machine not horizontally | New alignment of machine | |
| Control cam misadjusted | Set the control cam | |
| Unwinding device and idler pulley are not aligned | New alignment of unwinding device and idler pulley | |
| Offset stacking of film | Adhere to tolerances | |
| Wrong width of film reel | Exchange material | |
| Braking power of unwinding station too high | Adapt braking power of unwinding station | |
| Film rips out of the transport chain or clipping mechanism | Film width is too narrow | Exchange material |
| Bending of the film | Adhere to tolerances | |
| Bad closing tension | Revise closing tension | |
| Dancer stroke is misaligned to index | Adjust dancer stroke | |
| Excessive TD shrinkage | Exchange material | |
| Crinkles or folds/wrinkles | The transport chain pulls on one side only (wear) | Tighten or exchange the transport chain |
| Alignment of machine not horizontally | New alignment of machine | |
| Control cam misadjusted | Adjust control cam | |
| Wrong width of film reel | Exchange material |
| Problem | Cause | Solution |
|---|---|---|
| Cracknels, bubbles, or surface marks | Air inclusions between heating plate and film | As a basic principle: keep forming temperature as low as possible |
| Sandblast and Teflon®-coating of heating plate | ||
| Mask heating plate with Teflon® | ||
| Raster heating plate with holes of 0,8-1,1 mm | ||
| Position heating plate lower than the frame | ||
| Reduce heat plate vacuum pressure | ||
| Cloudy parts | Temperature of heating plates too high | Adapt temperature |
| Heat plate vacuum pressure too high | Reduce heat plate vacuum pressure | |
| Dirty or worn heat plates | Clean or replace / recoat plates | |
| Cristallisation (danger with APET-films) | Temperature of heating plates too high | Adapt temperature |
| Index / cycle too slow | Increase index / cycle speed | |
| Whitebreak | Temperature of heating plates too low | Adapt temperature |
| Index too fast | Slow index speed |
| Problem | Cause | Solution |
|---|---|---|
| Insufficient moulding / cold forming | Forming temperature too low | Adapt temperature of heating plate |
| Forming pressure too low | Adapt forming pressure | |
| Forming time too short | Adapt forming time | |
| Vacuum too low | Revise vacuum system | |
| Revise evacuation holes | ||
| Revise gasket of sealing frame | ||
| Revise sealing of forming tool | ||
| Downward movement of the plug too slow | Regulate downward movement of the plug | |
| Wrong thermoforming ratio | Adapt film thickness to thermoforming depth | |
| If applicable use plug | ||
| Mold / plug temperature too cold | Warm mold / plug | |
| Dancer stroke is misaligned to index causing neck-in and loss of seal / vacuum | Adjust dancer stroke | |
| Excessive TD shrinkage causing neck-in and loss of seal / vacuum | Exchange material | |
| Deforming of formed part | Temperature of the forming tool too high | Pay attention to temperature of the forming tool, if applicable install cooling device for forming tool |
| Cooling time too short | Optimize cycle | |
| Air eject pressure too high / early | Reduce pressure / adjust onset timing | |
| Material breaks when thermoformed | Thermoforming temperature too low / too high | Adapt thermoforming temperature |
| Film thickness too low | Adapt film thickness to thermoforming form | |
| Thermoforming ratio too high | Adapt film thickness to thermoforming form | |
| Edges of the package are too sharp | Change design of the package | |
| Dancer stroke is misaligned to index | Adjust dancer stroke | |
| Plug /assist plate speed too fast | Reduce plug / assist plate speed | |
| PE-layer breaks when thermoformed (with a plug) | Too low tolerance of the plug/too high friction between film and plug | Adapt size of plug to the mould |
| Plug (if heated)/temperature of the film too high | Reduce temperature of the plug and the mould | |
| Activation of plug too early | Adapt time sequence of plug | |
| PE layer sticks to heating plates | Reduce heating plate temperature of PE layer side | |
| Airmarks | Insufficient vacuum | Inspect vacuum system/increase vacuum pressure |
| Tool does not seal hermetically | Revise hermetical sealing | |
| Fish eyes or inclusions in the film which might break open | Comply with quality specifications | |
| Vacuum time/vacuum level is set too low | Increase vacuum time/vacuum level | |
| Film rips out of the transport chain / index mechanism | The temperature of the heating plate is too low which leads to a high tension on the film transport chain | Increase temperature |
| Dancer stroke is misaligned to index | Adjust dancer stroke | |
| Excessive TD shrinkage | Exchange material |
| Problem | Cause | Solution |
|---|---|---|
| Film rips out of the film transport chainZelle | Filling weight too high; the package is not underpinned | Adapt filling weight to the package |
