Continuous rinsing and whitening method for pure cotton grey cloth

Abstract

The invention provides a continuous rinsing and whitening method for pure cotton grey cloth. The continuous rinsing and whitening method comprises the following steps: S1, singeing: burning fuzz on the surface of a fabric by flame; s2, primary washing and drying: after singeing the grey cloth, washing the grey cloth on a 1 # washing machine to remove burnt gas and ash; s3, bleaching treatment: padding, steaming in a box, washing in three grids, drying in a column, and re-bleaching and whitening; s4, secondary water washing and drying, wherein five-grid water washing and three-column heat conduction oil drying cylinder drying are carried out; s5, shaping: performing padding, pre-drying and shaping to enable the fabric to obtain a stable size; s6, calendaring: carrying out calendaring treatment on the shaped finished fabric to endow the fabric with good luster; s7, preshrinking: performing preshrinking finishing on the shaped or calendered fabric to enable the fabric to reach the shrinkage rate index of a customer, and S8, packaging: inspecting, grading, rolling or packaging the finished product, and the method has the characteristics of heat energy saving, water saving, labor saving, good bleaching effect and high color fastness to chlorine bleaching.

Description

Technical Field

[0001] The invention relates to a pure cotton grey cloth dyeing and finishing pre-treatment technology, and in particular to a pure cotton grey cloth continuous rinsing and whitening method. Background Art

[0002] Fabric pretreatment is crucial to the dyeing and finishing effect of fabrics. Fabric pretreatment includes three processes: desizing, scouring and bleaching. Most of the printing and dyeing quality problems of fabrics are caused by poor pretreatment. Excellent pretreatment is the key to ensuring the quality of the finished product. Pure cotton woven fabrics contain a certain amount of pectin, wax, ash, cottonseed hulls and other substances as well as sizing applied during the weaving process. These must be removed during the pretreatment process to facilitate the subsequent dyeing, bleaching and finishing processes. The fluorescent brightener currently used is a fast-acting padding brightener. This brightener can also be achieved in one step, but this brightener has poor water washing color fastness. It loses 40% of its color at 60 degrees, and its color fastness is only 60%. Its color fastness to chlorine bleaching is even worse.

[0003] There is also another whitening method, whose fabric processing process includes grey cloth → turning the seams → singeing → desizing in a steamer, bleaching and washing → re-bleaching, whitening and washing on a roller dyeing machine to meet the requirements of chlorine bleaching resistance. This method requires one more step and uses more heat energy, water and labor. This method is currently more commonly used. Summary of the invention

[0004] The invention provides a continuous rinsing and whitening method for pure cotton grey fabric which saves heat energy, water and labor and has satisfactory bleaching effect and chlorine fastness.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is: A method for continuous rinsing and whitening of pure cotton grey fabric, comprising the following steps: S1: Singeing: Burn the fabric to remove the surface hair by flame; S2, primary washing and drying: After the grey cloth is singed, it is washed in the No. 1 washing machine to remove the burnt gas and ash, and to remove part of the iron ions on the pulp and cotton fiber; S3: Bleaching treatment: padding + steamer + 3-grid water washing + drying + re-bleaching and whitening: After water washing, the cloth roll first enters the padding tank for padding, and the grey cloth that has been dipped in the padding working solution enters the steamer, and after steaming, enters the 3-grid water washing, and then is dried in a column drying cylinder until half dry, and then dipped in the padding re-bleaching working solution for re-bleaching and whitening; S4: Secondary washing and drying, five-grid washing and two-column heat-conducting oil drying, to further wash away the floating color of the slurry and brightener and the residue of chemical additives, and improve the washing fastness; S5: shaping: padding, pre-drying and shaping are performed to make the fabric obtain a stable size; S6: Calendering: Calender the finished fabric to give it a good luster; S7: Pre-shrinkage: Pre-shrink the fabric after shaping or calendering to meet the customer's shrinkage index.

[0006] S8: Packaging: According to the customer's grading standards and packaging requirements, the finished fabrics are graded, rolled or packaged.

[0007] Furthermore, in the step S1, the singeing process uses a forward and reverse burner mode, a vehicle speed of 80-120 m / min, and a steam fire extinguishing mode.

[0008] Furthermore, in step S2, a two-grid water washing method is used in the one-time water washing and drying process, the temperatures of the 1# water washing grid and the 2# water washing grid are both set to 60-80°C, a chelating dispersant is added to the 2# water washing grid according to the amount of water in the water washing grid, the additive is 2-3 g / L, the oil inlet temperature of the dryer is set to 140-170°C, the vehicle speed is set to 50 m / min, and the vehicle speed is set to 50 m / min.

[0009] Furthermore, in step S3, the dipping and rolling method is multiple dipping and two rolling, the rolling material temperature is room temperature, and the rolling rate is 80-95% according to the thickness of the fabric.

