Processing method for reducing formaldehyde content and long-term release of pure cotton non-ironing fabrics

Abstract

The present invention belongs to the technical field of textile processing, and specifically relates to a processing method for reducing the formaldehyde content and long-term release of pure cotton non-ironing fabrics. The method comprises: (1) washing the pure cotton fabric that has not been subjected to non-ironing finishing for the first time, applying isopropyl alcohol first and then applying nanobubbles in the first washing process; (2) non-ironing finishing; (3) washing the pure cotton fabric after non-ironing finishing for the second time, applying soda ash first and then applying nanobubbles in the second washing process; (4) padding a formaldehyde scavenger in the stenting process. By fully removing the residual alkaline substances and free formaldehyde that is not cross-linked with cotton fibers in the pure cotton fabric in the washing process before and after the non-ironing finishing, the formaldehyde content is effectively reduced and its long-term release is avoided. At the same time, by padding the formaldehyde scavenger in the stenting process, the formaldehyde is fixed or converted into harmless substances, thereby achieving long-term and lasting safety. In addition, the washing process also helps to cross-link the resin with the cotton fibers, thereby improving the anti-wrinkle and non-ironing effect of the fabric.

Description

Technical Field

[0001] The invention belongs to the technical field of textile processing, and particularly relates to a processing method for reducing the formaldehyde content and long-term release of pure cotton wrinkle-free fabrics. Background Art

[0002] In the field of clothing materials, pure cotton fabrics are widely favored for their excellent moisture absorption and breathability, soft touch and comfortable experience. However, the unique properties of this natural fiber also bring challenges: cotton fibers are prone to wrinkles during wearing and washing, and need to be ironed frequently to maintain the shape of clothing, which undoubtedly brings inconvenience and additional care costs to consumers. To address this problem, the industry generally adopts non-ironing finishing technology, which aims to reduce clothing wrinkles through chemical treatment and achieve the convenience of wearing directly after washing without ironing. However, the current mainstream non-ironing finishing technology mainly relies on N-hydroxymethyl resin additives, which contain formaldehyde. During the wearing or long-term storage of clothing, formaldehyde may be slowly released, posing a potential threat to consumer health. In addition, pure cotton fabrics need to be treated with alkaline substances in the key link of mercerization in the finishing process. Although they are subsequently washed, it is difficult to completely remove all residual alkali. These residual alkalis can react slowly with N-hydroxymethyl resins in non-ironing finishing under certain conditions, further exacerbating the problem of long-term formaldehyde release and increasing consumers' concerns about product safety.

[0003] Chinese patent CN104562688A discloses a method for preparing environmentally friendly textiles with reduced formaldehyde, which includes the following aspects: (1) blocking hydroxymethyl groups; (2) producing low-formaldehyde products, when etherifying hydroxymethyl groups with lower alcohols, the stability of CN bonds can be improved; (3) adding polyols to the finishing liquid can reduce the amount of released formaldehyde to below 400 ppm. This invention can reduce formaldehyde, but cannot solve the problem of long-term formaldehyde release.

[0004] Chinese patent CN110791948A discloses a formaldehyde removal process for textiles, which comprises: rolling textiles containing formaldehyde in a sodium bisulfite solution or a sodium sulfite solution, rolling the rolled textiles to a sealed steamer for sealed steam washing; rolling the steamed textiles to an open-width squeezing machine for washing and dehydration, and then drying; rolling and packaging the dried textiles through a roll-up machine to form finished products; the invention rolls the textiles containing formaldehyde in a formaldehyde remover solution, which can react with formaldehyde, thereby effectively removing formaldehyde from the textiles, and further removing formaldehyde residues on the textiles through high-temperature steam washing and open-width washing; however, it cannot solve the problem of long-term release of aldehydes.

