Matte polycarbonate sheets have been designed specifically to reduce glare which is one of the undesirable properties of glazing materials. A number of matte polycarbonate panels are some of the best light diffusers with the ability of hiding filaments while eliminating “hot spots”. They have a reduced gloss and surface reflection. As a result, they can achieve a light transmission of about 40% and 72%. They have been designed to promote long lasting outdoor designs with high degree of weathering performance, excellent dimension stability and high temperature resistance.
There are a number of factors to consider when you would wish to purchase any glazing material. One of the most crucial factor to consider is the thermal characteristics of the matte polycarbonate sheets and they include:
The tensile heat distortion
it is mainly used to determine the heat performance of the polycarbonate sheet. The main focus is mainly on that particular temperature which the polycarbonate sheet will deflect when exposed to a given amount of load such as tension or compression. Generally, the matte polycarbonates, which are some of the most common types of amorphous products; change very slowly when exposed to increasing temperature in a linearly manner. This can continue until it reaches about 150°C where the polycarbonate panel may begin to soften. This is a very high temperature which cannot be attained under normal circumstances where these products are only used for glazing application.
The relative thermal index
this thermal characteristic is mainly used to describe continuous operation temperature. When matte polycarbonate panels are used as machine guards or any other glazing application, they are exposed to a given degree of operational temperature. Before the chemical and the mechanical properties degrade by 50%, it can take more than 10 years especially if high performance coating have been used. The most common elements of degradation such as increased haze and yellowness begin to manifest themselves after a long period of time. This is a critical test which every polycarbonate sheet must pass through since it is used to determine the warranty period.
this is yet another phenomenon associated with the thermal properties of polycarbonate materials. It basically refers to a decrease in size of a substance when exposed to the environmental temperature or heat for a very long period of time. The matte polycarbonate sheets are dimensionally stable even at a temperature of about 135°C. However, beyond this temperature, the change in dimensions can be noticeable. The degree of shrinkage may vary depending on the gauge of the polycarbonate sheet. For example, lighter gauge may shrink by about 0.5% while the heavier gauge may shrink by about 1-2%.
This is a clear indication that these sheets can be used in application where “hot spot” should be eliminated while withstanding the fluctuating environmental temperature. It is for these reasons that these products can be used for high temperature applications since they rarely lose their essential chemical and physical properties even when exposed to high temperature (below 135°C).