DE29607449U1 - Device for unwinding, cutting to length, welding, perforating and winding up a plastic tube or plastic half-tube web - Google Patents

Description

Sachsenring Automobiltechnik GmbH 08058 Zwickau

Device for unwinding, cutting, welding,

Perforating and winding up a plastic tube or plastic half-tube web

The invention relates to a device for unwinding, cutting to length, welding, perforating and winding up a plastic hose or plastic half-sleeve web, which can be unwound from a supply roll and, after processing, wound up onto a plurality of sleeves to form rolls of a specific size.

Such a device can be used to produce plastic bags wound up into rolls, which have a wide range of uses, particularly in the home, such as bags for packaging food or garbage bags, which can be easily separated from one another at the perforation when unrolling from the roll.

In the known devices of this type, the plastic web is brought to a standstill during each welding and perforation process and also for each roll change during winding. This reduces the overall throughput speed on such a device. Since the feed rollers must be brought to a standstill and then started again at the same time as the plastic web, high energy consumption results when operating these known devices.

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The invention is based on the object of creating a device of the type mentioned at the beginning, in which no standstill of the plastic sheet is required and in which a higher performance is achieved despite lower energy consumption.

This problem is solved with the features of claim 1.

According to an advantageous further development of the invention, it is provided that the welding device and the perforating device perform an eccentric rotation with each cycle, i.e. with each movement of the plastic hose or plastic half-hose sheet by a distance that corresponds to the distance between two consecutive perforations, whereby the welding device consists of two sets of two opposing welding rails, between which the plastic hose or plastic half-hose sheet is clamped once during each eccentric rotation for a time sufficient for a welding process.

According to a further embodiment of the invention, a square hollow strip is attached to each of the welding rails, to which a layer of silicone rubber is glued on the side facing the plastic hose or plastic half-hose web, on which a heating band that can be heated with electric current and two Teflon bands arranged on both sides next to the heating band are attached in the longitudinal direction, whereby the electric current is switched on automatically by the heating band while the welding rails are pressed against it.

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In order to be able to combine the welding process with the perforating process, it is provided that the perforating device is arranged between two welding rails lying next to one another, which consists of a perforating knife blade on one side and a cutting bar on the other side, whereby the welding rails arranged on one side of the continuous plastic hose or plastic half-hose web with the perforating knife blade in between are fastened to a first articulated arm and the welding rails arranged on the other side of the continuous plastic hose or plastic half-hose web with the cutting bar in between are fastened to a second articulated arm, and the two articulated arms are each mounted on two eccentric bolts that move synchronously to one another on circular paths and rotate in opposite directions.

In order to be able to adapt the pressure during the welding process to the thickness of the plastic sheet, pressure-controlled air cylinders are inserted between the articulated arm and the welding rails with the perforating knife blade in between, which control the pressure required for the welding process.

In order to be able to vary the cutting process, it is further provided that two rubber rollers driven in opposite directions by servo motors are arranged in front of the welding and perforating device, driving the running plastic hose or plastic half-hose web, the rotation speed of which depends on the movement sequence of the welding and perforating device and on the desired distance of the

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consecutive perforations can be controlled.

Since the welding process heats up the weld seam considerably, a cooling device is arranged after the welding and perforating device, which consists of a belt running diagonally downwards and designed as an endless belt that transports the plastic hose or plastic half-hose web without drive voltage.

However, in order to enable further transport, several feed rollers are provided which pull the plastic hose or plastic half-hose web from the cooling device after it has passed through a loop and feed it to a winding device, the rotation speed of which can be controlled by a sensor arranged at the end of the cooling device in such a way that the loop is always located between two points above and below the sensor.

In order to enable the replacement of a fully wound roll with an empty core without stopping the plastic web, the winding device is provided with a turning arm that brings a new core to be wound into the winding position after a preselected number of perforations per roll, a high-voltage reading head that detects the next perforation and a folding mechanism that cuts through the perforation and places the beginning of the next plastic tube or plastic half-tube web on the new core, while the finished roll can be placed on a storage table and the empty winding point can be equipped with the next new core.

In order to be able to wind the rolls tightly, the

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Winding tension can be switched from an initially lower value to a higher value as winding progresses using a tension switching device.

The advantages achieved with the invention are, in particular, that during the welding, perforating and winding process, no standstill of the plastic sheet or other moving parts of the device is required, so that lower energy consumption and, at the same time, greater performance are achieved.