[0010] Furthermore, the rolling working fluid is added with 15-30 g / L of quick-refining agent, 8-15 g / L of caustic soda, and 25-40 g / L of hydrogen peroxide according to the amount of water.

[0011] Furthermore, in step S3, the parameters of the steaming process after padding are set as a steamer temperature of 72-75°C, steaming for 35-50 minutes, three-grid water washing parameters are set to 80°C, the vehicle speed is 45-50 m / min, and then it is dried to semi-dryness through a column drying cylinder and then padded with a re-bleaching working solution, rolled and wrapped with plastic cloth, and then stacked for 3.5-4 hours.

[0012] Furthermore, the rebleaching and whitening working solution is composed of hydrogen peroxide, whitening agent, caustic soda, etc. The amount of hydrogen peroxide is 0.055% of the weight of the cloth shaft, the amount of whitening agent is 2.5-3.5% of the cloth shaft, and the caustic soda flow meter automatically adjusts the pH value to 9.0-9.5.

[0013] Furthermore, the secondary water washing and drying machine consists of a five-grid water washing grid and a three-column heat transfer oil drying cylinder. The temperature settings of the five-grid water washing grid are 50°C, 85°C, 85°C, 40°C, and 40°C respectively. The vehicle speed is set at 50-60 m / min, the rolling pressure is set to 0.25MPa, 0.25-0.3MPa, 0.25MPa, 0.4MPa, and 0.02MPa respectively, the tension frame tension is set to 0.2MPa, 0.25MPa, 0.25MPa, 0.25MPa, and 0.25MPa respectively, and the drying cylinder temperature is set to 110-125°C.

[0014] Furthermore, the pH value of the 4# grid and the 5# grid of the secondary washing and drying machine is 4.3-4.5.

[0015] Furthermore, in step S5, the shaping process adopts dipping and rolling, two groups of pre-baking and shaping, wherein the dipping and rolling method is one dipping and one rolling, the rolling rate is 55-65%, the pre-baking temperature is 110-130°C for group 1#, 100-110°C for group 2#, the shaping room temperature is 140-170°C, and the vehicle speed is 40-65 m / min.

[0016] The beneficial effects of adopting the above technical solution are: Compared with the process of "de-sizing, bleaching, washing in a steamer, and then re-bleaching and whitening on a roller", the invention has the characteristics of "de-sizing, bleaching, washing, re-bleaching and whitening" in one step, adopts the one-step whitening technology of de-boiling, bleaching and fluorescent whitening, and after whitening, it is washed twice, the water washing fluorescent whitening color fastness is close to 100%, and the color fastness to chlorine bleaching reaches level 3.5, which fully meets the quality requirements of hotels and hospitals for chlorine bleaching resistance and is recognized by users.

[0017] The present invention reduces one process step, saves 30-40% of heat energy, water, and labor for the bleaching, washing, and whitening processes. After the pure cotton cloth is fluorescently whitened, the color fastness to chlorine bleaching is slightly better than that of the two-step process. In addition, the process of the present invention is simple and automatically controlled, and is not affected by various factors such as ingredients, weighing, and temperature. The product has good consistency and avoids the problem of large axis difference. DETAILED DESCRIPTION

[0018] The present invention is further described below.

[0019] The present invention provides a method for continuous rinsing and whitening of pure cotton grey cloth, comprising the following steps: S1: Singeing: Burn the surface hair of the fabric with flames; the burner mode: one positive and one negative, the speed is 80~120 m / min, and the fire is extinguished with steam; the singeing process will make the surface of the fabric smoother, and the dye can better penetrate into the fabric during printing and dyeing, thereby improving the printing and dyeing effect. Singeing can also improve the feel of cotton fabrics, making them more comfortable, suitable for making clothes, sheets and other clothing. The singeing process needs to control the temperature well to avoid excessively high temperatures that cause the cotton fabrics to burn; S2: Single washing and drying: After the grey cloth is singed, it is washed on the 1# washing machine to remove the burnt gas and ash, and to remove some of the iron ions on the pulp and cotton fiber. The single washing and drying is mainly used for products that require high whiteness and good consistency, which can ensure that the subsequent process will not make the working fluid darker and darker, resulting in a gradual deterioration of the whiteness of the product; the single washing and drying process adopts a two-grid washing method. The temperatures of the 1# washing grid and the 2# washing grid are set to 60~80℃. In the 2# washing grid, a chelating dispersant is added according to the amount of water in the washing grid. The amount of chelating dispersant added is 2~3 g / L, the oil inlet temperature of the dryer is set to 140~170℃, and the vehicle speed is set to 50 m / min. , the vehicle speed is set to 50 meters / minute. The chelating dispersant is a highly efficient and multi-purpose organic chelate. It can soften water quality and has strong chelating and scum dispersing power for metal ions such as Ca2+, Mg2+, Fe3+, etc. It prevents the formation of sediments and scum produced by other dirt during dyeing and finishing processes, and can slowly dissolve and remove silica scale, calcium soap sediments and oligomers in the equipment, prevent metal salts from re-contaminating various fibers, improve the whiteness, brightness and color fastness of bleaching, dyeing and printing products, and prevent the white background of printed products and yarn-dyed products from being contaminated again.