| Zelle | Bending of the film | Adhere to tolerances |
| Problem | Cause | Solution |
|---|---|---|
| Crinkles,folds, or wrinkles | Unbalanced unwinding of sealing film | Revise unwinding station, e.g. adjust web tension |
| Curvature | Exchange sealing film if necessary | |
| Curling of sealing film in machine direction too strong | Exchange sealing film if necessary | |
| Wavy edges | Exchange sealing film if necessary | |
| Mis-alignment of roll | Adjust alignment | |
| Variation of dimension | Dimensional variation of repeating pattern | Revise length of repeating pattern |
| Adjust photoelectric cell |
| Problem | Cause | Solution |
|---|---|---|
| Package leaking / poor sealing | Film inserted incorrectly | Sealing layers of sealing film and base film have to be positioned inline |
| Sealing layers of sealing film and base film have to be compatible | Revise compatibility of sealing layers | |
| Sealing temperature too low/too high | Adapt sealing temperature | |
| Sealing time too low/too high | Adapt sealing time | |
| Sealing pressure too low | Increase sealing pressure | |
| Gasket of sealing tool worn | Exchange sealing gasket | |
| Membrane in upper part of sealing tool defective | Exchange membrane | |
| Sealing plate damaged | Exchange sealing plate | |
| Sealing plate not planar/level or flat | Revise planarity/level or flatness of sealing plate | |
| Sealing valve defective | Exchange sealing valve | |
| Heating elements defective | Exchange heating elements | |
| Contamination of sealing area with product | Pay attention to clean sealing areas | |
| Length of repeating pattern of sealing film too short, thereby high tension on heat sealed joint | Revise and maintain tolerances | |
| Filling level of the package too high | Reduce filling level of the package | |
| Speed of upper vacuum / vacuum of the valves too fast; the product is pulled onto the sealing area | Adapt vacuum speed | |
| Hot-tack of the film is not sufficient when applying upper valves | Apply other materials with improved hot-tack properties | |
| Adapt filling level of the package | ||
| Sealing film shrinks in transversal direction | Shrinking properties of sealing film | Revise shrinking properties of sealing film, if applicable, exchange material |
| Penetration of sealing film | Rapid ventilation of the package | Revise setting |
| Product with sharp edges | Pay attention to right positioning of the product within the package | |
| Travel or position of sealing device too low | Adapt filling level of the package/adjust sealing head stroke/ position | |
| Defective sealing (with skin packaging) | Sealing temperature too low/high | Adjust sealing temperature |
| Sealing layer contaminated with product | Pay attention to clean sealing areas | |
| Sealing layers of sealing film and base film are not compatible | Revise compatibility of sealing layers | |
| Sealing tool contaminated | Clean sealing tool | |
| Venting valves set up incorrectly | Revise setting | |
| Insufficient vacuum | Vacuum set too low | Revise setting |
| Evacuation time set too short | Revise setting | |
| Filter of vacuum pump plugged | Exchange filter/check vacuum system | |
| Valve of sealing tool leaky, sealing plate pushes downward | Exchange valve of sealing tool | |
| Non-return valve of sealing tool defective | Exchange non-return valve | |
| Product temperature | For humid food products, we recommend a maximum product temperature of 4°C | |
| Sealing membrane defective | Exchange sealing membrane | |
| Airmarks | Contamination of heat-sealed joint | Clean heat-sealed joint |
| Frame of sealing tool contaminated | Clean frame of sealing tool | |
| Sealing rubber defective | Exchange sealing rubber | |
| Sealing time too low | Adapt sealing time | |
| Buildup on/dirty sealing head | Clean sealing head | |
| Insufficient gas flushing | Gas valve contaminated | Clean gas valve |
| Flushing time too short | Revise alignment | |
| Gas flushing pressure too high | Revise alignment | |
| Wrong setting of gas mixing unit | Revise alignment | |
| Wrong composition of modified atmosphere | Adapt modified atmosphere to requirements of product to be packaged | |
| Sealing tool not hermetically closed | Revise tightness of sealing tool |
| Problem | Cause | Solution |
|---|---|---|
| Transverse cutting not successful | Punching knife too dull or defective | Sharpen punching knife or exchange punching knife |
| Punching knife positioned in a wrong angle | Adjust position of punching knife | |
| Wrong position of the knife bar | Adjust position of the knife bar | |
| Wrong knife material | Revise the hardness of the knife material | |
| Cutting impossible due to bending of the package | Adapt filling weight to the size of the package | |
