Device for shrinking a textile web

Abstract

A device (1) for shrinking a textile web (WB) between a drum (TR) and a rubber blanket (GT) is described, which is guided over rotatable rollers (U1, U2, U3, U4), wherein the rubber blanket (GT) is pressed against the drum (TR) in the entry area of ​​the web (WB) by a pressure roller (U1). According to the invention, the rubber blanket (GT) is deflected in the exit area of ​​the web (WB) via an exit roller (U4) and subsequently returned to the pressure roller (U1) via a tension roller (U3) and a deflection roller (U2), the positions of the pressure roller (U1) and the exit roller (U4) are adjustable with respect to the drum (TR) in order to adjust pressure against the drum (TR) and wrapping around the drum (TR), and a grinding device (SW) is arranged in the exit area, to which the rubber blanket (GT) can be directed by the movable exit roller (U4).that the position of the tension roller (U3) relative to the drum (TR) is adjustable to set the tension of the rubber blanket (GT), and that the deflection roller (U2) is positioned relative to the drum (TR) such that an angle (Wd) between a first tangent (G12) applied to the pressure roller (U1) and the deflection roller (U2) on one side facing away from the drum (TR), and a second tangent (G13) applied to the pressure roller (U1) and the tension roller (U3) on one side facing away from the drum (TR), lies in a range of 6° to 80°.

Description

[0001] The invention relates to a device having the features of the preamble of claim 1. Such a device is known from DE 103 30 338 B3.

[0002] In the known device, a rubber blanket is guided with its inner surface over three rollers, each of which deflects the blanket. One of the rollers is a pressure roller, which presses the rubber blanket against a drum referred to there as the "main cylinder." In the exit area of ​​the web, the rubber blanket is deflected over a discharge roller and subsequently guided in a straight line back to the pressure roller by a deflecting roller located below the drum. A pair of squeeze rollers is arranged between the deflecting roller and the pressure roller to press off any liquid applied by a water shower to a defined residual moisture level before the rubber blanket reaches the pressure roller. Swiveling nozzle bars are provided as additional cooling devices in the edge area of ​​the rubber blanket, which is not covered by the web.Undesirable cooling of the area of ​​the rubber blanket active on the drum, which is used to press the web of material directly against the outer surface of the drum, should be avoided.

[0003] From US Patent 6,279,211 B1, a device of the type mentioned above is known, wherein the outer surface of an endless rubber blanket is in constant contact with a grinding roller during the shrinking of a textile web and is thereby continuously ground down. This minimizes production interruptions for grinding the outer surface of the rubber blanket.

[0004] German patent application DE 24 13 050 A describes a device of the type mentioned above, in which a rubber blanket in the exit area of ​​the web is deflected over an exit roller designed as a tensioning and wrapping roller to combine the functions of tension and wrapping, and their modification, in one and the same roller. For this purpose, means are provided to move the tensioning roller in a generally tangential direction to the heated drum in order to increase or decrease the length and tension of the rubber blanket. Furthermore, means are provided to move this roller perpendicular to the aforementioned tangential direction towards and away from the drum in order to regulate the degree of wrapping of the rubber blanket around the drum.

[0005] DE 196 22 658 C1 discloses a device for shrinking knitted textiles with a shrinking channel formed by a heated shrinking roller and a shrinking cloth that partially encircles the shrinking roller. A shrinking flap is arranged in the inlet area between the shrinking roller and the shrinking cloth, which runs around a deflecting roller in this area. The knitted fabric to be treated is fed into the shrinking channel between the shrinking flap and the shrinking cloth. The geometric path along which the knitted fabric is fed into the shrinking channel is adjustable between a linear shape and a maximally convex shape. For this purpose, the position of the axis of the at least one deflecting roller is continuously or stepwise adjustable, in particular by a pivoting motion.By changing the shape of the geometric inlet path of the knitted fabric into the shrink channel, it is possible to adjust the device to knitted fabric of different quality and pretreatment, so that wrinkling in knitted fabric that does not show normal shrinkage behavior can be excluded.