An embodiment of the invention is shown in the drawing and is described in more detail below. It shows

Fig. 1 shows a cross section through the device according to the invention,

Fig. 2 is a plan view of this device,

Fig. 3 a cross-section through a welding and perforating device in this device,

Fig. 4 a plan view of this welding and perforating device, partly in section,

Fig. 5 a perspective view of a welding rail of the welding device and

Fig. 6 a cooling device for cooling the weld seams.

The cross section in Fig. 1 and the top view in Fig. 2

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show a plastic hose or plastic half-hose web 4 wound on a supply roll 1, which is driven by a take-off motor 2 via two pressure rollers 3 and, after leaving the supply roll 1, runs through a dancer system 5 which regulates the take-off motor 2 to a constant web speed.

Behind the dancer system 5, the plastic hose or plastic half-hose web 4 runs through two rubber rollers 6 that are pressed against it and then, due to its own weight, vertically downwards through a welding and perforating device 7, the details of which are shown in Fig. 3 in cross section and in Fig. 4 in plan view.

The rubber rollers 6 are driven in opposite directions by a servo motor, whereby their rotational speed can be controlled with an accuracy of one millimeter depending on the movement sequence of the welding and perforating device 7 and depending on the desired distance between the successive perforations.

The welding and perforating device 7 contains two pairs of opposing welding rails 20, with a square hollow strip 21 being attached to each of these welding rails 20, as shown in perspective in Fig. 5, to which a layer 22 of silicone rubber is glued on the side facing the plastic hose or plastic half-hose web 4, on which a heating band 23 that can be heated with electrical current and two Teflon bands 24 arranged on both sides next to the heating band 23 are attached in the longitudinal direction. Furthermore, between each two adjacent welding rails 20

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the perforating device is arranged, which consists on one side of a perforating knife blade 25 and on the other side of a cutting strip 26, which is provided with an adhesive coating for securely holding particularly smooth plastic hose or plastic half-hose strips 4 during the perforating process.

The welding and perforating device 7 is designed to be movable, in such a way that it performs an eccentric rotation with each cycle, i.e. with each movement of the plastic hose or plastic half-hose 4 by a distance that corresponds to the distance between two consecutive perforations, whereby the movement sequence of the welding and perforating device 7 during the welding and perforating process is adapted to the running speed of the plastic hose or plastic half-hose web 4 or at least almost adapted.

In order to achieve an eccentric rotation of the welding and perforating device 7, the welding rails 20 arranged on one side of the continuous plastic hose or plastic half-hose web 4 with the intervening perforating knife blade 25 are fastened to a first articulated arm 27 via a pressure bar 31 and the welding rails 20 arranged on the other side of the plastic hose or plastic half-hose web with the intervening cutting bar 26 are fastened to a second articulated arm 28 via a counter-pressure bar 32, whereby the two articulated arms 27, 28 are each mounted on two eccentric bolts 29 which are mounted on two synchronously

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eccentric disks 33 rotating relative to one another are attached, which are each driven by a servo motor via a shaft 34.

The two articulated arms 27, 28 rotate in opposite directions, whereby the plastic hose or plastic half-hose web 4 is clamped between the heating bands 23 of the welding rails 20 once during each rotation for a time sufficient for a welding process.

Between the pressure bar 31 and the welding rails 20, pressure-controlled air cylinders 30 are inserted, which adapt the pressure required for the welding process to the thickness of the plastic hose or plastic half-hose web 4.

As shown in Fig. 6, the plastic hose or plastic half-hose web 4 passes through a cooling device 8 after cutting to length, welding and perforating in order to cool the weld seam. The plastic hose or plastic half-hose web 4 is conveyed further on a belt 9 running diagonally downwards, designed as an endless belt, without drive tension and, after passing through a loop 11 at the end of the cooling device 8, is transported via several sliding rods 12 to a winding device 14. Two feed rollers 13 are provided for this purpose, the rotational speed of which can be controlled by a sensor 10 arranged at the end of the cooling device 8 in such a way that the loop 11 is always located between two points above and below the sensor 10.

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A turning arm 17 is provided in the winding device 14, which brings a new sleeve 16 to be wound into the winding position after a preselected number of perforations per fully wound roll 15. A turning mechanism 18 ensures that the finished roll is separated at the next perforation, which is recognized by a high-voltage reading head (not shown), and the new beginning of the further plastic tube or plastic half-tube web 4 is placed on a new sleeve 16. The finished roll 15 is then placed on a storage table 19 and the empty winding position is filled with the next new sleeve 16.