[0020] S3: Bleaching treatment: padding + steamer + 3-grid water washing + drying + re-bleaching and whitening: After washing, the cloth roll first enters the padding trough for padding, and the grey cloth that has been dipped in the padding working solution enters the steamer, and after steaming, enters the three-grid water washing, and then is dried in a column drying cylinder until half dry, and then dipped in the padding re-bleaching working solution for re-bleaching and whitening; in the original production process, in order to ensure the effect of bleaching and whitening, the grey cloth needs to be fully dried so that it can fully absorb hydrogen peroxide, whitening agent, etc., so generally two-column or three-column drying cylinders are used for drying. With this process, in order to solve the energy consumption, one-column drying cylinder can be used, which can also achieve good bleaching. The washing and whitening effect is achieved by multiple dipping and two rolling. The rolling material temperature is room temperature. According to the thickness of the fabric, the rolling rate is 80-95%. The materials are added to the rolling material working liquid according to the amount of water, and 15-30 g / L of quick-refining agent, 8-15 g / L of caustic soda, and 25-40 g / L of hydrogen peroxide are added. The parameters of the steaming process after dipping and rolling are set as a steamer temperature of 72-75°C, steaming for 35-50 minutes, three-grid water washing parameters are set at 80°C, and the speed is 45-50 m / min. After being dried by a column drying cylinder until semi-dry, it is dipped in the re-bleaching working liquid, rolled and wrapped with plastic cloth, and then stacked for 3.5-4 hours.

[0021] The rebleaching and whitening working solution is composed of hydrogen peroxide, whitening agent, caustic soda, etc. The amount of hydrogen peroxide is 0.055% of the weight of the cloth roll, the amount of whitening agent is 2.5-3.5% of the weight of the cloth roll, and the caustic soda is automatically adjusted to a pH value of 9.0-9.5 by a flow meter. The dyeing material formula includes hydrogen peroxide, chelating dispersant, liquid alkali, whitening agent, etc.

[0022] The quick-refining agent is mainly used to remove a large amount of pectin, fat wax, ash, nitrogen-containing substances and sizing agents in the weaving process of pure cotton woven fabrics. Removing these impurities is beneficial to the subsequent dyeing, printing and finishing processes. The quick-refining agent used by our company is 9BK and 9DW quick-refining agent purchased from Shijiazhuang Kunpu Chemical Co., Ltd. 9DW is a special structure that can effectively control and activate the decomposition of hydrogen peroxide at medium and low temperatures. It is suitable for the medium and low temperature rapid pretreatment process of pure cotton fabrics. The matching 9BK can make the fabric achieve good whiteness, reduce the breaking strength of the fabric, have high moisture absorption efficiency, low energy consumption, and soft feel.

[0023] S4: Secondary washing and drying, five-grid washing and two-column heat-conducting oil drying, to further wash away the floating color of the slurry and brightener and the residue of chemical additives, and improve the washing fastness; The secondary washing and drying machine consists of a five-grid washing grid and a three-column heat-conducting oil drying cylinder. The temperature settings of the five-grid washing grid are 50°C, 85°C, 85°C, 40°C, and 40°C, respectively. The vehicle speed is set at 50-60 m / min, the padding pressure is set at 0.25MPa, 0.25-0.3MPa, 0.25MPa, 0.4MPa, and 0.02MPa, the tension of the tension frame is set at 0.2MPa, 0.25MPa, 0.25MPa, 0.25MPa, and 0.25MPa, respectively, and the drying cylinder temperature is set at 110-125°C. The pH value of the 4# and 5# grids of the secondary washing and drying machine is 4.3-4.5. The pH value is stabilized at 4.3-4.5 by automatically controlling the addition of neutralizing acid in the water. The 4# and 5# grids are primary for adjusting the pH value of the fabric, so the temperature should not be too high. The pH value of the aqueous solution in the washing tank is 4.3-4.5, and the adjustment table is 4.2-4.3; the pH value of the dried cloth surface is between 6.5-7.0. If there is a slight discrepancy, it can be corrected in time when adjusting the color light in front of the setting machine. In the present invention, neutralizing acid is added in the 4# and 5# grids to adjust the pH value, which is used to neutralize the alkali in the cloth surface of the previous process, so that the pH value of the dried cloth reaches 6.5~7, which meets customer requirements. Compared with the traditional method of washing with a large amount of water, a large amount of water is saved. In the present invention, a pH value monitor is used for monitoring, and neutralizing acid is automatically added according to its changes to stably control the pH value of the water so that it remains within the set range.