[0006] The invention is based on the objective of improving a device of the type mentioned at the outset.

[0007] The problem is solved by a device having the features of claim 1. Advantageous further developments are the subject of dependent claims.

[0008] The device according to the invention is a rubber blanket shrinking machine for the compressive shrinking of a textile web or fabric. The shrinking of the web takes place between a driven and heated drum and an endless rubber blanket. The rubber blanket has an inner and an outer side. The rubber blanket wraps around a section of the drum. The outer side of the rubber blanket faces the drum. The inner side of the rubber blanket is guided continuously over several rotatable rollers. No two sections of the inner side of the rubber blanket come into contact with each other. The rotatable rollers are a pressure roller, a discharge roller, a tension roller, and a deflection roller. In the infeed area of ​​the web, the rubber blanket is pressed against the drum by a pressure roller. In the discharge area of ​​the web, the rubber blanket is deflected over the discharge roller and subsequently guided back to the pressure roller via the tension roller and the deflection roller.Between the pressure roller and the discharge roller, the rubber blanket wraps around a section of the drum's circumferential surface. The drum's circumferential surface can be heated. The web of material passes between the outer surface of the rubber blanket and the drum's circumferential surface. This compresses, shrinks, and fixes the web. The drum is rotatable, and its circumferential surface can be set in rotation, particularly by a drive coupled to the drum. The drum, or rather its axis of rotation, is stationary. The position of the pressure roller relative to the drum is adjustable to regulate the pressure of the rubber blanket against the drum.

[0009] The position of the pressure roller can be selected so that the distance between its circumferential surface and the drum's circumferential surface is approximately 60% to 90% of the blanket thickness during operation. This distance is adjustable to modify the shrinkage value, i.e., the percentage reduction of the web during the shrinking process. This distance can be increased to up to 200% of the blanket thickness when production is stopped or the blanket is changed. The blanket thickness can be at least 30 mm, and ideally ranges from 30 mm to 80 mm. The position of the discharge roller relative to the drum is adjustable to allow the blanket to wrap around the drum. This allows for modification of the shrinking web's fixation.The position of the tension roller relative to the drum is adjustable to set the tension of the blanket at a preset pressure of the blanket against the drum and a preset wrap of the blanket around the drum. The blanket tension is adjusted so that a sufficiently high tensile force acts on the blanket in the direction of movement to prevent vibrations of the blanket and wrinkling of the web. The blanket tension can be determined by geometric calculations based on the selected roller positions and can also be automatically adjusted by moving the tension roller.

[0010] The contact of the rubber blanket with the heated drum, the alternating bending of the blanket, the pressure exerted on the blanket, and the tensile stress within the blanket result in considerable thermal and mechanical stress on the circulating rubber blanket. The rubber blanket wears down, particularly on its outer surface, and therefore must be ground down periodically, especially if it is made of natural rubber. This reduces the thickness of the rubber blanket with each grinding process. A grinding device for grinding the outer surface of the rubber blanket is located in the exit area of ​​the web.

[0011] The grinding device can be arranged in a fixed position relative to the drum. The grinding device can also be a rotatable grinding roller. The movable outfeed roller allows the rubber pad of the grinding device to be positioned to perform the grinding process.

[0012] The deflection roller is positioned relative to the drum such that the angle between two tangents applied to the pressure roller is between 6° and 80°. The first tangent is applied to the pressure roller and the deflection roller on the side facing away from the drum. The second tangent is applied to the pressure roller and the tensioning roller on the side facing away from the drum. The angle between the first and second tangents is between 6° and 80°.

