Plexiglass is another name for acrylic plastic sheets. Acrylic plastic is a handy building material that has a variety of uses. While it offers certain advantages over conventional glass sheets, it also comes with a few limitations.
Plexiglass is durable and shatter resistant. You may have seen plexiglass barriers around the perimeter of hockey rinks for instance, where it does an excellent job keeping players and pucks within the play zone.
When comparing the insulating properties of materials, engineers use the thermal conductivity value or lambda, of the materials. The higher the lambda value, the more heat the material conducts, and therefore, the less it insulates. Iron, for instance, has a high lambda value, which is why holding one end of an iron spoon in your hand while exposing the other to fire will quickly result in a burn. The specially formulated plastics used on the handles of pots and kettles, on the other hand, have low lambda values and do not conduct much heat.
Acrylic vs Glass
The lambda value for acrylic is higher than that of glass. Acrylic has a lambda of 0.19 W/m.K (watts per meter per Kelvin). The specific value for glass depends on how the glass was treated and whether the glass is double glazed. To replicate the insulating properties of glass, the acrylic sheet has to be significantly thicker than the glass. Therefore, in comparing a sheet of glass and an equally thick layer of acrylic, the glass will insulate better.
Other Properties of Acrylic
Although acrylic cannot match glass for insulation, it can be superior in other ways. First, acrylic is less dense. An identical sized acrylic sheet will therefore weigh less than half as much as the glass sheet. Acrylic is also impact resistant, and especially useful where breakage can be an issue. Acrylic can withstand temperatures ranging from -30 to 160 degrees F. Should acrylic scratch, it is relatively easy to polish to get rid of the scratches. This is due to the softer surface texture of the material compared to glass, which also makes acrylic easier and safer to cut.