By Renaud Anjoran in 'Quality Inspection Blog'
Today I was in a factory of silicon products (cookware, phone covers…). My client was buying the cover for a TV remote control. Production started earlier this week, and I was called in urgently to find solutions to production quality issues.
The defect rate was roughly 40%… Because a world-class product designer came up with a cool-looking 3D blueprint, because a TV network operator approved it, and because the importer confirmed it could be done.
The beauty of China is that one can get a production running with very cheap moulds, which allows for a lot of flexibility and lower quantities per design. The drawback is that these moulds require lots of manual operators, which means more opportunities for defects.
The factory put in place a complex process:
Each operation creates its own defects. And some defects simply cannot be avoided. For example, the liquid silicon is not hard enough (in my opinion) and gets spread around a little with the solid silicon is compressed.
How to sold this issue? The temperature can hardly be modified (below 210 degres is not advised for silicon), and the warming time cannot be increased (or some pieces don’t “stick” to the mold any more).
All I could do is reduce some opportunities for defects by correcting some behaviors (and I am not even sure what they will do once I am gone) and by doing some tests.
But the fundamental issue is that such a design cannot be done properly in China. One needs highly automatic molds that cost many times more money.
This type of problem is no doubt encouraged by the distance between a French product designer and a Chinese factory that will be sourced after the project is approved. It is just not the way to proceed… The best designers, in my mind, should be familiar with the production constraints, or at least have a dialogue with factory technicians.
In some industries, so much has been achieved with such cooperation… They usually call it DFMA (Design For Manufacturing and Assembly).