Pre-processing of glass pieces before tempering are many and require step by step. Cutting glass pieces according to required dimension, drilling holes, and at the end edge processing. After all those are done, glass pieces must be washed and dried to prevent residuals and particulars on surfaces.
Later, glass pieces should be delivered from glass racks to tempering furnace at the same day. If pre-processed glass pieces could not be tempered in same shift in same factory, again they must be washed and dried just before tempering process.
Always transporting and conveying rollers of loading unit must be kept in clean and controlled. Sometimes, even surfaces of glass pieces are clean, they become dirty.