[0013] The invention has significant advantages: • The invention provides a special combination of technical measures which includes a change in the roller geometry in order to reduce, in particular, the thermal and mechanical stresses on the rubber blanket. • The wrapping angle of the rubber blanket around the drum and its pressure against the drum are adjustable independently of the rubber blanket tension and the wrapping angle of the rubber blanket around the pressure roller. • On the one hand, the pressure of the blanket against the drum and the degree of wrapping around the drum can be selected based on the requirements of the web, in particular the shrinkage and the required fixation. On the other hand, the wrapping of the blanket around the pressure roller can be adjusted independently, in particular reduced. • Reducing the wrapping of the blanket around the pressure roller can decrease the bending stress on the blanket. The tensile forces exerted on the blanket by the drum can also be reduced. This can decrease internal friction and heating of the blanket, thereby reducing the thermal stress on the blanket. • By adjusting the wrapping of the rubber blanket around the pressure roller, a nearly vertical movement of the rubber blanket between the tension roller, the deflection roller, and the pressure roller can be achieved. Coolant applied to the outer surface of the rubber blanket can thus flow downwards along its length. This prevents undesirably large quantities of coolant from flowing towards the center of the rubber blanket, where a lower cooling effect is not desired. The modified roller geometry according to the invention therefore enables more targeted cooling of the rubber blanket and allows the blanket to operate within its optimal temperature range. This can also lead to a lower thermal stress on the rubber blanket. • This results in significantly reduced wear and tear on the rubber sheet. • Instead of the previously usual rubber blanket thickness of 50 mm to 72 mm, the invention makes it possible to use thicker rubber blankets with a thickness of up to 80 mm and, thanks to the optimized roller arrangement, to achieve good shrinkage results even with a thickness of 30 mm. • Overall, the service life of the rubber blanket and / or the production speed of the shrinking machine can be increased. • As a result, the efficiency of the shrinkage process can be increased.

[0014] In a further embodiment, the rubber blanket can be guided along its inner surface over exactly four rollers. The rollers can be mounted to rotate freely. The deflection roller can be adjustable transversely to the vertical, particularly horizontally, with respect to the drum. This allows the position of the deflection roller to be changed with respect to the drum and with respect to the pressure roller. In particular, the positions of the tensioning roller and the deflection roller with respect to the drum can be changed so that the wrap angle of the rubber blanket around the pressure roller, with a preset pressure of the rubber blanket against the drum and with a preset wrap angle of the rubber blanket around the drum, can be adjusted such that the angle between the first tangent and the second tangent lies in a range of 6° to 80°.

[0015] The tension roller can be positioned below the drum, particularly below the lowest point of the drum. The tension roller can be displaceable along a direction of movement for position adjustment. This allows the tension roller's position relative to the drum and the other rollers to be changed. The direction of movement can be along the direction of a resultant force, which arises from the forces exerted on the tension roller by the rubber blanket due to its pretension. The positions of the rollers can be changed during the shrinking process. In particular, the angle between the first and second tangents can be changed during the shrinking process. This allows for fine-tuning and adjustment of the shrinking process during operation.

[0016] In a further embodiment, a cooling device can be assigned to the outer surface of the blanket below the deflecting roller. A cooling device can also be assigned to the inner surface of the blanket. The cooling device assigned to the inner surface of the blanket can be located outside the area between the deflecting roller and the pressure roller. A scraper, in particular a squeezing roller, can be assigned to the deflecting roller to remove coolant from the outer surface of the blanket. A temperature measuring device can be assigned to the outer surface of the blanket in the area between the deflecting roller and the pressure roller to record a temperature profile of the outer surface of the blanket. A humidification device can be assigned to the outer surface of the blanket in the area between the deflecting roller and the pressure roller.The contact area of ​​the blanket with the drum and / or with a web of material resting on the drum can be at least 15% of the blanket's outer surface area. The minimum distance between the circumferential surface of the pressure roller and the circumferential surface of the deflection roller can be a maximum of 125 mm. The minimum distance between the circumferential surface of the deflection roller and the circumferential surface of the tensioning roller can be at least 200 mm. The minimum distance between the circumferential surface of the tensioning roller and the circumferential surface of the drum can be at least 150 mm. This provides sufficient space for a cooling device located on the inside of the blanket. Furthermore, the aforementioned dimensions make it particularly easy to ensure that dripping water does not reach the blanket in the area between the deflection roller and the pressure roller.

