Pressed PVC Blanks vs. Blanks cut from PVC Sheets

[SUNBEARS]

Hello everyone!!

So I've done a bit of experimenting with blanks over the last couple years.. One question I have, before I have my guy cut up a sheet of PVC, is in regard to where or not there is any difference in the PVC material when blanks are made by being pressed or by being CNCed from a sheet.

I see several users on the forum that sell "PVC" blanks, @opcode66, @MyShank, etc.. MyShank claims surface noise as low as lacquers.

I had some blanks pressed not long ago and my surface noise was just not low enough for me to continue experimenting down that road. Any insight? Does PVC get harder after it is superheated and pressed than it might be if blanks were cut from a sheet?

Thanks!

Cheers,
Sunbears

[opcode66]

In short, not all PVC is the same. What is used in a press is slightly different than what is used to make white pipes for home construction. It is also different than what is sold in sheets. What is the difference? Additives.

Here are a list of additives from Wikipedia: heat stabilizers, UV stabilizers, plasticizers, processing aids, impact modifiers, thermal modifiers, fillers, flame retardants, biocides, blowing agents and smoke suppressors, and, optionally pigments.

This accounts for the difference you are seeing. Plastics used to make signs or cases are different from plastic used to press records. Even though it might all be "pvc".