DE102008025580A1 - Winding core for producing wound adhesive tape, has compression layer formed in carrier and provided with wave-shaped cross-section, where outer region of carrier is joined to upper side of compression layer - Google Patents

Abstract

The core has a compression layer (3) formed in a band-shaped carrier (2) i.e. polyvinyl chloride sheet, and provided with a wave-shaped cross-section. The carrier has an inner region comprising a lateral area to which a lower side of the compression layer is joined. An outer region of the carrier is joined to upper side of the compression layer. The compression layer has a material thickness of 0.15 millimeters to 0.4 millimeters. The carrier is coated with an adhesive i.e. acrylate adhesive.

Description

The The invention relates to a winding core for adhesive tapes, uses of the winding core for the Production of wound adhesive tapes and a wound adhesive tape.

Adhesive tapes will be for a long time for insulating, wrapping and bundling of wires, cables or other objects used. Such adhesive tapes, which are used for example in the automotive industry, usually comprise a band-shaped Support material which is coated on one side with an adhesive. For coating of the carrier material with the adhesive, in some cases, a primer on the side first of the carrier material applied to which then the adhesive is applied.

To Their purpose, these tapes are also called insulating tapes or Cable winding tapes designated.

The described tapes usually exist made of plasticized PVC films as a carrier material, on the one side the adhesive coating has been applied. Plasticized PVC films are hereafter for the sake of simplicity also referred to as soft PVC films.

Adhesive tapes on Basis of such soft PVC films are in automobiles for bandaging used by electrical wires to harnesses. Stand in the beginnings the improvement of electrical insulation when using this originally as insulating tapes developed adhesive tapes in the foreground, so must these now fulfill additional functions, like bundling and permanent fixation of a plurality of individual cables to one stronger cable harness, protecting the cables against mechanical, thermal and chemical environmental influences.

Around newer claims to comply with environmental protection, There has been a trend for years, solvents in production of adhesive tapes to avoid. In particular, in the automotive industry is increasingly required that the products used no solvents (which also VOCs ("volatile organic compounds ") be).

There for soft PVC films a coating with hot-melt adhesives technically difficult and consuming, this problem is usually the manufacturers solved with water-based adhesives. Examples of such water-based Adhesives are watery Styrene-butadiene copolymer adhesives (hereinafter referred to as SBR adhesives referred to) and acrylate adhesives. Usually, aqueous SBR adhesives used the solvent-based Rubber compounds are modeled.

Compared to SBR adhesives Acrylate adhesives offer certain advantages. For one thing, it stays behind a long-term storage of the self-repair mechanism (also millipede effect designated). This self-repairing mechanism shows up in that the adhesive is neither laked nor greasy. To the other carries the use of acrylate adhesives significantly improves the better temperature resistance of the total composite carrier material / primer / adhesive at. A carrier material is usually upgraded by a temperature class, if instead a rubber compound, an acrylate adhesive is used.

One Disadvantage of the use of acrylate adhesives in the production the tapes however, is an asymmetric volume effect that the acrylate adhesives have cause. This asymmetric volume effect causes a net increase in thickness of the entire adhesive tape, resulting in tensions within the adhesive tape, that on a winding tube wound up leads.

aqueous Adhesives have in combination with plasticized PVC films also the disadvantage that the plasticizer from the films in the adhesive diffuses, thereby causing an excessive, internal tension between the individual layers of the wound into a roll of adhesive tape comes. This tension leads then, provided no countermeasures are made to a deformation of the role, what also called "telescoping" becomes. Another negative effect is the bleeding of the adhesive mass, the also referred to as "oozing" becomes. Although these disadvantages can be changed by some formulations for some Adhesives or special roll cores with foam but both options are not worth striving for.

A changed formulation leads to significant cost increases. Foam-coated roll cores consist of a paper core with a foam sheath that acts as a compression layer serves. Such a roll core is not only very expensive, it is also disadvantageous for waste disposal and environmental reasons.

task The invention is to the disadvantages of the prior art remove. In particular, a winding core should be specified, on the one hand effectively prevents telescoping and oozing and on the other hand cheaper can be produced.

These The object is solved by the features of claims 1, 13 and 16. Advantageous embodiments The invention will become apparent from the features of claims 2 to 12 as well as 14 and 15.

To proviso the invention provides a winding core for an adhesive tape, the one carrier and a compression layer, wherein the compression layer has a wavy Cross section has. The compression layer is preferably concentric to the longitudinal axis of the carrier educated.

In a first embodiment adjoins the compression layer on the lateral surface of the carrier. This will be between the lateral surface of the carrier and the compression layer cavities educated.

