SE413682B - SET TO MAKE A SEGMENT THERMAL BONDED FABRIC FABRIC - Google Patents

Description

7504770 ~ ë? or the other side of the fabric touched at a printing surface. With this limitation of the secondary bonds, however, comes the disadvantage that only a small number of patterns of primary bonds can be achieved at the points of impact of the printing surfaces during the rotation of the rollers.

By calendering a fibrous web between two rollers, which each have a printing pattern and which correspond sufficiently accurately to each other, it would be possible to obtain any desired pattern with both primary and secondary bonds, but to maintain such a close fit. is not practically possible, or at best very costly, when using rollers which are large enough for the production of wide fabrics and which have printing surfaces which are small enough for the fabrics to have advantageous properties and an attractive appearance.

I The best possible physical and visual properties of the bonded fabric are directly or inversely related to the number of bonds, and the properties obtained are thus the result of a compromise. Fabrics produced so far have not had the best combination of properties for all purposes, especially for fabrics for garments where properties are desired which are closely reminiscent of conventionally woven and knitted fabrics and which have an appealing appearance. Known fabrics of the type in question usually have a geometrically regular pattern of primary bonds, which is not aesthetically pleasing. , I e.g. U.S. Patent No. 5,542,654 discloses a nonwoven fabric in which the fibers are bonded together in a rhombic pattern by rolling between two rollers, at least one of which is not smooth but grooved. An object of the present invention is to provide a method for producing segmented woven fabrics of irregular or random bond size and shape, which method is such that a repetition in the pattern is impossible or difficult to detect, the pattern being visually substantial. independent of mechanical shifts in a calender roll used to press the segment bonds. It is an advantage of the method that regulation of the properties of the bonded fabric and minimization of secondary bonding is made possible with a high degree of flexibility in the regulation.

A new aesthetic appeal in segment-bound fabric and a new method of producing the same have now been developed, whereby the various problems of excessive secondary bonding, pattern limitation, dull appearance and mechanical difficulties are overcome.

The invention thus relates to a method of producing a fabric thermally bonded fabric by a fibrous web containing at least one t 75Û4770'4. part distributed therein, thermally bonding material, is passed through the nip between cooperating calender rolls, at least one of which is heated and which rolls have different pattern surfaces, which are characterized in that a certain irregularity in the bound pattern is produced by the surface pattern on one roll consisting of printing surfaces which are continuous and the surface pattern of the second roll consists of printing surfaces which are insulated projections, the central surface of the projections simultaneously in the roll nip being located at different distances from the longitudinal axis of the nearest continuous printing surface, so that pressure surfaces that face each other in the nip overlap to different extents and form bonds of different sizes and shapes.

According to a preferred embodiment of the invention, the insulated projections are arranged in such a way that they form in echelong arranged, overlapping or overlapping rows of adjacent projections, the rows having a direction which deviates from the new line of the rollers. This way of arranging the projections serves to break the regularity of the pattern in a different direction on the fabric surface and prevents, in cases where the printing surfaces are annular or helical, any possibility of "slamming" when the rollers rotate. When the continuous printing surfaces are in the form of longitudinal strips, it is not possible to remove the "slammer" phenomenon, which can only be reduced by reducing the distance between the strips and / or increasing the roll diameter.

The term "continuous printing surface" here refers to a printing surface which extends around substantially the entire periphery or along substantially the entire length of the roll. Such printing surfaces can e.g. have the shape of circular or elliptical rings, spirals or longitudinal_band.

