Abstract: A method for manufacturing a plastic composition, comprising: mixing thermoplastic polymer material particles and thermoset composition particles comprising cured thermoset polymer, the mixing comprising rising the temperature of the composition and at least partly melting the surface of thermoplastic polymer material particles, and simultaneously mixing the particles allowing thermoset composition particles adhere to the thermoplastic polymer material particles, and cooling the composition.

Abstract: A transverse stretching device comprises two stretching wheels and endless bands arranged against them and revolving around band guide rolls so that a plastic film to be stretched is arranged at its both edges between a stretching wheel and a band. The stretching wheels and the bands are arranged in such a way that in the direction of travel of the plastic film they are further apart from each other at the end than in the beginning, whereby the transverse stretching device stretches the plastic film in the transverse direction. The stretching wheels are rims open in the center and the device includes heating means arranged through the rims at least at some angle between the stretching wheels.

Abstract: Plastic material and nucleating agent are fed into an extruder, and the plastic material is subjected to cell forming. The substances in question are extruded into a plastic film preform, simultaneously cooling the material to prevent foaming. The film preform is stretched in such a way that cavitation bubbles are generated in the film. The cell forming takes place in connection with stretching and relaxation. In other words, in the solution the cell forming is caused to take place when the plastic is not in a molten state.

Abstract: Fibre material and at least one plastic material is extruded in such a way that a composite product (11) is produced. To increase the strength of the product (11) and to improve its heat resistance, the at least one plastic material of the product (11) is cross-linked in such a way that at least a surface of the wall of the product (11) is provided with a cross-linking degree higher than the cross-linking degree of an inner part of the wall of the product (11).

Abstract: A film (5) is extruded from plastic material by means of an extruder. Material is mixed into the plastic (5a) of the plastic film (5) before the extrusion so that cavitation bubbles are formed in the material particles mixed into the plastic (5a) when the plastic film is stretched. The film (5) is orientated by stretching. After the extrusion the plastic film (5) is cooled slowly below the crystallization point of the plastic material before the orientation.

Abstract: The invention relates to a method and a an apparatus for processing various materials, the apparatus including at least two annular feed gaps placed one within the other. The beginning of each feed gap is provided with a grinding section (5), which is followed in the apparatus by a mixing section (10). The materials are processed in the grinding section (5), whereafter they are mixed in the mixing section (10), and the mixture is extruded into a product.

Abstract: An extrusion method and an extrusion device, whereby at least two different flows of material are supplied from the extrusion device to a nozzle. The nozzle comprises at least two nozzle chambers such that the material flowing through the first nozzle chamber forms an outer part of a product, and the material flowing through the second nozzle part forms an inner part of the product. The capacity of the nozzle chambers is changed, whereby the relative proportion of the different parts of the product can be varied. When the capacity of the nozzle chamber is decreased, the amount of material flowing therethrough increases at the outlet of the nozzle, and when the capacity of the nozzle chamber is increased, the amount of material flowing out there-through decreases at the outlet of the nozzle.

Abstract: In an extrusion method and an extruder, an annular material flow is created by extruding material into an annular extrusion channel (6). The extruder has a tubular filtering unit (7) arranged to the annular extrusion channel (6), whereby the annular material flow flows through the tubular surface of the filtering unit (7).

Abstract: A method and an apparatus for making a plastic film, and to a plastic film wherein the method includes extruding a film from plastic material by an extruder and orientating the film after extrusion. Material is mixed into the plastic so that when the plastic film is stretched, cavitation bubbles are formed in the material particles mixed into the plastic. After orientation, gas is arranged to act on the plastic film under high pressure so that the gas diffuses in the cavitation bubbles and causes overpressure in them. Thus it is possible to make a thin foamed film with a foaming degree of over 70%.

Abstract: A film is extruded from plastic material by an extruder. The film is orientated after extrusion. Material is mixed into the plastic so that when the plastic film is stretched, cavitation bubbles are formed in the material particles mixed into the plastic. During the orientation, gas is arranged to the plastic film under high pressure so that the gas diffuses in the cavitation bubbles and causes overpressure in them. Thus, it is possible to make a thin foamed film with a foaming degree over 70%.

Abstract: A method and an apparatus for extruding material, the material being extruded with an apparatus comprising at least one rotatable rotor and at least one stator, the rotor and the stator comprising grooves, whereby the grooves make the material move through the apparatus when the rotor is rotated. The rotor and stator surfaces facing each other have a wavelike cross-section, and the grooves are so arranged that at the ridge of a wave the depth of a groove reaches its maximum, and at the bottom of a wave the depth reaches its minimum. The bottom of the wave in the rotor is at the ridge of the wave in the stator and vice versa. This makes the material move alternately from a rotor groove to a stator groove, and back.

Abstract: A method and an apparatus for treating waste material. The apparatus has a conical rotatable rotor (3) placed between stators (1, 2). At least the stators (1, 2) have recesses (9) from which the material in the apparatus can be discharged when the rotor (3) is rotating. The rotor (3) has several openings (8a, 8b) in the axial direction of the apparatus through which openings at least some of the waste material passes. The edges of the recesses (9) and the openings (8a, 8b) of the rotor (3) are sharp so that the waste material supplied to the apparatus is ground by means of the sharp edges when it passes through the openings (8a, 8b).

Abstract: An apparatus for molding plastic including: (a) an injection space; (b) forming apparatus for supplying plastic material to the injection space, the forming apparatus having at least an inner conical stator and an outer conical stator and at least one rotatable rotor disposed outside of the inner conical stator; and (c) a piston for compressing the plastic material supplied to the injection space into a mold to form the plastic material into a shape determined by the mold.

Abstract: An extruder including: (a) at least two concentric stators including (i) an inner stator having at least an outer surface that is at least mostly conical and (ii) an outer stator having at least an inner surface that is at least mostly conical; (b) at least one rotatable rotor that is at least mostly conical; and (c) a supply conduit for supplying material into a space between the stators. The at least one rotatable rotor being disposed in the space between the inner stator and the outer stator. The at least one rotor includes a plurality of ducts that define passages through which material can flow from the space to an interior of the rotor. Each of the plurality of ducts defines an opening or groove that opens into the space. The supply conduit has a conduit end defining an orifice.