Clear Acrylic Balls
Acrylic, also known as PMMA or Polymethyl Methacrylate is a clear thermoplastic material, often used as a lightweight substitute for glass due to its durability and lightweight. Even with a density of 1.17 – 1.20 g/cm³, less than half that of glass, Acrylic or PMMA has an impact strength higher than both glass and polystyrene; though Acrylic’s impact strength is considerably lower than polycarbonate and some engineered polymers. At 3mm thickness, PMMA transmits up to 92% of visible light, giving a likeness of about 4% from each of its surfaces on account of its refractive index. It also filters ultraviolet (UV) light at wavelengths below about 300 nm.
Acrylic swells up and dissolves in many organic solvents; it also has poor resistance to many other chemicals. Its environmental constancy is superior to other plastics such as polystyrene and polyethylene, and PMMA is therefore often the material of choice for outdoor applications. PMMA has a maximum water absorption ratio of 0.3 – 0.4% by weight and tensile strength decreases with increased water absorption. Its coefficient of thermal expansion is relatively high at (5-10) x 10-5 /K.