摘要:
An extrusion die for foam sheet including a die body defining a manifold for conducting a split stream of heated and pressurized foamable thermoplastic melt through separate distribution channels to a die terminus. A pair of mating die lips are arranged on opposed sides of the melt and are constructed to adjustably slide toward and away from each other to vary the flow of a melt. The lips are each mounted to slide along an axis which is tilted rearwardly at an acute angle relative to an orthogonal to the sheet being formed. The mandrel is configured and adapted for quick withdrawal and replacement from an end of the die through a passageway extending through the die transverse to the direction of extrusion of a sheet.
摘要:
A method for the control of wall thickness of an extruded thermoplastic material. The method includes extruding a thermoplastic material from an extruder through a die gap formed between first and second die lips. One of the die lips has a plurality of separate sectors adjacent the die gap, with each sector having a circulating oil passageway therein. The circulating oil passageways are connected in a series along the die gap. The method includes circulating through each circulating oil passage, within each sector adjacent the die lip, a heat transfer oil from a common source at a selected heating or cooling temperature. The method includes controlling the rate of flow of said heat transfer oil in each sector by an adjustable flow control valve, in order to control the temperature of each sector, and thereby to adjust the viscosity of the thermoplastic material being extruded, and controlling the wall thickness of the extruded thermoplastic material.
摘要:
An extruder die apparatus, for the extrusion of a thermoplastic material, which die apparatus has an adjustable choke ring. The apparatus comprises an extruder housing having an axial bore for the extrusion of thermoplastic material therethrough from the inlet to the outlet of the bore, an inner die lip and an outer die lip about the bore and within the housing, the lips forming a concentric die gap passageway for the extrusion of a thermoplastic material from the one to the other end of the die, and a choke gap within said thermoplastic material flow passageway having a movably positioned choke ring. The choke ring has a plurality of individual, axially extending castellations thereon, some having oval receiving holes therein. These separate, castellated sections may be adjusted incrementally and independently by a plurality of eccentric bolts extending through the housing and the oval receiving holes, to provide selected areas within the choke gap having a restricted cross section thermoplastic material flow area. The restricted choke gap provides for an improved distribution of the thermoplastic material being extruded through the choke gap prior to being extruded through the die gap.
摘要:
The extrusion press comprises a block and a displacing body mounted in the block. The block includes an inlet duct, two feed ducts connected to it, transversely widened spaces connected to them and an outlet duct. The displacing body comprises a mounting portion and a guide portion and is located downstream of the inlet duct. It separates both feed ducts and both transversely widened spaces and projects with a sword-like piece of the guide portion into the outlet duct to form outlet gaps. It ends upstream of a mouth of the outlet duct providing an inner expansion chamber. The displacing body is free of a supporting member and held fixed from above and below by its mounting portion so that the thermoplastic material flow surrounds the sides of the sword-like piece running in the flow direction and surrounds the sword-like piece. At least the sword-like piece has a tempering passage system distributed over its length and breadth which is connected with a plurality of lateral connecting tubes for feeding and removing a tempering medium upstream of the sword-like piece.
摘要:
A thermoplastic foamed resin extruding operation is described which uses an inner die lip machined to vary the width of the die annulus or opening so that varying thicknesses or mass concentrations or densities of preselected desired width will be formed in the extruded resin sheet obtained therefrom. The mass concentration variations in the extruded sheet are coordinated with a downstream thermoforming operation involving deep and shallow draw forming or different sheet fabrications such as folding, scoring, cutting, etc.
摘要:
An extruder die assembly is provided having a die support body, an outer die member, an inner die member, and an actuator. The outer die member has an outer die lip. The outer die member is supported by the die support body. The inner die member has an inner die lip spaced from the outer die lip in order to provide an annular die gap therebetween. The inner die member is supported for movement by the die support body. The actuator is coupled with the inner die member to move the inner die member relative to the outer die member. A method is also provided.
摘要:
An extruder die apparatus, system and method for the extrusion of a thermoplastic material, which die apparatus has an adjustable choke ring. The apparatus comprises an extruder housing having an axial bore for the extrusion of thermoplastic material therethrough from the inlet to the outlet of the bore, an inner die lip and an outer die lip about the bore and within the housing, the lips forming a concentric die gap passageway for the extrusion of a thermoplastic material from the one to the other end of the die, and a choke gap within said thermoplastic material flow passageway having a movably positioned choke ring. The choke ring has a plurality of individual, axially extending castellations thereon, some having oval receiving holes therein. These separate, castellated sections may be adjusted incrementally and independently by a plurality of eccentric bolts extending through the housing and the oval receiving holes, to provide selected areas within the choke gap having a restricted cross section thermoplastic material flow area. The restricted choke gap provides for an improved distribution of the thermoplastic material being extruded through the choke gap prior to being extruded through the die gap.
摘要:
Apparatus for extruding thermoplastic material includes an extruder having inner and outer die lips adjacent an outlet end of the extruder for transporting an annular stream of thermoplastic material therethrough. The outer die lips are divided into a plurality of circumferential sectors. Each sector includes a passage for circulating heated oil for controlling the viscosity of the thermoplastic material being extruded. The temperature and flow of the heated oil flowing through each sector may be varied according to the required thickness of the product being extruded adjacent that sector. A ring-shaped channel carries the heated oil around the die lips for circulation into the individual sectors.