摘要:
When amorphous thermoplastic resin is supplied from a hopper, the resin is rotated by a screw in a barrel and generates frictional heat. In this point of view, in a melt extruder according to an aspect of the present invention, a temperature control zone that generates particularly high frictional heat is constantly cooled by a cooling device, and heated by a heating device to obtain a target temperature, thereby significantly reducing variations in barrel temperature. This can stabilize screw tip pressure, and reduce variations in thickness of a resin film discharged from the barrel.
摘要:
The apparatus and method that best results in low shear to melt shear-sensitive materials, such as polyethylene terephthalate, polyvinylchloride, acrylonitrile butadiene styrene, acrylics and/or resins with fiber fillers, without sacrificing process speed and/or cycle time, comprises the use of a barrel, screw and induction heating coil. The screw, in this case, preferably includes a low volumetric compression ratio, a relatively short feed section, an extended transition section, and a typical metering section.
摘要:
An expanded polystyrene (EPS) recycling and extruding machine is shown and described. The machine comprises a conveyor for transporting waste pieces of EPS of various sizes into the device. A housing surrounds upper and lower crushers that break down the EPS pieces in to progressively smaller pieces before depositing them through a screen that selectively prevents pieces above a predetermined size from passing. Below the screen, the small EPS pieces fall into a heated extruding mechanism that melts the pieces into a liquid and urges the liquid forward by means of an Archimedian screw to a nozzle, through which the reconstituted EPS is extruded for collection and reuse.
摘要:
A twin-screw extruder includes a barrel including a pair of chambers in communication with each other and a discharge port, and an extrusion molding die coupled with respect to the discharge port of the barrel. First and second screw sets are rotatably mounted at least partially within respective ones of the pair of chambers. The first and second screw sets each include a raker blade segment at the discharge port of the barrel that includes at least one flight element with a plurality of serrations extending therethrough. Each of the first and second screw sets also include a lobed kneading segment at the discharge port of the barrel that includes at least one flight element. One of the raker blade segment and the lobed kneading segment is located downstream from another of the raker blade segment and lobed kneading segment. A method of using the twin-screw extruder is also provided.
摘要:
An extrusion conveying apparatus, including an extruder that operates as a mixing device and is laterally supplied with components that are to be mixed, in particular components of a rubber mixture or thermoplastic elastomer. A volumetrically operating conveyor, in particular a gear pump, is connected to the output side of the extruder. A rotational speed or feed rate of the extruder is adjustable independently of the feed rate and volume flow of the conveyor. n−1 volumetric subsidiary conveyors are provided for passage of components therethrough where there are n components of a mixture. In particular component n is supplied in an undosed manner. A rotational speed or feed rate of the subsidiary conveyors is adjustable independently of the feed rate of the volumetrically operating conveyor.
摘要:
A system for processing plastic feed material includes a barrel having an upstream feed section and a downstream output section. A screw, supported for rotation in the barrel, cooperates with an inner surface of the barrel to form a path in which the feed material moves toward the output section. A heating system includes an induction winding encircling and extending along a portion of an outer surface of the barrel, and a gap interposed between the induction winding and the barrel and having a nonuniform thickness that varies around the periphery and corresponds to a varying wall thickness of the barrel.
摘要:
A polymeric composite useful for producing large shaped articles such as railroad crossties comprises a filler component having minimal reinforcing/structural characteristics; and a polymer blend including at least one polymeric stiffening component, at least one polymeric density component, and at least one polymeric flexibility component. The polymer blend can include post-consumer recycled thermoplastic polymers. To produce the composite, a multistage extruder brings a blend of polymer and filler materials to an extrudable threshold without completely liquefying the polymer blend. The extruded blend is cooled within a mold to form a shaped article such as a recycled composite crosstie. Exemplary recycled composite mixtures may include composite polymer materials, such as, polypropylene, High Density Polyethylene (HDPE), High Molecular Weight Polyethylene (HMW), Low Density Polyethylene (LDPE), ABS, Ethylene Vinyl Acetate (EVA), Linear Low Density Polyethylene (LLDPE), and combinations of these polymers. The filler may include talc, fly ash, potash, and combinations of these or other mineral powder products.
摘要:
A mixing apparatus for the treatment of a plurality of flowable components. The apparatus comprises an elongated housing having an upper component-introduction end and a downstream compound-discharge end. An elongated shaft is rotatably disposed within an elongated bore disposed within the housing. The shaft has a stator and rotor arrangement spaced longitudinally therearound. At least one rotor has an arrangement of fluid channeling conduits spaced apart on an annular surface thereof, wherein the conduit is of tapering narrowing dimension from a first longitudinal side of the rotor to a second longitudinal side of the rotor.
摘要:
A multi-shaft extruder is disclosed with at least two shafts for compounding and/or molding an elastomer staggered with filler, in particular rubber, with at least one softener and/or additives. The extruder comprises the following in succession in the direction of product transport: a feed zone, into which the elastomer and softener and/or additives are metered; a mastication/plasticization zone with at least one kneading element, into which the elastomer with the softener and/or additives is transferred to a flowable, cohesive mixture; a dispersing zone with at least one additional kneading element, in which the filler in the elastomer is comminuted and distributed; and the kneading elements having a comb and the extruder having a casing inner wall and wherein a gap with a gap width Z of about {fraction (1/100)} to about {fraction (1/10)} of the kneading element diameter D is present between the comb of the kneading elements and the casing inner wall of the extruder, wherein the diameter is defined as the maximal diameter of a kneading element from comb to comb.
摘要:
A method of manufacturing a mixture PTFE thread using a mixture PTFE powder consisting of PTFE: 73-95 wt %, MoS2: 3-25 wt %, Al2O3: 1-5 wt %, and Al(OH)3: 1-5 wt % comprises heat-retaining step for adding 18-25 wt % kerosene of a solvent to the mixture PTFE powder and keeping it warm at 30-50° C. for 40 to 50 hours, extruding the heat-retained mixture PTFE powder into a rod shape with a circular or elliptical cross section at the cylinder temperature of 70-90° C., rolling the extrusion at 100-150° C. into a 0.3-0.7 mm thick sheet shape, multiple-folding the sheet and passing the sheet through an oven at 250-270° C. at the rate of 10-40 cm/s, and stretching the folded sheet with a stretch ratio of 200-600% in multiple stages after heating the sheet at 450-500° C.