Dear All,
Our packaging engineer from Suzhou China would like to share below concept refer to welding area to you.
As you know, our EPE material becomes extremely hard after heat seal, especially in hot-plate(manual) process. It will affect the performance which the cushion occurs in drop testing and vibration testing. There is a case we just had recently.
Our customer Lenovo changed the painting process and material of one laptop. And then they do the all testing again with same material. Compare the previous testing, the current cushion scratch the unit during the vibration testing. The area as following highlighted red.