[0005] Chinese patent CN102851413A discloses a method for reducing the free formaldehyde content of fur and textiles and the equipment used in the method. The method is to hang the fur and textile to be treated above a closed container containing a formaldehyde dissolving enzyme solution and keep it at a temperature of 50-60°C for 6-8 hours; the volume of the formaldehyde dissolving enzyme solution in the closed container mL and the dry weight of the fur and textile to be treated in the container g are 1.1-1.5:1. The two ends of the closed container are respectively equipped with closed doors 1 and 2, the bottom of the closed container is provided with a fumigation treatment liquid tank, and the upper part of the closed container is fixed with a hanging rod. This invention can reduce the formaldehyde content, but it still fails to solve the problem of long-term formaldehyde release. Summary of the invention

[0006] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a processing method for reducing the formaldehyde content and long-term release of pure cotton non-ironing fabrics, by fully removing the alkali substances remaining in the mercerizing process of the pure cotton fabrics and the free formaldehyde that is not cross-linked with the cotton fibers in the washing process before and after the non-ironing finishing, so as to effectively reduce the formaldehyde content and avoid its long-term release. At the same time, through the tentering process, the imidazoline derivative formaldehyde scavenger is impregnated to fix or convert the formaldehyde into harmless substances, so as to achieve long-term and lasting safety. In addition, the washing process also helps to better cross-link the resin with the cotton fibers, thereby improving the anti-wrinkle and non-ironing effect of the fabric.

[0007] The technical solution adopted by the present invention is as follows:

[0008] The processing method for reducing the formaldehyde content and long-term release of pure cotton non-ironing fabrics comprises the following steps:

[0009] (1) First washing: The pure cotton fabric that has not been subjected to the non-ironing finishing is washed for the first time. In the first washing process, isopropyl alcohol is first applied, and then nanobubbles are applied;

[0010] (2) No-ironing finishing;

[0011] (3) Second washing: The cotton fabric after the non-ironing treatment is washed for the second time. In the second washing process, soda ash is first applied, and then nanobubbles are applied;

[0012] (4) Stretching: Formaldehyde scavenger is impregnated during the stretching process.

[0013] In the step (1), the first water washing is carried out in a water washing machine, which comprises water washing tanks No. 1 to No. 8, wherein 1 to 5 g / L of isopropanol is added to water washing tank No. 1, and nanobubbles are applied to the bottom of water washing tanks No. 2 to No. 6 by a nanobubble machine.

[0014] In the step (1), the speed of the washing machine is 30-60 m / min; the temperature of the No. 1 washing tank is 20-40°C, the temperature of the No. 2-6 washing tanks is 60-80°C, and the temperature of the No. 7-8 washing tanks is 20-40°C.

[0015] In the step (2), the permanent-ironing finishing liquid comprises 60-180 g / L of resin and 20-60 g / L of catalyst, the permanent-ironing resin is dihydroxymethyl dihydroxyethylene urea resin, and the catalyst is magnesium chloride.

[0016] In the step (2), the wrinkle-free finishing is carried out on a tentering machine, with two dips and two rolls, and drying at 100-120°C. After drying, the fabric is baked in a baking machine at a baking temperature of 140-160°C for 2-4 minutes.

[0017] In the step (3), the second water washing is carried out in a water washing machine, which comprises water washing tanks No. 1 to No. 8, wherein 1 to 2 g / L of soda ash is added to water washing tank No. 1, and nanobubbles are applied to the bottom of water washing tanks No. 2 to No. 6 by a nanobubble machine.

[0018] In the step (3), the speed of the washing machine is 30-60 m / min; the temperature of the No. 1 washing tank is 40-60°C, the temperature of the No. 2-6 washing tanks is 60-80°C, and the temperature of the No. 7-8 washing tanks is 20-40°C.

[0019] The diameter of the nanobubbles is 5-40 μm, and the ventilation volume is 0.2-0.6 m 3 / h.

[0020] The formaldehyde scavenger is an imidazoline derivative, preferably formaldehyde scavenger FDS, purchased from Zibo Lurui Fine Chemical Co., Ltd., with a dosage of 20-40 g / L.

[0021] The speed of the stentering machine is 30-60 m / min, two dipping and two rolling, the liquid carrying rate is 60-70%, and the drying room temperature is 90-110°C.

[0022] The processing method for reducing the formaldehyde content and long-term release of pure cotton non-ironing fabrics also includes singeing, desizing, mercerizing, stenting and pre-shrinking.

