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Why is polypropylene offered in a stress-relieved grade?

Stress relieved grades typically work better in parts that have undergone extensive fabrication.

Will adhesives work with polypropylene?

No, due to its chemical resistance, adhesives will not bond to polypropylene. Hot air welding and mechanical attachment are recommended techniques for joining parts.

What is the optimal forming temperature for polypropylene?

Forming temperatures of 300° F to 350° F consistently yield good part detail and quality.

What is an antimicrobial and why do you need one?

Antimicrobials were developed to address microbial concerns and to control the growth of microbes on the surface of a material. Surface growth of microbes on a material is called a biofilm or slime. The buildup of biofilm or slime on materials, both plastics and textiles, can lead to a high microbe count, foul odors, discoloration, as well as contribute to the material’s degradation.

What are the levels of polyethylene (PE)?

here are 3 levels of PE as follows:

Level One [LD-PE], [MD-PE], & [HD-PE]
Low density polyethylene [LD-PE]: (<0.930 g cm-3 / <0.0334 lb/in3)
Medium density polyethylene [MD-PE]: (0.930 to 0.940 g cm-3 / 0.0334 to 0.0338 il/in3)
High density polyethylene [HD-PE]: (>0.940 g cm -3 / >0.0338 ib/in3, MW approx. 100,000)
Level Two [HD-HMW] & [VHMW]
High density high molecular weight [HD-HMW] polyethylene: (MW 2000,000 to 500,000). Level Twos are manufactured by two methods distinguished by the catalyst system involved: the Ziegler method, which uses titanium halides, titanium esters and aluminum alkyls as catalysts, and the Phillips method, using a chromium oxide catalyst.

In all cases, the pressure is low, compared with the high-pressure methods. In the Ziegler method, the working pressures and temperatures are in the ranges 1 to 50 bar/14.2 to 711 psi and 20 to 150 degrees C/68 to 302 degrees F, while the Phillips method uses 30 to 40 bar/427 to 569 psi and 85 to 180 degree C/185 to 356 degrees F. Techniques involve suspension, solution, gas-phase and bulk methods [4] with correspondingly different pressures and temperatures. Under these conditions, ethylene molecules are anionically polymerized to predominantly linear degree of crystallinity (60 to 80%) and correspondingly high density of 0.942 to 0.965 g cm-3/0.0341 to 0.0349 ib/in3

There is also a very high density molecular weight [VHMW] polyethylene.

Level Three [HD-UHMW-PE]
High density ultra high molecular weight polyethylene [HD-UHMW-PE]: (>0.940 g cm -3 >0.0338 ib/in3, MW> 106 to 6 x 106). This is our trademarked polymer that is used in all of our applications.


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