Abstract:
An extrusion apparatus is used for extruding material through a nozzle (10) for forming a product In the nozzle (10), the material is pressed around rods (9) so that tubular cavities (13) are formed in the wall of the product. The rods (9) are hollow and the apparatus comprises channels (14) connected to the hollow rods (9) to enable flow in the tubular cavities (13).
Abstract:
Material is extruded with a device comprising at least two stators (1,2) one within the other and, between them, a rotor (3) in the shape of a convergent cone, the material being extruded from the device by rotating the rotor (3). The rotor (3) comprises openings (9), through which the material is led. The stators (1,2) comprise continuous grooves (8) for conveying the material out of the device. The stator grooves (8) alternately become lower and deeper, said grooves (8) being arranged such that when the groove of the inner stator (1) is low, the point of the groove of the outer stator (2) on the other side of the rotor (3) at a corresponding point is deep and vice versa.
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:
An aircraft which includes elements providing air circulation and directing the circulation along a housing. Different operational stages of the aircraft such as take off and level flight are achieved by using the same functionally interconnected elements. The circulation is achieved by fan elements that allow adjusting the blow direction and the blowing force of the flow. A stagnation point (SP) associated with the circulation is also formed if necessary below the housing and the aircraft can be steered by controlling the circulation and the position of the stagnation point (SP).
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:
An electromechanic film intended for transforming electric energy into mechanical energy and transforming mechanical energy into electric energy. The film (1) is dielectric and formed of cells (3), the ratio of the height and width of which cells is between 3:1 and 1:3. By joining two such films together and controlling them in such a way that in the first film (1) the electric field strength decreases and in the second film (1) the electric field strength increases, a bending acoustic element is provided.
Abstract:
The present invention relates to an electroacoustic transducer where the voltage of a capacitive acoustic element is controlled by charging and discharging the charge of the element via an inductance (L) by fast switches (K1, K2). In the case energy unconverted into the acoustic energy of the transducer can be transferred to an energy storage of an electrical circuit formed by the inductance (L) and the capacitance (C1, C2, C0) during each control sequence and in this way the transducer can be made to operate with a good coefficient of efficiency.
Abstract:
An aircraft having a frame (1) and at least a rotor (2a, 2b) for providing lift for the aircraft. The aircraft comprises elements for accommodation purposes. Furthermore, solar cells (5) are arranged on the aircraft for exploiting solar energy, and the rotor (2a, 2b) comprises elements for adjusting the rotor (2a, 2b) to exploit wind energy when the aircraft is substantially stationary.
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:
A tubular product has a tubular base layer, a tubular innermost layer made of plastic by continuous extrusion, and a tubular tie layer of foamed plastic between and adhered to the base layer and the innermost layer. The tie layer is made of melt processable adhesion plastic, is extruded simultaneously with the innermost layer against the base layer, and has better adhesions to the base and innermost layers than the base and innermost layers have to each other.