Study on production technology of warp knitted suede

Summary details the production technology of warp knitted Suede, analysis of the influence factors of warp knitted suede product performance and quality, in particular the raw material for cashmere yarn, organizational structure, and its raising, open fiber finishing, such as dyeing and sanded to give a more in-depth discussion. Keywords: Microfiber warp knitted suede StudyonProductionTechnologyofWarpKnittedSuedeFabricJiangGaoming (SouthernYangtzeUniversity,Wuxi214063,China) Abstract:Thispaperintroducestheprocessofthewarpknittedsuedefabric,analyzesthemainfactorseffectingitsperformanceandquality,andespeciallydiscussestheprocessofpileraising,fiberopening,andsuedingofitspileyarn,structuresandfinishingtechnology. Preface to Keywords:Superfinefiber,Warpknitting,Suedefabric1 natural suede is a symbol of beautiful, stylish, and expensive, but its high cost and limited by production can only meet the needs of a small number of people. Suede is the ideal replacement of natural suede. Warp knitted Suede is the processing of ultra thin wire to warp is made of suede fabric. Grey fabric after finishing, feel soft, either directly as a clothing material to produce into tomato overcome, bags, suits, shoes and other, can also be combined, and then further clothing, or other purposes. 2 selection of warp knitted suede material after a series of cashmere yarn of the warp knitted Suede finish, able to form a powder texture textured, showing “writing effect”, which is cashmere yarn with choice of raw materials. As of suede fabric substrate composition should consist of two requirements: first, needs to work closely to organizational structure, monofilament fiber requirements over the thick, to organize high-shrinkage fiber better. Second, the selection of monofilament fiber fabric textured requires finer fiber. More fluff number suede fabric surface, size smaller, stronger sense of fabric appearance simulation, single denier silk and suede effect of relationships as shown intable 1. Table 1 villi of monofilament fiber, dtex soft luster effect 1 rough writing basic no 0.2 0.5-free drying-free weak weak weak 0.1 very cool soft smooth merit from the early 70 ‘s of last century to the present, used in warp knitted suede material have changed. Before the 80 ‘s, suede cashmere yarn used raw materials are 100D/36f processed yarn, of polyester filament yarn is 50D/24f. Now, we have chosen to cashmere yarn materials generally fibers, such as Japan or Korea-Island fibers. Island fiber are generally two different types of polymers by twin screw composite spinning melt spinning machine and dedicated spinning components, make a group distribution in an orderly manner in the other group, ultra thin wires forming a rule of continuous cables , component after the solution to the sea, special small components of fiber-fiber in the rest of the island. In theory, for a certain amount of solvent, as long as the sea component soluble, soluble or insoluble Island components can be. But the actual application needs taking into account the toxicity of solvents, volatile factors, recovery equipment, previously selected polystyrene, heavy pollution, now general selection of water-soluble polyester (COPET) for the sea component. For example, PET (polyester) scattered COPET (polystyrene). In the dispersed PET fibre section is “island” status and the matrix of polystyrene is equivalent to “sea” State. Dissolve sea component of the adoption, the rest is a single component of fiber, can be made 0.2dtex fiber, most fine of up to 0.001dtex. -Island fiber with a soft feel and better light fastness, available dyes for dyeing; but the stiffness of the fabric and the bulk of poor. There is also a type of Orange Microfiber, it is formed by two immiscible polymer melt at the same time from multiple different components in a spinning out, after splitting away from each of the silk fiber is minimal. Orange-fiber with a high density and sufficient degree ofleavening, good stiffness, no sense of thick, but its poor fastness to light of draping and and not adapted to the printing. In the selection of cashmere yarn and yarn, we have to consider its fiber ratio. The so-called fiber ratio, of fabrics of cashmere yarn with yarn and fiber ratio. From the geometric structure of fabrics, veil and yarn fiber ratio-a can be expressed in the following: A=KxD1/D2K=L1/L2 type: a-fiber ratio; k-coefficient of fiber than; the total size of D1-pile of fibrosis, dtex;D2-of total fiber tissue fibers at the end, dtex; L1-suede organization coil length, mm; L2-organization at the end coil length, mm. In the case of fabric winding structure unchanged, fiber ratio changes can cause fabric density changes, and directly affect the textured effect. When you D1>D2, you can get the better of the cashmere; otherwise poor. Woven through on a variety of different specifications of Superfine fiber test and discovered, when K=1 A=1 are suede fibers and fiber ratio of formation organization critical point, theoretically, D2 and D1 changes in the