The interaction between pressure surfaces on one calender roll and opposing pressure surfaces on the other roller in the pair of rollers is described here, for the sake of simplicity, with regard to the new line of the rollers. This is of course not a static condition as this line is moved continuously during the rotation of the rollers. When the rollers have a diameter of a few centimeters to 50 cm or more, the nip pressure will at any moment be applied over a limited peripheral width of the nip, including several pressure surfaces in the peripheral direction. When calendering, an interaction between opposing printing surfaces can be more complicated than what is described here for the static situation and a new line without a limited width. Shifts in the relative fit between the rollers due to clearance and other mechanical variations in the calendering mechanism result in an increase in overlapping surfaces between certain notched pairs and a decrease in overlapping surfaces between other opposing pairs. The changes caused by the binding pattern due to these variations will pass substantially unnoticed due to the inherent needle variation of a product according to the invention. According to another preferred embodiment of the invention, the distances from the midpoints of the projections to the longitudinal axis of the continuous pressure surfaces vary from zero to half the width of the space between adjacent continuous pressure surfaces, whereby the rollers can not interfere with each other no matter how they fit together. , and whereby the pattern of primary bonds in a fabric will consist of partly large bonds arising from total surface contact between certain printing surfaces and partly very small bonds arising from mere contact in contact between other surfaces. Such a primarily bonded pattern gives a visually very interesting fabric texture, which visibly does not change mainly with variations in the relative fit between the rollers. Suitable fibrous webs according to the invention may consist of cut fibers, continuous fibers or mixtures thereof. Flour of cut fibers is usually produced by carding a cut fiber material, and flor of continuous fibers can be made according to a conventional method using an air jet to transport the fibers from any source and disperse them in a random pattern on a perforated conveyor belt. . An electrostatic charge can be applied to the fibers to increase their spread before being applied to the conveyor belt. Flour of cut fibers can be made from conventionally crimped fibers and sufficiently bonded fabrics can be obtained therefrom. However, it has been found that a bonded product with improved physical properties, especially with respect to tensile and tear strength, can be produced by the process according to the invention from a web consisting of non-crimped cut fibers. The absence of ripples in the cut fibers adversely affects the homogeneity of a web made only by carding, but this disadvantage can be reduced or overcome by applying a coating to the fibers before carding which increases the friction between the fibers, for example a lubricating mixture containing particles of an inert solid substance, such as silicic acid. Alternatively, the floret can be produced by carding followed by a propagation by means of air, or by direct propagation by means of air. A suitable machine for spreading by means of air is a Rando-Webber, manufactured by Curlator Corporation, in which the fibers are twice distributed in an air stream and laid as a flower on a perforated conveyor belt which separates them from the air flow. The final web is mainly anisotropic, unlike a carded web in which the fibers have a predominant orientation in the machine direction.

The thermoplastic material contained in a web according to the present invention may consist of particles distributed in the fiber web, or it may be in the form of distributed fibers with a lower softening or melting point than the other fibers in the web or, thirdly, so For example, the fluorine may consist wholly or partly of bicomponent fibers in which one component is at least present on the fiber surface and has a lower softening or melting point than the other component. The fibers in a web may be natural or artificial fibers or synthetic fibers apun of linear organic polymeric materials, such as molten spinnable polyesters and polyanides true copolymers of these types of organic linear polymers.

In the process of the present invention, both of the patterned rollers may be rigid or one or both may have some natural flexibility or limited flexibility to absorb and equalize minor pressure differences along the roll, in which case a rigid support roller counteracting the flexible roller is required.

