A controlled, variable speed vacuum pump with a flow limiter connected to the suction head of the vacuum pump conveys granular plastic resin material from a supply to receivers retaining and dispensing resin when needed by a process machine.

Methods of coating a base tube are disclosed. Various methods include passing a hollow base tube into a coating die while maintaining a chamber pressure outside the hollow base tube that is lower than a pressure within an inner lumen of the hollow base tube. Such methods can include extruding coating material onto the hollow base tube to form a coated hollow tube by delivering coating material into the coating die. Vacuum may be formed within the coating die proximate a point of impingement where the coating material is applied to the hollow base tube.

A method for producing filaments of polyacrylonitrile and an extrusion head for carrying out said method are provided, wherein the method comprises preparing a polyacrylonitrile polymer solution and passing said solution through an extruder plate that determines the formation of filaments, a central chamber being defined between the extruder plate and a floating plate connected to a vibrating system, said chamber being surrounded by a peripheral chamber into which the polymer solution is introduced under pressure. The polymer solution then passes through to the central chamber via small radial conduits that accelerate the material, and is subjected to vibration in the central chamber before passing through the extruder plate.

The invention relates to the production of PSA in a planetary gear extruder. During filling and after passing a passage on a dispersing ring using a lateral arm extruder, the products are degassed.

A method and a device for producing fibre-reinforced plastic mouldings, using coated fibre strands. For the coating of the fibre strands, an air flow of ionised air is produced and guided through a Venturi nozzle. Powder from a storage container is taken by means of a screw conveyor and supplied to the Venturi nozzle, a flow of a powder-air mixture being present or forming behind the Venturi nozzle in the direction of flow. This stream is introduced into a chamber and fibre strands that are earthed or ionised unlike the powder are passed through the chamber and through the powder-air mixture flowing through the chamber, powder particles being deposited on the fibre strands. The fibre strands guided out of the chamber therefore have a coating, and the fibre strands coated in this way are supplied to a plasticising device of an injection moulding machine or an extrusion machine.

Methods and systems for controlling the moisture content of biodegradable and bioresorbable polymer resin during extrusion above a lower limit that allows for plasticization of the polymer resin melt and below an upper limit to reduce or prevent molecular weight loss are disclosed. Methods are further disclosed involving plasticization of a polymer resin for feeding into an extruder with carbon dioxide and freon.

The present invention is directed to polymers and copolymers, and systems and methods for processing the same. Advantageously, the polymers and copolymers of the present invention have undergone processing in a falling strand devolatilizer and rotary disk finisher such that a low-cost, low-energy, and high-production-rate product is produced.

Apparatus has a vacuum pump for conveying granular plastic resin material from a supply to receivers retaining and dispensing resin when needed by a process machine with a flow limiter connected to the suction head of the vacuum pump, with the vacuum pump being a controlled, variable speed device.

A device (1a . . . 1i) for processing thermoplastic plastic is described, comprising a storage container (2) for receiving pieces of plastic particles or a conveying line (14) for conveying the pieces of plastic particles, and a conveying screw (3) following the storage container (2)/the conveying line (14) at a transfer opening (A). The device (1a . . . 1i) also comprises an extruder (4) following the conveying screw (3) and an air outlet (7) arranged opposite the transfer opening (A) and directed at this opening. A method for operating the device (1a . . . 1i) is also described, in which an air stream is aligned with the transfer opening (A). The strength and/or the direction of the air stream is adjusted or controlled as a function of a load on the extruder (4).

Methods of coating a base tube are disclosed. Various methods include passing a hollow base tube into a coating die while maintaining a chamber pressure outside the hollow base tube that is lower than a pressure within an inner lumen of the hollow base tube. Such methods can include extruding coating material onto the hollow base tube to form a coated hollow tube by delivering coating material into the coating die. Vacuum may be formed within the coating die proximate a point of impingement where the coating material is applied to the hollow base tube.