[0023] The singeing adopts front and back singeing, direct burning, the speed is 60-100 m / min, and the flame intensity is 8-14 mbar.

[0024] The desizing adopts enzyme desizing, the dosage is 5-30g / L, the temperature is 95-98°C, and the vehicle speed is 60-100m / min.

[0025] The mercerizing alkali solution concentration is 18-30Be, and the vehicle speed is 50-70m / min.

[0026] The temperature of the pre-shrunk rubber blanket is 100-110° C., and the vehicle speed is 40-60 m / min.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] (1) The processing method for reducing the formaldehyde content and long-term release of pure cotton non-ironing fabrics described in the present invention adopts nanobubble washing technology, fully utilizing the extremely high surface area and reaction activity of nanobubbles to penetrate into the fibers of pure cotton non-ironing fabrics and effectively remove the alkali substances and formaldehyde molecules remaining in the mercerizing process. This step not only prevents the residual alkali from slowly destroying the cross-linking between the resin and the cotton fibers and avoiding the long-term release of formaldehyde, but also converts the formaldehyde molecules into harmless substances through the efficient adsorption and reaction between nanobubbles and formaldehyde molecules and discharges them during the washing process, thereby significantly reducing the formaldehyde content in the fabric;

[0029] (2) The processing method for reducing the formaldehyde content and long-term release of pure cotton non-ironing fabrics described in the present invention, the washing process implemented before the non-ironing finishing not only removes harmful residual alkali, but also provides cleaner and more favorable conditions for the subsequent resin cross-linking, promotes the firm combination of resin and cotton fiber, and thus improves the wrinkle-resistant and non-ironing performance of the fabric. In addition, the second washing after the non-ironing finishing further removes free formaldehyde that is not cross-linked with cotton fibers, ensuring the ultimate safety of the fabric;

[0030] (3) The processing method for reducing the formaldehyde content and long-term release of pure cotton non-ironing fabrics described in the present invention introduces imidazoline derivatives as formaldehyde scavengers, and through padding treatment in the tentering process, the scavengers can stably react chemically with the formaldehyde molecules remaining in the fabric and those that may be released in the future, fixing them or converting them into stable and harmless substances. This long-lasting formaldehyde control mechanism greatly reduces the risk of subsequent formaldehyde release and provides users with a safer and healthier wearing experience. DETAILED DESCRIPTION

[0031] The present invention is further described below with reference to the embodiments, but they do not limit the implementation of the present invention.

[0032] The raw materials used in the examples and comparative examples are conventional commercially available raw materials unless otherwise specified, and the process methods used in the examples and comparative examples are conventional methods in the art unless otherwise specified.

[0033] Some of the raw materials used in the examples and comparative examples are described as follows:

[0034] Formaldehyde scavenger FDS was purchased from Zibo Lurui Fine Chemical Co., Ltd.;

[0035] Resin CR-E was purchased from Zibo Lurui Fine Chemical Co., Ltd.;

[0036] Catalyst CT-C was purchased from Zibo Lurui Fine Chemical Co., Ltd.;

[0037] Biological enzyme DS-HT was purchased from Zibo Lurui Fine Chemical Co., Ltd.

[0038] Example 1

[0039] The processing method for reducing the formaldehyde content and long-term release of pure cotton non-ironing fabrics comprises the following steps:

[0040] (1) Grey fabric preparation: The fabric is made of 80-neg pure cotton yarn in the warp direction and 80-neg pure cotton yarn in the weft direction, with a warp yarn density of 147 yarns / inch and a weft yarn density of 72 yarns / inch. The fabric structure is 2 / 2 weft weight flat;

[0041] (2) Singeing: Singeing on both sides, direct burning, speed 80m / min, flame intensity 12mbar;

[0042] (3) Desizing: Use biological enzyme DS-HT for desizing, dosage 30g / L, temperature 97℃, speed 80m / min;

[0043] (4) Mercerizing: sodium hydroxide solution concentration 24Be, vehicle speed 70m / min;