[0017] Further details and advantages of the invention are explained with reference to exemplary embodiments of the invention and the accompanying drawings. Identical and corresponding components are identified by corresponding reference numerals. The drawings show: Fig. 1 a schematic side view of a device according to the invention in a first operating state, Fig. 2 a view similar Fig. 1 to a second operating state of the device according to the invention, Fig. 3 a view similar Fig. 1 to a third operating state of the device according to the invention, Fig. 4 a schematic side view of part of the device of Fig. 1 for determining an angle between two tangents applied to a pressure roller, Fig. 5 Another embodiment of the device according to the invention with a relatively thick rubber sheet, Fig. 6 another embodiment of the device according to the invention with a relatively thin rubber sheet.

[0018] The in the Fig. The device 1 for shrinking a textile web WB, shown in Figures 1 to 3, contains a driven and heated drum TR. The drive and heating of the peripheral surface 2 of the drum TR are carried out in a manner known per se and therefore do not need to be described and illustrated in detail. An endless rubber blanket GT is guided with its inner surface 3 over four freely rotatable rollers U1, U2, U3, and U4. On its inner surface 3, the rubber blanket GT has a length of approximately 156 inches. The width of the rubber blanket transverse to the plane of the drawing is selected based on the maximum width of the web WB to be shrunk. The rubber blanket GT wraps around a section of the drum TR. The web WB passes through the device 1 between the outer surface 4 of the rubber blanket GT and the peripheral surface 2 of the drum TR. In the entry area of ​​the web WB, the rubber blanket GT is pressed against the drum TR by a pressure roller U1 and thereby compressed to approximately 75% of its thickness.In the exit area of ​​the web WB, the rubber blanket GT is deflected via an exit roller U4 and subsequently returned to the pressure roller U1 via a tension roller U3 and a deflection roller U2.

[0019] The position of the pressure roller U1 is horizontally adjustable relative to the drum TR to adjust the compression and pressure of the rubber blanket GT against the drum TR. A grinding device in the form of a grinding roller SW is located in the outfeed area. The position of the grinding roller SW relative to the drum TR is fixed. The grinding roller SW can be rotated by a drive (not shown) to grind the outer surface of the rubber blanket GT. The position of the outfeed roller U4 relative to the drum TR is adjustable to ensure that the rubber blanket GT wraps around the drum TR (see figure). Fig. 1 and Fig. 2. The wrapping of the rubber blanket GT around the drum TR is in Fig. 2 greater than in Fig. 1. In the operating state according to Fig. 2. The web WB thus remains in contact with the blanket GT for a longer period. This allows for stronger fixation of the web WB. The outfeed roller U4 can also press the blanket GT against the drum TR or the web WB, cf. Fig. 2. The operating status according to Fig. 2 can be used particularly for relatively heavy goods of, for example, 492 g / m² 2 This can be advantageous. In this case, if shrinkage is controlled, particularly exclusively, by adjusting the outfeed roller U4, the shrinkage process remains stable because the temperature and humidity of the web (WB) hardly change. The desired target shrinkage value can be achieved with tight tolerances. This enables increased production speed and leads to improved quality of the web (WB) exiting the device 1.

[0020] For a grinding process, the rubber blanket GT of the grinding roller SW can be supplied by the movable outfeed roller U4, cf. Fig. 3. In the case of the Fig. In the operating state shown in Figure 3, the (worn) outer surface 4 of the rubber blanket GT is ground down by the rotating grinding roller.

[0021] The rubber blanket GT is guided between the discharge roller U4 and the deflection roller U2 via a tension roller U3. The position of the tension roller U3 is adjustable along a displacement direction V. This displacement direction V corresponds to the direction of a resultant force exerted by the rubber blanket GT on the tension roller U3 due to its tension. After the pressure of the rubber blanket GT by the pressure roller U1 has been preset, and after the wrap of the rubber blanket GT around the drum TR by the discharge roller U4 has been preset, the tension acting circumferentially on the rubber blanket GT is adjusted to the desired value by moving the tension roller U3.