[0024] In addition, during the water washing process of the present invention, a liquid level meter is used to monitor the liquid level change, and water is automatically replenished according to the water consumption to keep the liquid level within the set range. In the present invention, a circulating pump is used to circulate in the feeding tank and the batching tank to make the ingredients uniform and realize automatic control to avoid the influence of various factors such as ingredients, weighing, temperature, etc., so that the product consistency is good and the problem of large axis difference is avoided.

[0025] S5: Shaping: padding, pre-drying and shaping are performed to make the fabric obtain stable size under certain time and temperature conditions; The shaping process uses dipping and rolling, two groups of pre-baking and shaping, among which the dipping and rolling method is one dipping and one rolling, the rolling rate is 55~65%, the pre-baking temperature is 110~130℃ for group 1#, 100~110℃ for group 2#, the shaping room temperature is 140~170℃, and the vehicle speed is 40~65 meters / minute.

[0026] The padding process mainly involves padding the blue-purple liquid, using the effects of slurry, softener and neutralizing acid to make the fabric reach the whiteness, color and feel provided by the customer. The working liquid composition is (the following ingredients are added according to the solution volume): A301 blue (concentration 1%) 30~700 ml / L; A701 purple (concentration 1%) 80~1200 ml / L; Whitening agent MST 4~30 g / L; Stiffener or starch 1~20 g / L; Neutralizing acid 0.1~4 g / L A301 is a lake formed by coupling the blue-light-bearing insoluble dye chromophore and the chromophore; A701 is a lake formed by coupling the violet-light-bearing insoluble azo dye chromophore and the chromophore. Both are widely used in printing coatings, with excellent acid and alkali resistance, chlorine bleaching resistance, and can act on cotton fibers and other fibers. The use process is simple, the cost is low, and it is easy to operate. The letters and numbers in the names are numbers, which are easy to distinguish and have no other meanings.

[0027] Brightener MST is a liquid pad dyeing brightener suitable for cotton and other cellulose fabrics. It has the characteristics of good level dyeing, excellent whiteness, good stability, resistance to hard water, acid and alkali, and can be used in the same bath with resin finishing agents.

[0028] Stiffeners are substances used to improve the appearance of fabrics, increase their elasticity and fullness, and impart stiffness.

[0029] S6: Calendering: Calender the finished fabric to give it a good luster. Calendering can be divided into light gloss, medium gloss and heavy gloss according to customer requirements. The speed is set at 10~40 m / min, the pressure of light gloss is set at 46~60 tons, cold rolling at room temperature, the pressure of medium gloss is set at 68~80 tons, cold rolling at room temperature, the pressure of heavy gloss is set at 90~110 tons, and the temperature is set at 80~105℃ for hot rolling.

[0030] S7: Pre-shrinkage: Pre-shrink the fabric after shaping or calendering to meet the customer's shrinkage index.

[0031] S8, Finished product packaging: According to the customer's grading standards and packaging requirements, the finished fabrics are graded, rolled or packaged. For example: C32*32 78*65 90" finished fabric packaging requirements are as follows: two sections of rolls of about 240 meters, plastic cloth inside and woven bag outside, self-adhesive label, the label should write the order number. C30*78*65*205CM, roll number, number of meters, another example: about 200 meters per roll, roll with the front side facing inward, sew the joints firmly, keep the length, allow for additional opening, mark well, stamp on the label, and keep the strip. Specific embodiments Example 1

[0032] A method for continuous rinsing and whitening of pure cotton grey fabric, comprising the following steps: S1: Singeing: Burn the surface hair of the fabric with flames; the flame mouth mode: one positive and one negative, the speed is 80 meters / minute, and the fire is extinguished with steam; the singeing process will make the surface of the fabric smoother, and the dye can better penetrate into the fabric during printing and dyeing, thereby improving the printing and dyeing effect. Singeing can also improve the feel of cotton fabrics, making them more comfortable, suitable for making clothes, sheets and other clothing. The singeing process needs to control the temperature well to avoid excessively high temperatures that cause the cotton fabrics to burn; S2: One-time washing and drying: After the grey cloth is singed, it is washed on the 1# washing machine to remove the burnt gas and ash, and to remove part of the iron ions on the pulp and cotton fiber; the one-time washing and drying process adopts a two-grid washing method, the temperature of the 1# washing grid and the 2# washing grid are both set to 60°C, and the chelating dispersant is added to the 2# washing grid according to the amount of water in the washing grid, the addition amount of the chelating dispersant is 2 g / L, the oil inlet temperature of the dryer is set to 140°C, and the vehicle speed is set to 50 m / min.

