What information do you have on glazing with ACRYLITE® extruded (FF) acrylic sheet?

Glazing
  • Working with ACRYLITE®
  • Test Data Results
  • Fire Test Performance
  • Equipment Materials and Suppliers
  • Product Properties
  • Care & Maintenance
  • Application Advice
  • Cementing
  • Glazing

What information do you have on glazing with ACRYLITE® extruded (FF) acrylic sheet?

Applications

Glazing applications for ACRYLITE® extruded (FF) acrylic sheet include:

  • Interior partitions
  • Exterior storm windows
  • Room dividers
  • Sun and wind screens
  • Skylights
  • Interior insulating windows
  • Storm door windows
  • Picture frames
  • Fascia panels
  • Dome structures

Planning and Design

This section gives advice for:

  • Available Products
  • Light Transmission
  • Solar Energy Control
  • Sound Transmission
  • Thermal Conductivity
  • Hardness and Rigidity
  • Strength and Stresses
  • Expansion and Contraction
  • Compatibility

Available Products

Sizes Thickness Standard Colors Protective Masking
Up to 96" x 120" 0.060"-0.500" Colorless,* Transp. Bronze 7C049, 8C030, 7C024, White WT030, WT031, Transp. Gray 7C025 (OTHER SOLAR COLORS AVAILABLE) Polyethylene film and latex paper

* Textured sheet available up to 48" x 96"

Light Transmission

Colorless, smooth ACRYLITE® extruded (FF) sheet has glass's clarity and 92% light transmission. Colorless ACRYLITE® extruded (FF) sheet is warranted for ten years not to lose more than 3% in light transmission. Contact Roehm America LLC for a copy of the warranty.

Solar Energy Control

Transparent ACRYLITE® extruded (FF) colored sheets cut glare and solar energy transmission. These sheets are available in various densities, as shown in the table below. The density range helps the architect, designer, or homeowner to choose a color density providing adequate daylight without excess glare or solar heat.

The table lists light and solar energy transmission percentages for transparent colors. Transparent-colored ACRYLITE® extruded (FF) sheets transmit the same percentage of light through all thicknesses with the same color number (data for white sheets apply to 1/8" thickness only), as shown in the left column. The formula for shading coefficients is as follows:

Shading Coefficient = (Solar heat gain of ACRYLITE® extruded (FF) sheet) / (Solar heat gain of 1/8" clear glass)

Transmission of Transparent Colored ACRYLITE® extruded (FF) Sheet

Color Name & Number   Light Transmission Solar Energy Transmission Shading Coefficient
Colorless 0A000 92% 89% 0.98
Bronze 8C030 10% 20% 0.45
Bronze 7C049 27% 35% 0.61
Bronze 7C024 45% 56% 0.76
Gray 7C026 12% 26% 0.61
Gray 7C025 29% 42% 0.72
White WT030* 29% 34% 0.43
White WT031* 47% 63% 0.74
White WT032* 72% 79% 0.93

*White colors' values listed for 1/8" thicknesses only

NOTE — Custom colors: Custom colors such as 7C036 Grey and 7C054 Bronze are available. Contact your Roehm America LLC distributor for current availability.

Sound Transmission

A barrier's sound reduction depends on its weight per square foot, surface area, rigidity, and airtightness. The latter is important — acrylic sheet with good sound reduction may not improve the performance of a non-airtight window. In airtight surroundings, sound reduction increases with increased sheet thickness (wt./sq. ft.) and decreases with increased area. Doubling the area increases transmission several decibels. Use the following values of sound pressure and loudness reduction for acrylic in airtight, resilient settings.

Sound Reduction

ACRYLITE® extruded (FF) Sheet Thickness Average Sound Transmission (dB) Loss 100-3200 Hz STC Rating
3.0mm (1/8") 22 23
4.5mm (3/16") 25 26
6.0mm (1/4") 28 28
9.5mm (3/8") 30 30

Thermal Conductivity

A material's thermal conductivity, or ability to conduct heat, is called the k-factor. This is an inherent property independent of thickness and surroundings.

The k-factor of ACRYLITE® extruded (FF) = 1.3 BTU/(hr.)(sq. ft.)(°F/in. thick)

The k-factor is a physical property of a material. The U-factor, or overall heat transmission coefficient, is the amount of heat which will pass through one square foot of a specific thickness of material per hour. This factor, expressed in BTUs, measures heat loss or gain through a window. U-factors depend on specific conditions (e.g., single or double-glazing) and differ for summer and winter. Listed below are U-factors for several thicknesses of ACRYLITE® extruded (FF) sheet for single-glazed, vertical installations, based on ASHRAE (American Society of Heat, Refrigeration, & Air-Conditioning Engineers) summer and winter design conditions.

U-Factors in BTU/(hour)(sq.ft.)(°F)

ACRYLITE® extruded (FF) Sheet Thickness Summer Conditions Winter Conditions
3.0mm (1/8") 0.98 1.06
4.5mm (3/16") 0.94 1.02
6.0mm (1/4") 0.90 0.97
9.5mm (3/8") 0.83 0.89

Total heat loss or gain through a window due to temperature differences, expressed in BTUs/hr., = window area, sq. ft. x (indoor temp-outdoor temp)°F x U-factor (from above table). Include solar-radiated heat gain within a structure to find total heat gain. ACRYLITE® extruded (FF) sheet insulates better than glass. When single-glazed, its U-factor is about 10% lower than that of equally thick glass. This material is also more resistant than glass to thermal shock and stresses caused by temperature differences between the opposite surfaces of a window.

