Abstract: A molten polymer filtration assembly includes at least three independently controllable and removable filter housings which extend from a common inlet passage to a common outlet passage, thereby providing parallel flow paths for polymer filtration. Each of the filter housings includes an inlet valve controlling the flow of polymer from the inlet passage, an outlet valve controlling the flow of polymer to the outlet passage, and a filtration passage which extends between the inlet and outlet valves and houses a candle-type filtration element. When the inlet and outlet valves are opened, the filter housing is on-stream and allows polymer to flow from the inlet to the outlet passage. Each filter housing is individually controllable, and can be set in an on-stream state independent of the state of any of the other filter housings, such that any number of filter housings can be on-stream at a given time.

Abstract: An extrusion system is provided with a screen changer between in-line screw sections. An in-line seal diverts high pressure, high temperature foamable material toward the screen changer. The seal may have reverse flights to provide a visco-dynamic seal. The screw sections and the seal may be located in a common barrel housing. The screw sections and the seal may be integrally rotated as a single in-line unit. A device including an injection valve may be attached to the upstream screw section to introduce a foaming agent into the material being extruded.

Abstract: A process and a corresponding device for filtering plastics in an injection molding machine having a plasticizing unit and a mold cavity. A slide having a receptacle for a filter element is arranged between the plasticizing unit and the mold cavity. A piston cylinder displacing unit is mounted parallel to a principal axis of the plasticizing unit so as to be slideably contactable by the slide holding the filter element. The displacement unit has a filter holder surrounded by a filter preheater for the insertion and preheating of a fresh filter element. The slide is displaced so that the filter receptacle in the slide corresponds to the filter holder in the displacement unit thereby enabling a spent filter element to be ejected while simultaneously inserting the fresh filter element into the receptacle. The slide is then returned to its operating position in which the filter element is acted upon by the plastic casting substance.

Abstract: The present invention includes a filtration apparatus for an injection molding machine where the injection molding machine includes a screw housed within a bore for generating molten polymer. A tip member extends axially from the screw. The tip member has radially extending upstream and downstream flanges positioned axially apart from each other. A filter encircles the tip member and is capable of filtering the molten polymer. An annular ring member encircles the tip member and is slidably positioned within the bore between the upstream and downstream flanges. The ring member is capable of sliding between the flanges for directing the molten polymer through the filter or preventing back flow of the molten polymer past the upstream flange.

Abstract: The filter intercepts dirt emanating from a molten-polymer extruder. The filter is clamped between perforated support plates, and a rotor sweeps the holes in the upstream plate. The rotor defines a cavity which communicates with a small sector of the holes at any one time. The cavity is openable to drain, via a valve. The melt is under high pressure, to which the cavity is exposed. The rotor is rotated by a drive-shaft, and the drain is located co-axially with the drive-shaft.

Abstract: Apparatus for continuously filtering molten polymer comprising: an arbor seated in a fixed support, the arbor having inlet and outlet ports for respectively receiving contaminated and discharging filtered melt, the ports communicating with openings in a pair of housings rotatably mounted on the arbor; a plurality of filter pod assemblies outwardly of and mounted on the rotatable housings, each assembly having a filter for contaminated melt and intake and discharge openings intermittently alignable with the ports on rotation of the housings to position a clean filter in the path of the contaminated melt and to remove the filter from the path when blocked with contaminants; passages associated with the inlet and outlet ports of the arbor and the housings for gradually establishing a flow of melt into a clean filter as it is rotated into filtering position; and thermally dilatable seal between the rotatable housings and the arbor to seal the housings and the arbor during the filtering of contaminated melt by a f

Abstract: Apparatus and a method for extruding a honeycomb, providing reductions in curvature or bowing of the extruded honeycomb structure, employs a bow deflector positioned upstream of the extrusion die, the bow deflector comprising adjoining, independently rotatable, first and second aperture plates of tapering thickness, the degree of bow reduction depending on the relative rotational position of the aperture plates and the resulting magnitude of the pressure/flow velocity gradient imparted by the plates on the flow stream entering the die.