The insulated projections which form the printing pattern on one roll of a pair of calender rolls can be designed in different ways, for example in the form of sui points with flat or slightly domed top surfaces and with square, rectangular, circular or otherwise shaped cross-sections. the top has a cross-sectional area of a few tenths or hundreds of maa. The projections can be designed on the roll surface by suitable machining or by etching. The continuous printing surfaces, which can have a width of 0.1-1 mm, are most easily produced by machine machining in a lathe or a milling machine or by knurling. If the intermediate space between the printing surfaces is different on the two rollers, the varying relative fit between opposing printing surfaces can be achieved by appropriately choosing the size of the insulated projections and that of the pattern formed. If the spacing between the printing surfaces is equal, an inclination of one pattern relative to the other at a small angle is the easiest way to achieve the deviating relative fit between opposing printing surfaces. This method also has the advantage that the pattern of primary bonds applied to a fabric can be radically changed simply by applying one pattern at another oblique angle. Due to the varying relative fit according to the invention between opposing printing surfaces, the fixed or regular pattern of segment bonds which is characteristic of previous methods and in which the bonds also have a substantially regular size and shape, can be replaced by patterns of bonded surfaces and above all of primary bonds without a regular shape and surface, whereby the regular pattern from the printing surfaces on each calender roll is broken up and cannot be discerned in the complete pattern on the fabric produced. As a result, the central portions of the bonded surfaces adjacent to any substantially straight line across the fabric will vary in distance from this line. This adjusts the variations in the relative fit between opposing surfaces of the rollers due to clearance in gears or other mechanical irregularities during rotation, as the resulting bonds are hidden by the final, irregularly bound pattern, and a fabric is obtained with a comfortable and attractive appearance, good feel and good killing properties.

A fabric bonded according to the invention has on both sides patterns of strongly bonded segments, formed where opposite pressure surfaces cover each other in the nip, and patterns of comparatively weakly bonded surfaces where the web has come into contact with a heated pressure surface on only one roller and the heat has been high enough. to effect a certain fusion between adjacent fiber segments. Such weak bonds are difficult to detect to the naked eye but can be easily seen under a microscope. For simplicity, the tightly bonded segments are called primary bonds and the loosely bonded surfaces are called secondary bonds. In addition, there are surfaces in the fabric which are substantially unbound and have not been in contact with a printing surface on any of the rollers.

The visual difference between the three different types of surfaces on a bonded fabric can be increased by superficial metallization of the fabric surface.

In order to obtain the best possible properties, especially with regard to the feel and draping properties, the fabrics after the binding may need a light mechanical processing, such as the bending and curving that occurs when washing or dyeing the fabric. Fabrics made from mixtures of different fibers, in particular mixtures of bicomponent and one-component fibers of synthetic polyanides or polyesters, have an untreated condition immediately after bonding, and no slight mechanical treatment is required, and the production of such fabrics can be simplified. The invention is further illustrated by means of the accompanying pictures, wherein Fig. 1 shows a pattern of printing surfaces on a calender roll, which pattern consists of parallelogram-like isolated projections arranged in dense echelon in Fig. 2 shows a pattern of continuous printing surfaces. on a calender roll which consists of a row of evenly spaced rings arranged around the periphery, Fig. 3 shows a pattern of printing surfaces on a calender roll which has been applied by etching, in Fig. 4 shows one side of a bonded fabric according to the invention wherein the pattern of primary bonds formed during passage between a pair of calender rollers, one according to Fig. 1 and the second according to Fig. 2, and one pattern is inclined at an angle of 2 ° relative to the other, Fig. 5 shows a fabric bonded between rollers according to Fig. 4, but with an inclined angle of 8 °, Fig. 6 shows one surface of a fabric bonded during passage between a roller according to Fig. 2 and a roller according to Fig. 3, which patterns are each applied axially around the periphery of the respective roller, and Fig. 7 shows one side of a fabric bonded between rollers in the same way as in Fig. 6 but with an angle of 5 °.

In these images, white surfaces in Figures 1-3 represent printing surfaces and in Figures 4-7 primary bonds. All images are mainly in full scale.

From the primarily bonded patterns shown in Figs. 4 and 5, it is clear that the denser breaking of the line pattern in Fig. 2 when a larger oblique angle is used. Figures 4 and 5 also show the varying bonding surfaces along some imaginary nip line (the machine direction being downwards on the paper), achieved by the varying relative fit between opposing pairs of printing surfaces.

Fig. 6 shows a pattern of primary bonds of varying shape on the surfaces, achieved by the choice of respective bonded patterns, but without any skew.

Fig. 7 shows the effect when two selected patterns, such as those in Fig. 6, are adapted to each other and one is simultaneously inclined relative to the other at a small angle.

