Processes for manufacturing engineered composite objects

Abstract

Methods for forming composite objects, wherein the methods comprise providing a plurality of material particles, applying a liquid adhesive to at least a portion of the plurality of material particles, wherein the adhesive is comprised of droplets, at least about 80% of the droplets having an average droplet diameter of about 50 to about 200 microns, to form a material / adhesive mixture, and forming the material / adhesive mixture into a composite object.

Description

CROSS-REFERENCE TO RELATED APPLICATION [0001] This application is based upon, and claims priority under 35 U.S.C. § 119(e) of, provisional U.S. Patent Application No. 60 / 628,628, filed on Nov. 17, 2004, the entire contents of which are incorporated herein by reference.BACKGROUND OF THE INVENTION [0002] Various types of engineered composites, including wood-based composites such as flakeboard, waferboard, particle board, and strand board, are known and used in many high-strength and stiffness requirement industries, such as, e.g., construction applications. Strand board, particularly oriented strand board, has enjoyed success as a building material since its introduction to market in approximately 1982. [0003] Engineered composites are materials in which two or more different materials are combined to form a single structure with an identifiable interface between the two or more materials. In general, the properties of the composite depend on the constituent materials and the interfa...

AI Technical Summary

Benefits of technology

[0010] The present invention relates to methods of forming composites and more specifically, methods of forming composites wherein a narrow distribution of resin droplets are applied to material particles. Composites formed in accordance with the methods of the present invention exhibit improved performance properties with respect to strength and durability, including improvement in properties such as internal bond strength (IB), modulus of rupture (MOR), modulus of elasticity (MOE), and / or thickness swelling (TS). Additionally, composites prepared in accordance with the methods of the present invention can achieve suitable performance properties in accordance with known composites with significantly decreased resin usage. Accordingly, economic advantage in process is realized.

Problems solved by technology

Depending on the intended end-use, production of oriented strand board and other engineered wood composites can require the creation of durable bonds between and among the strands or particles using synthetic adhesives, waxes or modifiers as well as a considerable amount of effort and energy to bond the particles together and provide high mechanical properties, strength, dimensional stability, and durability.

This method possesses inherent drawbacks, including difficulty in controlling the size of the droplets of resin that are distributed among the strands.

However, while some degree of control over droplet size may be achieved, it is far from optimum.

These problems are particularly disadvantageous as the mechanical properties of the end products can be linked to the application of the resin in a specific, optimum droplet size.

Resin droplets from the lower end of the distribution (smaller than, e.g., about eleven micrometers) can easily become aerosolized and may pose a health hazard for personnel.

Removal of such aerosolized droplets from work areas is required and often mandates the use of an expensive exhaust system and filter system in the area where the resin is being applied.

Additionally, when using a spinning disk atomizer, excessive resin leaving the spinning disk with substantial kinetic energy may build up on the walls of the blender, necessitating costly cleaning procedures that may require use of hazardous cleaning materials.

In either instance, large quantities of resin, which can often be rather expensive, can be wasted.

Moreover, large quantities of resin droplets which are outside of an ideal range but which neither accumulate on the walls of the equipment or become aerosolized can still provide less than optimum mechanical properties.