DFM Analysis

Even though most of product designer would check out their design work when it’s finished, however it’s not 100% perfect for every design work. as the product designers might vary a lot at their experience and capability. 

So when we take a plastic injection molding project from client, the first thing is to perform a fitting inspection and see if there is any interference or mismatch issue. If so, we will highlight the finds and provide improved solution quickly, then our client will update their design soon. In this way, we can greatly avoid engineering change or mold modification after mold tooling is ready. It’s more than time and money saving, but efficiency and confidence improving!

As we know, thickness of part wall directly affect product appearance as well as part strength. A great thickness of wall design will lead to an excellent plastic injection molding product.  

According to our project experience, most of product design has a reasonable thickness of wall, but some of startup or medium size companies who might have bad injection molding design at part thickness, which result in shrinkage or warpage defects.   

Our professional injection molding team would help check out customer’s drawing if all of part thickness are reasonable. If not, we will definitely provide improvement report, so that our clients can optimize their design immediately.

Since plastic injection molded part is not as strong as metal or other material part. especially when the plastic part thickness or structure is thin, it’s very easy to have warping or crack issue. 

When we perform a DFM, our engineer will dig into every part structure to see if all of them are strong enough for product usage. If necessary, we will help clients to add enhancement ribs or rounds. However it should be very scientific to evaluate the thickness of ribs that would be added, if the thickness of rib is too thick, it would result in sink mark defect. In some case, after we added a rib on the injection mold tool, the mold steel would become very weak, so we might consider to add part thickness, instead of adding ribs. Otherwise the mold tool will be break up easily. 

A draft angle is used to enable plastic injection molded part to be released from mold tooling without scratch or block. When we design a plastic part, a 0.5~3.0 degree of draft angle is necessary.

However it is not all of product designers have this kind of experience, when we take a molding project from clients, we must perform a full inspection to check out if their 3D model are reasonably created with necessary draft. The number of angle really depends on part structure.

Most of time, we have to help clients add draft on their 3D model or provide suggestion so they can update drawing by themselves. 

It’s estimated that 80% of product designers had background at plastic injection molding field, it’s not strange to see some of design model could not be able for plastic injection mold making. When we take a plastic injection molding project from client, our engineers take full inspection on customer’s drawing, and see if all of part structures are available for injection molding. Otherwise we might advise clients to adjust part structure or use sliders(or lifters) to achieve those structure. 

A full checklist including ribs, bosses, holes, windows, slots will be particularly evaluated, and ensure every molded part could be released smoothly. 

There are so many different types of plastic material that can be used for plastic injection molding product, but which material is the best suitable one for your product? Yes, it’s a hard question as well as a common question.

When we choose a plastic material, we will need to consider material properties(strength, flexibility, surface finish, etc), molding properties(flow-ability, shrinkage rate, deformation rate, etc),  using environment( temperature, chemical resistance, electric-conductivity, etc), and cost.

Our experienced engineer team will double-check if all of part material are reasonably-defined.