The invention is further elucidated below by means of examples, and the ripple ratio has been calculated as follows: extended county d - rippled county d X 100 rippled length 750477Û-La 8 F The draping coefficient was measured by the method according to Cusick, J. Text. Inst. 1968, 59, T253.

Some properties were measured in two directions; the longitudinal direction or machine direction and the transverse direction or transverse direction, and these are indicated as MD and CD, respectively, in the following examples.

Ex el el As molten spun, fresh fibers, which consisted of two-component fibers with a shell around a core and in which the shell consisted of nylon 6 and the core of nylon 66 in the proportions 35:65 parts by weight, was partially drawn and distributed by means of an air ejector on a perforated conveyor belt, which air ejector moved laterally over the conveyor belt to form a sluice laid web with a weight of 70 g / m2, in which the fibers had a toughness of 2.5 g / decitex, an elongation at break of 120% and a decitex of 4.

At a speed of 7.5 n / min, the web was then treated with heat under pressure in the nip between 1 m wide calender rolls, both of which were heated to a temperature of 200 ° C and which were combined with a nip pressure of 20 kg / cm, both rolls had patterns of printing surfaces, one roller continuous and the other roller discontinuous, with depressions in between. The pattern of die-continuous printing surfaces on one roller was that shown in Fig. 3, the top surfaces of each printing surface having the dimensions 2.64: c0.90 mm and at the top being axially and longitudinally separated by a gap of 1.28 mm , and the printing surfaces had a height of 1.0 mm. This roller had a diameter of 195 nn.

The pattern of continuous printing surfaces was in the form of bands, 0.38 mm wide at the surface and 0.73 mm high and separated at a distance of 1.42 mn at the surface. The latter roller also had a certain flexibility so that it could equalize the nip pressure provided by a steel pipe with a wall thickness of 13 mn and an outer diameter of 127 mm. The pattern of discontinuous pressure surfaces on the upper roller was applied axially and around the periphery, and the bands on the lower roller were axially parallel.

The conditions in the nip caused the component in the sheath around the fibers to become adherent, while the component in the core remained unaffected, and upon cooling, bonds formed between adjacent fibers in a pattern of primary bonds reminiscent of that of Fig. 6.

The product had an attractive appearance, excellent draping after washing and the properties listed below before and after a simple wash in water at 60 ° C: 7504770-h 9 Properties Untreated After washing weight, g / nz _ 13 84 Draping coefficient,% 73 _ 27 ßrotthållfaatnet, kg / g / cm nn 356 286 cn 411 386 ßro öj elongation, st nn 61 48 co vs 14 nlvnalifaathet, g / g / mz nn se 31 _ 'co 29 27 MD measured in the make-up direction CD measured across the make-in direction Exemgel 2 Two-component component polyester having a core of poly (ethylene terephthalate) having an intrinsic viscosity (IV) of 0.65, IV measured at 25 ° C in a solution of o-chlorophenol, and a shell of a 15 mol% ethylene isophthalate / terephthalate copolyester (IV 0.55), which components were present in the ratio 2: 1 core to casing, spun in molten state, drawn to a decitex of 3.3, mechanically crimped in a chamber crimp box to 3.5 crimps / cm with a crowning ratio of 34% and cut to lengths of 50 mm. The cut fibers thus prepared were mixed with the same amount of cut fibers of poly (ethylene terephthalate) with IV equal to 0.63, 3.3 deticex, 50 mm length, 3.5 ripples / cm and a crimp ratio of 34%, and formed : for a flor weighing 142 g / m2 using a conventional, air-conditioned device (Rando-Webber manufactured by Curlator Corporation). The floret is consolidated by light needling with 36 gauge 5 barb needles arranged in an alum-parted pattern on a needle board, the needles penetrating 1 the floret to a depth of 4 mm. Floret had to pass the needle board at a speed that gave about 46 needles per cmz.

