Oct 18, 2019
After changing the color or material on plastic processing machines, the new production often causes problems due to material residues within the plasticizing unit or the hot runner.
In order to avoid this, cleaning granulates are used, which make the material switch easier.
As a result of a chemical or mechanical cleaning action, residues, for example in the cylinder of the injection molding machine or on the screw, are dissolved and rinsed out.
Through the use of cleaning granules, the wasted material during production of molded parts and the time for material or color changes is reduced. The duration of the cleaning process depends essentially on the manufacturer’s specifications. While some manufacturers specify reaction times, cleaning granules exist entirely without residence times and can be injected directly after plasticizing. As a rule of thumb two to three times of the maximum dosage volume are required as quantity. The notes of each manufacturer about the quantity should be considered as a reference.

Plastic: Cleaning Granulate
Related topics:
Cylinder Cleaning
Screw Cleaning
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This glossary of plastic industry is provided by PLEXPERT Canada Inc.
Oct 25, 2019
Hygroscopic plastics must be dried before processing. For this purpose different drying systems are available. The group of dry air systems includes the so-called compressed air dryer.
Instead of air dehumidified in adsorption dryers, this system uses pre-dried compressed air, which is decompressed, heated, and then distributed in the material container. With compressed air dryers can reach a dew point of -20 °C and lower. Compressed air dryers are suitable for small and large quantities. The energy-efficient further development of the compressed air dryer is the two-circuit compressed air dryer. These systems use ambient air and / or exhaust air to preheat the granules and require only a fraction of compressed air compared to conventional compressed air dryers to provide a dry atmosphere.

Plastic:
Compressed Air Dryer for drying hygroscopic plastics.
Related topics:
Adsorption Dryer
This information and services are provided by:

This glossary of plastic industry is provided by PLEXPERT Canada Inc.
Dec 11, 2018
Polymers with a lightly cross-linked molecular structure are called elastomers.
The molecular chains can move relative freely between the cross-links giving them an elastic behavior.
Elastomers are used for rubber bands, tires, springs, etc.
Typical elastomers are rubber, silicone and polyurethane.

Dec 27, 2018
The investigation of the maximum flow length of a polymer at specific processing parameters (temperatures, speeds and pressures) can be done with a flow spiral mold.
The flow path needs to be long enough, so that no material can fill the cavity completely.
For easier measurement, marks will be used inside the cavity to recognize the length faster.
Comparing two materials with the flow spiral allows to find the better one for production (for the chosen parameters).

Jan 8, 2019
Glass fibers added into the polymer matrix raise the strength and rigidity of a plastic part.
The fibers are oriented during the injection molding process dependent on the melt flow.
The orientation differs over the wall thickness.
At weld lines, the fibers position perpendicular to the flow direction.
The mentioned effects lead to an anisotropic material behavior.
Anisotropy has an essential influence on strength, rigidity, shrinkage and deformation of the part.
