Method of making thermoplastic hardboard from acetylated mat
AssigneeUnited States Gypsum Company
InventorsCynthia B. House, Robert J. Leichti
Life of this patent
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Abstract
A wet-felted mat of wood fibers is acetylated by coating the mat with a quantity of acetic anhydride ranging from 5 to 70% by volume of the mat and heating the mat at a temperature of from 150.degree. to 300.degree. F. while confining substantially all of the acetic anhydride within the mat for about 20 to 120 minutes. The acetylated mat is pressed into hardboard which may be bent into a variety of loops, spirals, helices, and other curvilinear shapes to make articles of furniture, protective packaging products and the like.
Claims9
A method for acetylating wood fiber comprising the steps of forming said wood fiber into a substantially dry mat, coating the mat with from about 5% to about 70% by volume of acetic anhydride, enclosing the mat in a sealed space, heating the enclosed mat at a temperature of from about 150.degree. F. to about 300.degree. F. for a period of from about 20 minutes to about 120 minutes, and removing by-product acetic acid and residual anhydride.
A method for preparing an acetylated wood fiber mat comprising the steps of coating a substantially dry wood fiber mat with from about 35% to about 120% by weight of acetic anhydride, enclosing the coated mat in a sealed space, heating the enclosed mat at a temperature of from about 150.degree. F. to about 300.degree. F. for from about 20 minutes to about 120 minutes, and removing by product acetic acid and residual anhydride.
A method for preparing a thermoplastic hardboard comprising the steps of coating a substantially dry wood fiber mat with from about 35% to about 120% by weight of acetic anhydride, enclosing the coated mat in a sealed space, heating the enclosed mat at a temperature of from about 150.degree. F. to about 300.degree. F. for from about 20 minutes to about 120 minutes, drying the acetylated mat, and compressing said mat at a temperature of from about 400.degree. F. to about 500.degree. F.
Dependencies are inferred from the claim text.