value of value is proportional to the change. Therefore, fiber ratio must be greater than 1, preferably within the 1.5~2, so pile coverage certainly good, so in practical application, should be A>1,D1>D2,L1> L2¡£ In short, using fiber as raw material of warp knitted suede fabric with elastic on polyurethane finishing can make fabrics like leather, with a high sense of suede and “writing effect”. Mainly for: good dimensional stability, dry cleaning, washing, DP; moth, mildew and storage convenience; wide color spectrum, the brightly; good sewing; windproof breathable; Ze gentle; feel full. 3 organizational structure of the warp knitted suede warp knitted suede velour surface consisting mainly of the comb before cross, extension of its line through fuzzing, coloring, cropping, sanding process, such as the formation of short, dense, uniform, homogeneous fluff. Such as the extension of the line is too long, though easily raising, but raising too long, affecting the cost of the product, finished the body is not ideal. At design time, should not insist on raising easy, and should be conducive to a short, dense fluff requirement, select cashmere needle organizations, as appropriate. Down the length of the best 0.1~1mm is the principal. Shorter than the threadbare 0.1mm easily, prejudicial to the look of Suede, longer than 1mm are easy to snarl. Warp knitted suede the need for closer to organizational structure, organizations can be a-bar, or a two-bar, which is actually based on the product surface density and cost requirements to determine. If only when they are a-bar, choice of yarn will need to consider the contraction of, after pretreatment, fabric width to shrink around 35~45%. Fabric after pulling, cutting, grinding, raising pile warp on the surface being ripped, yarn still need to maintain a certain strength, so that their products comply with the dress code. Warp knitted suede fabric often used the Velvet flat and inclined flat organizations as shown in Figure 1. In addition, if two reverse-bar mats yarns, is conducive to weaving, but curl serious, is not conducive to fleece processing; two to mat-bar with yarn, resolve of curling, which is raising. At the same time for selvedge formation, at the time of processing and a spandex yarn on the edge. Warp knitted suede fabric tension control is very important, pile yarn and size of the yarn tension control and finishing equipment choice is reasonable or not, suede effect will be. Suede fabrics are concerned, combed yarn tension before small, combed yarn tension after to be bigger, but you want to select a suitable. Excessive tension in woven fabric appears to jump the phenomenon; such as fleece yarns and yarn tension close, by finishing, cashmere and the contraction, the warp on the suede pile formation of arc, which will cause feathering and sanding process difficult. 4 warp knitted suedefinishing technology of warp knitted Suede finish general process is: raising early white slab ¡ú shaping ¡ú ¡ú ¡ú clipped ¡ú open fiber dyeing ¡ú heat setting ¡ú grinding ¡ú final inspection ¡ú volume. Because white fabric uneven, varying width, so before raising, must first scheduled processing, heat setting temperature cannot be too high, simply fabric wrinkle removal, oil on canvas, line width. Otherwise fibers due to the effects of heat, structural changes and is difficult to pile. General temperature between 155~165¡æ more appropriate, and for raising future setting temperature may be appropriate to high, usually 185~195¡æ. Speed 30m/min Super feed larger. Raising directly to a fabric finishing, pile raising effects better, even, after dyeing finishing by color is bright, good shade. Several important finishing process are discussed below. 4. 1-fiber technology of Sea-Island fiber dissolve sea component after is made in the fabric, leave Island components to form a continuous Microfiber fabric. Sea component on the solubility of warp knitted suede effect is crucial. COPET dissolved in water in accordance with law of swelling before dissolving. COPET composition, structure, molecular weight and the influence of external conditions on dissolving certain, external conditions effects on COPET dissolved as shown in Figure 2. Curve 1 of water-soluble polyester in 95 ¡æ dissolved in hot water. It first to dissolved mainly; curve 2 for water-soluble polyester in 95 ¡æ Xia, 0.5%NaOH water solution in the of dissolved situation, it also has a dissolved expansion dissolved process, but dissolved expansion more slow, dissolved last also has residues property, this may is because Na+ , and OH-the ion of exists, damage has polymer of dissolved balance, makes dissolved speed became more slow, also NaOH also and polymer in the of some components produced has reaction, generated has precipitation, curve 3 for water-soluble polyester in 95 ¡æ Xia containing 0.5%NaOH ,1g/L1227 promote agent water solution in the of dissolved situation, because in water in the joined has 1227 surfactant, thus, water-soluble polyester in dissolved expansion of while surface also occurs has hydrolysis, became small molecular and promote has hydrolysis of for, makes dissolved speed speed up. And can be adjusted according to the different situations to control the contents of NaOH dissolved speed. Open fiber process was conducted in alkaline solution, the sea component completely dissolved is favourable, but on the fiber has also created a general PET Island hydrolysis, thus, to reach the Sea Island fiber components completely dissolved, their rate of weight loss than the sea component proportion of larger. If the sea when the component is 20%, fiber weight loss rate of general control of the island at around 22-26%, the sea component can be completely dissolved. General open fiber technology curve as shown in Figure 3. 