Surface embossing is often used to produce a patterned surface finish on Vical acrylic parts for applications such as lighting fixture panels where specular reflections might be annoying. The patterned surface is obtained by blowing the hot Vical acrylic sheet against a mold having a textured surface finish.

Positive air pressures of 50 to 75 psi (4 to 6 tons total force per square foot) must be used to obtain a uniform overall pattern. Large high capacity presses are required to provide enough clamping force to resist these pressures. The press must also close quickly so that the surface of the sheet does not cool too much before forming.

Metal mold surfaces must be kept hot and temperatures must be uniform over the mold surface to prevent chilling of the sheet and loss of surface detail. If a matte finish is desired, the surface of the mold should be covered with pure white wool felt which will act as an insulating blanket and reduce the chilling effect of the mold while producing a uniform matte surface of the Vical acrylic.

Forming Acrylic Sheet