Organic Biocide for Long-Lasting WPC Composites

WEB EXCLUSIVE A new organic biocide is said to significantly increase the lifespan of wood plastic composites (WPCs), by ‘dramatically’ reducing the adverse effects of mold or microorganisms that cause discoloration. Preventol MPT 11 from Germany’s Lanxess AG (U.S. office is in Pittsburgh, Penn.), is specially tailored for WPC applications and reportedly is based on a careful combination of materials that provide this organic material with effective protection from fungi that can cause discoloration and damage. According to the company, mold-repellent additives used in the production stage of WPCs, typically inorganic preparations such as zinc borate, should be viewed with caution as they must be used in extremely high dosages and therefore make recycling and thermal recycling more difficult. In contrast, organic biocides generally have lower active concentrations. However, the high extruder temperatures of up to 200 C and the need for rapid and homogeneous distribution within a compound despite the lower dosage means that the use of such products in WPCs places very high demands on the formulation. Preventol MPT 11 is said to meet this challenge by effectively blocking the growth of range of microorganisms including Penicillium funiculosum and Aspergillus niger. Said to be effective at low dosages—0.1% to 0.4% compared to 5% for zinc borate--Preventol MPT 11 can be simply added to the extruder with other additives such as bonding agents, UV stabilizers and pigments. The additive is then reportedly distributed throughout the composite rapidly and very effectively. Lanxess is initiating an approval process for Preventol MPT 11 as part of the EU’s Biocidal Products Directive (BPD), so that users will be freed of the burden of the administrative outlay associated with submitting their own registration. (800) LANXESS * www.lanxess.com