WO2023110512A1

WO2023110512A1 - Adhesive tape, in particular wrapping tape for sheathing cables in automobiles

Info

Publication number: WO2023110512A1
Application number: PCT/EP2022/084518
Authority: WO
Inventors: Timo Leermann
Original assignee: Certoplast Technische Klebebänder Gmbh
Priority date: 2021-12-15
Filing date: 2022-12-06
Publication date: 2023-06-22

Abstract

The invention relates to an adhesive tape, in particular wrapping tape for sheathing cables in automobiles, comprising a textile support on the basis of synthetic fibers and/or synthetic filaments, and an adhesive coating applied to one or both faces, the synthetic fibers and/or synthetic filaments being produced at least to some extent on the basis of a recycled PA (polyamide) plastic material. The recycled PA plastic material is obtained from the processing of industrial and/or post-consumer wastes.

Description

Adhesive tape, in particular wrapping tape for sheathing cables in automobiles

Description:

The invention relates to an adhesive tape and in particular a wrapping tape for sheathing cables in automobiles, with a textile backing based on plastic fibers and/or plastic threads, and with an adhesive coating applied to one or both sides, the plastic fibers and/or plastic threads being at least partially based on a PA (polyamide) plastic recyclates are made.

Adhesive tapes in which the textile backing is produced on the basis of plastic fibers or plastic threads with at least partial recourse to plastic recyclates are, for example, the subject of DE 20 2021 106 836 U1 of the applicant. Only PET (polyethylene teraphthalate) plastic recyclates are used here, which are easily and numerously available. Because such PET plastic recyclates are typically obtained from the processing of plastic hollow bodies and in particular PET bottles. Accordingly, the PET plastic recyclate in question is available in large quantities and at a low price, which favors processing and industrial use.

In addition, adhesive tapes with a textile backing and an adhesive coating applied to one or both sides are described in the applicant's DE 20 2019 100 588 U1, in which the textile backing is produced at least partially using bio-based polymers. In addition, bio-based polymer fibers and/or polymer threads are used. These can be produced by extrusion.

The use of bio-based polymers for the production of the textile carrier as an alternative to the use of PET plastic recyclates is particularly resource-saving because such bio-based polymers are produced using renewable raw materials based on plant materials. Plants or lactic acid have proven to be beneficial here. In this case, there is no need for a costly and sometimes energy-intensive processing of plastic waste, which makes bio-based polymers increasingly competitive.

Apart from PET plastic recyclates, no other plastics (apart from PET) have been used in practice and for the production of adhesive tapes for the reasons described above. In addition, the production of such adhesive tapes is still in its infancy, but is favored by the large and inexpensive availability of such PET plastic recyclates from bottles.

The generic prior art according to DE 10 2014 119 524 A1 already addresses an adhesive tape based on a sewn fleece backing with bicomponent fibers, in which at least the sewing threads required at this point can be made partially or completely from recycled plastics. Recycled polyester (PS), polyamide (PA), polyethylene (PE), polypropylene (PP) or polyurethane (PUR) are described in very general terms and not specified in detail, but without mentioning any further details. This can be attributed to the fact that at the time of registration (December 23, 2014) the processing of PET plastic recyclates was at best known. In this regard, reference is made to the explanations in DE 20 2021 106 836 U1 on the processing of PET obtained from hollow plastic bodies. This has basically worked.

More recently, some adhesive tapes have been described as wrapping tapes for sheathing cables in automobiles, some of which use PA (polyamide) fibers or threads in the production of the textile backing. An example of this is described in DE 20 2006 002 210 U1, which emphasizes the high abrasion resistance in connection with the use of polyamide as the fiber material, but at the same time lists the high costs as a disadvantage. In addition, the lack of hand tearability is criticized, so that the use of polyamide as a fiber material is limited to special cases. For this reason, PA plastic threads for the production of textile carriers for winding tapes for sheathing cables in automobiles have been produced in practice exclusively from new material (PA virgin). This is where the invention aims to remedy the situation overall.

The invention is based on the technical problem of providing an adhesive tape and in particular a wrapping tape for sheathing cables in automobiles, which has the advantages generally known with the use of plastic fibers and/or plastic threads based on a polyamide, such as tear strength and abrasion resistance, with reduced production costs at the same time combined.

To solve this technical problem, an adhesive tape of this type is characterized within the scope of the invention in that the PA (polyamide) plastic recyclate is obtained from the processing of industrial and/or consumer waste.

The industrial waste used at this point is advantageously that which results, for example, from fiber or thread production. Here, the invention is based on the knowledge that such yarn waste can be used advantageously as PA plastic recyclate.