[0033] S3: Bleaching treatment: padding + steamer + 3-grid water washing + drying + re-bleaching and whitening: after water washing, the cloth roll first enters the padding tank for padding, and the grey cloth that has been padded in the padding working solution enters the steamer, and after steaming, enters the three-grid water washing, and then is dried by a column drying cylinder to be half dry, and then padded in the re-bleaching working solution for re-bleaching and whitening; the padding method is multiple padding and two padding, the padding temperature is room temperature, and the padding rate is 80% according to the thickness of the fabric. The materials are added to the padding working solution according to the amount of water, and 15 g / L of quick refining agent, 8 g / L of caustic soda, and 25 g / L of hydrogen peroxide are added; the parameters of the steaming process after padding are set as a steamer temperature of 72°C, steaming for 35 minutes, and the parameters of the three-grid water washing are set at 80°C, and the speed is 45 m / min. After being dried by a column drying cylinder to be half dry, it is padded in the re-bleaching working solution, rolled and wrapped with plastic cloth and stacked for 3.5 hours.

[0034] The rebleaching and whitening working solution is composed of hydrogen peroxide, whitening agent, caustic soda, etc. The amount of hydrogen peroxide is 0.055% of the weight of the cloth roll, the amount of whitening agent is 2.5% of the weight of the cloth roll, and the caustic soda is automatically adjusted to a pH value of 9.0 by a flow meter.

[0035] S4: Secondary washing and drying, five-grid washing and three-column heat-conducting oil drying, to further wash away the floating color of the slurry and brightener and the residue of chemical additives, and improve the washing fastness; The secondary water washing and drying machine consists of a five-grid water washing grid and a three-column heat-conducting oil drying cylinder. The temperature settings of the five-grid water washing grid are 50°C, 85°C, 85°C, 40°C, and 40°C, respectively. The vehicle speed is set at 50 m / min, the padder pressure is set to 0.25MPa, 0.25MPa, 0.25MPa, 0.4MPa, and 0.02MPa, respectively, the tension of the tension frame is set to 0.2MPa, 0.25MPa, 0.25MPa, 0.25MPa, and 0.25MPa, respectively, the drying cylinder temperature is set to 110°C, and the pH values ​​of the 4# and 5# grids of the secondary water washing and drying machine are 4.3.

[0036] S5: Shaping: padding, pre-drying and shaping are performed to make the fabric obtain stable size under certain time and temperature conditions; The shaping process uses dipping and rolling, two groups of pre-baking and shaping, among which the dipping and rolling method is one dipping and one rolling, the rolling rate is 55%, the pre-baking temperature is 110℃ for group 1#, 100℃ for group 2#, the shaping room temperature is 140℃, and the vehicle speed is 40 meters / minute.

[0037] The padding process mainly involves padding the blue-purple liquid, using the effects of slurry, softener and neutralizing acid to make the fabric reach the whiteness, color and feel provided by the customer. The working liquid composition is (the following ingredients are added according to the solution volume): A301 blue (concentration 1%) 30 ml / L; A701 purple (concentration 1%) 80 ml / L; Whitening agent MST 4 g / L; Stiffener or starch 1 g / L; Neutralizing acid 0.1 g / L S6: Calendering: Calender the finished fabric to give it a good gloss. Calendering can be divided into light gloss, medium gloss and heavy gloss according to customer requirements. The speed is set at 10 m / min, the light gloss pressure is set at 46 tons, and cold calendering is performed at room temperature.

[0038] S7: Pre-shrinkage: Pre-shrink the fabric after shaping or calendering to meet the customer's shrinkage index.

[0039] S8, Packaging: According to the customer's grading standards and packaging requirements, the finished fabrics are graded, rolled or packaged. Example 2

[0040] A method for continuous rinsing and whitening of pure cotton grey fabric, comprising the following steps: S1: Singeing: Burn the fabric to remove the hair on the surface; Burner mode: one positive and one negative, speed 120 m / min, use steam to extinguish the fire; S2: One-time washing and drying: After the grey cloth is singed, it is washed on the 1# washing machine to remove the burnt gas and ash, and to remove part of the iron ions on the pulp and cotton fiber; the one-time washing and drying process adopts a two-grid washing method, the temperature of the 1# washing grid and the 2# washing grid are both set to 80°C, and the chelating dispersant is added to the 2# washing grid according to the amount of water in the washing grid, the addition amount of the chelating dispersant is 3 g / L, the oil inlet temperature of the dryer is set to 170°C, and the vehicle speed is set to 50 m / min.

[0041] S3: Bleaching treatment: padding + steamer + 3-grid water washing + drying + re-bleaching and whitening: after water washing, the cloth roll first enters the padding tank for padding, and the grey cloth that has been padded in the padding working solution enters the steamer, and after steaming, enters the three-grid water washing, and then is dried by a column drying cylinder to be half dry, and then padded in the re-bleaching working solution for re-bleaching and whitening; the padding method is multiple padding and two padding, the padding temperature is room temperature, and the padding rate is 95% according to the thickness of the fabric. The materials are added to the padding working solution according to the amount of water, and 30 g / L of quick refining agent, 15 g / L of caustic soda, and 40 g / L of hydrogen peroxide are added; the parameters of the steaming process after padding are set as a steamer temperature of 75°C, steaming for 50 minutes, and the parameters of the three-grid water washing are set at 80°C, and the speed is 50 m / min. After being dried by a column drying cylinder to be half dry, it is padded in the re-bleaching working solution, rolled and wrapped with plastic cloth and stacked for 4 hours.

