DE1809856A1 - Fabric made of fibers glued together and process for its manufacture - Google Patents

Description

Fabric glued together from fibers and process for making it It is well known that the maximum possible strength of the fibers is obtained with fiber structures, if this is stretched to a large extent to its full length and in an aligned position in one Association are held together. Stretching devices are used in the textile industry used to make yarn and thread from continuous, from individual Fibers formed strands partially achieve such alignment. Recently one has used stretching devices with which the fiber strands are spread and stretched are, so that flat corrugated webs of aligned fibers are formed, the afterward be glued by suitable adhesives and afterwards form a self-supporting fabric. When the webs are stretched up, they are made of staple fibers approximately 80 to 95% of the fibers are oriented in the machine direction. A great deal alignment is important to the present invention and is conventional over to distinguish carded webs in which only about 50 to 70% of the fibers are in Are aligned lengthways. The designation "upright track" indicates in the following always a 3 tooth in which the fibers are between about 80 to 95% in the machine direction are aligned.

Have webs of stretched fibers connected with adhesive compared to conventionally carded and similarly glued webs pro Weight unit a potentially higher tensile strength. However, it is difficult maintain the orientation of stretched fibers in such webs while the adhesive is applied, with which the fibers become a coherent, self-supporting Railway should be connected. This is a particular problem with processing a very thin, light-weight structure of stretched and aligned fibers with little denier, see B. in the range between 0.5 to 3 or an equivalent thereof. Non-glued fiber structures, which are made exclusively from highly stretched fibers in of the order of magnitude mentioned above are extremely sensitive, and it is difficult to keep the fibers of such webs stretched and in alignment to hold while a suitable adhesive is applied. Because the teeth are so fine sInd, the adhesive must be applied in such a way that it makes firm contact enters with the majority of the fibers in order to achieve sufficient strength and you get a usable, self-supporting product. The glue should also be flexible enough to allow for a stiffening and a loss of the desired Avoid feeling when touching.

Lubricants that have sufficient substance to meet these requirements and strength can best be achieved with an immediate printing process be carried on the web. If the web is strong enough and the fibers are oriented is unimportant, this technique can be used without difficulty. If those However, printing technology is used for fibers emerging from the stretching device, the high loads are not able to cope with, even when reducing the Adhesive on low * possible adhesive strength found that the adhesive tends to Pulling fibers out of the stretched web so that the aligned dressing destroyed and the desired uniform construction torn apart.

The invention is based on the object of avoiding these disadvantages. This is the case with one made of fibers glued together Substance according to the invention achieved in that the fibers of the fabric are stretched to a largely full length are aligned between about 80 to about 95 in one direction and one Stack length in the range between about 1.5 cm and about 7.5 cm with a minimum length of 2.5 cm for the majority of the fibers, and that for the cohesion of the Fibers in their stretched and aligned state have such a relaxed pattern Made of flexible adhesive, it is used to ensure that the spacing in the pattern is smaller than the average length of fibers and not more than 25 ffi of the total area of the fabric is covered.

In a further embodiment of the invention there is a method for Manufacture of such a fabric in that several strands of fibers next to each other arranged a stretching device for producing a web of upright, aligned Fibers are fed that a relaxed pattern of flexible glue on the surface of a carrier tape provided with a repellent layer is printed on which is then taken with the web, which is still kept under tension Pressure is brought into contact so that the individual fibers are embedded in the adhesive be, whereupon the adhesive is allowed to harden or is caused to harden, and that then the bonded fiber web is stripped from the carrier tape.

The invention provides a product with high strength in the longitudinal direction.

The invention is explained in more detail below with reference to the drawing. 1 shows a perspective view of a device for implementation of the method according to the invention; Fig. 2 is a schematic side view of another Execution of the device; 3, 4 and 5 show various examples in plan view of products made according to the invention.