In a second embodiment is the compression position in the carrier self trained. Preferably, the carrier comprises a first, radially inner region, on whose lateral surface the Bottom of the compression layer adjacent, and a second, radially outer region, which is adjacent to the top of the compression layer. In this embodiment be between the bottom of the compression layer and the lateral surface of the first area and between the top of the compression layer and the radially inner surface the second area cavities educated.

The Formation of the cavities is on the wavy Attributed cross section of the compression layer. Leave the cavities a compression of the compression position. The compression layer according to the invention so can the particular when winding an adhesive tape on the Winding core and the later Expansion of the adhesive mass resulting forces. This allows the Waiver of a foam layer, what in the production and the Disposal of the winding core is of particular advantage.

Under the term "compression position with wavy Cross section "is according to the invention in particular a situation understood, the ring-shaped or tubular shaped is, wherein the wall of the ring or tube has a wave-shaped cross-section having. The compression layer with a wave-shaped cross section will be described below also as wavy Called compression layer. The compression layer may be in the wearer or on the carrier be educated.

Surprisingly It has been shown that neither the exact shape or size of the undulating compression position nor the exact alignment of the wave-shaped compression position the carrier affect the compression and thus the telescoping behavior of a roll of adhesive tape. Therefore, the compression layer can be arbitrarily shaped as long as they are a wavy one Cross section has. For example, the waves of the compression layer in the axial direction of the winding core spirally or parallel to the longitudinal axis of the carrier run. By when winding the tape and through The expansion of the adhesives resulting forces is a compression of the Compression position causes and thus a change in shape of the adhesive tape roll prevented.

The Compression layer preferably has a material thickness of 0.15 to 0.4 mm. The maximum extent of the compression position (Wave height) in the radial direction preferably 1 to 3 mm. It can all or only a part of the maxima of the crests the maximum extent the compression layer in the radial direction. In the latter Fall should be the wave crests whose maximum is the maximum extent the compression position, be evenly distributed over the compression layer. Thus, you can the crests of the compression layer have the same maximum extension or different maximum expansions in the radial direction exhibit.

The material thickness the compression position influences the compression behavior of the compression layer, while the maximum extent of the compression layer the compression path certainly.

All or part of the minima of the troughs of the compression layer may become in contact with the lateral surface of the carrier are located. In the latter case, the troughs, their minima should be in contact with the lateral surface the carrier stand, evenly over the Be distributed compression position.

The Compression layer is preferably before placing it on the carrier preformed to receive its undulating cross-section. To This preforming then becomes the undulating compression layer on the carrier applied.

Of the The winding core may further comprise a second layer disposed on the radially outer surface of the compression layer is applied. The maxima of the wave crests of the Compression layer in contact with the underside of the second layer are located. In this way, there are cavities between the second layer and the compression layer formed. The second layer is covered the troughs and close the winding core to the outside down. The second layer ensures a flat surface for the tape to be wound, which simplifies the winding process and ensures that the first layer of the roll-wound Do not stick tape through the adjacent wavy surface of the tape Compression layer is deformed.

Of the Carrier, the compression layer and the second layer are preferably of the same Formed paper material or different paper materials, wherein it is particularly preferred that they are made of the same paper material are formed. It is particularly advantageous if the winding core according to the invention Completely made of a material, such as a paper material is because it simplifies its manufacture and disposal and thus Saves costs. Are different paper materials provided, so should at least similar ones Paper materials chosen become. Paper materials are then similar in the sense of the invention, if their joint disposal according to environmental regulations permissible is.

The Paper material for the compression position selected is, preferably has a residual moisture content of 1 to 10%. The Residual moisture influences the compression behavior of the compression layer.

Of the carrier preferably has a circular or annular Cross-section on, leaving the carrier cylindrically is. Preferably, the winding core is formed as a winding tube, to which the carrier has an annular cross-section should have. The carrier takes care of the necessary strength of the winding core. On the lateral surface of the carrier Preferably, the compression layer is applied, so that the compression layer the lateral surface of the carrier Completely encloses. The strenght the jacket of the annular or tubular support needs Not to be further described here, as they are for the compression behavior is irrelevant. It can, for example, between 2 and 5 mm, in particular 3 mm.

Of the Inner diameter of the hub, comprising the carrier, the Compression layer and, if provided, the second layer, can from Vary from 1 "to 6". The length of the hub in his axial direction can be 9 mm to 1.8 m.

Of the inventive winding core is especially as a hub for tapes suitable. The tape is doing on the hub in known Wound, whereby a roll-shaped adhesive tape is obtained. The adhesive tape can be used, for example, for insulating, winding and fixing of wires and cables.

