Plastics for Outdoor Applications

Weatherable plastic sheet materials perform well in outdoor environments

Some plastic materials such as fluoropolymers are inherently UV stable and can be readily used in outdoor applications. However, most unmodified plastics will eventually become brittle and exhibit changes in appearance when used outdoors. Due to advances in polymer technology, it is now possible to modify plastics that would otherwise quickly degrade in outdoor environments with additives, coatings, and/or coextruded surfaces to extend their outdoor life. These enhanced plastic materials have excellent weatherability and will often provide many years of service in outdoor applications.

The service life of a plastic part in an outdoor environment will depend on a number of factors including:

  • Latitude (North-South position on the earth)
  • Climate (the operating temperature range and the presence or absence of humidity)
  • Orientation of the part in relation to the sun
  • Part geometry
  • The color of the material
  • Mechanical stresses on the part

These are all important considerations when selecting a plastic material for your outdoor application.

Transparent plastic sheet for outdoor glazing - UV resistant acrylic and polycarbonateTransparent plastic sheet materials for outdoor glazing

UV resistant grades of acrylic and polycarbonate sheet are frequently used for outdoor glazing. Both materials are less than half the weight of glass and have better impact resistance than glass. Acrylic sheet offers the advantage of superior light transmission compared with polycarbonate. Additionally, thermoformable grades of acrylic sheet generally require less drying prior to thermoforming compared with polycarbonate. Polycarbonate has superior toughness compared with acrylic and it is often specified when outstanding impact strength and durability are required.

Outdoor glazing applications for plastics include:

  • Skylights
  • Sun room windows
  • Security glazing for embassies and detention centers
  • Bus shelter glazing
  • Barrel vaults and canopies
  • Windows for military vehicles
  • Windows for construction, agricultural, and mining equipment

Material options for outdoor glazing applications:

Acrylic – OPTIX®, DURAPLEX® (impact modified)

Polycarbonate – Makrolon®, Makrolon® 15

SentryGlas® Interlayer – used as a bonding layer between sheets of glass for security glazing, hurricane windows, open-edged railings, facades, and canopies

Plastics for outdoor signs - acrylic and polycarbonate sheet materialsPlastics for outdoor signs

Acrylic and polycarbonate sheet materials are widely used for signs because they come in a wide variety of colors, have outstanding aesthetic properties in reflected light (daylight) and transmitted light (for back-lit signs), and they are easy to form into complex shapes including letters and company logos. LED diffusing grades of acrylic and polycarbonate are specially engineered to diffuse light from LED lamps. These materials enhance the appearance of signs that are back lighted with LEDs. Acrylic and polycarbonate materials are easy to paint, print, and bond with adhesives and solvent cements.

Material options for outdoor sign applications:

Makrolon® polycarbonate sheet and OPTIX® and Plexiglas® acrylic sheet are available in UV stable grades that are good choices for outdoor sign faces and channel letters.

Polycarbonate - Polycarbonates have superior impact resistance compared with acrylics and they are often specified when durability during shipping and installation are required. Polycarbonate is also preferred for signs that are to be installed in areas where the potential for vandalism is high.

Acrylic - Acrylics generally have superior optical properties compared with polycarbonate materials.

Fluted olefins - Plastic sheet materials such as Coroplast® are inexpensive and easy to print. They are ideal choices for yard signs including real estate signs and election signs that are intended for short-term outdoor use.


Plastic material replaces wood, C-TEK® Rideboard™ Expanded PVC fencePlastics for wood replacement

Amusement park, playground, and marine structures that have traditionally been made from wood are moving towards safer, longer lasting plastic sheet materials. Unlike wood, plastics won’t rot, swell, suffer from insect damage, or create splinters. Most outdoor grade plastics are colored throughout the material, which eliminates the need for painting. Some of the most popular plastics for wood replacement include C-TEK® Rideboard™ and UV stabilized polyethylenes.

Wood replacement options include:

UV stabilized HDPE (high density polyethylene) sheet materials are durable, wear and tear resistant, and available in many bright colors. These plastics are scratch resistant, easy to fabricate, and easy to clean. They are widely used for playground components, amusement park structures, boat parts, and outdoor cabinetry.

UV stabilized UHMW-PE (ultra high molecular weight polyethylene) sheet is often used for marine dock fendering applications where outstanding durability, impact resistance, and abrasion resistance are required.

C-TEK® Rideboard™ formulated with expanded PVC and wood flour, is a durable, light brown direct wood replacement material. It has low moisture absorption, low thermal expansion and contraction, and it is easy to fabricate with woodworking tools. C-TEK® Rideboard™ can be painted and glued.

Improve appearance and performance with outdoor plastics

We have years of experience providing UV-resistant plastics that hold up outdoors. Our technical experts are here to help you with material selection for your outdoor application. To learn more about all of our plastic materials suitable for use outdoors, please contact us today.

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Frequently Asked Questions
Can plastic materials be used outdoors?

Weatherable grades of plastic sheet are used for a wide variety of outdoor applications, however over time solar radiation, temperature fluctuations, moisture, pollutants, and atmospheric gasses can damage plastics. The service life of a plastic material in an outdoor environment will depend on a number of factors including latitude, climate, the orientation of the part in relation to the sun, the part geometry, the color of the material, and the mechanical stresses on the part.

How will sunlight, temperature changes, and moisture affect plastic parts?

UV from sunlight will attack many plastics, resulting in discoloration and embrittlement. The rate of degradation depends on the UV stability of the polymer and the use of UV stabilizers, top layers, and/or coatings to protect the material. Lower latitudes, high temperature, and humidity can accelerate the weathering process.

How will outdoor weathering affect the properties of a transparent plastic material?

The most common types of degradation from weathering are embrittlement of the material and color change (yellowing) over time. Transparent plastics can become hazy when used outdoors. Acrylics tend to be the most weather-resistant of the transparent plastics and acrylic materials will be slower to develop haze over time. Polycarbonates are highly susceptible to UV degradation and these materials are often capped or coated with UV blocking layers to slow the development of haze and color shift.

Will the color of a pigmented plastic fade when it is used outdoors?

The ability of a plastic to resist color fading is based upon a number of factors including the UV stability of the base polymer and the UV stability of the pigment. These vary considerably from material to material. Additionally, some plastics contain UV absorbers and/or UV resistant cap layers to enhance their weatherability. Bright colors such as reds, yellows, greens and blues often contain high loadings of organic pigments and these colors are more likely to fade over time. 

Can laboratory tests be used to predict how long a plastic material will last outdoors?

Accelerated weathering tests including ASTM D2565, ASTM D4459, ASTM DG155, ISO 4892, and SAE J1885 use Xenon arc exposure to assess how a plastic will perform outdoors. Although these tests provide useful information, they do not precisely predict with how long a plastic part will last in an outdoor environment. A typical guideline is that it takes 1500 hours of xenon arc exposure to achieve the same amount of radiation as 12 months of outdoor use in Florida.