In fact, such yarn waste is observed, for example, in the industrial manufacture of flat products such as parachutes, kites, sails and also textiles. Such textiles are often processed into fireproof clothing. Such textiles can also be used to produce automotive accessories such as airbags. In addition, the yarns in question can also be processed into fishing nets, for example.

This means that in addition to waste, for example from fiber or thread production, waste from automobile production can also be considered as a source for such PA plastic recyclates. In the context of automobile manufacture, the aforementioned waste is not only produced in the production of airbags, but also and particularly in the production of vehicle components such as lamp housings, fuel lines, tanks, pedals, etc. In this context, polyamides and in particular glass-fibre reinforced polyamides are often used. which, due to their high mechanical strength, are replacing many metal parts in vehicle construction because they are easier to manufacture overall and are lighter. In addition, complicated geometries can be realized in this way, as well as components in hybrid construction, i.e. in combination with other materials such as steel and recently even aluminum. Examples of this are bumpers or other body parts.

In addition, polyamides are also used in the production of housings for power tools, so that the industrial waste also occurs in this context as waste from the production or recycling of power tools and can be used according to the invention as PA plastic recyclate. In addition to power tools, polyamides are also used as a housing material for electronic components because they are particularly

are temperature-resistant and in this context allow temperatures of up to over 260°C for a short time without any significant change in shape.

In addition, general waste from mechanical engineering is a potential source, because precision engineering is increasingly using polyamides to manufacture gears, rollers, screws and nuts. Waste from filter manufacture is also suitable as an additional or alternative source. Because polyamides are often used as materials for filter fabrics, for example in connection with dialysis filters.

In addition, polyamides are also used, for example, in the manufacture of hoses in medical technology. In addition, as a suture material in surgery. In any case, the production and also the recycling of such hoses, for example for dialysis, is often associated with waste which, according to the invention, can advantageously be used as PA plastic recyclate. This means that the processed waste can be waste that arises during the production and/or recycling of the specified products.

This also applies to another source of PA plastic recyclate in the form of industrial waste. In fact, the industrial waste can also be that from fishing technology. Here, the invention is based on the knowledge that, for example, industrial fishnets typically consist of a net that is formed by knotting a thin thread. Polyamides are usually used for the thread. In addition to such fish masses, polyamides or polyamide threads are also used for other applications in fishing technology, for example for the production of ropes, as a component of rigging, etc., although the fishing nets or fish masses are by far the largest component here. Anyway it may be at this point

The processed waste is again waste that is generated during production and/or recycling, in particular of fishing nets that are available as PA plastic recyclate for the reasons outlined and logically.

In addition to using the industrial waste already explained in detail above, consumer waste can also be used as a source of recyclate. Consumer waste can be consumer goods such as clothing, mattresses, power tools, automobiles, but also foils, in particular PE (polyethylene)ZPA foils. This means that it is possible to recycle, for example, fireproof clothing or mattresses and to obtain the PA plastic recyclate used according to the invention from them. The same applies to the previously mentioned sails, kites, parachutes, etc.

A particularly large amount of PA plastic recyclate is produced during the preparation and recycling of automobiles, because this is where polyamides are increasingly used for lamp housings, fuel lines, tanks and also structural components. This applies in particular to glass fiber reinforced polyamides. Such glass fiber reinforced polyamides can recently also be processed and used as a source for PA plastic recyclate, as WO 2020/212186 A1 shows. Because this is about a process for recycling glass fiber reinforced plastics and in particular plastics based on polyamide.

In this context, the procedure is also and advantageously such that the PA plastic recyclate is mixed with PA virgin (new plastic) for processing the industrial waste and/or consumer waste. Here, the invention is based on the knowledge that to the textile carrier

processed PA plastic recyclates may not have the desired properties in terms of strength and abrasion resistance, so that depending on this, a certain proportion of PA virgin (new plastic) must or should be added.

In fact, it is generally worked in such a way that the mixing ratio has a maximum of 80% by weight PA plastic recyclate and up to 20% by weight PA virgin. In particular, a ratio of 70 percent by weight PA plastic recyclate and up to 30 percent by weight PA virgin is observed. The invention particularly preferably works with a mixing ratio of 60% by weight PA plastic recyclate and up to 40% by weight PA virgin.

Overall, it must be taken into account that the plastic recyclate contains or can contain an additional maximum of 10% by weight of non-plastics and/or foreign plastics. These non-plastics can be foreign matter in the PA plastic recyclate such as dirt, metal residues or PE residues and/or foreign plastics from the recycling of foils or other foreign components. The proportion of non-plastics and/or foreign plastics is very particularly preferably at most 5% by weight and in particular 2% by weight.

