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US 4,014,737 AGranted
Method of molding preform having 600% by weight water
OwnerRobert M. Brennaninventor
Life of this patent
Estimating the term…
Abstract
A molded cellulosic article, such as a loudspeaker cone, is formed without an intermediate drying step by first forming a pre-form having 600 - 900% water on a water pervious wire net, inserting the pre-form directly into a hot press, and drying the pre-form to less than about 5% by weight water in the hot press at a pressure less than about 400 psi and at a temperature of 400.degree. - 450.degree. F.
Claims15
A method of forming a molded cellulosic article comprising
- forming a pre-form comprising a wet layer of cellulosic fibers, having at least about 600% by weight water, on a water-pervious wire net by contacting the wire net with a water slurry of cellulosic fibers and drawing the fibers onto the wire net by suction through said wire net.
- disposing the pre-form having at least about 600% by weight while water on said wire net, onto a first die surface of a mold,
- contacting the pre-form, having at least about 600% by weight water, with a second die surface of said mold, and
- drying the pre-form having at least about 600% by weight water to less than about 5% by weight water in a heated press by pressing said wet layer of cellulosic fibers on said wire net in said heated press between said die surfaces at a pressure less than about 400 p.s.i., while allowing resulting steam to escape from said mold through said wire net and through said cellulosic fibers.
1 more element
A method of forming a molded cellulosic article comprising
- forming a pre-form comprising a wet layer of cellulosic fibers, having at least 600% by weight water, on a water-pervious support means by contacting the support means with a water slurry of cellulosic fibers and drawing the fibers onto the support by suction through said water-pervious support;
- disposing the pre-form comprising cellulosic fibers having at least 600% by weight water while on the water-pervious support means, onto a first die surface of a mold,
- contacting the pre-form comprising cellulosic fibes having at least 600% by weight water on said water-pervious support means, with a second die surface of said mold, and
- heating at least one of said die surfaces and pressing said wet layer of cellulosic fibers, having at least 600% by weight water, between said die surfaces at a pressure less than about 400 psi, while allowing resulting steam to escape from said mold through said water-pervious support means, to substantially dry said cellulosic fibers.
1 more element
A method of forming a molded article comprising
- forming a pre-form comprising a wet layer of cellulosic fibers, having at least 600% by weight water and having at least 50% fibers with a length of at least 1.0 mm., on a water-pervious support member;
- disposing the pre-form and support member onto a first die surface of a mold, while the pre-form contains at least 600% by weight water and at least 50% fibers with a length of at least 1.0 mm.;
- contacting the pre-form of cellulosic fibers, having at least 600% by weight water and having at least 50% fibers with a length of at least 1.0 mm., with a second die surface of said mold, and
- drying the pre-form of cellulosic fibers, having at least 600% by weight water and having at least 50% fibers with a length of at least 1.0 mm., in a heated press maintained at a pressure and for a period of time sufficient to remove substantially all of the water contained in the pre-form but insufficient to press the cellulosic fibers through the support member, such that steam generated in the heated press can laterally escape therefrom.
1 more element
Dependencies are inferred from the claim text.