In the embodiment according to FIG. 1, several are made of textile fibers existing strands ii from storage cans, not shown, via a guide comb 13 drawn in a juxtaposed Anadnung into a stretching device 15, the several Includes pairs of knurled rollers 14 and 14a. The roller pairs are by means of a known transmission driven so that the peripheral speed of a pair always greater than that of the previous pair iG when passing through the stretching device 15, the individual fibers are subjected to tensile stress and spread apart so that they have a flat, corrugated arrangement largely aligned Form fibers in the form of a web 16. The web 16 is, as described below, brought into contact with a carrier tape 17 while maintaining the tension, a pattern of glue has been applied to the surface beforehand. With the present Embodiment, the carrier tape 17 consists of a continuous paper tape, which is treated with a repellent at least on its upper side. Such repellent layers are known and can be silicones, tetrafluoroethylene, Contain bed acid metal complexes, certain acrylic polymers and similar substances. Heat-resistant films or thin metal strips treated with repellent substances can also be used as a carrier tape. Before the web 16 from the carrier tape 17 is detected, the latter is provided on its with the repellent layer Surface with a pattern of resilient, thermoplastic adhesive, as indicated at 18a and 18b. At 18a the glue is on the underside of the Carrier tape, which, however, after passing the roller 19 to the top, whereby the Pattern 18b then directly touches the web 16. The pattern is for illustration purposes only made visible. The carrier tape 17 is at a speed around the roller 19 out, which is slightly greater than the conveyor speed of the last The pair of rollers 14 and 14a is to keep the web 16 under slight tension hold so that the stretched fibers are in their aligned and fully stretched State remain. A heated roller 20 drives the carrier tape 17 at one speed which continues to generate sufficient voltage.

In order to apply the adhesive to the carrier tape in the method described to apply, this is passed from a supply roll 21 through a gap, -der between a pressure roller 22 and one resting against this with light pressure Roller 24 is located. The surface of the pressure roller has a gravure pattern 23 provided, the adhesive 25 from the container 26 receives. The excess part of the applied material is removed by a Abstreifmeger 27, so that only the intaglio pattern in-the surface of the roller remains filled.

The pressure roller 22 then transfers this metered amount of the adhesive in a predetermined pattern on the underside of the repellent layer provided carrier tape 17. The pattern shown in Fig. 1 has the form of interrupted, parallel lines running across the tape that form a masonry-like pattern which is designated by 31 in FIG. 4.

Since the surface of the carrier tape 17 with a repellent layer is provided, the adhesive does not penetrate into the carrier tape, but remains largely as a sticky mass on its surface. The printed After leaving the pressure roller, carrier tape 17 is drawn around roller 19, which is is located just behind the stretching device 15 and is - as mentioned above - with a Peripheral speed driven, which is slightly greater than the conveyor speed which is the last two roles in the stretching device. The one from the stretching device Exiting web 16 is on the adhesive 18b, which is located on the carrier tape 17 applied, and the contact under tension is made by the adhesive and maintain the speed difference. The persistence of tension prevents the fibers in the web from losing their aligned position.

The printed tape 17 with the tensioned web thereon 16 is then drawn around a heated roller 20 where the bonding and curing of the adhesive with firm contact with the web 16 largely completed and thus the individual fibers are glued together. So that the glue is perfect hardens, it is desirable that the combination of carrier tape and fiber web form a large wrap angle on the roller 20. A calender roll 28 is located under pressure on the roller 20 where the combination leaves the roller so complete embedding of the fiber web 16 in the adhesive by additional pressure is effected. In this way the fibers are largely maintained while maintaining their aligneddn Glued position.

After leaving the calender roll 20, the bonded web 16a of the repellent layer of the tape 17 is stripped off and into a finished roll 29 wound up. In most cases, the material is still clamped before it is stripped. The carrier tape 17 is wound up into a roll 30 for reuse.

With the method according to the invention, a light, glued one is thus achieved Web produced from upstretched fibers in which the fibers are in their by the stretching device create-uen aligned position are anchored. During application and hardening of the adhesive, the web 16 is kept under constant tension, whereby a Structure with high strength / weight ratio is obtained.

