ACRYLITE® LED Sign Grade is a versatile thermoplastic sheet that is rigid, tough, lightweight, and offers ease of fabrication and machining. Learn more about this materials physical properties below.
ACRYLITE® LED Sign Grade is a modified acrylic sheet with much higher impact strength than glass or standard acrylic sheet. (Testing per ASTM D 5420).
It is more rigid than many other plastics including polycarbonates, co-polyesters, and vinyls. Sign grade has greater surface hardness than polycarbonates and is less susceptible to surface marring during fabrication, installation, and sign usage.
This material offers excellent weather-ability. It will withstand most outdoor conditions for many years without significant deterioration of clarity, color, or physical properties. Actual results will vary due to differences in exposure to sunlight, moisture, heat, and environmental pollutants.
Strength and Stresses
Tensile strength of this sheet is 8,800 psi at room temperature (ASTM D 638). Continuous loads well below 8,800 psi will lead to stress crazing and eventual failure. For applications subject to continuous loading's, the design should allow for a load that will not exceed 600 psi at 23 °C (73 °F).
Expansion and Contraction
Like most other plastics, it will expand and contract due to temperature changes. Its co-efficient of thermal expansion is about 3 times greater than that of metal and about 8 times greater than that of glass. The fabricator must be aware of this and make appropriate provisions. A 48” panel will expand and contract approximately 0.002” for each °F change in temperature. In outdoor use, where summer and winter conditions differ as much as 100 °F, a 48” sheet will expand and contract approximately 1/4”.
This sign grade can be used at temperatures up to 160 °F. When colorless sheet is exposed to temperature extremes, as in the case of thermoforming, it will take on a white, translucent appearance. Once the sheet is allowed to return to room temperature, it will return to its original, high light transmitting clarity. Typical outdoor temperature variations encountered in use will cause little or no visible changes in the material's appearance.
Colorless ACRYLITE® LED sign grade has a light transmittance of greater than 87%.
Cutting & Machining
It has outstanding cutting and machining properties and can be cut by a variety of methods. All of the same types of machining operations that are used with standard acrylic sheet can be performed on this material. Due to its proprietary formulation, it provides opportunities for increased production efficiencies in cutting, routing, and drilling.
It will soften as the temperature is increased above 220 °F. As the temperature is increased, the sheet passes through a thermoelastic state to the thermoplastic state. The change is gradual rather than sharply defined. Forming temperatures range from 270 °F to 350 °F. Because the sheet gradually becomes thermoplastic, certain procedures should be considered during thermoforming. If the sheet is to be hung in an oven, it is necessary to use a continuous clamp rather than several individual clamps. This will prevent permanent deformation of the sheet between the clamps. If the sheet is heated by infrared heaters supported in a horizontal frame, it may be necessary to have control of the heaters positioned over the center of the sheet. This will prevent overheating in the center of the sheet, which could cause an excessive amount of sagging of the sheet. Shrinkage will occur in the machine direction when heating is performed without clamping. Shrinkage will range from 1-5%, depending on the thickness and forming temperature. Expansion can be expected in the cross machine direction. This will range from 0-2%, depending on the thickness and forming temperature.
Common solvent cements or polymerizable cements work well for joining sign grade to itself, other acrylic sheet materials, and to trim caps for channel letters. Care must be taken to provide a sheet edge that is machined properly and that contains low stress. A generous quantity of cement should be applied to ensure the surfaces being cemented are completely wetted. Avoid cement contact with polished edges.
It may be annealed at 180°F with the heating and cooling times dependent on the thickness of the sheet. An approximate guideline is as follows: annealing time in hours equals the sheet thickness in millimeters, and the cool down period in hours also equals sheet thickness in millimeters.
It's a combustible thermoplastic. Precautions should be taken to protect this material from flames and high heat sources. This sign grade usually burns rapidly to completion if not extinguished. The products of combustion, if sufficient air is present, are carbon dioxide and water. However, in many fires, sufficient air is not available and toxic carbon monoxide will be formed, as it will when other common combustible materials are burned. We urge good judgement in the use of this versatile material.
Chemical resistance was determined at a test temperature of 68 °F (20 °C), and a relative humidity of 50%. Care should be taken when using the table below as chemical resistance is very dependent on temperature and the material’s moisture content. In practice, chemical resistance is dependent not only on internal and external stresses, but also to a large extent on the method of fabrication. We recommend that appropriate testing be carried out in doubtful cases and technical advice be requested from Roehm America LLC by calling 207-324-6000.