PET system
PET Solid State Polymerizing System
Pellet quality from a used PET bottle is improved by a molecular weight adjustment
The difference in the pellet quality is equalized by solid state polymerizing and a diversion as virgin PET resin.
- Application
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- Molecular Weight Adjustment For Crushed PET Bottle Resin Material
Product features
The quality demand and conditions for using a reground PET Bottle.
As the resin for PET Bottle molding by Solid State Polymerization.
One of the reasons, which can not divert virgin PET resin to the solid state polymerization process of the reground PET resin as it is because the quality of the pellet resin, which carries out solid state polymerization, differs.
By the reground PET resin, in order to pelletizing at the melting extrusion process of reground PET Bottle molding, quality deteriorates by heat decomposition.
Degree of intrinsic viscosity of the resin is falling, but also the value of a carboxyl end group and aldehyde increases at the same time, then it has a bad influence on a color tone.
The increase in a carboxyl end group reduces polymerization speed and solid state polymerization conditions differ from the conditions of virgin PET resin.
Moreover, since degradation will progress reground resin further if prolonged solid state polymerization processing is carried put, in order to prevent this, compared with virgin resin, adaptation of quiet conditions is needed.
Since the degree of demand of quality is severe, especially in case of the resin used for PET Bottles, it is necessary to fully consider at the setup of solid state polymerization conditions.
A Demand of Quality
The high temperature polymerization is easier for the removal and reduction of impurities which are
- Acetaldehyde
- Low cyclic oligomer contained
- High whiteness
- Transparency
- Molding properties (for injection molding and orientation blow molding)
as a demand item