Known adhesives can be used, but advantages result When using plastisols, the colloidal solutions of synthetic plastics in a suitable organic ester plasticizer, and those under the influence Develop good adhesive strength when exposed to heat, but remain soft and flexible at the same time. Many adhesives of this type are known, however, according to the present Product manufactured in accordance with the invention, in particular vinyl chloride polymers and copolymers of vinyl chloride with other vinyl plastics that have a plasticizer made from organic Containing phthalates, sebacinates, adipates or phosphates are particularly suitable proven. These substances result in a fast-curing plastisol adhesive that stands out through relatively low viscosity, low tendency for plasticizer migration and a minimal Volatilization. Such adhesives remain soft and after curing flexible and ensure that the end product has the desired softness and creates the desired feeling when touched.

Having generally described the invention as follows a detailed embodiment is given.

An endless paper tape made of Kraft paper was used as the carrier tape 17 No. 40, which was provided with a repellent layer on both sides. The repellent layer in the present case was a Werner-type chromium complex in isoproponal, which is available under the trade name Quilon.

One side of the repellent layer was covered with a plastisol adhesive in a masonry-like pattern of spaced parallel, interrupted ones Lines that extended across the tape were printed. The pattern made of material covered about 20 ffi of the surface. The glue was used in an amount of about 7.2 g / m2 and consisted of about 100 parts of polyvinyl chloride, which is about 48 Parts by weight of dioctyl phthalate and solvent to a Brookfield viscosity of about 3200 centipoise using a # 4 spindle at 20 rpm became. The multiple strands consisted largely of 6.4 cm long Fibers, from 1.5 denier viscous rayon fed to a stretching device, around a flat web of drawn up fibers 2 weighing approximately 8.5 g / m in which approximately 90% of the fibers are aligned parallel in the machine direction was. The stretched web came into contact after being discharged from the stretching device brought with the adhesive printed carrier tape 17. The web was during their passage from the stretching device to the printed carrier tape by drive of the carrier tape at a slightly higher speed than the conveyor speed the web held under tension by the stretching device. The one with the carrier tape The combined web was then tensioned over a roller heated to about 1630 ° C pulled, whereby the adhesive largely hardened and pressed the fibers into it were then calendered. The calender stage is not important, but useful to get a smoother and more firmly bonded product.

The stretched sheet set by the adhesive was then removed from stripped from the carrier web and wound into a roll. After stripping the conveyor belt was also wound up separately for further use.

Except the ones in Big. 1 and 4 shown patterns with interrupted Lines that are spaced in a parallel array across To extend the web, other patterns can be used. Examples of such Patterns are shown in FIGS. 3, 4 and 5. In these figures the glue is with 31, while the aligned fibers have the reference numeral 32. It Many other patterns can of course also be used. Preferably that is Use X pattern, however, loosened it up so that the entire area was covered by the adhesive Area no more than 25% of the total area, preferably only about 15 P or less covered by this area. It is also important that no matter what pattern The desired loosened configuration was used, the distance between the adhesive zones - measured in the longitudinal direction of the web, smaller than the average length of fibers should be in order to maintain the integrity of the web in the transverse direction.

The fibers used in the process can be common to textiles Be staple fibers. This includes both natural and synthetic Fibers, e.g. cotton, viscose or acetate rayon, nylon, polyester, acrylonitrile, Polyolefins and the like. In synthetic fibers, a denier range is between 0.5 and 3 preferred. However, a coarser denier can also be used. Preferably The fibers should also have a staple length in the range between 1.5 and 7.5 cm and have more, the majority should be in the range of 2.5 cm in length. The stretched one Railway should be as easy as this in relation to the processing possibility is possible on the stretching device. Appropriate tracks in one weight range between 3.6 to 23.9 g / m2 could be stretched with success: and fixed with glue at speeds between 6 and more than 150 m / min. The trindling method can also be used to produce sheets with a higher weight will.

