Additives are available for the following criteria.
Release is not the main issue, thermoplastics do not tend to stick, however for extreme polymers we have additives to facilitate this.
- Excellent dispersion and homogenisation of fillers, glass fibres and pigment improving component quality as well as processing.
- Better flow into complex structured moulds.
- Lower friction between screw and barrel means less energy consumption.
- Food contact and medical grades available.
- Self lubricating grades available for moving parts.
- Scrap material which will not process can be brought back into specification.
RELEASE AGENTS FOR THERMOPLASTICS
For many years WÜRTZ release agents are used with the best results for the processing of all kinds of thermoplastics. These products guarantee optimum releases without adverse secondary effects.
There are two possibilities to improve the unmoulding of thermoplastics:
1. The mould is treated with external release agents. The products introduce here are free of silicones and have affinity to the mould surface.
2. Internal release agents are added to the polymer.
The second possibility means mixing of the internal release agent (mostly powder) to the granulate.
The dosage of the internal depends on facts, like geometry of articles, fillers, etc. Normally the dosage varies between 0.01 and 0.3%. For first trials we recommend to add 0.2%
Besides an excellent release effect internals offer the following advantages:
Better dispersion of fillers, glass fibres or pigments (no stripes) in the polymer resulting in a better quality of the finished articles.
Better flow properties, complicated mould structures are filled quicker and easier (faster cycles); reduction of injection pressure is possible.
Less friction between pommel resp. screw and cylinder effects reduced energy consumption of the processing machine at constant production capacity.
The attached list shows recommendations for the various polymers.
Checklist for the Use of Internal Release Agents
Checklist for the Use of BgVV-approved Internal Release Agents