Abstract: A spin pot for spinning synthetic polymer fibers has a polymer filter, a spinneret downstream of the polymer filter, and an electroformed perforated screen positioned between the polymer filter and the spinneret. The screen is most preferably electroformed nickel and includes an annular non-perforated region which bounds a perforated central region. The electroformed perforations prevent debris that may become dislodged from the filter unit from blocking the spinneret orifices thereby creating undesired "slow-holes".

Abstract: A continuous flow filter changer for a fluid having a filter carrier assembly for intermittent sliding transition displacements in a filter channel to align adjacent filters thereon successively with a filter aperture in the flow passage. The duration of each such transition is substantially less than that between transitions. A ring shaped seal sealingly connects between the flow passage upstream thereof and a filter aligned with said aperture to prevent fluid flow except through said filter. The clearance for sliding between the filter carrier assembly and the filter channel is controlled to allow for such displacements while limiting the fluid leakage from the filter channel during a single transition to a predetermined level.

Abstract: A filtering method and apparatus for continuously filtering a polymeric melt, which includes a plurality of filter chambers which are arranged in a melt flow path parallel to one another. Also, an intermediate filter is arranged parallel to the filter chambers. When one of the filter chambers is disconnected for the purpose of cleaning or replacing the filter element therein, the intermediate filter is connected synchronously in the melt flow path and, after the filter chamber is cleaned, or the filter element is exchanged, the flow is switched back through the filter chamber, and the intermediate filter is again disconnected.

Abstract: A filtering method and apparatus for continuously filtering a polymeric melt, which includes a plurality of filter chambers which are arranged in a melt flow path parallel to one another. Also, an intermediate filter is arranged parallel to the filter chambers. When one of the filter chambers is disconnected for the purpose of cleaning or replacing the filter element therein, the intermediate filter is connected synchronously in the melt flow path and, after the filter chamber is cleaned, or the filter element is exchanged, the flow is switched back through the filter chamber, and the intermediate filter is again disconnected.

Abstract: In a filter changing device with a flow path for the plastic in which one two or more filters can be inserted into the flow path as desired, the invention proposes to fit the filter support in such a way that it can assume a working back rinse and filter change position, in which, in the back rinse position, the plastic is caused to reverse its direction of flow through two interconnected flow channels without permitting air to penetrate into the filter changing device and in which there is free access to one of the filters in the filter changing positions. As the back rinse position can succeed a filter changing position, it is possible to clear the whole filter changing device of occluded air before a plastic processing plant starts production.

Abstract: In a filter apparatus 1, a central filter rod 6 is arranged in the interior 14 of a filter housing 2, the diameter d of which filter rod tapers in the direction of flow of the plastic melt. On the filter rod 6 are arranged filter discs 7 which are parallel to one another and have outer and inner diameters of equal size. The filter apparatus 1 operates as a continuous-flow filter apparatus in which the plastic melt flows in via an intake 4 and flows out via an outlet 5. A filter housing wall inner surface 3 tapers in the direction of flow of the plastic melt, so that a gap width h.sub.a (x) between a filter disc outer rim 8 and the filter housing wall inner surface 3 decreases in the direction of flow of the plastic melt.

Abstract: An improved process and apparatus for producing a thermoplastic resin foam by mixing a thermoplastic resin, a blowing agent and other necessary components in a molten state and extruding the mixture to expand. The apparatus comprises a metering zone provided at the front end of the rotating shaft in an extruder, a kneading zone provided closer to the rear end than the metering zone, and a plurality of perforated plates mounted on the surface of the shaft in the kneading zone. The outside diameter of said shaft is made smaller than that of the screw in the metering zone as measured at the bottom of channels. This feature combines with the perforated plates to insure uniform mixing and consistent extruding operations.