[0044] (5) First washing: The cotton fabric without ironing treatment is washed for the first time in a washing machine with a speed of 50 m / min. The washing machine includes washing tanks No. 1 to No. 8, in which 3 g / L of isopropyl alcohol is added to washing tank No. 1, and the temperature of washing tank No. 1 is 30 °C. Nanobubbles are applied to the bottom of washing tanks No. 2 to No. 6 by a nanobubble machine. The diameter of the nanobubbles is 27.5 ± 12.5 μm, and the ventilation volume is 0.4 m 3 / h, the temperature of No. 2~6 washing tanks is 70℃, and the temperature of No. 7~8 washing tanks is 30℃;

[0045] (6) Non-ironing finishing: The non-ironing finishing liquid is 120g / L of resin CR-E and 40g / L of catalyst CT-C. Non-ironing finishing is carried out on a tenter frame, two dips and two rolls, drying at 110℃, and then baking in a baking machine at a temperature of 150℃ for 3 minutes;

[0046] (7) Second washing: The cotton fabric after the wrinkle-free finishing is washed for the second time in a washing machine with a speed of 50 m / min. The washing machine includes washing tanks No. 1 to No. 8, in which 1.5 g / L of soda ash is added to washing tank No. 1, and the temperature of washing tank No. 1 is 50 °C. Washing tanks No. 2 to No. 6 are added with nanobubbles at the bottom of the washing tank by a nanobubble machine. The diameter of the nanobubbles is 27.5 ± 12.5 μm, and the ventilation volume is 0.4 m 3 / h, the temperature of No. 2~6 washing tanks is 70℃, and the temperature of No. 7~8 washing tanks is 30℃;

[0047] (8) Tentering: In the tentering process, the formaldehyde scavenger FDS was dipped and rolled, the dosage was 30g / L, the tentering speed was 50m / min, two dips and two rolls, the liquid rate was 65%, and the drying room temperature was 100℃;

[0048] (9) Preshrinkage: blanket temperature 105°C, vehicle speed 50m / min.

[0049] Example 2

[0050] The processing method for reducing the formaldehyde content and long-term release of pure cotton non-ironing fabrics comprises the following steps:

[0051] (1) Fabric preparation: Warp pure cotton 60 Ne single yarn, weft pure cotton 60 Ne single yarn, warp density 140 strands / inch, weft density 100 strands / inch, fabric structure 1 / 1 plain weave;

[0052] (2) Singeing: Singeing on both sides, direct burning, speed 60m / min, flame intensity 8mbar;

[0053] (3) Desizing: Use biological enzyme DS-HT for desizing, dosage 10g / L, temperature 95℃, speed 60m / min;

[0054] (4) Mercerizing: sodium hydroxide solution concentration 18Be, vehicle speed 50m / min;

[0055] (5) First washing: The cotton fabric without ironing treatment is washed for the first time in a washing machine with a speed of 60 m / min. The washing machine includes washing tanks No. 1 to No. 8, in which 1.5 g / L isopropyl alcohol is added to washing tank No. 1, and the temperature of washing tank No. 1 is 20 °C. Nanobubbles are applied to the bottom of washing tanks No. 2 to No. 6 by a nanobubble machine. The diameter of the nanobubbles is 30 ± 10 μm, and the ventilation volume is 0.2 m 3 / h, the temperature of No. 2~6 washing tanks is 60℃, and the temperature of No. 7~8 washing tanks is 20℃;

[0056] (6) Non-ironing finishing: The non-ironing finishing liquid is 60g / L of resin CR-E and 20g / L of catalyst CT-C. Non-ironing finishing is carried out on a tenter frame, two dips and two rolls, drying at 100℃, and then baking in a baking machine at a temperature of 140℃ for 2 minutes;

[0057] (7) Second washing: The cotton fabric after the wrinkle-free finishing is washed for the second time on a washing machine with a speed of 60 m / min. The washing machine includes washing tanks No. 1 to No. 8, in which 1 g / L of soda ash is added to washing tank No. 1, and the temperature of washing tank No. 1 is 40 °C. Washing tanks No. 2 to No. 6 use a nanobubble machine to apply nanobubbles at the bottom of the washing tank. The diameter of the nanobubbles is 30 ± 10 μm, and the ventilation volume is 0.2 m 3 / h, the temperature of No. 2~6 washing tanks is 60℃, and the temperature of No. 7~8 washing tanks is 20℃;

[0058] (8) Tentering: In the tentering process, the formaldehyde scavenger FDS was dipped and rolled, the dosage was 20 g / L, the tentering speed was 60 m / min, two dips and two rolls, the liquid rate was 60%, and the drying room temperature was 90 °C;

[0059] (9) Preshrinkage: blanket temperature 100°C, machine speed 60m / min.

