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Dark-Color Siding

Latest Weatherguard Formulation Is a Highly Weatherable Acrylic-Based Compound for Dark-Color Cap Layers Applied to Rigid PVC in Existing Profile Coextrusion Lines

PAWTUCKET, RI, U.S.A., June 15, 2020: A series of acrylic-based compounds for highly weatherable, dark-color outer or “cap” layers in PVC exterior products is the newest addition to Teknor Apex Company’s extensive portfolio of custom capstocks for building products. The company has given the entire range of these capstocks the new brand name Weatherguard™.

After 10,000 hours in QUV® accelerated weathering tests, Weatherguard WG-8000 Series compounds exhibited a color change of less than 1 Delta E for black, a significant improvement over an industry standard acrylic grade with comparable physical properties (see table). This accelerated weathering performance is coupled with a high resistance to a phenomenon called “water whitening,” a weathering defect caused by high humidity and rapid temperature changes that is most notable in dark colors such as black and dark bronze.

The combination makes for a unique set of properties for applications where high aesthetics are required, according to John Macaluso, industry manager, building and construction, for the Vinyl Division of Teknor Apex.

“Weatherguard WG-8000 Series capstock compounds exhibit similar or improved impact-resistance in comparison with acrylics commonly used in capstock applications today,” said Mr. Macaluso. “We can modify the base technology to meet specific gloss targets, and we can customize processing properties, making it unnecessary for building product manufacturers to retool—particularly valuable in the case of complex profiles such as window and door profiles.”

Mr. Macaluso also noted that the enhanced weatherability and low heat build of Weatherguard WG-8000 compounds is important in light of the trend among manufacturers to lengthen coverage in warranties.

The new compounds add to an already extensive series of capstock compounds in the Weatherguard product line, including formulations for use with PVC substrates in railings, fencing, siding, windows, and doors, plus other capstock products for polyolefin substrates used in the WPC deck market. Teknor Apex supplies these products on a custom basis, with formulations tailored to customer requirements for color, gloss level, and many other properties.


About Teknor Apex. Teknor Apex Company, a privately held firm founded in 1924, is one of the world’s leading custom compounders of plastics. Teknor Apex produces flexible and rigid vinyl, thermoplastic elastomers, nylons, color masterbatches, specialty chemicals, and hoses. The company is headquartered in Pawtucket, RI, U.S.A. and operates thirteen manufacturing facilities worldwide in the United States, Belgium, Germany, China, and Singapore. To learn more visit:

The Vinyl Division of Teknor Apex Company is a leading manufacturer of custom compounds, including Apex? flexible and rigid vinyl, Flexalloy? vinyl elastomers, Fireguard? low-flame, low-smoke compounds, and Halguard? low-smoke, halogen free, flame retardant compounds and elastomers. The Division is a global supplier to the appliance, automotive, construction, medical device, wire and cable, and other industries.

READER INQUIRY INFORMATION: Address all mail inquiries to Teknor Apex, 505 Central Avenue, Pawtucket, RI 02861 U.S.A. Tel: 1-401-725-8000. Tel. from U.S. only: 1-800-554-9892. Fax: 1-401-729-0166. E-mail: