Durable wood-plastic composite flooring for trailers

Abstract

A composite wood flooring system for a vehicular trailer floor comprising: a plurality of wood boards, each wood board comprising a top surface and a bottom surface opposite the top surface; and a filled thermoplastic composite layer comprising a thermoplastic polymer and a discontinuous filler, the thermoplastic layer being substantially bonded to the top surface of each wood board.

Description

1. FIELD OF THE INVENTION [0001] This invention relates to improved laminated wood flooring suited for both covered and exposed floors of vehicular trailers. In particular, the invention provides for flooring that allows the use of wood species of low hardness to produce moisture and scuff resistant floor boards. 2. DISCUSSION OF THE BACKGROUND ART [0002] Conventional wood flooring for over-the-road closed van trailers, truck bodies and containers is normally manufactured with hardwoods, such as oak, hard maple, birch, beech, ash, etc. Lower grades of green lumber at the thickness of 4 / 4 (nominal 1 inch) or 5 / 4 (nominal 1¼ inch) are used as the starting material. This lumber has a large amount of defects, which are not allowed in the flooring product. An average of more than 50% of the lumber is either discarded or lost in the flooring manufacturing process. The lumber is suitably dried in special drying chambers under controlled conditions to moisture content of about 8%. The dried...

AI Technical Summary

Benefits of technology

[0023] One aspect of this invention is to provide wood flooring with all of the attributes of conventional laminated hardwood flooring and improvements in the areas of moisture resistance, durability, surface characteristics, manufacturability and cost. Such improvements allow the floor board of this invention to be for use in all types of vehicular trailers, including vans, flatbeds, containers, truck bodies, horse trailers, etc., and also for other applications such as decks. Specifically, the floor board of this invention relies on the strength of conventional laminated wood flooring. To improve the manufacturing process, certain relatively lower cost wood species such as southern yellow pine, Douglas fir, spruce, western larch and yellow poplar are preferred. These woods are typically about 50% to 60% of the cost of oak for the same or similar grade. At the price of lower grade oak, it is possible to purchase the above mentioned woods in a high strength grade (such as MSR or machine stress rated) with little or no structural defect. This allows tremendous cost savings over conventional oak and maple hardwoods. However, these woods have much lower surface hardness compared to oak and maple. Hardness is important to prevent wear at the top side of flooring. To solve this issue, a low-cost filled plastic layer is bonded to the top side at a minimum and further to the other sides of floor board depending on the application or end-use environment of flooring. The plastic can be a thermosetting or a thermoplastic polymer, but thermoplastic polymer is preferred for lower cost and ease of manufacturing. Fillers can be flour, chips, flakes, strands, dust, shavings and particles of wood, lignocellulosics, natural plant fibers, m...

Problems solved by technology

However, these woods have much lower ...

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