This device can be used to produce both double seams (when using a plastic half-tubular sheet that is open on one side) and bottom seams (when using a plastic sheet that is closed on all sides). In the second case, one of the two heating bands 23 is simply switched off. However, pure film cuts can also be produced, whereby the welding device is not required. In this case, both heating bands 23 are switched off.

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Claims (13)

Sachsenring AutomobiLtechnik GmbH 08058 Zwickau PROTECTION CLAIMS 1. Device for unwinding, cutting, welding,
Perforating and winding a plastic hose or plastic semi-hose web (4) which is fed from a
Supply roll (1) can be unwound and after processing onto a variety of cores (16) to rolls (15)
can be wound up to a certain size, characterized in that a movable
Welding device and a movable
Perforating device are provided, whose
Movement sequence during the welding process
or during the perforation process of the
constant throughput speed of the
Plastic hose or plastic half-hose web (4) is adapted or at least almost adapted. 2. Device according to claim 1, characterized in that the welding device and the perforating device are moved with each cycle, that is to say with each advance of the plastic hose or plastic semi-hose web (4) by a distance which corresponds to the distance between two
of consecutive perforations, perform an eccentric rotation. 3. Device according to claim 2, characterized in that the welding device consists of two
opposite welding rails (20),
between which, at each eccentric orbit, the
Plastic hose or plastic semi-hose sheet 16 631.2 - Hl/Cl - (4) is clamped once for a time sufficient for one welding operation. 4. Device according to claim 3, characterized in that a square hollow strip (21) is attached to each of the welding rails (20), to which a layer (22) of silicone rubber is glued on the side facing the plastic hose or plastic half-hose web (4), on which a heating band (23) that can be heated with electric current and two Teflon bands (24) arranged on both sides next to the heating band (23) are attached in the longitudinal direction. 5. Device according to claim 4, characterized in that the switching on of the electric current through the heating band (23) takes place automatically during the pressing of the welding rails (20). 6. Device according to one of claims 3 to 5, characterized in that the perforating device is arranged between each two adjacent welding rails (20), which consists on one side of a perforating knife blade (25) and on the other side of a cutting bar (26). 7. Device according to claim 6, characterized in that the welding rails (20) arranged on one side of the continuous plastic hose or plastic half-hose web (4) with the intervening perforating knife blade (25) on a first articulated arm (27) and the welding rails (20) arranged on the other side of the continuous plastic hose or plastic half-hose web (4) 16 631.2 - Hl/Cl - Welding rails (20) with the cutting bar (26) in between are fastened to a second articulated arm (28), whereby the two articulated arms (27, 28) are each mounted on two eccentric bolts (29) that move synchronously to one another on circular paths and rotate in opposite directions. 8. Device according to claim 7, characterized in that pressure-controlled air cylinders (30) controlling the pressure required for the welding process are inserted between the first articulated arm (27) and the welding rails (20) with the perforating knife ring (25) located therebetween. 9. Device according to one of claims 1 to 8, characterized in that two rubber rollers (6) are arranged in front of the welding and perforating device (7) and are driven in opposite directions by servo motors and drive the continuous plastic hose or plastic semi-hose web (4), the rotational speed of which can be controlled depending on the movement sequence of the welding and perforating device (7) and depending on the desired distance between the successive perforations. 10. Device according to one of claims 1 to 9, characterized in that a cooling device (8) is arranged after the welding and perforating device (7), which consists of a belt (9) designed as an endless belt that runs diagonally downwards and conveys the plastic hose or plastic half-hose web (4) further without drive tension. 16 631.2 - Hl/Cl - 11. Device according to claim 10, characterized in that several feed rollers (13) are provided which pull the plastic hose or plastic half-hose web (4) from the cooling device (8) after it has passed through a loop (11) and feed it to a winding device (14), the rotational speed of which can be controlled by a sensor (10) arranged at the end of the cooling device (8) in such a way that the loop (11) is always located between two points above and below the sensor (10). 12. Device according to claim 11, characterized in that in the winding device (14) a turning arm (17) is provided which brings a new sleeve (16) to be wound into the winding position after a preselected number of perforations per roll (15), furthermore a high-voltage reading head which recognizes the next perforation and a folding mechanism (18) which cuts through the perforation and places the beginning of the further plastic tube or plastic half-tube web (4) on the new sleeve (16), while the finished roll (15) can be laid down on a storage table (19) and the empty winding position can be equipped with a next new sleeve (16). 13. Device according to claim 12, characterized in that a tensile force switching device is provided which switches the winding tension from an initially lower value to a higher value as the winding progresses. 16 631.2 - Hl/Cl -