Warpage reduction

[Sanjay_paul]

What are the causes of warpage? And what are the ways of reducing or controlling warpage?

[bernor_mf]

Hi Sanjay,

There are several factors that could cause a part to distort.

When considering the contributors to warpage, it is convenient to identify shrinkage due to:

•Variation in shrinkage from region to region (differential shrinkage).

•Temperature differences from one side of the mold to the other (differential cooling).

•Variations in the magnitude of shrinkage in directions parallel and perpendicular to the material orientation direction (orientation effects).

(From on-line help  Contributors to warpage )

Have a look at this video.

Pack and Warp

It goes through the details, and will help to clarify.

See also: Warpage problems

Hope this helps.

Regards.

Berndt

[mppkumar]

Hi @Sanjay_paul

warpage caused due to (refer this link; https://knowledge.autodesk.com/support/moldflow-insight/learn-explore/caas/CloudHelp/cloudhelp/2017/...)

1) differential shrinkage - Packing profile need to be adjusted or increase / decrease gate & runner sizes or add (or delete) gates or thickness optimization

2) differential temperature - cooling circuits need to be modified in such a  way we are having almost uniform core & cavity temperature

3) differential orientation - gate need to be placed in a way to get uniform orientation of fiber

4) corner effects - only applicable to mid-plane and DD meshes, where heat is getting accumulated @ the corners of a box type structures - cooling or part design need to optimized (https://knowledge.autodesk.com/support/moldflow-insight/learn-explore/caas/CloudHelp/cloudhelp/2017/...)

to identify which is major cause of warpage in an analysis, you need to run the warp analysis with "isolate cause of warpage" refer the below link

https://knowledge.autodesk.com/support/moldflow-insight/learn-explore/caas/CloudHelp/cloudhelp/2017/...

[Anonymous]

Hi Sanjay

Thank You

Rajendra

[madhukeshwart · Accepted solution]

1. The first step is measuring how much the part has warped with the current processingm conditions. The results from the warpage analysis are compared to the tolerances for the part to determine if the part is acceptable or not. When the parts don't meet the tolerances, the warpage must be reduced.

Determine the Cause of Warpage, If the part warps more than the tolerance allows, the warpage must be reduced. 

2.complex interaction of part geometry, material, and processing parameters that lead to warpage &warpage can be broken down to three main causes as discussed in including:
• Orientation effects• Area shrinkage effects• Differential cooling effects

Once these three main causes of the warpage can be determined, the warpage can be reduced.

3.Reducing the amount of warpage to get it below the tolerance involves addressing the primary cause of warpage . Fixing the primary cause of warpage can be done in many ways. The numbers beside possible ways to fix the warpage refer to steps numbered in

Often, reducing the amount of warpage is an iterative process. Several possible solutions could be found and evaluated to determine which one is most practical or economical. Many times it will take several iterations before the warpage is reduced enough.

[Anonymous · Accepted solution]

@Sanjay_paul there are many factors which will affect the plastic parts warpage, if we have control on below factors then we can easily identify the parts maximum controllable warpage, because we cannot make/mold flat or non-warpage plastic parts. Plastic part will warp..!! how much we can control is the key which should start from Product design - Tool design - Production, each stage need different interpretations with experience.

1. Plastic product design (thickness,Bside features..etc)

2. Gate location & Controlling the flow ( If we optimized the flow we can solve maximum amount of problem in the plastic parts)

3. Tool design (Cooling,ejection system..etc..)

4. Production (Process optimization, Mold temperature controls etc...)

again its about experience to identify due to which warpage is happening in the part & then only you can start thinking on how to control them to reduce the warpage on that phase. it may be prodcut design or may be changing the Mold temperature..!!!!