Know-How - Materials

Materials Part 6 of 7: Annealing Tips for Thermoplastic Polyurethanes
TPUs form physical, rather than chemical, crosslinks that can be broken by reheating. Formation of these crosslinks can be sped up by annealing, which improves a variety of properties.

Materials Part 5: Annealing Tips for Crosslinked Polymers
As with semi-crystalline thermoplastics, annealing can be used in thermosetting polymers to obtain a level of crosslinking that may not be possible within the molding cycle.

Materials: Annealing Tips for Semi-Crystalline Polymers: Part 4
You can forgo the elevated mold temperatures normally recommended for high-performance semi-crystalline materials. But it’s risky and likely to yield parts that under-perform expectations … assuming that they emerge from the anneal...

Part 3 Materials: Annealing Tips for Semicrystalline Polymers
For these polymers, annealing is done to establish a level of crystallinity that cannot be practically obtained within the parameters of a normal molding cycle. Here’s some guidance on setting annealing time and temperature.

Materials: Annealing Tips for Amorphous Polymers, Part 2
In amorphous polymers, annealing is performed to draw down the internal stresses to a level not achievable within the conditions of a normal molding process. But a few parameters are important to achieving the desired results.  

Materials Part 1: What Annealing Can Do for Your Process
Relatively rapid cooling rates in processing introduce internal stress. If functional problems in use result, annealing may draw down the stress to levels that may not be achievable during processing.

Polyethylene Fundamentals: Part 6 of 6
Don’t assume you know everything there is to know about PE because it’s been around so long. Here is yet another example of how the performance of PE is influenced by molecular weight and density.