[0022] The position of the deflection roller U2 is horizontally adjustable in relation to the drum TR and is determined in relation to the rollers U1 and U3 using two tangents G12 and G13, cf. Fig. 4. The first tangent is applied to the circumferential surface 5 of the pressure roller U1 and the circumferential surface 6 of the deflection roller U2 on a side of the pressure roller U1 facing away from the drum TR. The second tangent G13 is applied to the circumferential surface 5 of the pressure roller U1 and the circumferential surface 7 of the tension roller U3 on a side facing away from the drum TR. The tangent G12 and the tangent G13 have an angle Wd to each other. In the first embodiment of the Fig. For 1 to 4, the angle Wd is approximately 30°.

[0023] Fig. Figure 5 shows an embodiment of the device 1 with a relatively thick rubber sheet GT and a relatively large angle Wd. Fig.Figure 6 shows an embodiment of the device 1 with a relatively thin rubber blanket GT and a relatively small angle Wd. Here, the rubber blanket GT runs almost vertically upwards over a shortened distance between rollers U2 and U1, while the rubber blanket GT also runs almost vertically upwards over a longer distance between rollers U3 and U2. Such an arrangement is particularly suitable for relatively lightweight materials, for example, 120 g / m². 2 This can be advantageous.

[0024] Cooling devices K1 and K2 are assigned to the outer surface 4 of the rubber blanket GT. The smallest distance between the circumferential surface 5 and the circumferential surface 6 is 100 mm or less. The smallest distance between the circumferential surface 6 and the circumferential surface 7 is 250 mm or more. The smallest distance between the circumferential surface 2 and the circumferential surface 7 is 150 mm or more. This design provides sufficient space for a cooling device K3, which is assigned to the inner surface 3 of the rubber blanket GT. The cooling devices K1, K2, and K3 can supply the rubber blanket GT with cooling fluid in a manner known per se. A scraper device in the form of a squeeze roller QW is arranged downstream of the cooling device K1. This roller, together with the deflecting roller U2, forms a pair of rollers to squeeze a film of water from the surfaces 3 and 4 of the rubber blanket GT.The dripping water does not reach the area between the deflecting roller U2 and the pressure roller U1, and therefore cannot uncontrollably reach the web WB. A temperature measuring device TS is arranged downstream of the squeeze roller QW to record a temperature profile of the outer surface 4. A humidification device FA is located downstream of the temperature measuring device TS. The determined temperature profile of the outer surface 4 is processed by a controller (not shown) of the device 1 to control the coolant distribution and coolant quantity of the cooling units K1, K2, and K3. Furthermore, the temperature profile is used to control the humidification device FA. Reference symbol list 1 Device 2 Circumferential area TR 3 Inside GT 4 Outside GT 5 Circumferential area U1 6 Circumferential area U2 7 Circumferential area U3 FA humidification system G12 first tangent G13 second tangent GT Rubber Cloth K1 cooling unit K2 cooling unit K3 cooling unit QW crushing roller SW grinding roller TR Drum TS temperature measuring device U1 pressure roller U2 deflection roller U3 tension roller U4 outlet roller V Direction of movement WB Goods Railway Wd Angle