[0042] The rebleaching and whitening working solution is composed of hydrogen peroxide, brightener, caustic soda, etc. The amount of hydrogen peroxide is 0.055% of the weight of the cloth roll, the amount of brightener is 3.5% of the weight of the cloth roll, and the caustic soda is automatically adjusted to a pH value of 9.5 by a flow meter. The dyeing material formula includes hydrogen peroxide, chelating dispersant, liquid alkali, brightener, etc. A brightener with good solubility at room temperature is used to avoid forming a lot of precipitation at the bottom of the material tank, or reacting to form sticky floating objects.

[0043] S4: Secondary washing and drying, five-grid washing and three-column heat-conducting oil drying, to further wash away the floating color of the slurry and brightener and the residue of chemical additives, and improve the washing fastness; The secondary water washing and drying machine consists of a five-grid water washing grid and a three-column heat-conducting oil drying cylinder. The temperature settings of the five-grid water washing grid are 50°C, 85°C, 85°C, 40°C, and 40°C, respectively. The vehicle speed is set at 60 m / min, the padder pressure is set to 0.25MPa, 0.3MPa, 0.25MPa, 0.4MPa, and 0.02MPa, the tension of the tension frame is set to 0.2MPa, 0.25MPa, 0.25MPa, 0.25MPa, and 0.25MPa, respectively, the drying cylinder temperature is set to 125°C, and the pH value of the 4# and 5# grids of the secondary water washing and drying machine is 4.5.

[0044] S5: Shaping: padding, pre-drying and shaping are performed to make the fabric obtain stable size under certain time and temperature conditions; The shaping process uses dipping and rolling, two groups of pre-baking and shaping, among which the dipping and rolling method is one dipping and one rolling, the rolling rate is 65%, the pre-baking temperature is 130℃ for group 1#, 110℃ for group 2#, the shaping room temperature is 170℃, and the vehicle speed is 65m / min.

[0045] The padding process mainly involves padding the blue-purple liquid, using the effects of slurry, softener and neutralizing acid to make the fabric reach the whiteness, color and feel provided by the customer. The working liquid composition is (the following ingredients are added according to the solution volume): A301 blue (concentration 1%) 700 ml / L; A701 purple (concentration 1%) 1200 ml / L; Whitening agent MST 30 g / L; Stiffener or starch 20 g / L; Neutralizing acid 4 g / L S6: Calendering: Calender the finished fabric to give it a good luster. Calendering can be divided into two types according to customer requirements: medium calendering with a pressure of 80 tons and cold calendering at room temperature.

[0046] S7: Pre-shrinkage: Pre-shrink the fabric after shaping or calendering to meet the customer's shrinkage index.

[0047] S8, Packaging: According to the customer's grading standards and packaging requirements, the finished fabrics are graded, rolled or packaged. Example 3

[0048] A method for continuous rinsing and whitening of pure cotton grey fabric, comprising the following steps: S1: Singeing: Burn the surface hair of the fabric with flames; the flame mouth mode: one positive and one negative, the speed is 100 meters / minute, and the fire is extinguished with steam; the singeing process will make the surface of the fabric smoother, and the dye can better penetrate into the fabric during printing and dyeing, thereby improving the printing and dyeing effect. Singeing can also improve the feel of cotton fabrics, making them more comfortable, suitable for making clothes, sheets and other clothing. The singeing process needs to control the temperature well to avoid excessive temperature causing the cotton fabric to burn; S2: One-time washing and drying: After the grey cloth is singed, it is washed on the 1# washing machine to remove the burnt gas and ash, and to remove part of the iron ions on the pulp and cotton fiber; the one-time washing and drying process adopts a two-grid washing method, the temperature of the 1# washing grid and the 2# washing grid are both set to 70°C, and the chelating dispersant is added to the 2# washing grid according to the amount of water in the washing grid, the addition amount of the chelating dispersant is 2.5 g / L, the oil inlet temperature of the dryer is set to 155°C, and the vehicle speed is set to 50 m / min.

