Printing and creasing process for all-cotton fabric

Abstract

A full cotton fabric printing and wrinkling process, comprising the following steps: fabric preparation, yarn weaving into the required fabric, the required fabric after pretreatment yarn shrinkage to form a raw wrinkled crepe fabric; printing on the machine, the raw wrinkled crepe fabric is put on the screen printing machine to carry out traditional screen printing; printing aftertreatment, the printed fabric is fixed; setting and hand feeling treatment, the printed product is wrinkled again, the printed product is dried by hot air and cold air, and the fabric fiber is rapidly twisted and shrunk to be wrinkled again under temperature difference; and sizing finishing, the finished fabric is completed. After the printing wrinkles are damaged, through the subsequent high-temperature drying, cloth arranging and cold air drying steps, the fabric is loosened by physical rotation, and the curling stress of the cotton fiber is released through temperature control, so that the fabric fiber is rapidly twisted and shrunk under temperature difference, thereby helping the fabric to wrinkle again and return to the most stable state, and the wrinkles of the fabric are maintained.

Description

Technical Field

[0001] This invention relates to the field of fabric processing, specifically to a printing and wrinkling process for all-cotton fabrics. Background Technology

[0002] my country is a major textile producer. With the continuous advancement of science and technology, there are now two ways to print cotton crepe fabric. One is to print and then wash and wrinkle the fabric. However, wrinkling the fabric after printing can easily cause the printed color to change. The other is to wash and wrinkle the greige fabric before printing. However, printing the fabric after wrinkling limits the printing method.

[0003] Existing printing technologies for all-cotton fabrics are mostly traditional screen printing and digital printing. Digital printing is suitable for flat fabric surfaces, while since the fabric is wrinkled before printing, gauze and crepe fabric are more suitable for printing on traditional screens. However, the fabric must be flattened during the printing process to avoid issues such as white spots in the print and uneven coloring caused by the unevenness of the fabric in traditional screen printing.

[0004] According to the aforementioned existing technology, stretching the fabric will damage the wrinkles to a certain extent, and it will be impossible to restore the wrinkles to a relatively wrinkled, uniform and lasting texture in the finished product. Furthermore, since the wrinkles of crepe fabric are uneven and the shrinkage rate is unstable, the unstable shrinkage rate of the fabric can easily cause instability in the size of the garment during the subsequent garment production process. Summary of the Invention

[0005] The main technical problem this invention addresses is how to maintain the wrinkle-like texture of fabrics.

[0006] One embodiment provides a printing and wrinkling process for all-cotton fabrics, comprising the following steps:

[0007] The greige fabric is prepared by weaving the yarn into the desired fabric. After pretreatment, the yarn shrinks to form a crepe greige fabric with the original wrinkled feel.

[0008] The crepe fabric with its original wrinkled texture is placed on a screen printing machine for traditional screen printing.

[0009] Post-printing treatment involves fixing the color of the printed fabric.

[0010] Shaping and hand-feel treatment;

[0011] The printed finished product wrinkles again. The printed fabric is exposed to hot and cold air, and the fabric fibers quickly twist and wrinkle again under the temperature difference.

[0012] The fabric is then fixed in width and finished.

[0013] In another embodiment, the re-wrinkling of the printed finished product includes:

[0014] Fabric dehydration;

[0015] Hot air circulation drying, with a drying temperature of 85℃~100℃;

[0016] Organize the cloth and untangle the knots;

[0017] Cold air is used for drying, with a drying temperature of 20℃~30℃. The fabric fibers quickly twist and shrink under the temperature difference and return to their most stable state.

[0018] In another embodiment, during fabric dehydration, the dehydration speed is controlled, and the speed is automatically reduced when the peak speed is reached, thereby controlling the dehydration time and preserving the wrinkled effect.

[0019] In another embodiment, during the printing process, the crepe fabric is laid flat, stretched, and fixed in the transverse direction before traditional screen printing is performed.

[0020] In another embodiment, the post-printing treatment includes:

[0021] After printing, the crepe fabric is cooled to maintain a constant temperature.

[0022] Temperature-stable crepe fabric is steamed in a steamer.

[0023] After steaming, the crepe fabric undergoes a washing process.

[0024] In another embodiment, the washing process includes:

[0025] After steaming, the crepe fabric is pre-washed with room temperature water.