The fluorine was then calendered at a speed of 3 rpm between patterned rollers, the same as in Example 1, both of which were heated to a temperature of 195 ° C and which were combined to a nip pressure of 31 kg / cm.

The unbonded fabric had the following properties when untreated: Weight, g / m2 142 Draping coefficient,% 79 Breaking strength, g / g / cm MD 60 CD 138 Elongation at break,% MD 19 CD 62 Tear strength, g / g / m2 MD 12 CD Example g 3 g of lightly concentrated more weighing 133 g / m 2 were prepared according to the description in Example 2 of a mixture of the same amounts of wool and cut bicomponents of polyamide having the composition given in Example 1 with a decitex of 3.3, a length of 100 mm, 5.3 ripples per cm and a ripple ratio of 20%.

The floret was calendered at a speed of 3 m / min between patterned rollers, both of which were heated to a temperature of 217 ° C and which were brought together to a nip pressure of 31 kg / cm. One roller had the pattern according to Fig. 3 with insulated printing surfaces, as described in Example 1, and the other roller had a spiral thread (left-hand thread) with 5.2 threads per cm, which had a substantially square shape and a width of the printing surface of 0 , 32 mm. The latter vala consisted of a flexible steel tube down 127 mm outer and 112.5 mm inner diameter.

The fabric, segment-bound fabric, had the following properties in the untreated state: weight, g / az 133 Draping coefficient,% 77 Breaking strength, g / g / cm MD 132 CD 67 Elongation at break,% MD 27 CD 54 Level needle strength, g / g / m2 now 1.5 ~ CD 7.5 Exengel 4 A lightly consolidated fleece with the weight 122 9 / m2, was prepared as described in Example 2 of cut nylon 6 fibers with a decitex of 6.7, a length of 72, 5 mm, 11.6 ripples / cm and a ripple ratio of 24%.

The fluorine was then calendered at a speed of 3 m / min between patterned rollers, both of which were heated to a temperature of 200 ° C and which were brought together at a nip pressure of 31 kg / cn. The lower flexible roll had a pattern of strips according to Example 1, and the upper roll, which had a diameter of 195 mm, had a pattern according to Fig. 1 of parallel-arranged, parallelogram-shaped printing surfaces of size 3.22: <0, 84 in the peripheral and axial directions, respectively, at a distance from each other of 0.58 mm and 0.71 mm in the peripheral and axial directions, respectively, and the longer dimension of the pressure surfaces extended substantially perpendicular to the wing shaft.

The fabric produced in segment-bound fabric had the following properties in untreated admixture: weight, g / m2 122 Draping coefficient,% 73 Breaking strength, g / g / cm MD 93 CD 103 ßroe bending,% nn 16 CD 34 Grating needle strength, g / 9 / mg nn 5.2 1 cn 3.7 Example 5 A lightly consolidated web weighing 129 g / ma was prepared as described in Example 2 from a mixture of cut nylon 6 and nylon 66 fibers in the same amounts by weight. The nylon 6 fibers were of the type described in Example 4, and the nylon 66 fibers had a decix of 3.3, a length of 51 mm, 5 ripples per cm and a ripple ratio of 18%.

The floret was calendered at a speed of 3 m / min between patterned rollers, the same as in Example 4 and at the same roll temperature and nip pressure.

The fabric produced in segment-bound fabric had the following properties in the untreated condition: weight, g / ma 129 Draping coefficient,% 79 Breaking strength, g / 9 / cm MD 151 'cn 211 root elongation,% of 29 cn 34 Rivnallfastnet, q / 9 / ma now 12.9 cv 6.9 In the mentioned experiments rollers with a length of 1 m were used, but rollers with another length and diameter or two rigid rollers can also be used in the method according to the invention.

