Warpage Analysis

Do you have many warpage or shrinkage issues in plastics parts?  How close dimensional tolerance do you need for assembly/functional requirements?  Many of these questions and problems may show up at the tryout if you do not perform a full moldflow, cooling, and warpage analysis of the part before you build your tool.

What is Warpage Analysis

Since every plastic part goes through shrinkage process after molding, it is very critical to compensate for proper shrinkage, select proper gating, proper packing and cooling cycle. However, with advances in many plastics materials with many compounds such as glass  fibers, carbon fibers, minerals,  mica, calcium carbonate and many other fillers, materials can be improved for many structural properties and allow parts to meet many structural and functional requirements. This complicates the shrinkage and warpage behavior of molded plastics which is not uniform nor it is predicable without some advanced warpage analysis. The shrinkage is not uniform and it differs from flow direction to cross flow direction. Sometimes differences in cooling and orientation of fibers and polymer links also causes part to behave differently in different direction. Part design plays an important role to control some of this warpage, but it is not as simple as just adding more structure to the part neither it is simply matter of flow leaders. A scientific warpage analysis goes through all variables of part design, materials, tooling, and processing to predict the warpage behavior and that is why it is always better than simply doing trial and error.  

Warpage Analysis Expertise Matters 

Warpage analysis experts must understand which warpage model theory to use, effects of material compounding, full understanding polymer chemistry and compounds, use proper analysis set up, use proper gating, and proper molding set up to predict this accurately. Since users of moldflow simply run iterations without full understanding complesxity of material theory, warpage models and also have limited ability to relate how material, design, tooling, and processing work together, lastly may not have full understanding of design and FEA for structural and functional effects on any changes of product design. Our latest technological tools and complete expertise of design, tooling, molding, and materials will make a difference in upfront solution for these issues. We can help you with proper shrinkage allowances or even redesign the tool/product to avoid warpage issues before you start building your tool.  If redesign is not feasible, then we can help in tool design for proper gating, cooling, some modifications to materials, and process design to minimize warpage deflections before cutting tools. 

Why Perform Warpage Analysis

Many tool and process experts can probably select gating locations, but may not be sure about flow balance or warpage issues without the help of CAE techniques.  Any negligence in warpage issues can probably cost the highest amount money in tooling and process problems that may dictate complete rebuilding or redesign of tool. We recommend to use warpage analysis once you have fairly good part design that meets most of your general design and functional requirements. It is better to do this before part design is released for tooling. This gives you the best options to control warpage behavior. Once the mold is built, warpage analysis can still help resolve some issues, but there may be limitations on your product design, tooling changes, processing changes, material changes which also limits the ability to control the overall part warpage. Discuss your concerns with us and then make an educated decision. It does not cost a dime to consult with us for every one of your plastics parts, we are here to help resolve issues and will recommend only the most valuable options to you. Furthermore, if you are our customer, then we will offer initial review of your product design and make recommendations on further steps of any engineering needs for you before you start cutting the steel.

Warpage can be due to differential shrinkage, differential orientation, differential cooling, type of material, process set up, and product design, therefore you must use the right source that have complete expertise (not someone who can run software) to resolve the issue or suggest the option of redesigning the parts, making appropriate mold changes, proper processing set up, simple modifications to the materials. See how we can help you solve your warpage problems, help build warpage in the tooling, compare every details of parts and analysis warpage prediction, and most importantly solve your problems that can save you cost and timing over the life cycle of any particular part. See more in example of warpage analysis link.