What is the difference between PP(polypropylene) and CPP?

[Tae Hwan Kim]

To my knowledge, CPP means cast-polypropylene, which I've seen used in a coaxial cable. Some cables use CPP as dielectric material. My question is:

1. what is the difference between PP(polypropylene) and CPP?
2. How is CPP made?
3. Is the permittivity and loss tangent of CPP different from that of PP?

thank you. :)

 

[Asymptotic]

I've seen used in a coaxial cable.

What manufacturer and part number?
I'm familiar with PE and TFE, but have never seen coax using a PP dielectric core.

 

[Tae Hwan Kim]

What manufacturer and part number?
I'm familiar with PE and TFE, but have never seen coax using a PP dielectric core.

here it is:)

 

[Baluncore]

CPP = Cast PP
https://www.mitsuichemicals.com/film_cp_cast_polypropylene.htm

There will be little difference in dielectric constant between PP and CPP. They are the same material so the coefficient of thermal expansion will have a greater effect on capacitance than will the production process.

 

[Tae Hwan Kim]

CPP = Cast PP
https://www.mitsuichemicals.com/film_cp_cast_polypropylene.htm

There will be little difference in dielectric constant between PP and CPP. They are the same material so the coefficient of thermal expansion will have a greater effect on capacitance than will the production process.

thank you sir :)

 

[Asymptotic]

A manufacturer makes PP core coax cable ...I learn something new every day. :)

 

[rbelli1]

Considering they produce 5km reels this must be done with some type of extrusion process. Casting a 5km part would be difficult to put it mildly.

http://www.profol.com/en/about-cpp-film-faq.html

Based on the information linked above I would guess that there is a post extrusion sizing and cooling die to maintain tighter tolerances vs simple extrusion.

BoB

 

[Baluncore]

Cellular polypropylene, CPP, with a dielectric constant of about 1.3 is used as a dielectric in some data cables.

Google Books.
Cable Engineering for Local Area Networks. Barry J. Elliott. Page 94.

 

[rbelli1]

Cellular polypropylene, CPP,

So is the CPP in the datasheet probably Cellular not Cast?

BoB

 

[Baluncore]

Looks like it.
http://www.vtt.fi/inf/pdf/publications/1998/P361.pdf