METHOD AND DEVICE FOR PRODUCING A HAND-TEARABLE TEXTILE ADHESIVE TAPE

Abstract

The invention relates to a method and a device for producing a hand-tearable textile adhesive tape. First of all, a textile carrier tape (T) is treated, using a processing liquid (4) which acts upon the fibres, for long enough for its tear-resistance to fall below 100 N/cm. The textile carrier tape (T) is then washed and neutralised, and lastly a coating comprising an adhesive is applied to at least one side of said textile carrier tape (T).

Claims

1. A method of making a hand-tearable textile adhesive tape comprising the following method steps: treating a textile support tape with a processing liquid capable of weakening fibers until a tensile strength of the tape is less than 100 N/cm; subsequently washing and neutralizing the textile support tape; and finally applying a coating containing an adhesive to at least one side of the support tape.

2. The method according to claim 1, wherein the textile support tape is treated with the processing liquid in a continuous or a discontinuous process.

3. The method according to claim 2, wherein the textile support tape is guided continuously through a treatment device at a predefined speed and in at least one pass.

4. The method according to any one of claim 1, further comprising the step of: using the textile support tape a lye or an acid as the processing liquid.

5. The method according to claim 1, further comprising the step of: heating the processing liquid to a temperature of least 50 C.

6. The method according to claim 1, further comprising the step of: using a woven textile support tape made of polymer filaments as the textile support tape.

7. The method according to claim 6, wherein the textile support tape is a polyester woven textile support tape.

8. The method according to claim 7, further comprising the step of: alkalinizing the polyester woven textile support tape.

9. The method according to claim 8, wherein the polyester woven textile support tape is alkalinized using sodium hydroxide.

10. The method according to claim 9, wherein the sodium hydroxide has a concentration of at least 10 g/l.

11. The method according to claim 1, wherein the textile support tape is treated with the processing liquid for a treatment time of at least 4 minutes.

12. The method according to wherein the textile support tape is treated in the treatment device using a liquor ratio of 1:20 and more.

13. A system for making a hand-tearable textile adhesive tape, the system comprising: a supply for textile support tape; a treatment device in which the textile support tape from the supply is treated with a processing liquid capable of weakening fibers until a tensile strength of the tape is less than 100 N/cm; a washer for washing and neutralizing the textile support tape after the treatment; and a final applicator for coating at least one side of the support tape with an adhesive.

14. The system according to claim 13, wherein the treatment device is designed as an alkalinization unit.

15. The system according to claim 13, further comprising: a cleaning station for removing oils or grease from the textile support tape upstream of the treatment device.

Description

[0030] The invention will be described in more detail below based on one drawing showing only a single illustrated embodiment. The only FIGURE shows a system for making a hand-tearable textile adhesive tape.

[0031] The FIGURE shows a system for making an adhesive tape. For this purpose, the system first of all has a supply 1 holding a roll of a textile support tape T to be fed to the treatment system described below. The textile support tape T in the supply 1 may be a textile web that can be cut into individual adhesive tape strips having a predefined length at the end of the production process to be described.

[0032] Downstream in a travel direction A from the supply 1 of the textile support tape T is a treatment device 3 in which the textile support tape T from the supply 1 is treated with a processing liquid 4. It is apparent that the processing liquid 4 has a liquid level shown with dashed lines in the treatment device 3 or the treatment bath therein, and the support tape T is guided in a meander in the processing liquid 4 or through its surface. The treatment device 3 is equipped with roller vats for this purpose that guide the textile support tape T in a meander over deflection rollers multiple times through the processing liquid 4.

[0033] The textile support tape T is treated in the treatment device 3 with the processing liquid 4 until the tear strength or tensile strength thereof is less than 100 N/cm. The processing liquid 4 in fact acts on the fibers of the textile support tape T.

