Matrix optimizes capstock resins.

Which base resin gives the best cost and performance in a given color of capstock on a PVC or wood composite profile? A way to organize the choices was presented by Aspen Research Corp. (sub. of Andersen Corp.), White Bear Lake, Minn., at the 9th Wood & Biofiber Plastic Composites conference in May, sponsored by the Forest Products Laboratory (FPL) in Madison, Wis. Aspen produced a matrix chart with base resins down the left side from acrylic (most expensive) at the top to PVC (least expensive) at the bottom with blends in between. An acrylic cap can be applied as thin as 4 mm, while PVC is used at 8 to 10 mm. Acrylic is more effective at blocking uv than PVC, so color retention is much higher, making acrylic better for dark colors where fading shows more.

In the matrix, colors are sorted from left to right along the top from light (higher Hunter L value) to dark. How a given color will perform in a given resin appears in the diagonal area where color and base resin bands intersect. The lower right quadrant shows resin choices that are unsuitable for the corresponding colors of capstock, while the upper left quadrant shows material choices that are over-qualified, but may be appropriate for a special application. FPL: [phone], ext. 208/www. forestprod.org * Aspen Research: [phone]/www.aspenresearch.com

[GRAPHIC OMITTED]