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Effect of mold temperature on HTN

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JonathanG

Mechanical
Joined
Jun 12, 2001
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US
Does anyone out there have any experience of the effect of mold temperature on the properties of DuPont HTN? We manufacture encapsulated coils. We have used a lot of PET in the past, but hydrolysis in the application is a problem. We have started using high temperature nylon (HTN51G35HSL), but have kept the mold temperature down to 90 DegC for a number of reasons (rather than the recommended 130+ DegC). The parts seam to work well, but my manufacturing people tell me this is a bad thing to do. Dimensional stability is not critical, toughness is an advantage more than strength. Any comments??????
 
you should use the recommended mould surface temperatures to get the best mechanical properties. In addition, if the moulding is subject to high heat in service you will get post-mould shrinkage and possible distortion. You may wish to try a similar, easier processing material made by EMS-Chemie called Grivory. It's a partially aromatic nylon blend, v stiff with high tensile strength and low water take-up. It's also cheaper than HTN!
 
I agree with Pud. Service temperatures above tool temps can cause distortion problems.
Annealing of parts above tool temp before use might be an idea.

The ability to run hot water through tools can be more straightforward than using oil heaters. Solvay have a number of hot-water-mouldable Amodal grades also worth considering possibly with the properties you need.
 
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