Fig. 2 shows another embodiment of the method according to the invention. With this arrangement, a plurality of fiber strands 41 are drawn through the stretching device 45 stretched and aligned and as a tensioned Paserbahn 46 with an endless carrier band 47 brought into contact, the surface of which has repellent properties, and on which a pattern of adhesive has previously been applied. The carrier tape confirms z. B. made of woven glass fibers, the surface of which is coated with a tetrafluoroethylene plastic is coated. Before the web 46 is applied to the carrier tape 47, the latter printed with a pattern of adhesive by means of the pressure roller 42. Preferably the platen 42 has a gravure pattern of the type described above. The adhesive 43 is fed to the pressure roller 42 through a feed roller 44, the excess of the adhesive is removed by a doctor blade 40. The printed tape runs around a guide roller 48 at a speed slightly greater than the conveyor speed the last Pair of rollers of the stretching device is? so that the fibers are kept under tension in the web brought into contact with the carrier tape. The tape 47 with the applied web 46 then runs with pressure to a heated Roller 49. The heated roller 49 hardens the adhesive while being pressed of the tape, the fibers are more securely embedded in the adhesive. The carrier tape 47 and the web 46 are cooled by a fan 57 after leaving the drum 49, to make sure the glue has hardened. After cooling down, they will Carrier tape and the web with the fibers embedded in the adhesive at the fold-up point 50 separated. The web 46 then passes over rollers 55 and 56 and becomes roller 49 returned, where it is pressed on by means of a calender roller 51. This calendering process leads to a smoother web and a further setting of the adhesive, so that a stronger cohesion between glue and fibers is achieved. The calendered web then runs over guide rollers 52 and the spool carrier roller 53, after which they finally is wound up as a finished coil 54.

As has already been described with reference to FIG. 1, this is the calendering process not essential, but leads to a smoother and stronger cohesion of the product. The end product is similar to the product1 that you get when using the in conjunction with the method described in Fig. 1 is obtained.

The end product can easily be used as a wrapper for sanitary napkins, Bandage eye and the like can be used because its properties are low Weight, high porosity and its good strength-to-weight ratio in the longitudinal direction are useful for such uses. The product can also be further processed in which several layers are placed on top of one another, eo that an additional Strength in the transverse direction gives and another application in sanitary products is possible. In the case of a version with a greater weight, an application is also possible for disposable wipes, dusters, towels, sheets, iron covers, medium and The like. Such a stratification can be achieved by simply going through several individual ones Layers of the material are produced by a heated calender. The material can also be laid across to improve strength in the cross direction see below reach.

- patent claims -

Claims (7)

Claims: 1. Fabric glued together from fibers, characterized in that that the fibers of the fabric are stretched to a large extent to the full length, between about 80 to 95% unidirectional and a stack length in the range between about 1 cm and about 7.5 cm with a minimum length of 2.5 cm fo the majority of the fibers, and that for the cohesion of the fibers in their straightened and in the aligned state, such a loosened pattern of flexible adhesive serves that the distances in the pattern are smaller than the average length of the fibers and a maximum of 25% of the total area of the fabric is covered. 2. Fabric according to claim 1, characterized. that its weight ranges between about 3.6 to 23.9 g / m2. 3. Fabric according to claim 1, characterized. that the fibers are made of Cotton, viscose-rayon, acetate-rayon, nylon, polyester, acrylonitrile or polyolefins exist and in one Denier Calc are between about 0.5 and 3. 4. Fabric according to claim 1, characterized in that the adhesive is a Is plastisol. 5. A method for producing a fabric according to claim 1, characterized characterized in that several strands of fibers arranged side by side in a stretching device are fed to produce a web of stretched, aligned fibers, that a loosened pattern of flexible adhesive on the with a repellent Layer provided surface of a carrier tape is printed, which then brought into contact under pressure with the web, which is still kept under tension so that the individual fibers are embedded in the adhesive, after which one lets the adhesive cure or causes it to cure, and then the bonded Fiber web is rubbed by the carrier tape. 6. The method according to claim 5, characterized. that the fiber web and heating the carrier tape prior to separating it. 7. The method according to claim 5, characterized. that they are finished glued web is then hot calendered. Blank page