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 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: 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: Natural fiber material and binding agent is fed to a materials treating apparatus, and a composite product is formed of these with the apparatus. Also material reacting with water is fed to the apparatus. The natural fiber material is fed in such a form that its moisture percentage is more than 1%, whereby the material reacting with water reacts with the water present in and/or released from the natural fiber material. Thus, the composite product comprises natural fiber material, binding agent and material having reacted with the water in the natural fiber material.