The percentage of the surface area of the fabric occupied by primary bonds, calculated as the product of the percentage of each roll surface occupied by printing surfaces, is given below, as well as the ratio of the printing surfaces of the rollers. vsou770-4 12 Example Printing surfaces,% Primary Ratio between the bonding surface printing surfaces 1 25 and 21 _ 5.3 1.2 2 25 and 21 5.3 1.2 3 25 and 18 4.5 1.4 4 46 and 21 9 , 7 2.2 5 46 and 21 9.7 2.2 fLarge bonding areas tend to give stiffer fabrics and small bonding areas_tend to give less coherent fabrics. Furthermore, true primary bonding surface can be achieved with rollers having the same printing surfaces or with rollers having different printing surfaces, which give greater seconds bonding on one side, which increases the rigidity of the fabric, and at the same time gives less secondary bonding on the other side, which reduces the fabric: resistance to abrasion and bumping. 2 It is therefore preferable to use equal print surfaces so that fabrics with balanced bonding are obtained on the two sides. Strict observance of a balanced binding, however, causes an unnecessary restriction on the choice of needle and is not required. Different areas of use for the fabrics also provide different working conditions for fabric production. It is generally advantageous to use pairs of rollers for which the product of the printing surfaces is between 2 and 20%, and more preferably between 5 and 12%, and for which the ratio of the printing surfaces is less than 5-1. In the method described here, calender rolls have been used to create patterns of bonded surfaces on a fibrous web. However, the more impractical pressing of a web in sections between plates in a press can also be used without deviating from the idea of the invention, but such alternatives are usually slow and more difficult to perform. O

Claims (11)

7504770-4 1.) Claim 1. A method of making a segment thermally bonded fabric by passing a fibrous web containing at least a portion of thermally bonding material distributed therein through the nip between cooperating calender rolls, at least one of which is heated and which has different surface patterns. , characterized in that a certain irregularity in the bonded pattern is produced by the surface pattern on one roll consisting of printing surfaces which are continuous and the surface pattern on the other roll consists of printing surfaces which are insulated projections, the center surface of the projections which are simultaneously in the roll nip are located at different distances from the longitudinal axis of the nearest continuous printing surface, so that printing surfaces which face each other in the nip overlap to different extents and form bonds of different size and shape . 2. A method according to claim 1, characterized in that the pattern of insulated projections is symmetrical and uniform, but inclined at a small angle relative to the axes of the rollers. 3. A method according to claim 1 or 2, characterized in that the insulated projections on one roll form in echelong arranged, overlapping or overlapping rows with directions deviating from the new line. 4. A method according to any one of claims 1-3, characterized in that the distances between the central surfaces of the insulated projections and the longitudinal axis of the continuous printing surfaces vary from zero to half the width of the space between adjacent continuous printing surfaces. 5. A method according to any one of claims 1-U, characterized in that the fibrous web being treated contains cut fibers, continuous fibrous threads or mixtures thereof. 6. A method according to claim 5, characterized in that the fibrous web being treated contains fibers or fiber strands made from spinnable, synthetic organic polymers. e A method according to claim 6; characterized in that the organic polymer consists of one or more polymers selected from the group consisting of polyesters, polyamides and copolymers thereof. 8. A method according to claim 6 or 7, characterized in that vsouvvoán 11+ comprises the fibers or filaments of or consisting of two-component fibers, in which one component is at least partially present on the fiber surface and has a lower softening or melting point than the other component. 9. A method according to claim 8, characterized in that the fibrous web being treated consists of a mixture of cut one-component and two-component fibers. _ 10. A method according to any one of claims 1-9, characterized in that the fibrous web being treated contains or consists of cut, non-crimped synthetic organic fibers. 11. ll. A method according to any one of claims 1-8 and 10, characterized in that the fibrous web being treated contains cut natural fibers. PROMISED PUBLICATIONS: Great Britain 848 976 (DDAH 1/54) Germany 1,933 589 (D04H 13/00) US 3,325,302 (117-10), 3,542,634 (161-88), 3,607,992 (264-1)