[0060] Example 3

[0061] The processing method for reducing the formaldehyde content and long-term release of pure cotton non-ironing fabrics comprises the following steps:

[0062] (1) Grey fabric preparation: 100 Ne 3-ply cotton in warp direction, 20 Ne 100 Ne single yarn core-spun spandex 105 denier in weft direction, warp density 118 yarns / inch, weft density 70 yarns / inch, fabric structure 2 / 2 twill;

[0063] (2) Singeing: Singeing on both sides, direct burning, speed 100m / min, flame intensity 14mbar;

[0064] (3) Desizing: Use biological enzyme DS-HT for desizing, dosage 5g / L, temperature 98℃, speed 100m / min;

[0065] (4) Mercerizing: sodium hydroxide solution concentration 30Be, vehicle speed 70m / min;

[0066] (5) First washing: The cotton fabric without ironing treatment is washed for the first time in a washing machine with a speed of 30 m / min. The washing machine includes washing tanks No. 1 to No. 8, in which 5 g / L isopropyl alcohol is added to washing tank No. 1 and the temperature of washing tank No. 1 is 40 °C. Nanobubbles are applied to the bottom of washing tanks No. 2 to No. 6 by a nanobubble machine. The diameter of the nanobubbles is 22.5 ± 17.5 μm and the ventilation volume is 0.6 m 3 / h, the temperature of washing tanks No. 2 to 6 is 80℃, and the temperature of washing tanks No. 7 to 8 is 40℃;

[0067] (6) Non-ironing finishing: The non-ironing finishing liquid is 180g / L of resin CR-E and 60g / L of catalyst CT-C. Non-ironing finishing is carried out on a tenter frame, two dips and two rolls, drying at 120℃, and then baking in a baking machine at a temperature of 160℃ for 4 minutes;

[0068] (7) Second washing: The cotton fabric after the wrinkle-free finishing is washed for the second time on a washing machine with a speed of 30 m / min. The washing machine includes washing tanks No. 1 to No. 8, in which 2 g / L of soda ash is added to washing tank No. 1, and the temperature of washing tank No. 1 is 60 °C. Nanobubbles are applied to the bottom of washing tanks No. 2 to No. 6 by a nanobubble machine. The diameter of the nanobubbles is 22.5 ± 17.5 μm, and the ventilation volume is 0.6 m 3 / h, the temperature of washing tanks No. 2 to 6 is 80℃, and the temperature of washing tanks No. 7 to 8 is 40℃;

[0069] (8) Tentering: In the tentering process, the formaldehyde scavenger FDS was dipped and rolled, the dosage was 40g / L, the tentering speed was 30m / min, two dips and two rolls, the liquid rate was 70%, and the drying room temperature was 110℃;

[0070] (9) Preshrinkage: blanket temperature 110°C, vehicle speed 40m / min.

[0071] Example 4

[0072] The processing method for reducing the formaldehyde content and long-term release of pure cotton non-ironing fabrics comprises the following steps:

[0073] (1) Grey fabric preparation: The fabric is made of 80-neg pure cotton yarn in the warp direction and 80-neg pure cotton yarn in the weft direction, with a warp yarn density of 119 yarns / inch and a weft yarn density of 96 yarns / inch. The fabric structure is high-grade Oxford spinning.

