ETFE or ETFE material is of high heat resistance performance, but it is very expensive, for microwave resistant plastic, PP might be a good choice.
Here is an example we have made for one of our clients from US.
This is a mesh basket, at the beginning, the customer decided to go with high temperature ABS material. As usual, we discussed the part details such as parting line, gate type/location, draft angle, wall thickness and the other potential issues/proposal with the customer before mold making, this is called DFM process.
MAJOR PROBLEMS WE FOUND DURING DFM PROCESS.
1. Draft angle: as shown below, the green surface is straight, we propose to add 1 degree of draft angle, if we don’t add draft angle for this, it will be scratched when ejected.
2. Wall thickness: the wall thickness of some areas are too thin, there will be risk of short shot, so we propose to increase the wall thickness for better filling.
All the proposed changes were approved, and then we started mold 3D design and ordered the steel and mold base. During the mold making process, mold progress pictures were provided frequently for reference.
The mold and T1 samples were finished within the scheduled time, but there will be flash when the part is fulfilled because the thickness of the ribs is thin, the problem was solved after we increased the thickness.
We did the samples using 3 kinds of high temperature ABS material, the overall quality of the samples is outstanding，but when the customer microwaved them and they almost immediately melted or caught fire. We knew from the customer he has old baskets were made of ABS and they did not do this after being microwaved for essentially 8 hours straight. So we ask him to ship us one of the old baskets for reference of the plastic type. It turned out that it is made of high temperature resistant PP. We tried 3 times again with several types of PP material and it finally worked in the microwave.
After checking the samples, the customer placed a mass production order directly.