This part of GB/T 9345 specifies methods for determination of the ash of poly(ethylene terephthalate) (PET), poly(butylene terephthalate) (PBT) and copolymers of the two, both filled and unfilled. The general procedures given in GB/T 9345.1-2008 are followed. For unfilled materials, method A or method C of GB/T 9345.1-2008 is used. For filled and glass-fibre reinforced materials, method A of GB/T 9345.1-2008 is used.
For glass-fibre filled materials, containing flame retardant, antimony trioxide, and/or other, volatilizable additives, for instance pigment zinc sulfide, a modification is incorporated to remove these as volatile bromine component(s).
2 Normative Reference
The following normative documents contain provisions which, through reference in this text, constitute provisions of this part of GB/T 9345. For dated references, subsequent amendments (excluding corrections), or revisions, of any of these publications do not apply to this part. However, parties to agreements based on this part are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative document referred to applies.
GB/T 9345.1-2008 Plastics—Determination of Ash—Part 1: General Methods (ISO 3451-1:1997, IDT)
3 Principle
3.1 Unfilled materials
Direct calcination by burning the organic matter and treating the residue at a high temperature until constant mass is reached (GB/T 9345.1-2008, method A).
GB/T 9345.2-2008 The following standards are cited：
