Quality of Flexible HDPE Conduits melted from the recycled HDPE material 1

[LJthien]

Upon recently visiting a HDPE pipes manufacturer, I come to know that they also produce Flexible HDPE conduits from recycled HDPE material as an alternative for limited orders and at lower unit price. Referring to IEC 61386-23 or ASTM D3350, I found nothing relating to recycled HDPE material as well as I have no idea if products manufactured from brand-new PE granulars and recycled HDPE material are similar have same quality.
Could you advise me if HDPE conduits are manufactured from recycled HDPE material without quality deviation? Thanks

 

[EdStainless]

Are they certified to the same standards? Go through the same testing? I am not sure what about them would be any different.

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[IRstuff]

There's bound to be some contaminants that weren't fully removed in the prep process for recycled materials, which might, or might not, affect product longevity or performance, beyond what's testable by spec.

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[Comcokid]

Just to clarify things here, are we talking recycled HDPE or are we talking (what I call) regrind HDPE. Regrind or reprocessed being in-house HDPE extrusion/reject parts/mold waste that is ground-up and reused having never been subject to actual use or waste-stream/waste-recovery contamination. I view these differently but sometimes they're both referred to as recycled.

 

[Compositepro]

Thermoplastic polymers degrade rapidly at their melt/process temperatures. Degradation means that the molecules break at certain locations and the molecular weight decreases. This leads to a loss of strength and increased brittleness. It can also result in a loss in electrical resistance and color change. The more times a polymer is melted to more degraded it becomes. Polymers also degrade from environmental exposure like sunlight and ozone. So recycling/regrind will always lead to some reduction in properties. Where this is not acceptable only "virgin" material is used.

 

[LJthien]

Are they certified to the same standards? Go through the same testing?

No any certification has been granted for "HDPE conduit from recycled material" process/product so far, as well as no standard or certifying body is speaking up this.
I need to check out its quality level comparing with virgin ones supposing that this recycle issue may be formulated sooner or later as it suits Eco-friendly movement to day.

 

[LJthien]

Just to clarify things here, are we talking recycled HDPE or are we talking (what I call) regrind HDPE.

From what I have observed at the factory, there is certainly a very small amount of regrind HDPE (defective products) but the dominant volume is the used HDPE products.

 

[LJthien]

@ Compositepro
Thanks a lot. Since I am not specialized in HydroCarbon material, could you advise some resources that I can study further for the degradation of re-melted HDPE material (reduction of strength & increase of brittleness).

 

[Compositepro]

You can find information with Google. Polymer degradation is a very broad topic that you should familiarize yourself with so that you will understand the technical literature specific to HDPE. Most plastics are formulations that contain additives like anti-oxidants, All manufacturers will have multiple grades. They will behave differently.