Tensile Strength

[shayne31]

Good Morning,

I've recently become immersed in a raging debate as to what has the largest influence on Tensile Strength of an extruded product (in this case PA6/6 on a 58mm twin). It has been my understanding that material porosity, resulting from inadequate devolitization and moisture content, can have an inverse effect. I also believe that filler integrity will influence this characteristic i.e. fiberglass strand length integrity. I was hoping someone within this forum could shed some light on the subject of Tensile Strength. Better yet, is anyone aware any empirical truths regarding mechanical profiles and their influence on Tensile Strength?

Cheers

 

[patprimmer]

Fibre orientation vs direction of test will have an immense effect.

Aspect ratio of the fibre will have a significant effect.

Surface area to volume ratio of the fibre will have a significant effect.

Surface treatment of the fibre will have a significant effect.

Moisture content when tested will have a profound effect on nylons.

Moisture effect during processing will have a variable effect, depending on the sensitivity of the polymer to hydrolysis. It will be quite a lot in nylon if it is enough to generate voids. It will be even a greater effect for PC or polyesters. In fact PBT, PET, PC and nylons all have an ester link that is broken in the presence of heat and water.

Sheer generated from the screw will have a variable effect depending on the polymer.

Ummm Tensile strength is directly related to tensile strength. Maybe I misread part of your question.

Thermal history during processing can have a significant effect.

All of these depend on degree or magnitude of exposure.


Regards

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