Abstract: The screen changer of the invention is structured such that a material discharge passage formed in a housing is brought into communication with the in-flow passage of a through passage formed in the housing through the upstream chambers of through passage portions respectively formed in slide bars, and the molten materials that have passed through the in-flow passage in the initial operation of the extruding machine are discharged into the above material discharge passage, thereby being able to remove the mixtures remaining in the extruding machine prior to the normal operation of the extruding machine.

Abstract: A filter for high-viscosity fluids can be used in small to large-sized units, shows no thermal deterioration of the contents, and allows simple, rapid, and safe exchanging of the filter units and has a structure in which at least one filter element is built in, such that when a filter unit having an inlet opening and an outlet opening has the aforementioned inlet opening attached to the outlet opening of the unit on the upstream side and the aforementioned outlet opening attached to the inlet opening of the unit on the downstream side, two supporting plates, one fixed and one movable, are attached to an inlet-side adapter and an outlet-side adapter, the aforementioned filter unit is surrounded by said fixed supporting plate and movable supporting plate, and by moving the movable supporting plate, the various connecting parts can be closed and opened.

Abstract: Disclosed is a temperature control system and a kneading-mixing extruder apparatus implementing the temperature control system. The temperature control system includes a flow passage formed in a stationary disc having a plurality of holes provided in a kneading mechanism of the extruder apparatus, a fluid supply device for supplying temperature-adjusted fluid into the flow passage and a temperature control device for setting the temperature of the stationary disc to a desired target temperature.

Abstract: A spinning pack with a sand filter for the melt spinning of thermoplastics, whereby at least one perforated plate with evenly distributed D-shaped holes with slanting openings that taper conically in the direction of flow is placed in the direction of flow in front of and/or behind the sand filter. Spinning packs according to the invention surprisingly give highly uniform distribution and flow of thermoplastic melt through the sand filter.

Abstract: A plastic injection molding machine is provided which includes a filter for the continuous removal of foreign particulate contaminants from molten resin. The molding machine has a filter assembly with a passage for molten plastic resin and also includes a movable filter body containing a plurality, e.g, two, removable filters movably supported within the filter assembly for transporting the filter element between at least a pair of alternate positions, including an operative position within the passage containing the molten plastic resin and a non-aligned inoperative position. The filter body has a bored opening containing the filter and an accumulation chamber for storing the foreign material upstream of the filter.

Abstract: A control device for at least two partial fluid ducts comprises a common fluid supply duct and a common fluid removal duct. The fluid supply duct is connected with the fluid removal duct by at least two partial fluid ducts. A filtering device, a valve device each having a blocking element, and a stop valve are each located in a corresponding partial fluid duct. Each blocking element of the valve device operates in such a way that the blocking element can be moved between a first (open) position, in which the fluid flowing through the partial fluid duct in which it is located is filtered, and a second (closed) position, in which the fluid is filtered in the other partial fluid duct, whereas at the same time the filtering device provided in the partial fluid duct in which it is located is washed by the fluid flowing in the reverse direction. Furthermore, each blocking element can be brought from the first position into the second position and vice-versa by rotating the blocking element.

Abstract: A device for filtering a fluid, particularly a molten plastic, with a fluid-supplying canal and a fluid-draining canal is described, whereby two plate-like filters are movably arranged in and across the flow direction of the fluid to be filtered between the fluid-supplying canal and the fluid-draining canal. Hereby the fluid-supplying canal (4) is connected with the fluid-draining canal (5) by a single connecting canal (6).

Abstract: A filter member includes a breaker plate having an increased filtering area without any deterioration in screen back-up capability. This filter member is adapted to filter off impurities of resin melt and is disposed in a resin passage. The filter member includes a screen and a breaker plate for backing up the screen. The breaker plate has resin passageways in the form of elongated slits extending as intersecting the flow direction of resin material.