[0026] Wash the crepe fabric in 80℃ hot water.

[0027] Crepe fabric is soap-washed at 85℃.

[0028] Crepe fabric is washed and removed from the vat.

[0029] In another embodiment, during the shaping and hand-feeling treatment, the color-fixed fabric is heat-set and then softened with a softener.

[0030] In another embodiment, the pre-printing treatment of the desired fabric includes: fabric preparation, singeing, creping, dehydration, tumble drying, and weft straightening to obtain a dried crepe fabric with the original wrinkled feel.

[0031] In another embodiment, the fabric is prepared by weaving the required fabric using alternating twisted yarns or strong and weak twisted yarns.

[0032] In another embodiment, the wrinkling process employs a loose-feed washing machine for wrinkling, including:

[0033] Desizing involves removing residual sizing material from the fabric by adding a dispersant and washing with water.

[0034] Scouring involves adding scouring agents and caustic soda to remove residual impurities from the greige fabric and improve the fabric's processing performance.

[0035] Oxygen bleaching involves adding hydrogen peroxide to remove pigments from the fabric fibers, increasing whiteness and resulting in a whiter-looking crepe fabric.

[0036] According to the cotton fabric printing wrinkling process in the above embodiment, after the printed wrinkle is destroyed, through the subsequent steps of wet cloth-dehydration-high temperature drying-cloth sorting-cold air drying-finished product, the fabric is loosened by physical rotation, and the internal stress of the cotton fiber curl is released by temperature control, thereby helping the fabric to wrinkle again. The fabric fibers quickly twist and shrink under temperature difference and return to the most stable state, which is more conducive to the durability and stability of the fabric wrinkle. Attached Figure Description

[0037] Figure 1 This is a process flow diagram of the cotton fabric printing and wrinkling process in the embodiments of this application;

[0038] Figure 2 This is a flowchart illustrating the process of re-wrinkling the printed finished product in one embodiment. Detailed Implementation

[0039] The present invention will now be described in further detail with reference to specific embodiments and accompanying drawings. Similar elements in different embodiments are referred to by associated similar element reference numerals. In the following embodiments, many details are described to facilitate a better understanding of this application. However, those skilled in the art will readily recognize that some features may be omitted in different situations, or may be replaced by other elements, materials, or methods. In some cases, certain operations related to this application are not shown or described in the specification. This is to avoid obscuring the core parts of this application with excessive description. For those skilled in the art, detailed description of these related operations is not necessary; they can fully understand the related operations based on the description in the specification and general technical knowledge in the art.

[0040] Furthermore, the features, operations, or characteristics described in the specification can be combined in any suitable manner to form various embodiments. At the same time, the steps or actions in the method description can be rearranged or adjusted in a manner obvious to those skilled in the art. Therefore, the various orders in the specification and drawings are only for the clear description of a particular embodiment and do not imply a necessary order, unless otherwise stated that a particular order must be followed.

[0041] The serial numbers assigned to components in this document, such as "first" and "second," are used only to distinguish the described objects and have no sequential or technical meaning. The terms "connection" and "linkage" used in this application, unless otherwise specified, include both direct and indirect connections (linkages).

[0042] With the advancement of science and technology, there are now two methods for printing cotton crepe fabric: one is to sand wash and wrinkle the fabric after printing, but this can easily cause color discoloration of the printed fabric; the other is to sand wash and wrinkle the greige fabric before printing, which limits the printing process. Current printing technologies for cotton fabrics are mostly traditional screen printing and digital printing. Digital printing is suitable for flat fabric surfaces, but because the fabric is wrinkled before printing, crepe fabric is more suitable for traditional screen printing. However, the fabric must be flattened during the printing process to avoid issues like white spots and uneven coloring caused by uneven fabric texture in traditional screen printing. Flattening the fabric will damage the wrinkle texture to some extent, making it impossible to restore a sufficiently wrinkled, even, and durable wrinkle texture in the finished product. Furthermore, because the wrinkle texture of crepe fabric varies, its shrinkage rate is also unstable, which can easily lead to dimensional instability during garment production.

[0043] In this embodiment of the invention, the main technical problem to be solved is how to maintain the wrinkleness of the fabric. After the wrinkleness of the print is destroyed, the fabric is loosened by physical rotation through the steps of high temperature drying and cold air drying. Then, by controlling the temperature, the internal stress of the cotton fiber's curl is released, and the fabric fibers quickly twist and shrink under the temperature difference, thereby helping the fabric to wrinkle again and return to the most stable state, thus maintaining the wrinkleness of the fabric.

