PHR (Parts Per Hundred Resin): refers to the number of additives per 100 parts of resin (or base raw material) and is a specific unit of measure in the plastics and rubber industries.
To produce 100kg of PVC soft goods, if the formula requires “PVC resin 100 phr, plasticizer 50 phr, stabilizer 3 phr,” the amounts of each component are:
PVC resin: 100kg (basic, 100 phr corresponds to actual mass);
Plasticizer: (50/100) x 100kg = 50kg;
Stabilizer: (3/100) x 100kg = 3kg.