摘要 |
Treatment for the dimensional stabilization of containers in PET or COPET obtained by injection-blow molding consisting in subjecting to heat treatment during the blowing phase, preforms obtained from PET or COPET upgraded in the solid state in the presence of small quantities (0.01-0.2 % by weight) of a dianhydride of an aromatic tetracarboxylic acid, preferably pyromellitic dianhydride.
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