Adhesive bonding and miscellaneous chemical manufacture – Methods – Surface bonding and/or assembly therefor
Reexamination Certificate
1998-08-10
2001-05-08
Cole, Elizabeth M. (Department: 1771)
Adhesive bonding and miscellaneous chemical manufacture
Methods
Surface bonding and/or assembly therefor
C156S166000, C156S073500, C156S305000, C156S307100
Reexamination Certificate
active
06228199
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Technical Field
This invention relates to a synthetic wood composition, a method of preparation for forming such a synthetic wood composition, and an article made from such a synthetic wood composition. In one aspect, this invention relates to a novel synthetic wood article resistant to attack by fungi and termites and which is efficient and safe to manufacture and produce.
2. Background
Natural wood is susceptible to attack by fungi and termites. Natural wood is particularly susceptible to attack by fungi and termites, after having become seasoned, or when the wood is held in contact with moist earthen ground. The wood becomes degraded and loses important structural and decorative features that it had before breaking down from the fungi or termite attack.
Prior attempts to protect natural wood have used chemical treatments on the wood to circumvent the shortcomings of natural wood, when seasoned, to become susceptible to attack by fungi and termites. Such prior chemical treatments on the natural wood involve procedures such as wolmanizing and the like. Wolmanizing is the application of copper, chromium, and arsenic compounds under pressure to cure the wood and act as a preservative. These prior chemical treatments have environmental distaste because of the toxic nature of the chemicals used.
Another drawback of natural wood is that it remains unsuitable for applications in areas where fire proofing is desired.
Another drawback of natural wood is that defects such as knots, warps, and voids are a disadvantage aesthetically.
Another drawback of natural wood is that defects such as knots, warps, and voids degrade the mechanical properties of the wood.
INTRODUCTION TO THE INVENTION
An attempt to circumvent the degradation problems of natural wood can involve wood substitutes made using petroleum-based ingredients such as polyethylene (PE), polyethylene terephthalate (PET), polyvinyl chloride (PVC), and the like. Typically when using these petroleum-based ingredients, recycled stock is mandated by the high cost of new, never-before-used stock. Such new stock typically is not economically justified even in view of preferred resultant mechanical properties provided by the composites produced from new stock. So recycled stock is used.
However, over time, it has been found that recycled stock has a tendency to suffer creep in structural applications.
Although recycled stock formulations can be made to be resistant to fungal or termite attack, the formulations such as polyethylene (PE) and polyethylene terephthalate (PET) are not fire resistant. The recycled stock formulations such as polyethylene (PE) and polyethylene terephthalate (PET) require the expensive assistance of high additive filler loads to attain any appreciable fire proofing.
In the case of polyvinyl chloride (PVC), recycling poses environmental concerns.
Highly desirable would be a synthetic wood composition, or composite, that has the structural features and the aesthetic visual appeal of wood, but not the shortcomings of wood or its substitutes as available from the disclosures of the prior art.
Examples of synthetic compositions are disclosed in Soda et. al. U.S. Pat. Nos. 3,720,572 and 3,936,518, McCaskey, Jr., et. al. U.S. Pat. No. 4,044,185, Anstadt et. al. U.S. Pat. No. 4,141,944, and Shinomura U.S. Pat. No. 3,935,047. Although such formulations are resistant to fungal or termite attack, with the exception of PVC, these formulations are not fire resistant. They require the expensive addition of high filler loads to attain any appreciable fire proofing. Recycling of PVC poses environmental concerns.
Coupled with a tendency to creep, these formulations are unsuitable for use in structural applications.
Walls U.S. Pat. No. 3,662,446 uses a steel/fiberglass rod core shaft covered by a foamed layer. Upon exposure to cyclic weather conditions, the pores in the foamed layer act as sites of extensive frost heaving and the attendant mechanical damage to the products.
Armellini U.S. Pat. No. 5,536,541 employs materials of an indeterminate nature, and the Armellini method involves a complicated multi-step assembly.
Hindersinn U.S. Pat. No. 4,419,400 discloses pultruding glass fiber with a glycol modified phenolic resole. Handling of the resin during pultrusion exposes workers to the residual formaldehyde, which formaldehyde also would introduce unwanted porosity, as would other volatiles. Moreover, glycol modification reduces the thermal stability of the formulations, and confounding with the high peak processing temperatures, leads to enhanced porosity and, hence, frost heaving, as in Walls U.S. Pat. No. 3,662,446.
The high peak processing temperatures for the Hindersinn U.S. Pat. No. 4,419,400 formulations are necessary to achieve high line speeds, thereby to make the pultrusion process economically viable.
Phenolic laminating resins typically must use acid catalysts or high temperature post curing or both.
Phenol cures are relatively slow and must be carried out at higher temperatures.
Phenol is relatively easily dissolved and absorbed by body tissue and poses safety hazards to workers.
Formaldehyde now is labeled a carcinogen.
Dailey, Jr. U.S. Pat. Nos. 5,075,413 and 5,075,414 address some of these concerns by using resole-novolak mixtures which can be pultruded at lower (160° C.) temperatures. Owing to the physico-mechanical degradation of the fiber reinforcement at high pH (>10 pH), the Dailey, Jr. U.S. Pat. Nos. 5,075,413 and 5,075,414 are limited to low pH (<10 pH) and consequently suffer from long processing (>0.06 Hour) times.
Greatly advantageous would be a composition or composite resin system which provides a synthetic wood composition, or composite, that has the structural features and the aesthetic visual appeal of wood, but not the shortcomings of wood or its substitutes as available in the prior art and which could be produced at lower temperatures and high line speeds.
It is an object of the present invention to provide a novel composite substitute for natural wood.
It is an object of the present invention to provide a novel composite substitute for natural wood having the structural features and the aesthetic visual appeal of wood.
It is an object of the present invention to provide a novel composite substitute for natural wood which overcomes the problems associated with wood degradation.
It is an object of the present invention to provide a novel composite substitute for natural wood which overcomes the problems associated with fungal and termite attack.
It is an object of the present invention to provide a novel composite substitute for natural wood which overcomes the problems associated with the natural aesthetic defects and shortcomings of natural wood such as knots and warps.
It is an object of the present invention to provide a novel composite substitute for natural wood which is free of the non-homogeneous appearance of natural wood caused by defects.
It is an object of the present invention to provide a novel composite substitute for natural wood which provides the aesthetic characteristics of wood and the desired termite and fungal resistance while providing the fire and flame resistance of the synthetic composites.
These and other objects of the present invention will be described in the detailed description of the invention which follows. These and other objects of the present invention will become apparent to those skilled in the art from a careful review of the detailed description.
SUMMARY OF THE INVENTION
The product and process of the present invention provide a synthetic wood product and method of making, including a plurality of continuous glass fibers oriented substantially in the longitudinal axis, contacting the fibers with a resorcinol modified resin binder, and pultruding the fibers and binder into a synthetic wood article. In one aspect, the synthetic wood material is oxidatively treated to restore color. In one aspect, the fibers and binder are precoated, e.g., such as with a furfuryl alcohol resin, prior to the pultrusion step to form th
Balaba Willy M.
Bryan, III Thomas J.
Balaba Concrete Supply, Inc.
Cole Elizabeth M.
Glantz Douglas G.
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