[0034] In the illustrated embodiment, the textile support tape T is a polyester woven textile support tape that is alkalinized using sodium hydroxide as the processing liquid. The sodium hydroxide is present in a concentration of at least 10 g/l and typically has a temperature of at least approximately 50 C. and more. The maximum concentration of sodium hydroxide is 40 g/l, and the maximum temperature is approximately 80 C. In addition, the textile support tape T is treated in the treatment device 3 for at least 4 minutes.

[0035] This means that the treatment time of the textile support tape T within the treatment device 3 is set to at least 4 minutes or more. This treatment time is derived from on the speed with which the textile support tape T is guided through the system shown in the FIGURE in the travel direction A. This speed is approximately 10 m/min and can be increased to approximately 40 m/min.

[0036] In this way, the treatment time of 4 minutes or more can be specified and set as a function of the physical dimension or length of the treatment device 3. Overall, tensile strength values of less than 100 N/cm are achieved in this connection at the end of the treatment device 3, and a reduction of the tensile strength of at least 5% compared to the starting condition is achieved when a speed of approximately 40 m/min in the travel direction A is employed and the temperature of the processing liquid 4 or of sodium hydroxide having a concentration of 40 g/l is more than 50 C., and preferably approximately 80 C. The residence time in this case is approximately 4 minutes.

[0037] As a result, for example, the tensile strength of the textile support tape T of approximately 105 N/cm in the starting condition, or in the state in the supply 1, is reduced to values of approximately 100 N/cm or 95 N/cm and less at the end of the treatment device 3. This explains a percentage decrease in tensile strength of at least 5%, and of 10% and more in this example.

[0038] The described reduction in tensile strength can basically be attributed to the known fact that, during the described alkalinization process within the treatment device 3, the overall diameters of the individual fibers are reduced by the processing liquid 4 acting on the fibers. The reason for this is that alkalinization results in peeling of the surface of the textile support tape T that, from a chemical point of view, represents a degradation of the polyester chains due to a base-catalyzed saponification process. As a result, structural changes of the textile support tape T are observed, with a simultaneous loss of mass of the individual fibers.

[0039] Upstream of the treatment device 3 in the travel direction A is a cleaning station 2. This is used in particular to remove any oils or grease from the textile support tape T that may still adhere from the upstream weaving process. As was already described, the treatment device 3 as a whole and in the illustrated embodiment is designed as an alkalinization unit 3. However, the cleaning station 2 can essentially also operate similarly to the treatment device or alkalinization unit 3. In this case, the treatment device 3 and the cleaning station 2 must be considered as one unit 2, 3 that as a whole ensures the above-described properties of the textile support tape T at the output of this unit 2, 3, or at the output of the treatment device 3. This, of course, is not mandatory.

[0040] A steamer or a steaming device 5 follows the treatment device 3 in the travel direction A. The steamer 5 is configured with a treatment chamber filled with saturated steam here of water. Respective seals 6 are provided at the input port and are the output port of this treatment chamber of the steamer 5, the seals being designed as liquid seals in the illustrated embodiment.

[0041] As described above, the steamer 5 ensures that the overall treatment time of the textile support tape T can be varied. The longer the textile support tape T remains in the treatment chamber of the steamer 5, the shorter is ultimately the treatment time, since the saturated water vapor with which the textile support tape T is treated in the steamer basically ensures that the action of the processing liquid, or of the sodium hydroxide 4, on the textile support tape T is reduced or attenuated. Consequently, the processing time using the processing liquid 4 ultimately refers only to the time when the textile support tape T is in the treatment device 3.

[0042] After passing through the steamer 5, the textile support tape T reaches a washer 7 that has individual washing chambers 7. The textile support tape T is again guided in a meander through the individual washing chambers 7, so that not only is the processing liquid 4 rinsed off the textile support tape T in the washer 7, but the support tape T also undergoes neutralization. The reason for this is that the conditions are set, at least in the output-side washing chamber 7, in such a way that a pH of approximately 7 is present there so that overall pH conditions are neutral. At the input and at the output, the washer 7 also has sprayers 8 that direct water directly onto the textile support tape T at the input and at the output.

