Polypropylene (PP)

PP + GF30 (30 % Glass Fiber)

Low density, good flowability, light and economical. Stiffened by talc/glass fiber; copolymers have good impact strength.

Processing temperatures

Melt (injection) temperature255 °C
Mold surface temperature60 °C
Ejection temperature125 °C

Typical values. They vary (±) with grade and manufacturer; see the data sheet.

Physical properties (typical)

Density1.13 g/cm³
Shrinkage (flow / cross)0.3 / 1.2 %
Specific heat1.45 kJ/kg·K
Thermal conductivity0.28 W/m·K
Latent heat of crystallization (approx.)87 kJ/kg

Drying

Usually no drying is required (check if it is moist).

For exact conditions see the material data sheet. Drying guide →

Points to watch

  • Warpage and shrinkage differences (especially in filled grades)
  • Effect of mold temperature in hinge applications
  • UV/heat stability requires additives

Typical use: Automotive, packaging, household goods, closures, living hinges

Defects common with this material

Warpage

The part distorts or bends after it leaves the mold.

warpage · distortion · bowing

Sink mark

A dent on the surface opposite a thick section; the surface is drawn inwards.

sink mark · depression · sink

Dimensional variation and shrinkage differences

Part dimensions fall outside the tolerance or vary from cycle to cycle.

dimensional error · shrinkage · out of tolerance

Short shot (incomplete fill)

The cavity does not fill completely; the farthest or thinnest area of the part stays incomplete.

incomplete fill · underfill · non-fill

Flash

Plastic escapes through the parting line or around the ejector pins.

flash · overflow · parting line flash

Other grades in the same family

PP (Polypropylene, Pure Homopolymer)

Semi-crystalline, polyolefin240 °C melt · 50 °C mold

PP (Copolymer / Impact Copolymer)

Semi-crystalline, polyolefin230 °C melt · 40 °C mold

PP + Talc 10 %

Semi-crystalline, polyolefin235 °C melt · 45 °C mold

PP + Talc 20 %

Semi-crystalline, polyolefin235 °C melt · 45 °C mold

PP + Talc 30 %

Semi-crystalline, polyolefin235 °C melt · 45 °C mold

PP + Talc 40 %

Semi-crystalline, polyolefin235 °C melt · 45 °C mold

Do the values for this material not match your grade? and we will correct them.