Pipe and Profile Extrusion: Formulating new solutions for wood alternatives

The growth of high-end wood/plastic composites (WPC) and virgin plastic wood replacement products has created a need for new additive/resin packages.

“These high-end exterior wood replacement applications are compounded to give visual and performance advantages over wood,” says Jason Hart, director, marketing, with chemicals distributor Stochem Inc. “Each producer seems to be taking a very different approach, so the formulations are very customer specific. The choice of resin, additives and pigments is very different from one manufacturer to another.”

However, as the market develops, Hart expects to see some streamlining of formulations and additive packages according to end use category.

Honeywell has already targeted one family of products at the WPC sector. Its A-C OptiPak product range contains customized lubricants to achieve increased throughput and a proprietary lube-coupling additive to deliver increased structural strength without negative effects on throughput.

Trials of the OptiPak 100 package indicate decking producers can achieve increased throughput with 30 percent lower lubricant loading. As well, OptiPak 100 has proven more stable than current lubrication systems.

A-C OptiPak 300 is a multi-functional additive that can enable manufacturers to achieve significant increases in flexural strength and up to a 30 percent decrease in moisture absorption.

“With A-C OptiPak 300, wood/plastic composite producers can meet or exceed their products’ current physical properties with thinner and lighter deck boards,” explains Richard Heat, senior technology manager, Honeywell.

Lonza’s Acrawax C is also frequently used in wood/plastic composites. This ethylene bis-stearamide wax contributes to processing as a flow enhancer or internal lubricant additive, says Victor Satov, product sales manager, Canada Colors and Chemicals Ltd.

Satov notes that mica and talc can also contribute to heat dissipation, board stiffness and weight reduction.

Struktol’s TR 016 anionic surfactant has proven to be an effective process and dispersion aid for wood fibre-filled polyolefins. The additive is a blend of a fatty acid metal soap and an amide. The amide has sites available for hydrogen bonding, and is therefore able to act as a physical coupling agent between polymer systems and a range of fillers.CPL