4. 2 After dyeing of fabrics through open fiber technology, fully before the dye must be washed, water to large, to make the fabric of lye to fully neutral, first 70 ¡æ washed 10min in 1g/L acetate-containing solution, then rinse , for PH value in 6.5~7 this context. If there is insufficient water, residual alkali impurities and fiber stranded in cloth, prone to dyeing. In addition to contracted color dyeing process, have a great impact on the fabric shrinkage, related to fabric’s density and post operation. Dyeing process of influencing factors, first of all is the dyeing effect of temperature on suede. Heating effect of polyester fibers in General, their contract with temperature change, between the 80~100¡æ to obtain significant results. Dyeing temperature of 120~130¡æ. This increase shrinkage and increasing density and fluffy fabrics is beneficial. Second is in the process of dyeing effect of tension on the Suede, fabric dyeing process is the ideal State in longitudinal and transverse force uniform, but in fact because the fabric dyeing machine for vertical movement, vertical tension than horizontal. Sometimes so that the fabric has a good sense of polyurethane for leather finishing, solvent polyurethane finishing, solvent stripping to disperse dyes have a certain role, that is, color lighter, General chromatic aberration around at the 0.5~1.5 level. So when determining color and dyeing, in normal usage increase on the basis of 5~10%, in addition to strictly control the heating rate (60~130¡æ), the holding time of not less than 45min, best 60min. You can now use water soluble polyurethane resin for finishing. 4. 3 sanded finish sanding process is the suede warp-knitted fabric in a certain amount of tension and pressure and speed into the sanded area under the control of, under Emery roll or belt of high speed rotating, make raising surface coil breaking down to form a directional lodging. Sanded finish is an important production of warp knitted suede-like process, has a large influence on textured fabrics simulation. Fluff of length and cover density main by following 6 a factors of effect: Qian comb needle back pad yarn of length; into cloth speed; mill hair sand roll of speed; fabric and sand roll of contact way; sandpaper sand material of shape and specifications; pressure roll and sand roll Zhijian of spacing 5 by series suede cashmere of performance series suede cashmere after measured, the aspects performance index as table 2 by as shown in. Table 2 detection project measured results breathable rate, mm/s64.70 top breaking strong, N282.20 elongation rate,% direct to 19.88 transverse 12.56 elastic reply rate,% direct to 54.48 transverse 36.3 resistance wash color fastness as is color 4-5 white cloth dip color 4 resistance perspiration fastness as is color 4-5 white cloth dip color 4 resistance friction fastness dry motorcycle 4 wet motorcycle 4 [note] elongation rate project: will load 14.7N; elastic reply rate project: 14.7N, repeatedly stretch number 5 times. 6 conclusion 6. 1 factors influencing of Suede, and whichtype of fiber, fiber diameter, fabric as the main factors such as organizational structure, the type of finishing agent. With these factors according to end use of the products of process parameters to decide. 6. 2 the suede fabric fiber used by most of the species of Sea-Island fiber for polyester. Microfiber not only maintained the excellent characteristics of the common chemical fiber, and has a soft, drape well, imitation silk good results, good for sanding process, comfort advantages, using Microfiber suede best simulation of production. 6. 3 size of the machine should be based on actual use to select, with the present manufacturers of most used machines, for example, E28 suede fabric loose, feel soft, suitable for direct fabric, E32 comparison of fabric close, feel relatively hard , suitable for composite substrates. 6. 4 on the organizational structure of the base fabric, warp knitted suede on the structure is similar to natural suede, feel and performance of the products better. 6. 5 open fiber technology is an important finishing process of warp knitted Suede, to sea of Sea-Island fiber components completely dissolved, adding a certain amount of hydrolysis enhancers, and fiber loss rates should be controlled to a scale bigger is better than the sea component.