A variable extrusion die apparatus includes a first die into which an extrusion material is injected. A second die is coupled to the first die and has an extrusion nozzle having a shape corresponding to a cross section of an extrusion product. A swivel core is rotatably installed in the extrusion nozzle, wherein a cross section of the extrusion nozzle is varied by rotation of the swivel core.

A ram extrusion apparatus including a die having several thermal zones, a hopper for introducing a granular polymer resin to the die, and a ram for moving the granular polymer resin through the thermal zones of the die and out from an outlet end thereof at a temperature above the crystalline melt temperature of the polymer resin. The hopper may be designed to deliver the polymer resin into a resin inlet of the die in a plurality of specifically metered amounts which may vary across a width of the resin inlet end of the die. The apparatus may further include one or more finishing tables positioned after the outlet end of the die for receiving and moving the extruded resin away from the outlet end of the die so that there is no backpressure on the extruded resin, and which provide compression force and even cooling to the extruded resin.

A ram extrusion apparatus including a die having several thermal zones, a hopper for introducing a granular polymer resin to the die, and a ram for moving the granular polymer resin through the thermal zones of the die and out from an outlet end thereof at a temperature above the crystalline melt temperature of the polymer resin. The hopper may be designed to deliver the polymer resin into a resin inlet of the die in a plurality of specifically metered amounts which may vary across a width of the resin inlet end of the die. The apparatus may further include one or more finishing tables positioned after the outlet end of the die for receiving and moving the extruded resin away from the outlet end of the die so that there is no backpressure on the extruded resin, and which provide compression force and even cooling to the extruded resin.

A web. The web includes an array of discrete polymeric tubes; a plurality of spacer segments between at least a plurality of adjacent polymeric tubes; wherein polymeric tubes are hollow polymeric tubes; wherein the web is a continuous web.

In the manufacture of double-walled corrugated extruded pipe it is desirable to form an integral connecting cuff that is of a single wall thickness and typically of a large diameter. The mold blocks and process parameters for forming of the cuff as part of an otherwise double-walled pipe requires a transition as the cuff moves past the die outlets. The present invention allows for accurate sensing and control of air pressure and temperature as the cuff moves past the die outlets. Improvements in both the die tooling and the method of manufacture are disclosed.

The invention provides devices that are attached to an extruder making the operation thereof more efficient and convenient and allowing for a quick change over of parts used to make various products prepared in the extrusion process. A high pressure relief assembly is attached to the extruder that allows for the rapid release of pressure from the extruder at the end of the process by venting product under pressure from the extruder and the extruder also has attached thereto a quick assembly locking device that allows for the exchange of assemblies, such as a density control assembly and other assembles, without the removal of nuts, bolts, and clamps by attaching the assembly to an arm that can be moved in and out of place in front of the extruder and wherein the device has a locking mechanism that seals and releases the assembly from the extruder.

An extrusion die with adjustable land channel can be formed of a die body that includes a first die body portion and a second die body portion, a first lip body, a second lip body, and a land channel body. The extrusion die can have a flow channel that includes a land channel terminating in an outlet orifice. The flow channel may be bound on one side by the first die body portion, the land channel body, and the first lip body. The flow channel may be bound on an opposite side by the second die body portion and the second lip body. In some examples, the length of the land channel is adjustable by configuring the land channel body and/or first lip body to move across the width of the flow channel.

Polyvinyl acetal films with less blocking tendency and which allow for escape of gas during laminating to form laminated composities are prepared by a process for embossing a film comprising plasticized polyvinyl acetal with a roughness Rz on at least one surfaces of 20 to 100 μm by the steps of a. extruding of plasticised polyvinyl acetal to a film with a stochastic roughness of the surfaces of Rz=1 to 70 μm, b. embossing at least one surface of the film obtained in step a) with channels having a depth of 5-50 μm, a width of 10-200 μm and a pitch of 50-2500 μm, wherein c. the surface roughness of the elevations between the channels is at most 20% lower as obtained in step a).

A coextrusion adapter, including a central conduit having an inlet end and an outlet end and having bottom and top walls that define the height of the central conduit and side walls that define the width of the central conduit, as well as at least one coextrusion conduit having an inlet end and an outlet end. The outlet end feeds into the central conduit near or in the vicinity of the bottom and/or top wall thereof, downstream of the inlet end of the central conduit, and adjusting devices are provided, which are allocated to each outlet end of the at least one coextrusion conduit and are composed of a plurality of adjusting elements, which collectively extend across the width of the outlet end and by actuating drives, are adjustable independently of one another so that it is possible to change the inner width of the respective width section of the outlet end. Adjacent to the outlet end at least one of the side walls has a receiving bore into which it is possible to insert a displacing element that protrudes beyond the side wall into the central conduit.

A rubber extrusion device includes a sensor which detects a deviation from a preset reference position of a rubber extrudate extruded from an extrusion port. Based on this detection data, a control unit provides control for correction of the deviation by adjusting a position of a die relative to a head along a leading end surface of the head or a rotational speed of a screw. A rubber material is mixed and kneaded while being extruded forward by a screw installed inside a cylinder. Resultant unvulcanized rubber is fed into an extrusion flow path and extruded from the extrusion port formed in the die.