[0074] (2) Singeing: Singeing on both sides, direct burning, speed 90m / min, flame intensity 12mbar;

[0075] (3) Desizing: Use biological enzyme DS-HT for desizing, dosage 30g / L, temperature 97℃, speed 90m / min;

[0076] (4) Mercerizing: sodium hydroxide solution concentration 25Be, vehicle speed 60m / min;

[0077] (5) First washing: The cotton fabric without ironing treatment is washed for the first time in a washing machine with a speed of 40 m / min. The washing machine includes washing tanks No. 1 to No. 8, in which 4 g / L isopropyl alcohol is added to washing tank No. 1 and the temperature of washing tank No. 1 is 40 °C. Nanobubbles are applied to the bottom of washing tanks No. 2 to No. 6 by a nanobubble machine. The diameter of the nanobubbles is 27.5 ± 12.5 μm and the ventilation volume is 0.5 m3 / h, the temperature of No. 2~6 washing tanks is 70℃, and the temperature of No. 7~8 washing tanks is 40℃;

[0078] (6) Non-ironing finishing: The non-ironing finishing liquid is 150g / L of resin CR-E and 50g / L of catalyst CT-C. Non-ironing finishing is carried out on a tenter frame, two dips and two rolls, drying at 110℃, and then baking in a baking machine at a temperature of 150℃ for 3 minutes;

[0079] (7) Second washing: The cotton fabric after the wrinkle-free finishing is washed for the second time on a washing machine with a speed of 40 m / min. The washing machine comprises washing tanks No. 1 to No. 8, wherein 1.5 g / L of soda ash is added to washing tank No. 1, and the temperature of washing tank No. 1 is 55 °C. Nanobubbles are applied to the bottom of washing tanks No. 2 to No. 6 by a nanobubble machine. The diameter of the nanobubbles is 27.5 ± 12.5 μm, and the ventilation volume is 0.5 m 3 / h, the temperature of No. 2~6 washing tanks is 75℃, and the temperature of No. 7~8 washing tanks is 40℃;

[0080] (8) Tentering: In the tentering process, the formaldehyde scavenger FDS was dipped and rolled, the dosage was 40g / L, the tentering speed was 40m / min, two dips and two rolls, the liquid rate was 65%, and the drying room temperature was 100℃;

[0081] (9) Preshrinkage: blanket temperature 110°C, vehicle speed 45 m / min.

[0082] Example 5

[0083] The processing method for reducing the formaldehyde content and long-term release of pure cotton non-ironing fabrics comprises the following steps:

[0084] (1) Grey fabric preparation: 50-neg cotton single yarn in warp direction, 50-neg single yarn core-spun spandex 40 denier in weft direction, warp density 112 strands / inch, weft density 100 strands / inch, fabric structure 2 / 1 twill;

[0085] (2) Singeing: Singeing on both sides, direct burning, speed 70m / min, flame intensity 10mbar;

[0086] (3) Desizing: Use biological enzyme DS-HT for desizing, dosage 15g / L, temperature 97℃, speed 70m / min;

[0087] (4) Mercerizing: sodium hydroxide solution concentration 21Be, vehicle speed 60m / min;

[0088] (5) First washing: The cotton fabric without ironing treatment is washed for the first time in a washing machine with a speed of 40 m / min. The washing machine includes washing tanks No. 1 to No. 8, in which 3.5 g / L isopropyl alcohol is added to washing tank No. 1, and the temperature of washing tank No. 1 is 40 °C. Nanobubbles are applied to the bottom of washing tanks No. 2 to No. 6 by a nanobubble machine. The diameter of the nanobubbles is 30 ± 10 μm, and the ventilation volume is 0.5 m 3 / h, the temperature of washing tanks No. 2 to 6 is 70℃, and the temperature of washing tanks No. 7 to 8 is 40℃;

[0089] (6) Non-ironing finishing: The non-ironing finishing liquid is 100g / L of resin CR-E and 34g / L of catalyst CT-C. Non-ironing finishing is carried out on a tenter frame, two dips and two rolls, drying at 110℃, and then baking in a baking machine at a temperature of 140℃ for 3.5min.