| Puncture resistance of sealing film too high | Select right material | |
| Toughness of base film too high | Select right material | |
| Wrong position of die cutter | Adjust position of die cutter | |
| Punching pressure too low | Increase punching pressure | |
| Punching speed too low (typical problem with APET) | Increase punching speed | |
| Wrong geometry of punching knife | Adapt geometry of punching knife to material | |
| Pneumatic conduit loose or defective | Revise | |
| Hydraulic oil level too low | Increase hydraulic oil level | |
| Hydraulic cylinder leaky | Revise hydraulic system | |
| Rubber springs defective | Exchange rubber springs | |
| Magnetic valve does not switch | Measure tension at magnetic valve | |
| Punching knife contaminated with product | Clean punching knife | |
| Material accumulation | Punching knife dull or defective | Sharpen punching knife or exchange punching knife |
| Incorrectly installed cutting bars/wrong cutting bars installed | Revise and exchange if necessary | |
| Sticking of the film due to too high sealing temperature | Adapt sealing temperature, if necessary, coat cutting tool with Teflon® | |
| Package overloaded | Adapt filling level | |
| Punching knife damages sealing film | Above fixed punching knife sticks out of the support | Adjust position of the punching knife |
| Problem | Cause | Solution |
|---|---|---|
| Longitudinal cutting not successful | Slitting knife too dull or defective | Sharpen slitting knife or exchange slitting knife |
| Wrong sense of rotation of knife driving shaft | Revise electronic steering of the device | |
| Slip/COF of base film too low | Revise film properties, if feasable, apply film with improved slip properties | |
| Knife driving shaft distorted | Revise knife driving shaft, exchange if necessary | |
| Slitting knife contaminated with product | Clean slitting knife | |
| Wrong knife material | Revise the hardness of the knife material | |
| Impact strength of base film too high | Select right material | |
| Wrong geometry of slitting knife | Adapt geometry of slitting knife to the processed material | |
| Longitudinal cutting within the package | Wrong position of slitting knife | Revise position of slitting knife |
| Speed of conveyor belt too high in comparison with cutting speed | Adapt speed of conveyor belt to cutting speed | |
| Packages with different filling weights in multilane machines | Revise filling weights of packages |
| Problem | Cause | Solution |
|---|---|---|
| Under-formed parts (poor definition) | Low temperature | Check for holes in the part and/or white blushing |
| Increase preheat temperature in 5°C increments | ||
| High temperature | Check for holes in part | |
| Decrease temperature in 5°C increments | ||
| Low pressure | Check line pressure (90-110 psi recommended) | |
| Check for air leaks | ||
| Excess shrinkage (necking in) | High temperature | Decrease temperature in 5°C increments |
| Sticking | Check for sticking in preheats and tooling | |
| Air timing | Check to ensure that forming air does not blow prior to the closing of the mold | |
| Plug timing | Check to ensure that plug is not coming in prior to the closure of the mold | |
| Sticking | Mold too hot | Check chiller |
| Recommend mold temperature 10°-15°C | ||
| No seal | Low seal temperature | Increase seal temperature in 10°C increments |
| High seal temperature | Check for heat-seal coating separation from foil | |
| Decrease seal temperature in 10°C increments | ||
| Lidding compatibility | Check with supplier for compatibility of lidding material with seal surface | |
| Leaking seals | Improper material distribution | Check material thickness of seal flange on unsealed formed web (variation of 10-15 microns is normal) |
| If variation is >20-25 microns, adjust forming for improvement | ||
| Warped platen/bad heat element | Using heat-sensitive paper, check for even heat and pressure | |
| Correct any problems |
| Problem | Cause | Solution |
|---|---|---|
| Under-formed parts (poor definition) | Low temperature | Check for holes in the part and/or white blushing |
| Increase preheat temperature in 5°C increments | ||
| High temperature | Check for holes in part | |
| Decrease temperature in 5°C increments | ||
| Low pressure | Check line pressure (70-100 psi recommended) | |
| Check for air leaks | ||
| White blushing | Low temperature | Increase preheat temperatures in 5°C increments |
| High pressure | Decrease forming pressure to ~70-75 psi | |
| Crazing/striations | High temperature | Decrease temperature in 5°C increments |
| Excess shrinkage (necking in) | High temperature | Decrease temperature in 5°C increments |
| Sticking | Check for sticking in preheats and tooling | |
| Teflon® coating recommended | ||
