Abstract: A multilayer plastic film having a heat-sealable surface layer is initially provided at a process temperature above a heat-sealing temperature of the surface layer. To prevent the surface layer from adhering onto a deflection roller, this layer must be cooled below the heat-sealing temperature. A cooling arrangement is positioned directly upstream from the deflection roller and blows cold air onto the heat-sealable surface layer. Thereby, the surface layer is rapidly cooled below the heat-sealing temperature, while most of the multilayer film is not substantially cooled and remains close to the process temperature. A counter-heater may heat the opposite surface of the plastic film as the cooling arrangement cools the heat-sealable surface layer.

Abstract: In the production of thin film that is extruded onto a cooling roller and then fed through a further treatment station such as stretching roller station, it may become necessary to stop the extrusion if a fault is present in the further treatment station. In order to avoid stopping the extrusion, a detour station with a roller set is positioned between the extrusion station and the further treatment station for detouring extruded film in response to a detected fault in any system component, except the extruder, whereby the extrusion can continue while the film is supplied to some other use while its supply to the further treatment station is interrupted. The detouring roller set includes at least one guide roller and a press-on roller that is automatically movable, for example by a piston cylinder device into a working position in response to a fault signal.

Abstract: A film or web stretcher particularly for thermoplastic film has a plurality of stretching cylinders, at least one or more of which cooperate with a press-on roller particularly at the inlet and/or outlet of the stretcher. A mounting arm (6) at each end of the stretcher cylinder permits the mounting of the press-on roller in such a way that the latter can be tilted through a limited angular range about the rotational axis of the stretching cylinder by a first drive. A second drive, such as a piston cylinder device adjusts the press-on roller relative to the stretching cylinder to thereby apply a press-on force. The first drive may, for example, be accomplished by a manually driven device for positioning the press-on roller and its cooperating components in any one of two end positions and in any position between the two end positions. The press-on roller may be directly mounted to the mounting arms (6) or through support brackets (9) to the arms (6).

Abstract: Tentering clamps for an endless tentering chain are formed so that two clamp bodies slideably mounted on at least one common guide bar can move toward each other and away from each other for adjusting the pitch. The guide bar or bars have entraining stop elements so positioned that an axial pulling force that moves the tentering chain, is transmitted through the guide bar or bars. The pitch is adjusted with the help of at least one, preferably two, toggle link mechanisms carrying a control roller engaging a guide rail. When the toggle links of the toggle link mechanism are straightened out in the travel direction of the tentering chain, the toggle link mechanism is substantially relieved of the axial tension force or load because the load passes through the guide bars (10) and the clamp bodies forming a pair. A plurality of such compound tentering clamp body pairs are linked by chain link plates and respective linking chain journal pins (23).

Abstract: Lengthwise stretching machines for thermoplastic synthetic films are equipped with mechanical or opto-electrical devices for detecting a tearing of the film or an accumulation of film on the stretching rollers and for stopping the machine when tearing or accumulation occurs, to protect the stretching rollers. Unallowable loads and possible damage to the roller bearings are avoided by mounting the bearing housings (1, 2) of each roller (3, 4, 5) of a lower roller (7) in the machine frame for cooperation with a force generating device (8) which presses the respective bearing housing (1, 2) toward oppositely located rollers (9, 10, 11) of an upper roller group (12) to an extent permitted by stops (14, 15) rigidly arranged on the machine frame (13). The rollers (3, 4, 5) of the lower group received in the bearing housing (1, 2) can overcome the pressing force of the device (8) to slide in a yielding direction away from the upper rollers, when a roller accumulates film thereon.

Abstract: A venting system for heat treating flat material webs or films has a drying chamber with a centrally arranged single blower for supplying treatment medium, such as heated and cleaned air, to the surfaces of the flat material. Air guide channels and ducts are so arranged that a single blower is fully sufficient while still obtaining a defined suction withdrawal of the air that has contacted the flat material surfaces. Sets of blowing nozzles face the surfaces of the flat material and are arranged for cooperation with suction nozzles for the return of the treatment medium to the suction side of the blower in a substantially closed treatment medium circulating circuit.

Abstract: A tentering chain is guided between two guide rails extending in parallel to each other. One guide rail (19a) is an outer guide rail with regard to a course followed by the chain, while the other guide rail (19b) is an inner guide rail. The chain links are hinged to each other by a journal pin which carries a first guide roller on an inner pin section between chain link plates, and a second guide roller on a cranked outer pin section. Thus, the rotational axes of these two guide rollers extend in parallel to each other and spaced from each other, so that one guide roller can only contact one guide rail, but not the other and vice versa. This feature prevents the reversal of the rotation direction of the guide rollers as they travel along the parallel guide rails.