Acrylic (PMMA)

Injection Molding | Good optical properties, high gloss, scratch-resistant

injection molding slide view image - pmma 1

Introduction

PMMA (acrylic) is a transparent thermoplastic and one of the world's most widely used plastics thanks to its processability and ease of coloration. Acrylic is also chemically stable with good mechanical properties and resistance to the elements.

Applications: Lenses, light shades, light pipes, optical fibers, signage.

Behavior: Acrylic has poor chemical resistance, and can be brittle and vulnerable to stress cracks. If this poses problems, PC can be substituted in. Extra draft is required during tooling.

Properties	Metric	Other
Density	1.01 – 1.20 g/cc	0.0365 – 0.0434 lb/in³
Hardness	68 – 113	68 – 113
Tensile Strength (Yield)	13.0 – 65.0 MPa	1890 – 9430 psi
Tensile Strength (Ultimate)	22.1 – 49.0 MPa	3210 – 7110 psi
Elongation at Yield	0.62 – 30 %	0.62 – 30 %
Elongation at Break	3.0 – 150 %	3.0 – 150 %
Dielectric Strength	18.0 – 50.0 kV/mm	457 – 1270 kV/in
Melt Temperature	180 – 274 °C	356 – 525 °F

Surface Finish

Painting

Painting the surface of a part improves its aesthetic appearance and can provide brand recognition to consumers. In addition, painting can have a protective effect on parts.

Screen Printing

Screen printing is a printing technique where a mesh is used to transfer ink onto a substrate, except in areas made impermeable to the ink by a blocking stencil.