Acrylic (Plexiglas, Acrylite)
Acrylic is undoubtedly the most familiar and versatile of polymer construction materials on the market today. It is a lightweight, rigid and weather-resistant thermoplastic which is at the same time dimensionally stable and shatter-resistant. In addition, acrylic is easily machined, heat formed or cemented and is clearer than glass with only half the weight.
Mechanical Properties
Acrylic sheeting will not sliver when shattered, breaking into rather large pieces.
Stress-crazing can occur with continuous loads below the max tensile strength of sheet, 10,000 psi. For glazing applications, continuously imposed design loads should not exceed 1,500 psi. For continuous loading, design loads should not exceed 750 psi at room temperature.
Local, concentrated stresses should be avoided. Large sheets should never refastened with bolts - install with frames.
Thermal Properties
Acrylic, like many other plastics, has a rather large coefficient of expansion, and the designer should plan for this. A 48'' sheet will expand or contract about .002'' for each degree F.
Some shrinkage occurs during heat forming, but post-forming stability is excellent.
Recommended temperature range: -30° F to 160° F, continuous use.
Chemical Properties
Acrylic sheeting also absorbs water in high humidity, resulting in dimensional changes of 0.2% to 80% relative humidity.
Acrylic has excellent chemical resistance and is colorless, tasteless and safe for food handling and transport.
Acrylic should not be used in contact with:
- aromatic solvents (benzene, toluene)
- chlorinated hydrocarbons (carbon tetrachloride)
- ethyl and methyl alcohols
- certain organic acids
- lacquer thinners, esters, ketone or ethers