Patents Assigned to Materials Research Innovations Corporation
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Patent number: 6261488Abstract: A method for suppression of weld line weakening by virtually eliminating weld lines is disclosed. The process involves the near explosive injection of a metered amount of foamed thermoplastic molding material into an enclosing compartment formed by partly closing a compression type mold followed immediately by compression molding of the well mixed foamed material. The process finds particular utility in the manufacture of very long fiber reinforced parts. Variations on mold design and clamping cycles yield a variety of parts having foamed regions surrounded by more dense un-foamed regions. The method is particularly well adapted to the manufacture of large, very long fiber reinforced, foam-centered, hard surfaced, light weight, rigid parts.Type: GrantFiled: November 2, 1994Date of Patent: July 17, 2001Assignee: Materials Research Innovations CorporationInventor: Rexford H. Bradt
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Patent number: 6143410Abstract: Process and product for manufacturing continuous fiber reinforced sheets and shapes. A pressurized extrusion process consisting of a paired and edge enclosing doctor blades that remove feed material from a pair of pinch rolls and contain such in an optimally heated environment and which provides suitable hot dies and enables extrusion of continuous reinforcements, cores or threads to be contained in the extrudite.Hopper feedable plastic pellets containing reinforcing fibers which are longer than the largest pellet dimension are disclosed. The fibers in an elongated web of fiber reinforced plastic are caused to be wrinkled or folded prior to cutting the web into pellets. One form of apparatus includes a set of conveyor rollers for moving the web, with later rollers moving more slowly than the input rollers, in conjunction with a crowding doctor blade which forces the web with a creping action from the input rollers.Type: GrantFiled: February 5, 1996Date of Patent: November 7, 2000Assignee: Materials Research Innovations CorporationInventor: Rexford H. Bradt
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Patent number: 6129539Abstract: A material transfer arrangement having a pair of generally cylindrical adjacent rolls which are counter-rotatable about their respective cylindrical axes and which define therebetween a nip between which material passes is disclosed. There is a corresponding pair of spaced apart doctor blades, each in close proximity to a corresponding one of the rolls so that material may be conveyed between the roll nip and the space between the doctor blades. In one form, the nip passes material to the space between the doctor blades and that space has a downstream restriction which causes the material to compress in an accordion-like way forming a corrugated material web. In another form, the doctor blades function to deliver thermoplastic extrudate to the nip between the rolls to form elongated sheets or webs of plastic material of improved uniformity.Type: GrantFiled: July 23, 1998Date of Patent: October 10, 2000Assignee: Materials Research Innovations CorporationInventor: Rexford H. Bradt
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Patent number: 5800765Abstract: A material transfer arrangement having a pair of generally cylindrical adjacent rolls which are counter-rotatable about their respective cylindrical axes and which define therebetween a nip between which material passes is disclosed. There is a corresponding pair of spaced apart doctor blades, each in close proximity to a corresponding one of the rolls so that material may be conveyed between the roll nip and the space between the doctor blades. In one form, the nip passes material to the space between the doctor blades and that space has a downstream restriction which causes the material to compress in an accordion-like way forming a corrugated material web. In another form, the doctor blades function to deliver thermoplastic extrudate to the nip between the rolls to form elongated sheets or webs of plastic material of improved uniformity.Type: GrantFiled: March 19, 1996Date of Patent: September 1, 1998Assignee: Materials Research Innovations CorporationInventor: Rexford H. Bradt
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Patent number: 5747548Abstract: Apparatus and method for the production of hopper feedable thermoplastic pellets having zones or compartments which contain physically separated reactants which react only after being melt-mixed, as in a screw type extruder, reciproscrew injection machine, or similar device which heat forms pellets into a larger mass. This new class of thermoplastic molding materials relies mainly on the relatively slow reaction kinetics of contained large molecule molding materials to provide a time interval after melt-mixing of zoned pelletized reactants in an extruder barrel or injection molding machine. During this time period, the thermoplastic molding material is easily filled into injection molds. As the reaction progresses, the material becomes more viscous and such flow is difficult or impossible. The involved reactions may continue after demolding at room temperature during a post molding cure, or appliance service generated heat may cause post molding cure.Type: GrantFiled: March 14, 1997Date of Patent: May 5, 1998Assignee: Materials Research Innovations CorporationInventor: Rexford H. Bradt