The textile backing produced in this way from the plastic fibers or plastic threads is advantageously a fleece, a woven fabric, a knitted fabric, a crocheted fabric, individually or in combination. This means that the textile backing can be designed either as a single layer or as a single layer or as a multilayer or multilayer. In the latter case, it is conceivable that, for example, a fleece backing is combined with a woven backing. In principle, the textile backing can also be equipped with a plastic coating on one or both sides. Typically, one has here

Backside coating opposite the adhesive coating proven to be particularly favorable in order to avoid any adhesion of the adhesive coating when the adhesive tape is rolled up on the textile backing.

The subject matter of the invention is also an elongate item such as, in particular, a cable set, which is sheathed with the adhesive tape in question. In principle, the adhesive tape for producing the elongate product can be wrapped around the product or cable harness as a longitudinal fold. However, it is just as conceivable and is encompassed by the invention for the adhesive tape to be wound helically or spirally around the cables of the cable set in order to produce the elongate product.

In addition, the adhesive tape of the invention usually has a temperature resistance of at least temperature class T3 according to LV 312 (10/2009). In this context, the temperature class T3 expresses that the sheathed cables and their cable insulation withstand the influence of the adhesive tape in combination with the increased temperature of 125 °C in the example of temperature class T3 without embrittlement for a minimum of 3000 hours.

In addition, the adhesive tape according to the invention is designed in such a way that its mechanical properties differ by only a maximum of 20%, advantageously by a maximum of 10%, from those adhesive tapes whose plastic fibers and/or plastic threads are made entirely of new material (PA virgin) with the same structure .

The mechanical properties mentioned are usually the abrasion resistance and the associated abrasion classes according to the LV 312 standard (10/2009). In fact, at this point the abrasion

classes A to G, as described in detail in DE 20 2014 011 328 U1. A deviation in the mechanical properties and in particular in the abrasion of the adhesive tape according to the invention by a maximum of 20% from an identically constructed adhesive tape in which the plastic fibers and/or plastic threads for producing the textile backing are made entirely of new material or new plastic with the same structure now means that the abrasion class achieved for the adhesive tape based on the new plastic is largely retained or at most a reduction by one abrasion class is observed. For example, there has been a decrease in abrasion class D (high abrasion protection) for the adhesive tape made from new plastic compared to the adhesive tape based on PA plastic recyclate fibers and/or PA plastic recyclate threads of the same structure, which achieves abrasion class C.

The mechanical properties mentioned can also be the elongation at break, which is determined according to the DIN EN 14410 standard. Typical elongations at break for such adhesive tapes are more than 20% and predominantly in the range from 30% to 40% for an adhesive tape with a carrier based on a new plastic, so that when using plastic threads based on recycled plastic, for example, the elongation at break decreases by the specified values 10% to 20% is observed or can be observed. In the example, this means that the elongation at break of the adhesive tape according to the invention is still greater than 15% or 16% and is preferably in the range from about 25% to more than 30%.

The same applies to the tear strength, which is generally above 100 N/cm and also falls only slightly in the case of the adhesive tape according to the invention, at least in the range between 10% and 20%.

at the maximum below the tear strength compared to the identically constructed adhesive tape with plastic fibers or plastic threads made of new material or new plastic with regard to its deviation. Of course, this depends very much on the respective textile structure of the wearer and is generally only to be understood as an example.

In contrast to the abrasion resistance, elongation at break and tear strength, however, with regard to the air permeability according to DIN EN ISO 9237 as well as with regard to the noise damping according to the previously mentioned LV 312, it can be expected that the adhesive tape according to the invention compared to an adhesive tape with the same structure a textile carrier made of new plastic shows no deviations. This means that the structural areal structure of the adhesive tape according to the invention corresponds to that of an identically structured adhesive tape made from new plastic.

Accordingly, the adhesive tape of the invention can replace the previously used adhesive tapes based on new plastic in practically all applications, in particular as a wrapping tape for sheathing cables in automobiles, without any significant deterioration in the result being observed at this point. This is where the main advantages can be seen.

The plastic recyclate obtained as a whole and from the industrial waste and/or consumer waste is then and regularly shredded if necessary. The snippets or "flakes" obtained in this way are then processed as granules by extrusion. Conventional procedures can be used for this. It is also possible to color the PA plastic recyclate.

It goes without saying that the textile carrier produced in this way can be produced in very different ways. For example, it is conceivable to work with a carrier made of a non-woven fabric with staple fibers or filaments that are partly made of PA plastic fibers or filaments based on PA plastic recyclate and partly made of PA plastic fibers or filaments based on new -Plastic or PA virgin are made. The mixing ratio of these plastic recyclate fibers or PA plastic recyclate fibers compared to the new plastic fibers or PA virgin fibers is in this case the previously described proportion of PA plastic recyclate compared to PA virgin im textile carrier produced in this way.

