Patent ID: 9744691
Date: 2017-08-29
CPC Classifications: B23P,B29B,B29C,B29K,B29L,C23C

Claim:
1. A mold having steel walls for the production of preforms made of polyethylene terephthalate, PET, by injection molding, comprising a coating of ceramic material with a thickness between 90 and 120 nm which coats the walls of the mold, wherein the coating is made of either a layer of Al 2 O 3 or a multilayer structure having a first layer made of Al 2 O 3 and a second layer made of TiO 2 , the mold producing the preforms with L/t>50, when L>100 mm or preforms with L/t>45 when L<100 mm, where “L” and “t” are the total length of the preform and the wall thickness of the preform, respectively.