[0049] S3: bleaching treatment: padding + steamer + 3-grid water washing + drying + re-bleaching and whitening: after water washing, the cloth roll first enters the padding tank for padding, and the grey cloth that has been padded with the padding working solution enters the steamer, and after steaming, enters the three-grid water washing, and then is dried by a column drying cylinder to be half dry, and then is padded with the re-bleaching working solution for re-bleaching and whitening; the padding method is multiple padding and two padding, the padding temperature is room temperature, and the padding rate is 85% according to the thickness of the fabric. In the padding working solution, materials are added according to the amount of water, and 25 g / L of quick refining agent, 10 g / L of caustic soda, and 30 g / L of hydrogen peroxide are added; the parameters of the steaming process after padding are set as a steamer temperature of 74°C, steaming for 45 minutes, and the parameters of the three-grid water washing are set as 80°C, and the speed is 47 m / min. After being dried by a column drying cylinder to be half dry, it is padded with the re-bleaching working solution, rolled and wrapped with plastic cloth and stacked for 3.7 hours.

[0050] The rebleaching and whitening working solution is composed of hydrogen peroxide, whitening agent, caustic soda, etc. The amount of hydrogen peroxide is 0.055% of the weight of the cloth roll, the amount of whitening agent is 3% of the weight of the cloth roll, and the caustic soda is automatically adjusted to a pH value of 9.2 by a flow meter. The dyeing material formula includes hydrogen peroxide, chelating dispersant, liquid alkali, whitening agent, etc.

[0051] S4: Secondary washing and drying, five-grid washing and three-column heat-conducting oil drying, to further wash away the floating color of the slurry and brightener and the residue of chemical additives, and improve the washing fastness; The secondary water washing and drying machine consists of a five-grid water washing grid and a three-column heat-conducting oil drying cylinder. The temperature settings of the five-grid water washing grid are 50°C, 85°C, 85°C, 40°C, and 40°C, respectively. The vehicle speed is set at 55 m / min, the padder pressure is set to 0.25MPa, 0.27MPa, 0.25MPa, 0.4MPa, and 0.02MPa, respectively, the tension of the tension frame is set to 0.2MPa, 0.25MPa, 0.25MPa, 0.25MPa, and 0.25MPa, respectively, the drying cylinder temperature is set to 120°C, and the pH values ​​of the 4# and 5# grids of the secondary water washing and drying machine are 4.4.

[0052] S5: Shaping: padding, pre-drying and shaping are performed to make the fabric obtain stable size under certain time and temperature conditions; The shaping process uses dipping and rolling, two groups of pre-baking and shaping, among which the dipping and rolling method is one dipping and one rolling, the rolling rate is 60%, the pre-baking temperature is 120℃ for group 1#, 105℃ for group 2#, the shaping room temperature is 150℃, and the vehicle speed is 55 meters / minute.

[0053] The padding process mainly involves padding the blue-purple liquid, using the effects of slurry, softener and neutralizing acid to make the fabric reach the whiteness, color and feel provided by the customer. The working liquid composition is (the following ingredients are added according to the solution volume): A301 blue (concentration 1%) 500 ml / L; A701 purple (concentration 1%) 600 ml / L; Whitening agent MST 20 g / L; Stiffener or starch 10 g / L; Neutralizing acid 2 g / L S6: Calendering: Calender the finished fabric to give it a good gloss. Calendering can be divided into light gloss, medium gloss and heavy gloss according to customer requirements. The speed is set at 30 m / min, the heavy gloss pressure is set at 100 tons, and the temperature is set at 100℃ for hot calendering.

[0054] S7: Pre-shrinkage: Pre-shrink the fabric after shaping or calendering to meet the customer's shrinkage index.

[0055] S8, Packaging: According to the customer's grading standards and packaging requirements, the finished fabrics are graded, rolled or packaged.

[0056] According to Examples 1-3, different finished products were obtained and graded. The water-washing fluorescent whitening fastness and chlorine bleaching fastness indicators are shown in the following table: Fluorescent whitening fastness to washing (grade) Color fastness to chlorine bleaching (grade) Example 1 4.6 3.7 Example 2 4.9 4 Example 3 4.8 3.9 Note: The grade assessment refers to the gray rating card, which is divided into 5 levels, with 1 being the worst and 5 being the best.

[0057] From the above, it is known that the present invention adopts a one-step whitening technology of deboiling, bleaching and fluorescent whitening, and after whitening, it is washed twice, and the water washing fluorescent whitening color fastness is close to level 5, and the color fastness to chlorine bleaching reaches more than level 3.5, which fully meets the quality requirements of hotels and hospitals for chlorine bleaching resistance, and is affirmed by users. The present invention reduces one process, saves 30-40% of heat energy, water, and labor for bleaching, washing, and whitening processes, and the color fastness to chlorine bleaching of pure cotton cloth after fluorescent whitening is slightly better than the two-step process. The present invention has a simple process, automatic control, avoids the influence of various factors such as ingredients, weighing, temperature, etc., has good product consistency, and avoids the problem of large axis difference.

