摘要:
A process and apparatus for producing a fibrous assembly. At least one fiber-forming polymer is extruded through a spinneret having numerous small openings. The process uses a die equipped with a spinneret having numerous closely spaced small openings and an opening ratio (.alpha.) of at least 30%. At least one fiber-forming polymer in the form of a shaped mass having a specified compression resistance is continuously stuffed into said die. Said shaped mass has a shape such that it measures more in one direction than in another. There is passed through the spinneret an electric current sufficient to give said fiber-forming polymer Joule heat required for cutting said polymer by partitioning members defining the numerous small openings of the spinneret. The cut fiber-forming polymer is taken up as fine streams.The present invention provides ultrathick aromatic polyamide fibers having an average cross-sectional area of about 0.01 mm.sup.2 to about 5 mm.sup.2 and comprising at least one fiber-forming aromatic polyamide and an inorganic or metallic fine powder or a fibrous material.
摘要:
Articles are blow molded from thermoplastic polymeric materials containing high proportions of fillers such as glass fibres. The method comprises extruding the filled polymeric material through a die having a mandrel for constraining the material into a tubular shape, coextruding between the die and the outer surface of the material, a liquid having a freezing temperature lower than that of the material, cooling the liquid and the outer surface of the material during their passage through the die to a temperature below the freezing temperature of the material but above the freezing temperature of the liquid while maintaining the inner surface of the material molten, squeezing the extrudate at suitable intervals to fuse the molten inner surface together and thereby seal discrete lengths, and inflating the sealed lengths to conform to a surrounding mold to produce a shaped article. Lamina shapes may be foam-filled to give stiff panels.
摘要:
A die formed of a series of concentric rings is disclosed. An outer body has a series of communication ports for the introduction of a heating medium. An inner body having the same axial thickness as the outer body is placed inside the outer and in the annular space defined between the inner and outer bodies a series of annular rings are placed. The annular rings each have a series of nozzles disposed in a circumferential ring and are formed with grooves on their outer walls to define jackets between the rings. The jackets are in communication with the communication ports to supply a heating medium to the jacket.
摘要:
This invention relates to a process for extruding particular shapes in thermoplastic material and, more precisely, flat plates, corrugated plates and the like or, in general, shapes having one section much larger than the other; said process being suited to eliminate the uneven feed of the molten material coming out from a die. This invention relates also to an improved extrusion machine which is particularly useful for carrying out the aforementioned process.
摘要:
In a process for melting, extruding, and forming a thermoplastic synthetic resin, wherein a deckle mounted on a die device of an extruder is moved lengthwise of a slit in the die to thereby vary the length of the slit and to adjust the width of a flat film being extruded, the improvement comprising stopping the leaking of the molten resin around the deckle portion by forcibly cooling the deckle with a cooling medium, such as air, water or the like, so as to increase the viscosity of the molten resin around the deckle, whereby a decreased fluidity of the molten resin occurs.
摘要:
An apparatus for the continuous extrusion molding of a curable polymeric material about an elongated conductor. The apparatus includes electrical induction heating means for the precise and isolated application of heat to a limited portion of a progressively advancing mass of curable polymeric material immediately prior to its continuous entry into and passage through a forming die and its molding therein to shape.
摘要:
A mandrel and bushing sizing die assembly has an annulus formed between the mandrel and the bushing of the assembly for passing plastic material therethrough and forming a thick-walled tubular product. A middle portion of the annulus has a thickness in the range of about 25-50 percent of the greatest thickness of a first end portion of the annulus and the second, discharge end of the annulus has a thickness greater than about 1/4-inch and greater than the thickness of the middle portion of the annulus.
摘要:
An apparatus for the production of articles with a compact smooth skin and a cellular core from polymer materials, which contain blowing agents, by injection molding or extrusion wherein the apparatus contains an electric heating element within a channel through which the polymeric material is passed.
摘要:
A multiple outlet flat film die apparatus and process which extrude separate streams of material to form any of various composites which may involve joining of similar or dissimilar materials, which includes individual manifold chambers separated from each other by heat insulating means inbetween. The heat insulating means in between such as for example heat insulating material between plates retards heat transfer between the materials. Each manifold is tapered toward its own die mouth; has separate melt inlets adapted for center, top and/or end feed operations; has separate pre-land and final land surfaces leading to individual outlet openings for precise control of melt flow; and has separate heat control means allowing precise temperature control for each melt as it flows toward the die. Temperature differentials may be extensive and may approach the difference between the original temperature of the melt delivered to each manifold. Heat differentials of 0.degree. to 200.degree.F. are an example. A differential push-pull adjustment system for the movable lip of each outlet opening inlcudes opposed alternatingly staggered thimble bolts for precise control of each individual profile layer. Methods of laminating the extruded layers to each other as well as to other substrates are included.
摘要:
A method for controlling the extrudate emerging from an extruder is provided by sealing a portion of the extrusion die opening with a deckle bar into which is incorporated means for affecting the temperature at the surface of the deckle bar. The embodiments of this invention provide deckle bars into which are incorporated means for heating, cooling and heating and cooling in combination.