[0044] One embodiment provides a printing and wrinkling process for all-cotton fabrics; please refer to [the relevant documentation]. Figure 1 It includes the following steps:

[0045] S1: Fabric preparation; yarn is woven into the desired fabric, and after pretreatment, the yarn shrinks to form a crepe fabric with the original wrinkled feel.

[0046] S11: Spinning. The required fabric is woven from alternating twisted yarns or strong and weak twisted yarns. The warp yarns are Z-twisted and the weft yarns are S-twisted. The twisted yarns are interwoven and the yarns untwist in opposite directions during the printing and dyeing process. The two opposing forces cause the fabric to form creases.

[0047] The fabric is woven to form a double-layer gauze fabric. The machine is a multi-arm loom with diamond-shaped joints. The inner warp is joined to the outer weft. The joint size is 1.3*1cm. Every 1.1cm in the gauze, there is a yarn that connects the two layers of gauze. This yarn makes the two layers of gauze tightly fixed together, making them more durable.

[0048] Inspection refers to checking the quality of the finished woven fabric. Generally, the purpose of inspecting the woven fabric is to check its quality. The inspection is carried out according to national standards and a four-point system. The inspection content includes two items: physical indicators and appearance defects. The former includes the length, width, weight, warp and weft yarn density and strength of the original fabric, while the latter includes spinning defects, weaving defects, various stains and damage.

[0049] Rewinding and sewing: In order to ensure the ignition of subsequent batch processing, the raw fabric is laid out flat through a rewinding machine and sewn together so that the ends are connected to form a continuous feeding of raw fabric.

[0050] S12: Singeing, which involves quickly passing the fabric through a burning flame to burn off the fuzz on the fabric surface, making the fabric smooth and beautiful.

[0051] Singeing is a process in which a fabric is quickly passed flat across a high-temperature flame or rubbed against a red-hot metal surface. The fuzz on the fabric surface heats up rapidly and ignites, while the denser fabric body heats up more slowly and leaves the flame or metal surface before reaching its ignition point. This achieves the goal of burning off the fuzz without damaging the fabric. Singeing prevents uneven dyeing and printing defects caused by the presence of fuzz during dyeing and printing. It can generally be achieved using equipment such as a gas singeing machine or a cylindrical singeing machine.

[0052] In embodiments of the present invention, the main parameters controlled in the singeing process are the fabric feeding speed and the air pressure. The fabric feeding speed affects the singeing time, while the air pressure affects the flame intensity. The singeed fabric not only removes the fuzz from the fabric surface, improving the fabric's luster and smoothness, but also improves the fabric's resistance to pilling and makes the fabric more crisp.

[0053] S13: Wrinkling, using a loose-type washing machine for wrinkling, including desizing, scouring, and oxygen bleaching;

[0054] To facilitate smooth weaving, the warp yarns are often sized to improve strength and abrasion resistance. The sizing on the greige fabric affects the fabric's water absorption and the quality of dyeing and finishing products, and also increases the consumption of dyes and chemicals. Therefore, the sizing should be removed before scouring. Desizing is the process of removing the residual sizing on the greige fabric by adding a dispersant and washing with water.

[0055] During cotton fiber growth, natural impurities (pectin, waxy substances, nitrogenous substances, etc.) are formed along with the fibers. After desizing, most of the sizing agent and some natural impurities are removed from the cotton fabric. However, a small amount of sizing agent and most of the natural impurities remain on the fabric. The presence of these impurities makes the cotton fabric appear yellowish and has poor permeability. Scouring involves adding scouring agents and caustic soda to remove residual impurities from the fabric and improve its processing performance. The principle is to use caustic soda and other scouring auxiliaries to chemically degrade, emulsify, or swell pectin, waxy substances, nitrogenous substances, and cottonseed hulls. After washing, the impurities are removed from the fabric.

[0056] After cotton fabrics are boiled, they still have natural pigments on the fibers, so their appearance is not white enough. If used for dyeing or printing, it will affect the brightness of the color. Oxygen bleaching is to remove the pigments on the fabric fibers by adding hydrogen peroxide, thereby improving the whiteness and obtaining a white crepe fabric.