[0090] (7) Second washing: The cotton fabric after the wrinkle-free finishing is washed for the second time on a washing machine with a speed of 40 m / min. The washing machine comprises washing tanks No. 1 to No. 8, wherein 1 g / L of soda ash is added to washing tank No. 1 and the temperature of washing tank No. 1 is 45 °C. Washing tanks No. 2 to No. 6 are provided with nanobubbles at the bottom of the washing tanks by a nanobubble machine. The diameter of the nanobubbles is 30 ± 10 μm and the ventilation volume is 0.5 m 3 / h, the temperature of No. 2~6 washing tanks is 65℃, and the temperature of No. 7~8 washing tanks is 40℃;

[0091] (8) Tentering: In the tentering process, the formaldehyde scavenger FDS was dipped and rolled, the dosage was 40g / L, the tentering speed was 40m / min, two dips and two rolls, the liquid rate was 65%, and the drying room temperature was 100℃;

[0092] (9) Preshrinkage: blanket temperature 105°C, vehicle speed 60m / min.

[0093] Comparative Example 1

[0094] The difference from Example 1 is that soda ash is not added in the second washing process, nanobubbles are not applied, and formaldehyde scavenger FDS is not impregnated in the tentering process, only deionized water is impregnated, and the rest is the same as Example 1.

[0095] Comparative Example 2

[0096] The difference from Example 2 is that isopropyl alcohol is not added in the first washing process, nanobubbles are not applied, and formaldehyde scavenger FDS is not impregnated in the tentering process, only deionized water is impregnated, and the rest is the same as Example 2.

[0097] Comparative Example 3

[0098] The difference from Example 3 is that isopropyl alcohol is not added and nanobubbles are not applied in the first water washing process, and soda ash is not added and nanobubbles are not applied in the second water washing process. The rest is the same as Example 3.

[0099] Comparative Example 4

[0100] The difference from Example 4 is that in the first water washing process, no isopropyl alcohol is added and nanobubbles are not applied; in the second water washing process, no soda ash is added and nanobubbles are not applied; in the stretching process, formaldehyde scavenger FDS is not impregnated and only deionized water is impregnated; the rest is the same as Example 4.

[0101] Comparative Example 5

[0102] The difference from Example 5 is that in the first water washing process, no isopropyl alcohol is added and nanobubbles are not applied; in the second water washing process, no soda ash is added and nanobubbles are not applied; in the stretching process, formaldehyde scavenger FDS is not impregnated and only deionized water is impregnated; the rest is the same as in Example 5.

[0103] The formaldehyde content of the fabrics prepared in Examples 1 to 5 and Comparative Examples 1 to 5 was tested respectively, and the testing method was as follows:

[0104] Refer to GB / T 2912.1-2009 to test the formaldehyde content (mg / kg) of the fabric after 1 day, 30 days and 90 days.

[0105] The test results are shown in Table 1.

[0106] Table 1 Performance test results

[0107]

[0108] It can be seen from the test data in Table 1 that Examples 1 to 5 adopt the processing method for reducing the formaldehyde content and long-term release of pure cotton non-ironing fabrics, which effectively reduces the formaldehyde content in the fabrics and ensures that the long-term stable release of formaldehyde is controlled within a safe range. Even after being placed for 1 day, 30 days and 90 days, they strictly comply with the formaldehyde standard (≤75 mg / kg) of Class B products in GB 18401-2010, which not only significantly optimizes the environmental performance of the fabrics, but also fundamentally ensures that the fabrics are harmless to the health of users during the entire use cycle.

[0109] In Comparative Example 1, isopropanol was added only in the first washing process and nanobubbles were applied, but soda ash was not added in the second washing process, nanobubbles were not applied, and formaldehyde scavenger FDS was not padded in the tentering process, only deionized water was padded, so the obtained fabric had a high formaldehyde content. However, the growth rate of formaldehyde release after long-term storage (30 days, 90 days) was lower than that of Comparative Examples 2 to 4, because isopropanol was added in the first washing process and nanobubbles were applied to reduce the release of formaldehyde after long-term storage.

[0110] In Comparative Example 2, no isopropyl alcohol was added in the first washing process, and no nanobubbles were applied. Only soda ash was added in the second washing process, and nanobubbles were applied. In the stretching process, the formaldehyde scavenger FDS was not immersed, but deionized water was immersed. The formaldehyde content of the fabric after one day of storage was close to the formaldehyde standard of Class B products in GB 18401-2010 (≤75 mg / kg), but it was still unqualified. In addition, the formaldehyde release also increased significantly after long-term storage.