[0043] After treatment with the processing liquid 4, the washer 7 for washing and neutralizing the textile support tape T is followed by a downstream dryer 9. Here, cylinder drying may be employed. In fact, the dryer 9 has multiple heated cylinders that can have a temperature of approximately 100 C. to 130 C., for example. After leaving the washer 7, the textile support tape T is guided in a meander over these individual cylinders of the dryer 9 and are dried. Finally, the dried support tape T is rolled up in a winder 10.

[0044] Downstream of this winder 10, the textile support tape T can then be coated in a further step on at least one side with an adhesive. For this purpose, an applicator 11 is provided in the illustrated embodiment that applies the adhesive in question, for example in the form of a hot melt, by spraying it onto one side of the textile support tape T. Of course, this is only by way of example. The support tape T thus coated can then be cut longitudinally and wound to form adhesive tape rolls 12.

[0045] As the only FIGURE shows, individual phases of the production of the hand-tearable textile adhesive tape according to the invention can be carried out separately from each other, both in terms of location and time. It is possible, for example, to initially weave the textile support tape T. This textile support tape T is then made available at the supply 1 for further processing. In a supplemental second production step, the described alkalinization process is carried out with subsequent washing, neutralizing and drying, at the end of which the hand-tearable textile support tape T is ready on the winder 10. In a further third step, this hand-tearable textile support tape T can then be coated on at least one side with the adhesive, as shown schematically in the upper portion of the FIGURE. At the end of this process, the individual adhesive tape rolls 12 are available. It goes without saying that all processes can also be implemented in one continuous line.

[0046] The textile support tape that is used, as already described above, is a polyester woven textile support tape. This may be dyed black. The permeability of this tape to air is typically less than 500 mPa/sec (EN ISO 9237:1995; 2.0 mbar). The longitudinal stretch to break is approximately 25 plus/min 5% (DIN EN 14410:2003). The thickness of the adhesive tape produced by this support tape T is in the range of approximately 0.1 mm. The basis weight is approximately 70 g/m.sup.2.

[0047] The woven fabric is composed of approximately 31 warp filaments/cm and approximately 27 weft filaments/cm. Fineness is more than 2500 dtex/cm for the warp filaments. A comparable number applies to the weft filaments.

[0048] Finally, it should also be emphasized that the treatment with the processing liquid 4 in the treatment device 3 is controlled in such a way that the textile support tape T essentially has a tensile strength of less than 100 N/cm at the output of the treatment device 3. To achieve this in detail, the procedure employed within the scope of the invention is substantially empirically adjusting the treatment time within the treatment device 3, the concentration of the processing liquid or sodium hydroxide 4, the temperature thereof and the speed of passage in the travel direction A, under consideration of the above-described parameters, and by measuring the corresponding tensile strength values.

[0049] However, essentially it is also possible, for example, to vary the speed of the textile support tape T in the travel direction A to achieve the desired control. In this case, the tensile strength of the textile support tape T is measured in the starting condition at the input of the treatment device 3, and the tensile strength of the textile support tape T is also measured after passing through the treatment device 3. Depending on whether the tensile strength is less than 100 N/cm at the output of the treatment device 3, the throughput speed of the textile support tape T in the travel direction A can then be raised, and thus productivity can be increased.

[0050] In contrast, if the tensile strength of the textile support tape T at the output of the treatment device 3 is above 100 N/cm, this measurement calls for decreasing the throughput speed of the textile support tape T in the travel direction A. As a result, the processing or residence time in the treatment device 3 increases, and it is to be expected that the tensile strength is thereby decreased, with otherwise identical parameters.

[0051] In this context, the throughput speed can be successively reduced until the tensile strength has the desired value of less than 100 N/cm at the output of the treatment device 3. A comparable process can also be employed when it comes to setting the percentage decrease in the tensile strength of at least 5% at the output of the treatment device 3 compared to the starting condition on the supply for the desired control.