Apparatus and methods for manufacturing compostable, biodegradable drink straws from polyhydroxyalkanoate (PHA) material are disclosed herein. Such apparatus may include a hopper that contains raw PHA material, an extruder that receives the raw PHA material from the hopper and produces extruded PHA material, one or more waters baths that cool the extruded PHA material, a puller that pulls a tubular stream of PHA material through the system, and a cutter that is configured to cut the stream of PHA material into finished straws. The finished straws may be soil- and marine-biodegradable, as well as home- and industrial-compostable.

An extruder or other similar tool head of a three-dimensional printer is slidably mounted along a feedpath of build material so that the extruder can move into and out of contact with a build surface according to whether build material is being extruded. The extruder may be spring-biased against the forward feedpath so that the extruder remains above the build surface in the absence of applied forces, and then moves downward into a position for extrusion when build material is fed into the extruder. In another aspect, modular tool heads are disclosed that can be automatically coupled to and removed from the three-dimensional printer by a suitable robotics system. A tool crib may be provided to store multiple tool heads while not in use.

Improvements in the extrusion of thermohardenable materials are achieved by cooling the material in the initial zone of the extruder and reducing residence time by use of a prescribed length to diameter ratio and screw speed, particularly useful for intermittent application during robotically controlled mass production.

A heat-insulating shroud for facilitating temperature control of a heated article includes a flexible cover, made from a heat-insulating material, for covering a surface of the heated article, at least one air inlet defined in a first section of the flexible cover, and at least one air outlet defined in a second section of the flexible cover. In a cooling mode of operation, the flexible cover defines an air channel over the surface of the heated article for channeling an air stream from the air inlet(s) over the surface of the heated article towards the air outlet(s). The channeling of the air stream facilitates cooling the heated article. In a heat-conservation mode of operation, the flexible cover of heat-insulating material insulates the heated article from heat loss. Each air outlet may have a closure that opens during the cooling mode of operation and closes during the heat-conservation mode of operation.

In order to be capable of reliably supplying a prescribed amount of fiber materials into a heating cylinder for each cycle and continuously manufacturing a homogeneous composite material, a plasticizing unit is provided with a fiber supply device 3 that supplies prescribed amount of fiber materials A2 having a prescribed length into the heating cylinder 1. The fiber supply device 3 is provided with: a cutting section 12 that cuts off a long fiber material A1 pulled out from a reel 11 into a prescribed length; a pressure-feeding section 13 that presses the fiber materials A2 having the prescribed length cut off by the cutting section 12 into the heating cylinder 1; and a fiber transfer device 45 that forcibly transfers the fiber materials A2 accumulated in the cutting section 12 to the pressure-feeding section 13. The pressure-feeding section 13 is constituted by a press cylinder 41 and a press piston 42, and the fiber transfer device 45 is constituted by a vacuum device.

A method of manufacturing a flow field plate includes mixing graphite and resin materials to provide a mixture. The mixture is formed into a continuous flow field plate, for example, by ram extrusion or one or more press belts. The continuous flow field plate is separated into discrete flow field plates. Flow field channels are provided in one of the continuous flow field plate and the discrete flow field plates.

Systems for producing superabsorbent polymer particles for use in agricultural applications are disclosed. A monomer is graft polymerized onto a starch to form a starch graft copolymer. The moisture content of the starch graft copolymer is reduced through use of an extruder.

A consumable material for use in an extrusion-based digital manufacturing system, the consumable material comprising a length and a cross-sectional profile of at least a portion of the length that is axially asymmetric. The cross-sectional profile is configured to provide a response time with a non-cylindrical liquefier of the extrusion-based digital manufacturing system that is faster than a response time achievable with a cylindrical filament in a cylindrical liquefier for a same thermally limited, maximum volumetric flow rate.

A device for reducing the microbiological contaminants of container products made predominantly of plastics materials feeds a plastics granulate to an extruder assembly (19) that melts the granulate. The granulate is subsequently supplied to a form-fill-seal machine for producing a container product. A guide assembly (35) guides the plasticated plastic material from the extruder assembly (19) to the machine. At least one guide assembly (35) has at least one flow or channel guide (41) for the melted plastics material, so that microbiological contaminants are guided predominantly into the interior of the wall of the polymeric tube that interior is enclosed by regions of the plastic material that are less contaminated.

Apparatus and methods for extruding plastic materials are disclosed. An exemplary apparatus comprises: a feeding portion; a melting portion in communication with the feeding portion and configured to transmit heat into material received from the feeding portion; and an output die in communication with the melting portion to permit extrusion of the material. The melting portion comprises: a melting barrel having an inner surface defining a melting chamber in communication with the feeding portion; and a melting insert inside the melting chamber. The melting insert comprises an outer surface in contact with the inner surface of the melting barrel where the outer surface comprises one or more open-ended channels formed therein. In some embodiments, the feeding portion and the melting portion may be thermally insulated from each other and a propeller of the feeding portion may be disposed entirely outside of the melting portion.