What is Thermal expansion coefficient of plastic?

The coefficient of linear thermal expansion measures the change in length per unit length of a material per unit change in temperature. Expressed as in/in/°F or cm/cm/°C, the CLTE is used to calculate the dimensional change resulting from thermal expansion. CLTE is especially important when components of an assembly have widely varying thermal expansion coefficients. Thermal expansion of a material is another important design factor, particularly in applications where plastic parts composed of Bayblend ET1000 resin are mated with metal parts or parts having metal inserts. Coefficient of linear thermal expansion was measured on injection molded samples according to ASTM D 696. Injection molding of these samples provided better consistency on repeat testing than values from sheet-extruded samples, though the numbers were close. Molding under ISO conditions minimizes molded-in orientation and results in more accurate values. Material in/in/°F x 10-5 cm/cm/°C x 10-5 Liquid Crystal (glass reinforced) 0.3 0.6 Polycarbonate (glass reinforced) 1.2 2.2 Nylon (glass reinforced) 1.3 2.3 TP Polyester (glass reinforced) 1.4 2.5 ABS (glass reinforced) 1.7 3.1 Polypropylene (glass reinforced) 1.8 3.2 Epoxy (glass reinforced) 2.0 3.6 Polyphenylene sulfide (glass reinforced) 2.0 3.6 Acetal (glass reinforced) 2.2 4.0 Epoxy 3.0 5.4 Polycarbonate 3.6 6.5 Acrylic 3.8 6.8 ABS 4.0 7.2 Nylon 4.5 8.1 Acetal 4.8 8.5 Polypropylene 4.8 (.000048) 8.6 TP Polyester 6.9 12.4 Polyethylene 7.2 13.0 Note: Above table factors are averaged for a given plastic type; thus, the factor will vary depending upon the actual grade of given plastic type. POLYPROPYLENE EXAMPLE: Factor Distance Temp. Chng. Expansion .000048 x 24" = .001152 x 60 DegF = .0690"