The Adhesive tape preferably has a band-shaped carrier, which on one side with an adhesive is coated. An exemplary adhesive tape comprises a film of plasticized polyvinyl chloride (PVC), which with a Poly (meth) acrylate adhesive, preferably a self-adhesive, is coated. The band-shaped carrier of the adhesive tape, for example, a thickness of 40 microns to 350 microns, preferably 70 μm to 150 μm. In principle, the winding core according to the invention is independent of all adhesive tapes the formulation of the band-shaped carrier for the Adhesive tape and the adhesive composition suitable.

The The invention is explained below with reference to drawings. there demonstrate

1 a schematic cross-sectional view of a roll-shaped adhesive tape with a first embodiment of the invention, the winding core, comprising a tubular carrier and a compression layer;

2 a schematic cross-sectional view of a roll-shaped adhesive tape with a second embodiment of the invention, the winding core, comprising a tubular carrier, a compression layer and a second layer adjacent to the compression layer;

3 a schematic cross-sectional view of a roll-shaped adhesive tape with a third embodiment of the invention, the winding core, comprising a tubular, zweeili gene carrier and a compression layer which is incorporated in the carrier; and

4 a schematic representation of the cut adhesive tape for testing the flagging behavior of the adhesive tape.

In the 1 shown first embodiment of the winding core according to the invention comprises a tubular support 2 that the core of the adhesive tape roll 1 forms. On the outer surface of the carrier 2 is a compression position 3 applied, which has a wave-shaped cross-section. The waveform is in 1 at the troughs 5 and the wave crests 4 recognizable. The troughs 5 are in contact with the outer surface of the carrier 2 while the wave mountains 4 in contact with the first, radially inner layer of the adhesive tape. The cavities 6 between the first, radially inner layer of the adhesive tape and the compression layer ( 3 ) On the one hand and between the outer surface of the carrier 2 and compression position 3 allow a reversible compression of the compression layer 2 when the wound tape expands.

It is in 1 to recognize that the wave crests and troughs can have different heights and widths. As explained, this is possible because of the exact shape of the compression layer 3 has no influence on their compressibility.

In the 2 shown second embodiment of the winding core according to the invention additionally has a second layer 8th on, on the radially outer surface of the Com pressionslage 2 adjacent to their maxima. This second location 8th is in contact with the first, radially inner layer of the adhesive tape 7 , The further location 8th prevents deformation of the inner layer of the adhesive tape 7 ,

The in 3 shown winding core consists of a two-part support 2 , in the compression position 3 is introduced. In this case, the carrier 2 a first radially inner region 2.1 and a second, radially outer region ( 2.2 ) on. The first, radially inner area 2.1 of the carrier 2 is in 3 tubular or annular. The first, radially inner area 2.1 However, it may be formed as a cylindrical solid body. The second, radially outer area 2.2 of the carrier 2 is ring-shaped or tubular. The inner diameter of the second, radially outer region 2.2 is larger than the outer diameter of the first, radially inner region 2.1 , wherein the difference between the inner diameter of the second, radially outer region 2.2 and the outer diameter of the first, radially inner region 2.1 the maximum extent of the compression position 3 corresponds in the radial direction. As in 3 shown, adjacent to the outer circumferential surface of the radially inner region 2.1 of the carrier 2 the bottom of the compression layer 3 while the top of the compression layer 3 to the radially outer region 2.2 of the carrier 2 borders. The troughs 5 the compression position 3 are thus in contact with the outer surface of the radially inner region 2.1 while the wave mountains 4 the compression position 3 in contact with the radially inner circumferential surface of the second region 2.2 are located.

Examples

It Adhesive tape rolls were produced with four different winding cores. For all rolls of adhesive tape, the same adhesive tape was used. This adhesive tape consisted of a carrier film of plasticized Polyvinyl chloride (PVC), which was coated with an acrylate adhesive. apart of the winding core used were all parameters in the production the rolls of adhesive identical. The winding core, if present including the Compression layer and the second layer, had one in all cases Diameter of 1.5 ''.

Prüfling 1:

Klebebandrolle mit einem Standard-Papierwickelkern (Vergleichsversuch);

Prüfling 2:

Klebebandrolle mit einem Papierwickelkern, der mit einer Polyethylenschaumstofflage überzogen war (Vergleichsversuch);

Prüfling 3:

Klebebandrolle mit einem Wickelkern gemäß 1;

Prüfling 4:

Klebebandrolle mit einem Wickelkern gemäß 2.