[0058] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for continuous rinsing and whitening of pure cotton grey fabric, characterized in that: The following steps are involved: S1: Singeing: Burn the fabric with flame to remove the surface hair; S2, primary washing and drying: After the grey cloth is singed, it passes through the 1# washing machine to wash away the scorch gas and ash on the cloth surface, and remove part of the iron ions on the pulp and cotton fiber; S3: Bleaching treatment: After washing, the cloth roll first enters the rolling tank for rolling, and the grey cloth that has been dipped in the rolling working solution enters the steamer, and after steaming, enters the three-grid water washing, and then is dried in a column drying cylinder until half dry, and then dipped in the rolling re-bleaching working solution for re-bleaching and whitening; S4: Secondary washing and drying, five-grid washing and three-column heat-conducting oil drying, further washing away the floating color of the slurry and brightener and the residue of chemical additives, improving the product's water-washing and chlorine-bleaching fastness; S5: shaping: padding, pre-drying and shaping are performed to make the fabric obtain a stable size; S6: Calendering: Calender the finished fabric to give it a good luster; S7: Pre-shrinkage: Pre-shrink the fabric after shaping or calendering to achieve the shrinkage index; S8: Packaging: According to the customer's grading standards and packaging requirements, the finished fabrics are graded, rolled or packaged.

2. A method for continuous rinsing and whitening of pure cotton grey fabric according to claim 1, characterized in that: In the step S1, the singeing process adopts a forward and reverse burner mode, a vehicle speed of 80-120 m / min, and a steam fire extinguishing mode.

3. A method for continuous rinsing and whitening of pure cotton grey fabric according to claim 1, characterized in that: In step S2, a water washing and drying process is performed by a two-grid water washing method, the temperatures of the 1# water washing grid and the 2# water washing grid are both set to 60-80°C, a chelating dispersant is added to the 2# water washing grid according to the amount of water in the water washing grid, the additive is 2-3 g / L, the oil inlet temperature of the dryer is set to 140-170°C, and the vehicle speed is set to 50 m / min.

4. A method for continuous rinsing and whitening of pure cotton grey fabric according to claim 1, characterized in that: In step S3, the dipping and rolling method is multiple dipping and two rolling, the rolling material temperature is room temperature, and the rolling rate is 80-95% according to the thickness of the fabric.

5. A method for continuous rinsing and whitening of pure cotton grey fabric according to claim 4, characterized in that: In step S3, 15-30 g / L of quick-refining agent, 8-15 g / L of caustic soda, and 25-40 g / L of hydrogen peroxide are added to the rolling working fluid according to the amount of water.

6. A method for continuous rinsing and whitening of pure cotton grey fabric according to claim 1, characterized in that: In the step S3, the parameters of the steaming process after padding are set as follows: the steamer temperature is 72-75° C., the steaming time is 35-50 minutes, the three-grid water washing parameters are set as 80° C., the vehicle speed is 45-50 m / min, and then the product is dried to semi-dryness by a column drying cylinder, then padded with a re-bleaching working solution, rolled, wrapped with plastic cloth, and stacked for 3.5-4 hours.

7. A method for continuous rinsing and whitening of pure cotton grey fabric according to claim 6, characterized in that: The rebleaching and whitening working solution is composed of hydrogen peroxide, whitening agent, caustic soda, etc. The amount of hydrogen peroxide is 0.055% of the cloth roll weight, the amount of whitening agent is 2.5-3.5% of the cloth weight, and the caustic soda flow meter automatically adjusts the pH value to 9.0-9.

5.

8. A method for continuous rinsing and whitening of pure cotton grey fabric according to claim 1, characterized in that: In step S4, the secondary water washing and drying machine consists of a five-grid water washing grid and a three-column heat-conducting oil drying cylinder. The temperature settings of the five-grid water washing grid are 50°C, 85°C, 85°C, 40°C, and 40°C, respectively. The vehicle speed is set at 50-60 m / min, the rolling pressure is set to 0.25 MPa, 0.25-0.3 MPa, 0.25 MPa, 0.4 MPa, and 0.02 MPa, respectively, the tension frame tension is set to 0.2 MPa, 0.25 MPa, 0.25 MPa, 0.25 MPa, and 0.25 MPa, respectively, and the drying cylinder temperature is set to 110-125°C.

9. A method for continuous rinsing and whitening of pure cotton grey fabric according to claim 8, characterized in that: Neutralizing acid is automatically added to the water in the 4# and 5# compartments of the secondary washing and drying machine to stabilize the pH value at 4.3-4.

5.

10. A method for continuous rinsing and whitening of pure cotton grey fabric according to claim 1, characterized in that: In step S5, the shaping process adopts dipping and rolling, two groups of pre-baking and shaping, wherein the dipping and rolling method is one dipping and one rolling, the rolling rate is 55-65%, the pre-baking temperature is 110-130°C for group 1#, 100-110°C for group 2#, the shaping room temperature is 140-170°C, and the vehicle speed is 40-65 m / min.