摘要:
The invention relates to an extrusion system for producing cylindrical semi-finished plastic products. The extrusion system comprises an extruder (1) for making available a pressurized plastic melt, at least one extrusion die (7) arranged on the extruder (1) and allowing the melt to leave the extruder (1) as a substantially cylindrical plastic strand (8), a calibration unit (2) which is mounted downstream of the extrusion die (7) and through which the freshly extruded plastic strand (8) passes, said calibration unit cooling the plastic strand (8) and giving it an outer diameter (d), a brake device (3) mounted downstream of the calibration unit (2) and adapted to introduce a variable axial force (A) into the plastic strand (8), said axial force being opposite to the advance of the plastic strand, and a force transducer (9) measuring the axial force (A) introduced into the plastic strand (8) by the brake device (3). The aim of the invention is to improve said extrusion system in such a manner that a better standard quality can be obtained and that it is suitable for the processing of high-temperature resisting plastics. For this purpose, the brake device (3) comprises at least one brake block (16) having a friction surface (19) which brake block is guided so as to be radially movable relative to the plastic strand (8). A radial force (R) is applied to the radially movably guided brake block (16) with its friction surface (19) resting on the periphery of the plastic strand (8) to introduce the axial force (A) into the plastic strand (8). The friction surface (19) has the shape of a grooved section of the surface area of a cylinder.
摘要:
A pump system (10) comprising a delivery assembly (22) configured to feed a solid material under operational power of a first drive motor (16), and a screw pump (24) comprising a housing (84) that at least partially defines a barrel (106) of the screw pump (10), an extrusion tip (82) secured to the housing (84) at a first end of the barrel (106), a liquefier (85, 342) secured to the housing (84) and intersecting with the barrel (106), and an impeller (94) extending at least partially through the barrel (106). The liquefier (85, 342) is configured to receive the solid material fed from the delivery assembly (22), to at least partially melt the received solid material, and to direct the at least partially melted material to the barrel (106), and the impeller (94) is configured to drive the at least partially melted material that is directed to the barrel (106) toward the extrusion tip (82) under operational power of a second drive motor (18).
摘要:
UHMWPE panels of large width may be ram extruded from a slit die in a stable process, by restraining a panel which exits the die below the crystalline melt temperature against movement away from the die by a back pressure device, so as to exert a back pressure between the back pressure device and the die, the back pressure device preferably constructed of a plurality of differentially adjustable elements so as to be able to compensate for changes in processing characteristics over time. Vertically restraining UHMWPE panels as they further cool also greatly improves product characteristics.
摘要:
Die Erfindung betrifft ein Verfahren zum Zuführen von Kunststoffgranulat in die Einlauföffnung (2) eines Kunststoffextruders (1), mit einem Speicherbehälter (9) und mit einem auf eine Wiegeeinrichtung (5) abgestützten Zwischenbehälter (3), wobei bei dem Verfahren die für den jeweiligen Auftrag verarbeitete, nach Gewicht bestimmte Menge an Material durch die Umdrehungen der Extruderschnecke bestimmt wird. Um ein Verfahren anzugeben, bei dem sich die Rezept- bzw. Auftragswechselzeiten erheblich verkürzen und Kunststoffgranulat eingespart wird, ist vorgesehen, daß der Zwischenspeicherbehälter (3) durch Öffnen des Auslaufs (7) des Speicherbehälters mit einer bestimmten, nach Gewicht bestimmten Menge von Kunststoffgranulat gefüllt und der Speicherbehälter (9) nach erneutem Schließen seines Auslaufs mit seiner konstanten Füllmenge gefüllt wird, wenn die Summe des Gewichts der Füllungen beider Behälter der verbleibenden, von dem Extruder zu verarbeitenden, nach Gewicht bestimmten Restmenge entspricht, daß die Förderung von Kunststoffmaterial in den Speicherbehälter unterbrochen und dieser einmal oder mehrmals geöffnet wird, bis die von diesem gespeicherte Menge in den Zwischenspeicherbehälter eingetreten ist.
摘要:
The present invention includes processes for making fibers, which processes include an extrusion step wherein molten polymers are extruded through an extrusion die (12), thereby forming at least one extruded filament (31); and an orientation step, wherein the filament (31) is drawn to align the molecules of the filament (31), and wherein multivariate data analysis techniques are used to analyze data regarding various process variables and, optionally, process variables are adjusted in response to the multivariate data analysis.
摘要:
An extrusion system utilizes single (30) or tandem extruders (102 and 103) and a mixer-cooler (104) to extrude a foamable extrudate through a die (37) in a sealable chamber. The foamable extrudate is shaped and calibrated within the chamber (40). The product exits the chamber to atmosphere on a continuous basis through a submerged orifice in a water baffle immersion seal. The seal includes the submerged orifice with a free wheeling guiding system upstream of the orifice. Immediately ahead of the guiding system, the parameters of the foam extrudate are sensed to control the configuration of the orifice on a continuous basis. Before the extrudate passes into the water baffle seal it moves over a floating dancer roll (65), the position of which controls a haul-off, such as a vacuum belt, at the tail end of the system. This avoids pushing on the extrudate.
摘要:
L'invention a pour objet un perfectionnement à un appareil de mesure de la contrainte de cisaillement d'une matière traitée dans une extrudeuse comprenant au moins une vis (1) entrainée en rotation à l'intérieur d'un fourreau allongé (2), ledit appareil de mesure comprenant d'une part une enclume mobile (12, 12a) disposée dans une chambre de mesure (11) ménagée dans le fourreau (2) et d'autre part un capteur de mesure (13) du déplacement de ladite enclume (12, 12a). La chambre (11) est rendue étanche par rapport à l'espace formé à l'intérieur du fourreau (2) par un organe d étanchéité (20) dont au moins une zone (20b) est solidaire de l'enclume (12, 12a) et possédant un faible module d'élasticité dans le sens de rotation de la vis (1) et un grand module d'élasticité dans l'axe de ladite vis.