The following test pieces were produced:

Test item 1:

Adhesive tape roll with a standard paper winding core (comparative experiment);

Test item 2:

Adhesive tape roll with a paper winding core coated with a polyethylene foam layer (comparative experiment);

Sample 3:

Adhesive tape roll with a winding core according to 1 ;

Test item 4:

Adhesive tape roll with a winding core according to 2 ,

at the test items 3 and 4, the wearer passed the compression layer and optionally the second layer of the same Paper material.

The samples 1 to 4 were prepared by methods which are usually used to determine the Flagging Ver be used on a laboratory scale and are set out in the specifications of the car manufacturers. Standard is the controlled temperature of adhesive baths with a carrier film made of plasticized PVC and given dimensions. Accordingly, the specimens were stored for five hours at 50 ± 2 ° C, then cut and measured the displacement of the cut side (telescoping). 3 shows a section 9 from a roll of adhesive tape with several superimposed layers 10 of the adhesive tape, whereby the width of the region A lying between the arrows is measured. The telescoping causes an increase in the width of the area compared to the width of the area before the temperature. Table 1 shows the change in width compared to the width before tempering.

The Adhesive tape rolls were visually checked for bleeding of the adhesive (oozing) examined.

• * Vergleichsversuche

The results of the tests are shown in Table 1: TABLE 1 Test item no. telescoping Oozing Before the exam [mm] After 5 h tempering [mm] 1* 0 7 Yes 2 * 0 0 No 3 0 0 No 4 0 0 No

• * Comparative experiments

From Table 1 shows that a compression layer to avoid the telescoping effect is necessary. Such a compression layer have the specimens 2 . 3 and 4 on. It was also found that the undulating compression position of the specimens 3 and 4 Telescoping and oozing are prevented as well as the foam layer. Because the compression position of the specimens 3 and 4 However, it may be made of paper, ie consists of the same material as the paper core, both cost advantages and environmental benefits are achieved with the test specimens according to the invention.

1

tape roll

2

tubular carrier

2.1

first area of the carrier 2

2.2

second area of the carrier 2

3

compression layer

4

Wellenberg

5

trough

6

cavities

7

wound duct tape

8th

second location

9

neckline the roll of tape

10

location of the tape

Claims (16)

Winding core for an adhesive tape, wherein the winding core is a carrier ( 2 ) and a compression layer ( 3 ), characterized in that the compression layer ( 3 ) has a wave-shaped cross-section. Winding core according to claim 1, characterized in that the compression layer in the carrier ( 2 ) is formed, wherein the carrier ( 2 ) a first inner area ( 2.1 ), on the lateral surface of the underside of the compression layer ( 3 ) and a second outer area ( 2.2 ), which is at the top of the compression layer ( 3 ). Winding core according to claim 1, characterized in that the compression layer ( 3 ) to the lateral surface of the carrier ( 2 ) adjoins. Winding core according to claim 3, characterized in that it further comprises a second layer ( 8th ), which on the radial outer surface of the compression layer ( 3 ) is applied. Winding core according to claim 4, characterized in that the maxima ( 4 ) the wave crests of the compression layer ( 2 ) in contact with the underside of the second layer ( 8th ) are located. Winding core according to one of the preceding claims, characterized in that the compression layer ( 3 ) has a material thickness of 0.15 to 0.4 mm. Winding core according to one of the preceding claims, characterized in that the compression layer ( 3 ) has a maximum extension in the radial direction of 1 to 3 mm. Winding core according to one of the preceding claims, characterized in that the wave crests of the compression layer ( 3 ) have the same maximum extension or different maximum extensions in the radial direction. Winding core according to one of the preceding claims, characterized in that the minima of the troughs ( 5 ) of the compression layer ( 3 ) in contact with the lateral surface of the carrier ( 2 ) are located. Winding core according to one of the preceding claims, characterized in that the support ( 2 ) and the compression position ( 3 ) are formed of the same material. Winding core according to one of the preceding claims, characterized in that the support ( 2 ), the compression position ( 3 ) and, if present, the second layer ( 8th ) are formed of the same paper material or different paper materials. Winding core according to one of the preceding claims, characterized in that it is designed as a winding tube, wherein the carrier ( 2 ) has an annular cross-section. Use of a winding core according to one of claims 1 to 12 for the production of a wound adhesive tape. Use according to claim 13, characterized in that the adhesive tape ( 7 ) has a band-shaped carrier which is coated on one side with an adhesive. Use according to claim 14, characterized that the band-shaped carrier a plasticized polyvinyl chloride film which is coated with an acrylate adhesive is coated. Adhesive tape, wrapped on a hub after one the claims 1 to 12.