Hardwood Plywood Adhesives for meeting CARB Exempt Status Earl Payton Sales Manager
Introduction • Need for a Lower Fuming Adhesive Systems • Adhesive Design Strategy • ULEF Adhesives • Designing an NAF polymer • NAF Adhesive • Conclusions
Market Drivers for a CARB Exempt System • What are the drivers? • The hardwood plywood markets have seen increasing regulation on formaldehyde emissions since onset of CARB • There are advantages (reduced testing) associated with using a ULEF or NAF system. • Market pull from end users as the general public becomes more conscious of “green” products. • US National Standard on the horizon?
Hexion Design Philosophy • Constraints: • System must be compatible with existing production and environmental equipment in customer’s facility. • Must be capable of passing HPVA HP-1 2004 “3 cycle soak” test. • The Hexion design philosophy is to find the most economical solution that satisfies all performance and regulatory requirements. • Hexion like other adhesive companies seeks to provide the market with solutions that are also a wise choice environmentally.
Hexion’s Commercially Available ULEF Resins • ULEF 600-05 • ULEF 600-04
ULEF 600-05 • Designed for CARB I compliance • CARB Phase I, Phase II and exempt status • Typical fuming levels = 0.03 - 0.06
ULEF 600-04 • Design for CARB Phase II • Lower fuming than 05 • Phase II, Exempt status • Typical fuming levels = 0.01 - 0.04
ULEF RESINS • Low emitting (CARB Phase II, exempt) • 3-cycle durability performance • Mix potlife advantages • Similar press cycles as pre-CARB UF’s • Similar gluing parameters as pre-CARB UF’s • Similar mix resin solids and total solids • Flexibility of fortification with melamine resin • Mix pH modifiers to reduce HP heat requirements
Thoughts on NAF Adhesive Design • Commercial systems for Hardwood plywood • Soy/ Polyamidoamine-epichlorohydrin (PAE) systems • Crosslinking polyvinyl acetate • Both systems above have positive attributes to offer; in building an adhesive system we need to follow the needs of the panel manufacturers and their downstream markets.
Development of a NAF Polymer for Hardwood Plywood Adhesive • Each adhesive developer must play to strengths. • As a result of multiple acquisitions Hexion has a broad technology portfolio it can pull from to develop new adhesive systems. This NAF system is a result of a cross divisional effort to apply acrylic latex polymer technology to the wood composites industry. • The new adhesive is adapted from an acrylic latex originally developed for the coatings industry. • Produced using emulsion polymerization with a non volatile content of ~47%, a viscosity of less than 100 cps and neutral pH. • The latex is combined with a protein source, usually soy based, using a mill’s existing mixing and applications equipment to produce a glue mix between 17,000 and 25,000 cps depending on ratios. • .009 to .025 ppm
Adhesive Mix for Hardwood Plywood Adhesive Mix • Water • Latex emulsion • Base (pH modifier) • Soy component Mix Characteristics • 42% non volatile content • Viscosity 17,000-25,000 cps • 8.8-9.2 lbs/gal
Ecobind: Cost Effective Emissions Solutions • Ecobind emission levels: • in composite wood products below the most stringent global standards • comparable to natural wood while meeting performance requirements • Ecobind resins: • can be used with existing mill equipment • have excellent shelf life • provide physical properties comparable to traditional binder solutions
Conclusions • The market will find the most economical solution that satisfies all performance and regulatory requirements. • Hexion offers ULEF adhesives designed to meet CARB Exempt • An acrylic latex has been developed with thermal and hydrophobic properties sufficient to pass HPVA HP-1 2004 “3-cycle soak” test for the hardwood plywood industry. • This NAF adhesive is cost competitive with other NAF systems and is low emitting. • We continue to optimize the formulations for the best cost/performance ratio. • The adhesive systems are compatible with existing hardwood plywood mixing and production equipment.