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.

Methods for extrusion of polyolefins (112) that control specific energy input to the extruder (102) for gel reduction. Disclosed herein is an example method for forming plastic products (120, 208) with reduced gels, comprising: melting a polyolefin resin (112) in extruder (102) to form a melt; adjusting specific energy input in the extruder (102) to reduce gels in the melt; and forming the melt into a polyolefin product (120, 208). Disclosed herein is also an example method for forming plastic products (120, 20) with reduced gels, comprising: melting a polyolefin resin in extruder (102) to form a melt; selecting a throttle valve (104) position for gel reduction; setting the throttle valve (104) at the selected throttle valve (104) position to restrict flow of the melt out of the extruder (102); and forming the melt into a polyolefin product (120, 208).

The present invention relates to an overturning device (10) for overturning a molten material (200) in a melt channel (110) comprising a melt inlet (20) and a melt outlet (30), wherein between the melt inlet (20) and the melt outlet (30) at least a melt guidance means (40) is assembled for a rearrangement of molten material (200) from the centre (22) of the melt inlet (20) to the edge (34) of the melt outlet (30) and for a rearrangement of molten material (200) from the edge (24) of the melt inlet (20) into the centre (32) of the melt outlet (30).

The present invention relates to an overturning device (10) for overturning a molten material (200) in a melt channel (110) comprising a melt inlet (20) and a melt outlet (30) wherein between the melt inlet (20) and the melt outlet (30) at least one melt guidance means (40) is assembled for a rearrangement of the molten material (200) from the center (22) of the melt inlet (20) to the edge (34) of the melt outlet (30) and for rearrangement of the molten material (200) from the edge (24) of the melt inlet (20) into the center (32) of the melt outlet (30).

A wood-grained polymer substrate includes a plurality of layers of different colors. The substrate is formed into elongated boards and used in the production of various end products similar to natural wood. Methods for producing the wood-grained polymer substrate are also provided.

The present invention relates to an overturning device (10) for overturning a molten material (200) in a melt channel (110) comprising a melt inlet (20) and a melt outlet (30), wherein between the melt inlet (20) and the melt outlet (30) at least one melt guiding means (40) is assembled for a rearrangement of molten material (200) from the centre (22) of the melt inlet (20) to the edge (34) of the melt outlet (30) and for a rearrangement of molten material (200) from the edge (24) of the melt inlet (20) into the centre (32) of the melt outlet (30).

An apparatus and method for forming as extruded variegated plastic profile, including a multi-manifold slotted feed block assembly having a primary input manifold assembly, a secondary input manifold assembly, a flow distribution assembly in fluid communication with the primary input manifold assembly and the secondary input manifold assembly, a zone assembly having at least one restrictor and at least one mixer, and optionally, an extra line manifold assembly in communication with the flow distribution assembly.

In one embodiment, a method of forming an extruded board includes mixing a resin and a foaming agent, melting the mixed resin and foaming agent to form a uniformly colored extrudate, differentially expanding voids formed from the foaming agent within the uniformly colored extrudate by passing the uniformly colored extrudate through a breaker plate, forming a board with the differentially expanded voids and uniformly colored extrudate, and forming lightened portions on an outermost surface of the formed board.

Melt conductor (1), in particular melt distributor or melt mixer, for an extruding die (2) of an extrusion facility (3), having a melt conductor block (4) with a multi-channel system (5), the multi-channel system (5) being arranged so as to extend three-dimensionally inside the melt conductor block (4) and having at least one input (6) and at least one output (7) for polymer melt, between one input (6) and one output (7) fluidically connected to the input (6) several branchings (8) arranged in series and several levels (9a, 9b, 9c) of sub-branches (10) being formed over several levels (12a, 12b) of divided melt channels (11a, 11b), m melt channels (11a) of the a.sup.th level (12a) with x.sup.th local cross-sections and n melt channels (11b) of the b.sup.th level (12b) with y.sup.th local cross-sections being present, wherein n>m if b>a, the y.sup.th local cross-sections of the melt channels (11b) of the b.sup.th level (12b) being smaller than the x.sup.th local cross-sections of the melt channels (11a) of the a.sup.th level (12a),

and wherein in the area of the multi-channel system (5), means for at least indirectly influencing polymer melt are arranged.

The invention relates to a melt conductor (1), in particular a melt distributor or melt mixer, for an extruding die (2) of an extrusion facility (3), comprising two or more melt conductor blocks (4a, 4b) and a multi-channel system (5), the multi-channel system (5) being arranged inside at least one of the melt conductor blocks (4a, 4b) with three-dimensional extension and having at least one input (6) and at least one output (7) for polymer melt, between one input (6) and one output (7) fluidically connected to the input (6) several branchings (8) arranged in series and several levels (9a) of sub-branches (10) being formed over several levels (12a, 12b) of divided melt channels (11a, 11b); with m melt channels (11a) of the a.sup.th level (12a) with x.sup.th local cross-sections and n melt channels (11b) of the b.sup.th level (12b) with y.sup.th local cross-sections being present, wherein n>m if b>a, the y.sup.th local cross-sections of the melt channels (11b) of the b.sup.th level (12b) being smaller than the x.sup.th local cross-sections of the melt channels (11a) of the a.sup.th level (12a). The invention further relates to an extruding die, an extrusion facility and to a method of operating the extrusion facility.