Claims

[1] Device (1) for shrinking a textile web (WB) between a driven and heated drum (TR) and an outer surface (4) of an endless rubber sheet (GT), which is guided with its inner side (3) over rotatable rollers (U1, U2, U3, U4), wherein the rubber blanket (GT) in the entry area of ​​the web (WB) is pressed against the drum (TR) by a pressure roller (U1), characterized by , that the rubber blanket (GT) in the exit area of ​​the web (WB) is deflected via an exit roller (U4) and subsequently returned to the pressure roller (U1) via a tension roller (U3) and a deflection roller (U2), that the positions of the pressure roller (U1) and the discharge roller (U4) are adjustable in relation to the drum (TR) in order to adjust the pressure of the rubber blanket (GT) against the drum (TR) and the wrapping of the rubber blanket (GT) around the drum (TR), that a grinding device (SW) for grinding the rubber blanket (GT) is arranged in the discharge area, to which the rubber blanket (GT) can be supplied by the movable discharge roller (U4), that the position of the tension roller (U3) relative to the drum (TR) is adjustable in order to adjust the tension of the rubber blanket (GT) with a preset pressure of the rubber blanket (GT) against the drum (TR) and a preset wrap of the rubber blanket (GT) around the drum (TR), and that the deflection roller (U2) is positioned relative to the drum (TR) such that an angle (Wd) between a first tangent (G12), which is applied to the pressure roller (U1) and the deflection roller (U2) on one side facing away from the drum (TR), and a second tangent (G13), which is applied to the pressure roller (U1) and the tension roller (U3) on one side facing away from the drum (TR), lies in a range of 6° to 80°. [2] Device according to claim 1, in which the positions of the tension roller (U3) and the deflection roller (U2) are variable with respect to the drum (TR) in order to adjust the tension of the rubber blanket (GT) and the wrap angle of the rubber blanket (GT) around the pressure roller (U1) with preset pressure of the rubber blanket (GT) against the drum (TR) and preset wrap of the rubber blanket (GT) around the drum (TR) such that the angle (Wd) between the first tangent (G12) and the second tangent (G13) is in a range of 6° to 80°. [3] Device according to claim 1 or 2, in which the rubber blanket (GT) is guided with its inner side (3) over exactly four rollers (U1, U2, U3, U4). [4] Device according to one of the preceding claims, in which the deflecting roller (U2) is adjustable transversely to the vertical, in particular horizontally, with respect to the drum (TR). [5] Device according to one of the preceding claims, in which the tension roller (U3) is arranged below the drum (TR). [6] Device according to one of the preceding claims, in which the tension roller (U3) is displaceable for position adjustment along a displacement direction (V) which runs along the direction of a resultant force resulting from the forces acting on the tension roller (U3) from the rubber blanket (GT) due to its tension. [7] Device according to one of the preceding claims, in which the positions of the rollers (U1, U2, U3, U4), in particular the angle (Wd) between the first tangent (G12) and the second tangent (G13), are changeable during the shrinking process. [8] Device according to one of the preceding claims, in which a cooling device (K1) is assigned to the outside (4) of the rubber sheet (GT) below the deflecting roller (U2). [9] Device according to one of the preceding claims, in which a cooling device (K3) is assigned to the inside (3) of the rubber blanket (GT) outside the area between the deflecting roller (U2) and the pressure roller (U1). [10] Device according to one of the preceding claims, in which a scraping device (QW), in particular a squeezing roller, is associated with the deflecting roller (U2) to remove coolant from the outside (4) of the rubber blanket (GT). [11] Device according to one of the preceding claims, in which a temperature measuring device (TS) is assigned to the outside (4) of the rubber blanket (GT) in the area between the deflecting roller (U2) and the pressure roller (U1) in order to detect a temperature profile of the outside (4) of the rubber blanket (GT). [12] Device according to one of the preceding claims, in which a moistening device (FA) is assigned to the outside (4) of the rubber blanket (GT) in the area between the deflecting roller (U2) and the pressure roller (U1). [13] Device according to one of the preceding claims, in which the contact area of ​​the rubber blanket (GT) with the drum (TR) and / or with a web of material (WB) lying on the drum (TR) is at least 15% of the area of ​​the rubber blanket (GT) on its outer side (4). [14] Device according to one of the preceding claims, in which the smallest distance between the circumferential surface (5) of the pressure roller (U1) and the circumferential surface (6) of the deflection roller (U2) is at most 125 mm. [15] Device according to one of the preceding claims, in which the smallest distance between the circumferential surface (6) of the deflecting roller (U2) and the circumferential surface (7) of the tensioning roller (U3) is at least 200 mm.

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