[0057] Specifically, a dispersant, scouring agent, caustic soda, and hydrogen peroxide are added to a loose-type washing machine. The process involves washing at 85°C for 60 minutes at a speed of 30 rpm; followed by water washing at 85°C for 50 minutes at 30 rpm; water washing at 85°C for 30 minutes at 30 rpm; and a cold water wash for 10 minutes. The dispersant, scouring agent, etc., used in this application are selected according to existing technology in terms of their dosage. During this process, the fabric undergoes a certain period of hot water or hot alkaline solution treatment, causing the yarns to shrink and form a crepe fabric with its original wrinkled texture.

[0058] S14: Place the crepe fabric into a dewatering machine for dewatering treatment;

[0059] S15: Place the dehydrated crepe fabric into a rotary dryer;

[0060] S16: Straighten the weft of the dried crepe fabric for subsequent printing.

[0061] S2: Printing on the machine. The crepe fabric with its original wrinkled texture is placed on the screen printing machine. After the crepe fabric is laid flat and the fabric is fixed in the horizontal direction, traditional screen printing is performed. Printing on cotton fabrics (woven fabrics and knitted fabrics) mostly uses reactive dyes. This is not only because reactive dyes have bright colors and a complete color spectrum, but more importantly, because reactive dye printed fabrics have a soft hand feel and good rubbing fastness. In the embodiments of this application, the type of dye is not limited, and the concentration, temperature and dyeing time can be set according to the specific dye.

[0062] S3: Post-printing treatment, color fixing of the printed fabric;

[0063] S31: The printed crepe fabric is subjected to constant temperature treatment by a cooling device to stabilize the temperature of the crepe fabric.

[0064] S32: Temperature-stable crepe fabric enters the steaming machine for steaming, allowing the printed crepe fabric to complete the absorption of moisture and heating of the fibers and pigment film, accelerating the reduction of dye and its dissolution on the fibers, allowing the dye to diffuse into the fiber interior and be fixed on the fiber, thus producing color fixation. The steaming process conditions vary depending on the properties of the dye and the fiber. In the embodiment of this application, the steaming temperature is 105℃ and the time is 10min.

[0065] S33: After steaming, the crepe fabric undergoes a washing process. Specifically, the crepe fabric is pre-washed in room temperature water for 10 minutes; then washed in 80℃ hot water for 20 minutes; then soaped at 85℃ (with 2-4g / L soaping agent added). During the soaping process, the soaping agent interacts with the dye through physical and chemical reactions, and utilizes the dispersion, suspension, and complexation effects of the soaping agent to prevent it from adhering to the fabric, thereby improving the soaping fastness and preventing staining; finally, the fabric is removed from the washing bath.

[0066] S4: Shaping and hand-feel treatment;

[0067] After color fixation, the crepe fabric is stretched and heat-set, which is generally done using a knitting stretching machine. A softener is applied to the crepe fabric on the knitting stretching machine to soften and finish it. In the embodiments of this application, the additives added during the stretching process include: softener hydrophilic silicone oil 5g / L, temperature 140℃, and speed 50M / min.

[0068] S5: The printed finished product wrinkles again;

[0069] Traditional screen printing requires the fabric to be stretched flat to prevent uneven printing and color application due to fabric roughness. However, stretching the fabric also damages its wrinkle-like texture. Therefore, the printed fabric is re-wrinkled after printing. The printed fabric is then exposed to hot and cold air, causing the fabric fibers to rapidly twist and wrinkle due to the temperature difference. The specific steps include:

[0070] S51: Fabric dehydration; Dyed fabric can be placed in a dehydrator for dehydration. The speed is set to 550 rpm, and the dehydration speed is controlled at the peak. The speed is automatically reduced, and the dehydration time is controlled to retain the original wrinkled effect.

[0071] S52: Hot air ring drying, using an industrial dryer YGZ-200, 50 meters / batch, similar to a household drum dryer. After placing the fabric in, set the drying temperature to 85℃~100℃ and the time to 20 minutes. When the machine is started, there will be protruding ridges inside the machine, which is equivalent to air tumbling. Under rolling and friction, the internal stress of the yarn is eliminated, and the fabric will be more fluffy and soft.