[0111] In Comparative Example 3, no isopropyl alcohol was added in the first washing process, no nanobubbles were applied, no soda ash was added in the second washing process, no nanobubbles were applied, and only the formaldehyde scavenger FDS was impregnated in the stretching process. The formaldehyde content of the fabric after 1 day of storage met the formaldehyde standard of Class B products in GB 18401-2010 (≤75 mg / kg), but the formaldehyde release of the fabric increased significantly after long-term storage (30 days, 90 days), and the formaldehyde content was unqualified.

[0112] In Comparative Examples 4 and 5, since no isopropyl alcohol was added in the first washing process, no nanobubbles were applied, no soda ash was added in the second washing process, no nanobubbles were applied, and no formaldehyde scavenger FDS was impregnated in the stretching process, only deionized water was impregnated, resulting in a high formaldehyde content in the prepared fabrics, and the formaldehyde release after storage (30 days, 90 days) showed a significant increasing trend.

Claims

1. A processing method for reducing the formaldehyde content and long-term release of pure cotton non-ironing fabrics, characterized in that: The following steps are involved: (1) First washing: The pure cotton fabric that has not been subjected to the non-ironing finishing is washed for the first time. In the first washing process, isopropyl alcohol is first applied, and then nanobubbles are applied; (2) No-ironing finishing; (3) Second washing: The cotton fabric after the non-ironing treatment is washed for the second time. In the second washing process, soda ash is first applied, and then nanobubbles are applied; (4) Tentering: impregnating the formaldehyde scavenger during the tentering process; In the step (1), the first water washing is performed in a water washing machine, which comprises water washing tanks No. 1 to No. 8, wherein 1 to 5 g / L of isopropanol is added to water washing tank No. 1, and nanobubbles are applied to the bottom of water washing tanks No. 2 to No. 6 by a nanobubble machine; In the step (3), the second water washing is performed in a water washing machine, which comprises water washing tanks No. 1 to No. 8, wherein 1 to 2 g / L of soda ash is added to water washing tank No. 1, and nanobubbles are applied to the bottom of water washing tanks No. 2 to No. 6 by a nanobubble machine; The diameter of the nanobubbles is 5-40 μm, and the ventilation volume is 0.2-0.6 m 3 / h.

2. The processing method for reducing the formaldehyde content and long-term release of pure cotton non-ironing fabrics according to claim 1, characterized in that: In the step (1), the speed of the washing machine is 30-60 m / min; the temperature of the No. 1 washing tank is 20-40°C, the temperature of the No. 2-6 washing tanks is 60-80°C, and the temperature of the No. 7-8 washing tanks is 20-40°C.

3. The processing method for reducing the formaldehyde content and long-term release of pure cotton non-ironing fabrics according to claim 1 is characterized in that: In the step (2), the permanent-ironing finishing liquid comprises 60-180 g / L of dihydroxymethyl dihydroxyethylene urea resin and 20-60 g / L of magnesium chloride.

4. The processing method for reducing the formaldehyde content and long-term release of pure cotton non-ironing fabrics according to claim 1, characterized in that: In the step (2), the process of the wrinkle-free finishing is two dipping and two rolling, drying at 100-120°C, and then baking at 140-160°C for 2-4 minutes.

5. The processing method for reducing the formaldehyde content and long-term release of pure cotton non-ironing fabrics according to claim 1, characterized in that: In the step (3), the speed of the washing machine is 30-60 m / min; the temperature of the No. 1 washing tank is 40-60°C, the temperature of the No. 2-6 washing tanks is 60-80°C, and the temperature of the No. 7-8 washing tanks is 20-40°C.

6. The processing method for reducing the formaldehyde content and long-term release of pure cotton non-ironing fabrics according to claim 1, characterized in that: The formaldehyde scavenger is an imidazoline derivative, and the dosage is 20-40 g / L.

7. The processing method for reducing the formaldehyde content and long-term release of pure cotton non-ironing fabrics according to claim 1, characterized in that: The speed of the stentering machine is 30-60 m / min, two dipping and two rolling, the liquid carrying rate is 60-70%, and the drying room temperature is 90-110°C.

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