Abstract: A multi-stage vacuum kneading-extruder includes a degassing chamber for storing material to be processed and reducing pressure of space for storing the material, a kneading-conveyer device for kneading while conveying the material sent from the degassing chamber, and an extruding mechanism for extruding the kneaded material, at a conveyer terminal end of the kneading-conveyer device, into a predetermined shape. The kneading-conveyer includes a pair of conveyer screws disposed one after another in a conveying direction of the material and a grinding-kneading mechanism interposed between the front and rear screws. The grinding-kneading mechanism includes a plurality of unit kneading mechanisms disposed in opposition to each other relative to the material conveying direction. Each of the unit kneading mechanisms includes an un-rotatable stationary disc, a rotary disc rotatable relative to the stationary disc and a stationary filter interposed between the stationary and rotary discs.

Abstract: An apparatus for mixing and kneading raw materials, such as soap, and extruding the mixture into a predetermined shape. The apparatus includes a cylinder having a rotatable plodder worm shaft, a levigating mechanism disposed at a longitudinal position of the cylinder and including a rotary disc and a fixed disc fixed to the cylinder. The rotary disc and the fixed disc are disposed side by side along the axial direction of the plodder worm shaft and define a plurality of through holes allowing passage of the material in the axial direction. A flow passage forming member is disposed within a moving passage of the material between the rotary disc and the fixed disc and forms a flow passage allowing passage therethrough of fluid maintained at a predetermined temperature. A fluid supplying/exhausting device is provided for supplying the fluid at a predetermined flow rate to the flow passage and exhausting the fluid from the flow passage forming member.

Abstract: A doormat manufacturing apparatus contains a spinning pack having a plane rectangular shape for spinning a large number of monofilaments, a plurality of extruders disposed at symmetrical positions in the longitudinal direction of the spinning pack for supplying a plurality of molten synthetic resins to the spinning pack, and a collecting mechanism for collecting monofilaments discharged from the spinning pack. The spinning pack contains a resin flowpath changeover unit arranged over a multihole nozzle plate, and the resin flowpath changeover unit is connected to each extruder by a respective communicating pipeline. The communicating pipelines are arranged at symmetrical positions in the longitudinal direction of the spinning pack. The resin flowpath changeover unit has a plurality of longitudinally extending main flowpaths, each of which communicates with a respective communicating pipeline via a respective zone flowpath and with a respective branch flowpath extending crosswise from the main flowpath.

Abstract: An apparatus for filtering plastic melts, which comprises a filter housing (1) having at least one cylindrical filter receiving chamber (8), and with a tubular filter cartridge (2) mounted in the chamber. An annular melt flow space (9) for the plastic melt is defined between the outer periphery of the filter and the inside wall of the chamber, such that the melt flows radially inwardly through the filter medium of the filter cartridge and into the central passage of the filter cartridge and then to an outlet opening of the housing. An additional melt flow outlet channel (12) is positioned adjacent the downstream end of the filter cartridge, and in one embodiment, the melt is able to flow via the additional melt flow outflow channel to the outside of the housing. In a second embodiment, the melt can flow via the additional melt flow outflow channel and an additional filter (11) and return to the main flow.

Abstract: The invention relates to a filter device for extruders and injection-molding machines for the continuous processing of thermoplastic, the throughflow bore in the screen plunger being of a round design in the region of the inlet side and of the screen chamber and narrowing ovally following on from the rear side of the screen pack, the long axis of the oval extending in the direction of the displacement direction of the screen plunger.

Abstract: The seals between the plates and a swingable or slidable sieve insert carrier can be hollow to receive a substance having a greater coefficient of thermal expansion than the metal shell of the seal so that the pressing force is generated by expansion of the substance.

