How to remove button, zipper, metal, glue, plastic from raw material?

By the "U" shape or nail beat roller, these kinds of waste are broken and shredded. 95% heavy waste like button, zipper, metal and high density plastic will drop out during this process. Other 5% will be remove by a strong magnet in transport pipe. Light waste like glue and plastic which have been broken and shredded, will be sucked out from raw material by wind power of fans.
It is worth mentioning that there is wastage during this production process, taking more spare part is sensible.