In addition, it is also conceivable in this context that the described non-woven fabric is strengthened by binders. In addition, additional threads can also be sewn into the non-woven fabric for strengthening, thereby realizing a sewn non-woven fabric. It is conceivable that only the sewing threads are designed as PA plastic recyclate threads, whereas the fleece as such is basically made of another plastic material, of PA virgin, of a mixture of PA virgin/PA plastic recyclate, etc.

In addition, the invention also includes a fleece which is additionally sewn over with threads that are produced on the basis of another plastic recyclate (as PA plastic recyclate). Threads or sewing threads made from recycled PET plastic and/or virgin PA have proven to be particularly good here. In contrast, the fleece is made on the basis of PA plastic recyclate.

Comparable variation possibilities arise in the event that the carrier is a woven fabric. In this case it is conceivable that the weft threads of the backing are constructed as PA plastic recyclate threads and the warp threads of the backing are constructed as PA virgin threads. Such an embodiment has proven itself in the event that a particularly high tear resistance in the longitudinal direction is to be achieved. Of course, the reverse procedure can also be used.

In addition, the invention also includes embodiments in which only the weft threads are designed as PA plastic recyclate threads, whereas the warp threads of the fabric in question can be made of another plastic, for example PET. Since the weft threads are typically responsible for the abrasion resistance of the adhesive tape, high abrasion resistance is achieved even with such an embodiment of the textile backing. At the same time, such an adhesive tape is designed so that it can be torn by hand because the PET threads running in the warp direction can easily be severed by hand at this point.

Either way, the desired property of the adhesive tape produced in this way can be specifically achieved or deepened by the targeted selection and mixing of the PA plastic recyclate fibers or PA plastic recyclate threads with the PA virgin fibers and/or PA virgin threads . Similar variation possibilities open up in the event that the textile backing is designed as a knitted or crocheted fabric and when a multi-layer backing is used.

Claims

Patent Claims:

1. Adhesive tape, in particular winding tape for sheathing cables in automobiles, with a textile carrier based on plastic fibers and/or plastic threads, and with an adhesive coating applied to one or both sides, the plastic fibers and/or plastic threads being at least partially based on a PA ( Polyamide) plastic recyclates are produced, characterized in that the PA plastic recyclate is obtained from the processing of industrial and / or consumer waste.

2. Adhesive tape according to Claim 1, characterized in that the industrial waste is waste, for example, from fiber or thread production, from automobile manufacture, from mechanical engineering and the manufacture of power tools, from filter manufacture, from hose manufacture and Medical technology and fishing technology as well as corresponding recycling processes are used individually or in combination.

3. Adhesive tape according to Claim 1 or 2, characterized in that the consumer waste is consumer goods such as clothing, mattresses, power tools, automobiles, sails, kites, parachutes, foils, etc.

4. Adhesive tape according to one of claims 1 to 3, characterized in that for processing the waste, the PA plastic recyclate is mixed with PA virgin (new plastic) in a predetermined mixing ratio.

5. Adhesive tape according to claim 4, characterized in that the mixing ratio is a maximum of 80% by weight PA plastic recyclate and up to 20% by weight

PA virgin, in particular a maximum of 70% by weight PA plastic recyclate and up to 30% by weight PA virgin and particularly preferably a maximum of 60% by weight PA plastic recyclate and up to 40% by weight PA virgin contains.

6. Adhesive tape according to one of Claims 1 to 5, characterized in that the PA plastic recyclate contains a maximum of 10% by weight, in particular a maximum of 5% by weight and preferably a maximum of 2% by weight of non-plastics and/or foreign base materials.

7. Adhesive tape according to one of Claims 1 to 6, characterized in that a fleece, woven fabric, knitted fabric or crocheted fabric is used individually or in combination as the textile carrier.

8. Adhesive tape according to claim 7, characterized in that the textile backing is produced as a mixture of fibers or filaments based on PA plastic recyclates and those based on PA virgin.

9. The adhesive tape as claimed in claim 7 or 8, characterized in that the fleece is additionally sewn over with threads which are produced on the basis of recycled plastic and in particular recycled PET plastic.

10. The adhesive tape of claim 7 or 8, characterized in that the fabric of the textile backing is constructed with weft threads constructed as PA plastic recyclate threads and PA virgin threads as warp threads, or vice versa.

11. The adhesive tape as claimed in one of claims 7 to 10, characterized in that the fabric of the textile backing is formed from a different plastic material with weft threads in the form of PA plastic recyclate threads and warp threads. 15

12. Adhesive tape according to claim 11, characterized in that the warp threads are PET warp threads.

13. Elongated goods, in particular cable sets, covered with an adhesive tape according to one of claims 1 to 12.

14. Elongated product according to claim 13, characterized in that the adhesive tape is wrapped around the product as a longitudinal fold.

15. Good according to claim 13, characterized in that the adhesive tape is wound helically around the good.