Abstract: A screen changer has not only the conventional slide bars with material injection channels and first air withdrawing channels, but also second air withdrawing channels, as well as material withdrawing channels when the slide bars are in an intermediate position where the filter portions provided through those slide bars in a direction normal to the axis are sealed and isolated within through-holes in the housing; said second air withdrawing channels communicate the topmost parts of the downstream compartments with the outside of the housing and are provided such that after penetrating through the slide bars, they extend along the outer surfaces of those slide bars; said material withdrawing channels are provided through the housing such that they communicate the exit ends of the downstream compartments with the outside of the housing.

Abstract: Spinning head for spinning polymer melts, having a filter cartridge made of a seamless metal cloth cylinder having an end cap and a connector, said cartridge being disposed within a melt passage having a conical taper toward the bottom. The connector is inserted into the melt channel and has a matching conical shape to seal against the channel wall. A die plate having a maximum area of 90 cm.sup.2 connects to the connector. An opening through the connector permits filtered polymer melt to flow from the filter cartridge through the connector to the die plate. A single filter cartridge is provided for each die plate, whereby the ratio of filter area to die plate area is at least 0.5:1.

Abstract: A vacuum kneading and extruding method includes the steps of separately and continuously measuring plural types of material and continuously feeding the material into a kneading and degassing tank; kneading the plural types of material fed, and degassing the material by decompressing a material accommodating space into a vacuum; kneading and transporting the material in a decompressed condition through a multi-stage kneading mechanism; and forming and extruding kneaded material in a predetermined shape. An apparatus for use in executing this method is included.

Abstract: The invention relates to a filter device for extruders and injection-molding machines, the screen elements being formed by a candle filter and, if required, by a plurality of candle filters, which are arranged in the circumferential direction on the screen plunger, extending parallel to the longitudinal axis of the screen plunger, and are flowed through from the outside inward for filtering purposes and from the inside outward for backwashing purposes.

Abstract: A filter for flitrating molten resin of the invention includes: a cylindrical filtering member formed with a large number of projections and recesses; and radially arranged rods in a supporter for supporting the cylindrical filtering member at arc-shaped projected portions, and is constructed such that molten resin material is allowed to pass through the filtering member at arc-shaped recessed portions. In this arrangement, it is possible to enhance the resistance of thermoplastic molten resin filter against filtering pressure as well as to ensure a large filtering area. Further, the filter may be constructed such that the cross-section of the aforementioned cylindrical member is made greater from the upstream side toward the downstream side. By this configuration, the flow rate of molten resin passing through the unit area of the filtering member is made uniform and consequently the collecting capacity of foreign substances is increased.

Abstract: A screen pack replacing apparatus in accordance with the present invention is arranged such that a single slide bar having at least two or four screen packs is slidably provided in a main body disposed on a cylinder. As the slide bar is moved, the screen packs can be replaced, and the overall configuration can be made compact and the filtering area can be made large.

Abstract: A cooking-extruding apparatus and method for the cooking-extrusion of biopolymers for the production of thermally treated food granulates, snack products, cereals or similar products. The cooker-extruder having a feeding hopper, a conveying screw, an exit nozzle, and at least one spatula-pump disposed between the conveying screw and the exit nozzle. Each spatula-pump includes a spatula element and plate having a matrix of holes. In operation, the spatula element assists the material being processed through the plate having a matrix of holes. An embodiment of the apparatus of the present invention includes the use of two conveying screws. The spatula-pumps are arranged serially such that the material being processed passes through one spatula-pump to the next until it is passed through the exit nozzle of the apparatus.

Abstract: The filter devices allow easy cleaning of various joint portions such as those located near changeover valves of the filter devices. Heating units which accommodate filter cases may be formed with openings which allow such joint portions between the filter cases and the heating units to be accessed and cleaned. Alternatively, the heating units may include two relatively movable parts which, when opened, allow the joint portions to be accessed once the filter cases are removed. The heating units themselves may be detachable from a support frame so as to expose other joint portions.