| Air timing | Check to ensure that forming air does not blow prior to the closing of the mold | |
| Plug timing | Check to ensure that plug is not coming in prior to the closure of the mold | |
| Sticking/fish-eyes | Heat platens dirty | Clean plates |
| Sticking | Teflon® coating worn | Replace Teflon® coating |
| Mold too hot | Check chiller | |
| Recommend mold temperature 10-15°C | ||
| No seal | Low seal temperature | Increase seal temperature in 10°C increments |
| High seal temperature | Check for heat-seal coating separation from foil | |
| Decrease seal temperature in 10°C increments | ||
| Sealing to wrong side | Check to ensure the correct surface is being sealed (PVC/ACLAR®) | |
| Leaking seals | Improper material distribution | Check material thickness of seal flange on unsealed formed web (variation of 10-15 microns is normal) |
| If variation is >20-25 microns, adjust forming for improvement | ||
| Warped platen/bad heat element | Using heat-sensitive paper, check for even heat and pressure | |
| Correct any problems | ||
| ACLAR® film separating at perforation | Knives not penetrating ACLAR® film | Increase depth of cut |
| Problem | Cause | Solution |
|---|---|---|
| Under-formed parts (poor definition) | Low temperature | Check for holes in the part and/or white blushing |
| Increase preheat temperature in 5°C increments | ||
| High temperature | Check for holes in part | |
| Decrease temperature in 5°C increments | ||
| Low pressure | Check line pressure (90-110 psi recommended) | |
| Check for air leaks | ||
| Excess shrinkage (necking in) | High temperature | Decrease temperature in 5°C increments |
| Sticking | Check for sticking in preheats and tooling | |
| Teflon® coating recommended | ||
| Air timing | Check to ensure that forming air does not blow prior to the closing of the mold | |
| Plug timing | Check to ensure that plug is not coming in prior to the closure of the mold | |
| Sticking | PVdC too hot | Heat platen facing PVdC should be 5-10°C cooler relative to PVC side |
| Heat platens dirty | Clean plates | |
| Teflon® coating worn | Replace Teflon® coating | |
| Mold too hot | Check chiller | |
| Recommend mold temperature 10-15°C | ||
| No seal | Low seal temperature | Increase seal temperature in 10°C increments |
| High seal temperature | Check for heat-seal coating separation from foil | |
| Decrease seal temperature in 10°C increments | ||
| Lidding compatability | Check with supplier for compatibility of lidding material with seal surface | |
| Sealing to wrong side | Check to ensure the correct surface is being sealed (PVdC/PVC) | |
| Leaking seals | Improper material distribution | Check material thickness of seal flange on unsealed formed web (variation of 10-15 microns is normal) |
| If variation is >20-25 microns, adjust forming for improvement | ||
| Sealing to wrong side | Check to ensure the correct surface is being sealed (PVdC/PVC) | |
| Warped platen/bad heat element | Using heat-sensitive paper, check for even heat and pressure | |
| Correct any problems |
| Problem | Cause | Solution |
|---|---|---|
| Web disappearance | Bending of the web | Set web tension , use of a new roll |
| Web tension too high | Reduce web tension , check for other possible settings | |
| Films gets opaque or is wavy | Film is sticking to the heating tool | Reduce the heat temperature |
| Clean the heating tools or replace coating | ||
| Badly formed or underformed parts | Low temperature | Check for holes for white blushing. Increase temperature in 5°C increments |
| High temperature | Thinning out of bottom - reduce temperature in 5°C increments | |
| Low pressure | Check line pressure (90 - 110 psi recommended), check for air leaks | |
| Excess shrinkage (necking in) | High temperature | Decrease temperature in 5°C increments |
| Sticking | Check for sticking in preheats and tooling | |
| Teflon® coating recommended | ||
| Air timing | Check to ensure that forming air does not blow prior to the closing of the mold | |
| Plug timing | Check to ensure that plug is not coming in prior to the closure of the mold | |
| Sticking | Heat platens dirty | Clean plates |
| Teflon® coating worn | Replace Teflon® coating | |
| Mold too hot or dirty | Check chiller | |
| Clean forming tool | ||
| No or bad sealing | Low seal temperature | Increase seal temperature in 10°C increments |
| Lidding compatability | Check compatibility of lidding material with seal surface (PP or PVC or others) | |
| Improper material distribution | Check material thickness of seal flange on unsealed, formed web: variation of 10 - 15 µm normal, if variation is > 20 - 25 µm, adjust forming for improvement | |
| Warped platen/bad heat element | Using heat-sensitive paper, check for even heat and pressure--correct any problem |