Semi-crystallinity in polymers is a commonly misunderstood concept since it cannot be demonstrated or easily visualized. Semi-crystalline polymers have all the softening characteristics of an amorphous polymer combined with the melting characteristics associated with semi-crystalline behavior. Question: What is different between melting amorphous and semi-crystalline polymers during recovery. note: I have addressed this in two […]
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Melting Amorphous Polymers
The melting of amorphous polymers is not like traditional liquids such as water. There is no specific temperature here the material tuns from solid form to liquid form since there is always some amount of polymer chain entanglement and inter-molecular attraction present to provide strength. Question: What is different between melting amorphous and semi-crystalline polymers […]
Circumferential Screw Speed
The circumferential screw speed from one machine does not directly relate to that of another machine, but it is a good starting point. This is because the material melt, shear, and flow characteristics within the screw channels will be different for each screw, so it is a machine-dependent parameter. Question: Is circumferential screw speed a […]
Test Sample Conditioning
The purpose of conditioning is to ensure the polymer chains are in a consistent state to ensure the testing is objective. The orientation, crystallinity, strength, and impact resistance of polymers can be easily influenced through conditioning. Question: My company deals with polymer compounding and we have an testing lab. According to ISO 291, we are required […]
Scientific Molding vs. In-Mold Labelling
A good in-mold labeling process must be reliable and consistent to ensure each part and cavity receives the same amount of pressure. Scientific Molding provides the basis for developing a robust and reliable injection molded part to which the label will adhere. Question: I am working at a location where in mold labeling is growing. […]