Abstract: A sealing device for sealing a slide plate translatable across an extrusion bore in a polymer filtration apparatus includes an annular seal having a sealing surface which is biased against the slide plate by an annular spring. The seal has a thrust surface which is angled relative to the sealing surface and is located at an opposite axial end of the seal from the sealing surface. The annular spring exerts radial forces against the thrust surface of the seal to bias the seal in an axial direction against the slide plate. Pressurized polymer in the extrusion bore further biases the seal against the slide plate.

Abstract: A device for producing honeycomb structural bodies, including an a extruding die, and a porous plate provided on a side of an inlet of the extruding die for the molding material, The passage resistance of the molding material through the porous plate is varied in a direction orthogonal to an extruding direction of the molding material.

Abstract: A filter for a synthetic resin melt has a housing formed from two blocks through which a melt channel for the passage of the plastics melt passes. A screen plate is rotatably mounted to intrude between the blocks and a plurality of recesses are distributed in a circular pattern around the periphery of the screen plate so that rotation can bring two of the recesses in to line with the channel. A plurality of filter elements are accommodated, one each in each recess, so that the plastic melt must pass through the filters in the recesses in line with the channel. To support the filter elements against melt pressure a stationary perforated plate is located in the channel immediately adjacent and downstream of the screen plate. By rotating the screen plate exhausted filter elements can be readily replaced. The filter elements are made of woven wire cloth and may be dished to prevent distortion of the mesh.

Abstract: An improved continuous large area polymer filter employs a single valve to control molten polymer flow into and out from at least two but preferably three or more filter assemblies. In a neutral position the valve apportions flow equally to each of the filter assemblies. When filters in any one of the assemblies becomes clogged and requires cleaning or replacement, the valve is repositioned to prevent flow into and out from the clogged assembly while continuing to apportion flow among the remaining assemblies. A small amount of polymer is bled from the selected assembly to effect depressurization and the assembly is removed, restored to function and replaced. The valve is repositioned to allow a slow bleeding of polymer into the restored assembly and the bleed valve is opened to allow air and air entrapped polymer to be removed from the assembly before returning it to service.

Abstract: Disclosed is a filter support for use as part of a screened packing, or filter system, in an extrusion process, wherein the filter support provides a rigid wall in the shape of a dome featuring flow passage holes through the wall such that the longitudinal axis of each hole is perpendicular to a plane tangent to the surface of the dome at the location of the hole.

Abstract: A filter apparatus for thermoplastic synthetic plastics material includes a screen carrier member having at least one screen nest, the screen carrier member being shiftable in a longitudinal direction in a housing. For backwashing the screen nest, the screen nest is in connection with a washing channel in a washing position of the screen carrier member In order to make the washing process quickly, effectively and uniformly over the surface of the screen and in order to avoid an additional loss of the mass in the main flow at the backwashing process, a storage space is provided in the screen carrier member which is filled in normal operation with cleaned melt. A piston in the storage space is shifted for moving the material provided in the storage space in the backwashing direction through the screen nest and into the washing channel.

Abstract: A filter assembly used in combination with an extruder producing a stream of pressurized molten plastic has an inlet plate formed with a Y-shaped inlet passage having a substantially circular-section upstream end adapted to receive the stream of pressurized molten plastic from the extruder. The inlet passage branches downstream of its upstream end and has a pair of downstream ends opening at substantially circular downstream ports. An outlet plate fixed immediately downstream of the inlet plate is formed with a Y-shaped outlet passage having a substantially circular-section downstream end. The outlet passage is branched symmetrically to the inlet passage upstream of its downstream end and has a pair of upstream ends opening at substantially circular upstream ports aligned with the downstream ports. A rotatable filter disk engaged between the plates is formed with a circularly annular array of substantially circular-section throughgoing holes each defining a respective substantially circular seat.

