CS229776B1 - Device for orientation and atebilization of polyolphine strips - Google Patents

Description

The present invention relates to a device for the orientation and fixation of polyolefin tapes. A known method of orientation and fixation of polyolefin tapes is performed by heating the tapes to an orientation temperature and stretching at this temperature, thereby orienting them. at fusing temperature »

The air tunnel is used for heating »During the heating to the orientation temperature, the tapes are braked by a system of slow-running cylinders and after heating they are pulled through the system of high-speed cylinders» For stretching the tapes are guided by the fixation zone.

The disadvantage is that due to the low heat transfer coefficient, the tunnel is relatively long, especially if the requirement for uniform and reproducible tape temperature is to be met »When one of the tapes breaks, the tunnel must open, thereby violating the tunnel temperature regime. technological conditions changed, which does not remain without affecting their quality »For these reasons, the thermal input of the tunnel may be sufficiently dimensioned, so that the equipment is energy-intensive»

The disadvantage is alleviated by the polyolefin strip orientation and fixation device according to the present invention, which comprises a free-running orientation roller with an adjustable distance from said rollers between a set of slow-running heating rollers and high-speed rollers. the first slow-running heater cylinder has locating pins with a smaller initial diameter than the cylinder itself and whose dimensions then smoothly pass »

229 776

An advantage of the proposed device is that the tapes that pass to the orientation and fixation device need not be cooled to a lower temperature than is necessary for the material to be rigid and which lies slightly below the orientation temperature. At this temperature, the tapes only heat up, which means energy savings. The tapes are heated on slow-running heating cylinders by direct contact. This heating is more efficient than hot air heating or infrared heating. When one of the strips breaks, the technological conditions do not change for others. The orientation is performed between the slow-running heating and the high-speed rolls on a freely rotating roller which is adjustable relative to the last slow-running heating roll. By adjusting the free orientation length, it is possible to adjust the attenuation path, which is advantageous in that it allows to control the taper of the oriented strip and thus to adjust its final dimensions. Another advantage of the device is the possibility to disable heating of any cylinder, which allows to adjust the technological mode and thus the final properties of the tapes. As well as heating to the orientation temperature on slow-running heating rolls, the heating to the fixing temperature on the fixing rolls is also performed. These rollers also allow the strips to relax by gradually reducing their diameters by a selected percentage to a certain size, so that the strips also relax during the fixation. As with orientation heating, it is also possible to switch off the heating of any of these rolls and thus change the final properties of the tapes.

In order to further elucidate the invention, a further description and attached drawing are shown, in which Fig. 1 schematically illustrates the orientation and fixation device; The device consists of a set of low-speed heating rollers 1 and high-speed rollers 2 driven by drives 9. Among them is a freewheel adjustable orientation roller 3. Behind the set of high-speed rollers 2 there are fixing rollers 4 whose diameter decreases according to the selected percentage of relaxation. . In cylinder systems, the first roller of the low-speed heating rollers 1, the last roller of the high-speed rollers 2, and the last roller of the fixation rollers 4

229 776 provided with rubberized pressure rollers 6 in which the pressure force can be controlled by a pressure medium pressure relief valve. Furthermore, said rollers are provided with a guide pin 2, FIG. 2 of a smaller diameter than the diameter of the roll itself. Guide pin diameter J? it passes continuously to the size of the cylinder, allowing the strip 7 to be guided under the rubberized pressure roller 6 without having to lift the pressure roller 6. This solution fulfills the requirements for work safety when operating the equipment.

The tapes 2 come from a refrigeration machine cooled to a temperature close to the orientation temperature to a set of slow running heater rolls 1. The first roll of this assembly is provided with a guide pin 2 ^{and a} rubberized pressure roll 6 as well as the last roll of high speed rolls 2. 7 reheated to the orientation temperature. The set of high-speed rollers 2 stretches the strips 7 and orient the strips on the freely rotatable orientation roller 3e. The distance 8 between the last slow-running heater cylinder 1 and the orientation roller 3 is adjustable, this allows adjustment of the tapering of the strips. The high-speed cylinders 2 are set at such a temperature that the strips are cooled but only enough to avoid too much heat to heat set on the set of fusing rollers 4.

Claims (1)

Apparatus for the orientation and fixation of polyolefin levers, consisting of a system of cylinders which are intended to be heated and whose circumferential speeds and diameters are adapted according to purpose, characterized in that the system of heated low-speed cylinders (1) and high-speed cylinders (2) is a freewheel orientation roller (3), the distance (8) of which is adjustable from said rollers, the first slow-running heater roll (1), the last of the high-speed rollers (2) and the last fixation roller (4) having guide pins (5) with a smaller initial diameter than the diameters of said rollers, whose dimensions are continuously transferred®