Hardness and Rigidity

Handle and clean ACRYLITE® extruded (FF) sheet carefully. Plastic surfaces aren't as hard as glass. ACRYLITE® extruded (FF) sheet is less rigid than glass or metals but more rigid than such plastics as acetate, vinyl, or polyethylene. Under wind load, deflection causes acrylic to bow and foreshorten. Consider maximum wind load and window size in selecting glazing panel thickness. Forming ACRYLITE® extruded (FF) sheet into ribbed or domed shapes improves rigidity and reduces deflection. Large, flat ACRYLITE® extruded (FF) sheets, if insufficiently supported, may deform permanently due to their weight or continuous loads such as snow. Increasing rigidity by forming minimizes cold flow.

Strength and Stresses

Though ACRYLITE® extruded (FF) sheet's tensile strength is 10,000 psi at room temperature (ASTM D 638), continuous loads below this value can cause crazing (numerous tiny cracks in the material). Frames can create continuous loads - keep such loads below 1,500 psi. Avoid localized, concentrated stresses. For this reason, and due to thermal expansion and contraction, install 4'x4' or larger ACRYLITE® extruded (FF) sheets in frames - don't use screws or bolts.

Expansion and Contraction

Like most plastics, ACRYLITE® extruded (FF) sheet expands and contracts 3 to 8 times as much as glass or metals. Allow for size variation in frame systems and other fixtures. A 48" panel expands or contracts about 0.002" for each °F change in temperature. In outdoor use, where summer and winter temperatures differ as much as 100°F, a 48" sheet expands and contracts almost ¼" (0.20"), or approximately ± 1/8" from mid-temperature conditions. Calculate expansion and contraction allowances from your installing temperature measurements.

To figure expansion and contraction, use a constant, the thermal expansion coefficient. The value for acrylic is 0.00004 in/(in.)(°F). Multiply panel length (inches) by the maximum possible temperature change and multiply the result by the coefficient. For example, if the temperature difference is 100°F (38°C) from winter night to noontime summer sun, an eight foot (96") acrylic sheet's length changes almost 3/8".

Total Movement = Sheet Length X Temperature Difference X Coefficient
  = 96 in. X 100°F X 0.00004
  = 0.38 in.        

For installation, expansion clearance = half-total movement. Most installations occur in the mid-temperature range (55-75°F or 7-22°C). If you install outside this range, figure clearances using the above formula. ACRYLITE® extruded (FF) sheet absorbs water in high relative humidities, leading to expansion. At relative humidities of 100%, 80%, and 60%, respective dimensional changes are 0.5%, 0.3%, and 0.2%. A temperature and/or humidity difference on opposite sides of a sheet may cause slight bowing toward the higher value. As the differential lessens, the sheet resumes its original position.

Dark-tinted ACRYLITE® extruded (FF) sheets (bronzes, grays excluding whites and ivories) with light transmission less than 60% and facing the south or southwest expand more than colorless sheet due to solar energy absorption. Movement of these panels is about 1.4 times that of colorless or lightly tinted sheet. For 96" (8 feet) of 131-2 Bronze (29% light transmission), it would be:

Total Movement = Sheet Length X Temperature Difference X Coefficient
  = 96 in. X 100°F X 0.00004
  = 0.38 in.        

For dark-tinted sheet: movement = 0.38 in. X 1.4 = 0.53 in.

Use ACRYLITE® extruded (FF) sheets at temperatures from -30°F to +190°F (-34°C to +88°C), depending on application. Don't exceed 160°F (61°C) in continuous service or 190°F (88°C) intermittently. All thermoplastics gradually lose tensile strength as the temperature exceeds 180°F (82°C).

Compatibility

ACRYLITE® extruded (FF) sheet is manufactured from polymethyl methacrylate, based on oil and natural gas. Some gasketing materials used with glass contain plasticizers (solvents). These can dissolve acrylic sheet, as can nail polish remover, paint thinner, or alcohol. Roehm America LLC has tested gasketing products which may contact acrylic sheet for any potentially damaging material. These tests cover the products listed in the Equipment and Materials Suppliers section at the end of this brief. Forward questionable products to Roehm America LLC for testing.

Codes and Regulations

ACRYLITE® extruded (FF) sheet meets the requirements of:

  • ANSI Z97.1 for use as a Safety Glazing Material in Buildings (for thicknesses equal to or greater than 0.080 inches)
  • ANSI Z26.1 AS-4, 5, 6, & 7 for use as a Safety Glazing Material for Glazing Motor Vehicles
  • Federal Motor Vehicle Safety Standard 302; Flammability of Interior Materials
  • Federal Motor Vehicle Safety Standard 205; Safety Glazing

Building Codes for use as a Light Transmitting Plastic:

  • ICC-ES Report ESR-1260.
  • New York City MEA #145-80-M

Please contact Roehm America LLC's Technical Center for more specific information.

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