[0072] S53: Fabric straightening, straightening the fabric, untangling knots, and preventing irreparable fabric tangles;

[0073] S54: Cold air ring drying, using industrial dryer YGZ-200, 50 meters / batch, after the fabric is put in, set the drying temperature to 20℃~30℃, time 20min, the fabric fibers quickly twist and shrink under the temperature difference and return to the most stable state.

[0074] The above-mentioned re-creeping process makes the fabric wrinkles more delicate, even, and regular. The principle is to loosen the fabric through physical rotation and then release the internal stress of the cotton fibers through temperature control, thereby helping the fabric to wrinkle again. Tests show that the shrinkage rate of printed fabrics that have not undergone ring drying is very unstable, while the warp and weft shrinkage rate of printed fabrics that have undergone ring drying can be controlled within ±3%.

[0075] S6: Fixed width finishing, knitting tenter speed: 50±2m / min; temperature: 1# 130±5℃, 2-5# 140±5℃, 6# 130±5℃; fabric drop: finished product +2cm±0.5cm; finished fabric;

[0076] In this embodiment, the fabric material is 100% cotton. In another embodiment, the crepe fabric used in this application can be a single layer, a double layer, or a triple layer.

[0077] The above examples illustrate the present invention only to aid in understanding it and are not intended to limit the scope of the invention. Those skilled in the art can make various simple deductions, modifications, or substitutions based on the principles of this invention.

Claims

1. A printing and wrinkling process for all-cotton fabrics, characterized in that, Includes the following steps: The greige fabric is prepared by weaving the yarn into the desired fabric. After pretreatment, the yarn shrinks to form a crepe greige fabric with the original wrinkled feel. The pre-printing treatment of the required fabric includes: greige fabric preparation, singeing, creping, dehydration, rotary drying, and weft straightening, to obtain a dried crepe fabric with the original wrinkled feel. For screen printing, the crepe fabric with its original wrinkled texture is placed on the screen printing machine. After the crepe fabric is laid flat and the fabric is fixed in the horizontal direction, traditional screen printing is performed. Post-printing treatment involves fixing the color of the printed fabric. Shaping and hand-feel treatment; The printed finished product is re-wrinkled. The printed finished fabric is subjected to hot and cold air, and the fabric fibers quickly twist and shrink under the temperature difference to re-wrinkle. The re-wrinkling of the printed finished product includes: fabric dehydration; hot air ring drying at a temperature of 85℃~100℃; fabric sorting to open up knots; and cold air ring drying at a temperature of 20℃~30℃. The fabric fibers quickly twist and shrink under the temperature difference and return to the most stable state. The fabric is then fixed in width and finished.

2. The cotton fabric printing and wrinkling process as described in claim 1, characterized in that, When the fabric is dehydrated, the dehydration speed is controlled, and the speed is automatically reduced when the peak speed is reached. The dehydration time is controlled to retain the wrinkled effect.

3. The cotton fabric printing and wrinkling process as described in claim 1, characterized in that, The post-printing treatment includes: After printing, the crepe fabric is cooled to maintain a constant temperature. Temperature-stable crepe fabric is steamed in a steamer. After steaming, the crepe fabric undergoes a washing process.

4. The cotton fabric printing and wrinkling process as described in claim 3, characterized in that, The washing process includes: After steaming, the crepe fabric is pre-washed with room temperature water. Wash the crepe fabric in 80℃ hot water. Crepe fabric is soap-washed at 85℃. Crepe fabric is washed and removed from the vat.

5. The cotton fabric printing and wrinkling process as described in claim 1, characterized in that, During the shaping and hand-feeling treatment, the fabric after color fixing is heat-set and then softened with a softener.

6. The cotton fabric printing and wrinkling process as described in claim 1, characterized in that, When preparing the greige fabric, the required fabric is woven from alternating twisted yarns or strong and weak twisted yarns.

7. The cotton fabric printing and wrinkling process as described in claim 6, characterized in that, The wrinkling process employs a loose-feed washing machine wrinkling method, including: Desizing involves removing residual sizing material from the fabric by adding a dispersant and washing with water. Scouring involves adding scouring agents and caustic soda to remove residual impurities from the greige fabric and improve the fabric's processing performance. Oxygen bleaching involves adding hydrogen peroxide to remove pigments from the fabric fibers, increasing whiteness and resulting in a whiter-looking crepe fabric.

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