Abstract: A fiber reinforced inorganic hardened body is manufactured from raw material consisting of a mixture of reinforcing fiber such as bamboo fiber, water-hardening inorganic binder and water by a manufacturing apparatus for stirring and mixing such raw material and forming it into a mat configuration laminated with the thin layers of fine fibers on both the front and rear sides of the thick layer of the normal raw material. The fine fiber material adhered with the water-hardening binder is partially separated from the main raw material at both the material supply side and material discharge side of a set of pin-type rolls. The portion of the fine fiber separated from the main raw material is first supplied to the upstream side of the forming conveyor to form a first layer of fine fiber.

Abstract: A filter assembly used in combination with an extruder producing a stream of pressurized molten plastic has an inlet plate formed with a Y-shaped inlet passage having a substantially circular-section upstream end adapted to receive the stream of pressurized molten plastic from the extruder, The inlet passage branches downstream of its upstream end and has a pair of downstream ends opening at substantially circular downstream ports. An outlet plate fixed immediately downstream of the inlet plate is formed with a Y-shaped outlet passage having a substantially circular-section downstream end, The outlet passage is branched symmetrically to the inlet passage upstream of its downstream end and has a pair of upstream ends opening at substantially circular upstream ports aligned with the downstream ports.

Abstract: An improved method of melt spinning linear polyethylene into fiber, especially fine denier fiber, with minimal fiber breakage is disclosed. The method includes imparting high shear into the polyethylene just prior to extrusion through the spinneret die and also results in lower die swell. The high shear can be imparted by use of sintered metal filter media, multiple stacks of fine mesh screens or similar shear inducing media. The method is especially effective when the linear polyethylene contains a relatively high molecular weight species, as determined using gel permeation chromatography with a low angle laser light scattering detector.

Abstract: In general, used thermoplastic liquid containers such as oil and solvent bottles are discarded. When recycling oil bottles, the usual practice is to wash the bottles with a solvent to remove oil therefrom. Washing of the bottles results in large quantities of used, oil-containing solvent, which present a disposal problem. A simple solution to the problem of recycling liquid containers with no preliminary washing or cleaning operation includes the steps of tumbling the bottles to promote liquid separation, shredding the bottles into small pieces and draining the liquid therefrom, grinding the pieces of plastic to yield a particulate thermoplastic, and mixing the particulate thermoplastic and any liquid remaining therein with an additive, e.g. an oil absorbent and a filler such as calcium carbonate, glass, mica or talc, and when the liquid is an oil, an absorbent to produce an extrudable mixture which can be used to form new containers.

Abstract: A sheet-like molding made of a liquid-crystalline polymer which can be processed in the liquid-crystalline melt is described. It contains less than 1 .times.10.sup.-1, preferably less than 2 .times.10.sup.-2, flow irregularities per cm.sup.3.

Abstract: A method for extruding a wide variety of plural-component fiber configurations in a spin pack utilizes one or more disposable distributor plates in which distributor flow paths are etched on one or both sides to distribute the polymer components to appropriate spinneret inlet hole locations. The etching process permits the distribution paths to be sufficiently small to facilitate issuing multiple discrete polymer component streams axially into each spinneret orifice inlet hole, whereby the resulting extruded fiber can be made up of at least one hundred side-by-side sub-fibers. If the adjacent sub-fibers are weakly bonded, they can be readily separated by agitation to significantly increase the effective yield from the spin pack and provide very fine and uniform fibers.

Abstract: A nozzle for injecting molten plastic includes a housing having an inlet and an outlet. Wires embedded in the housing serve to heat the housing. The housing defines a chamber, and a strainer is disposed in the chamber between first and second guides which are respectively located adjacent to the inlet and the outlet. The strainer and the guides divide the chamber into an outer compartment which surrounds the strainer and an inner compartment within the strainer. A rod extends through the inner compartment and carries first and second pistons which are slidably supported by the first and second guides, respectively, so that the rod can be moved between two terminal positions. Each of the pistons is provided with an axial blind bore and several radial bores which radiate from the associated blind bore.