Denim laser dyeing process

Abstract

The invention relates to the technical field of dyeing, in particular to a denim laser dyeing process which is characterized by comprising the following steps: S1, denim pretreatment: selecting base cloth: selecting pure cotton or cotton blended denim with the gram weight of 8-14 oz / yd2, namely 271-475 g / m < 2 >, pre-washing to remove flooding, and controlling the water content to be 6-8%; coating treatment is conducted, specifically, an environment-friendly anti-reflection coating is sprayed, the laser absorption efficiency is enhanced, the coating thickness is 10-15 microns, and the drying temperature is 80-90 DEG C; s2, laser parameter optimization: equipment configuration: a CO2 laser and an optical fiber laser are adopted, the power range is 20-200 W, the scanning speed is 300-1200 mm / s, and the diameter of a focusing spot is 0.1-0.3 mm; no chemical reagent exists in the whole process, the dye is vaporized only through laser, and the wastewater discharge amount is reduced by 95%.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of dyeing technology, in particular to a jean fabric laser dyeing process. BACKGROUND

[0002] In the field of textiles, in order to increase the surface effect of jeans, the commonly used fabric treatment method is to remove the dye by local chemical process to treat the fabric surface, or to achieve the worn-out treatment of the fabric surface by sanding and washing process, so as to achieve the desired effect of the fabric surface. However, the existing several ways have a large pollution in implementation, which will have a certain impact on the environment.

[0003] Laser numerical control laser engraving is a kind of laser equipment connected with laser engraving software, which realizes automatic engraving through drawing input and vaporizes the dye on the surface of the jean fabric through numerical control laser irradiation, so as to make the image pattern on various jean fabrics which will not fade. This kind of local dye removal method has no pollution to human body and environment, and has great popularization prospect in the textile industry at present.

[0004] The existing production process cannot realize clear gradient pattern, virtual bamboo joint and weave effect when the above-mentioned laser engraving technology is implemented. SUMMARY

[0005] The present application aims to provide a jean fabric laser dyeing process to solve the problems in the background art.

[0006] To achieve the above-mentioned purpose, the present application provides the following technical scheme: a jean fabric laser dyeing process, comprising the following steps:

[0007] S1, jean fabric pretreatment:

[0008] Base cloth selection: select pure cotton or cotton blended jean fabric with gram weight of 8-14 oz / yd 2 , i.e. 271-475 g / m 2 , prewash to remove floating color, and control the moisture content at 6%-8%;

[0009] Coating treatment: spray environmentally friendly anti-reflection coating to enhance laser absorption efficiency, coating thickness 10-15 μm, drying temperature 80-90℃;

[0010] S2, laser parameter optimization:

[0011] Equipment configuration: adopt CO2 laser and fiber laser, power range 20W-200W, scanning speed 300mm / s-1200mm / s, focusing spot diameter 0.1mm-0.3mm;

[0012] Gradation control: adjust laser energy density by gray scale, realize the gradual transition from light blue to white, that is, from light to deep;

[0013] Virtual bamboo joint: adopt pulse mode, interval scanning to form irregular stripes, simulate bamboo joint texture, pulse width 4ns-20ns;

[0014] S3, dynamic path programming:

[0015] Texture simulation: import digital texture template, that is, twill and herringbone, adjust laser path and overlap rate, form three-dimensional texture by multiple scanning and superposition;

[0016] 3D positioning system: adopt dynamic focusing mirror, adapt to the concave-convex surface of denim, ensure the consistency of engraving depth;

[0017] S4, post-processing technology:

[0018] Water washing and shaping: use continuous rope-shaped washing machine, water temperature 50℃-55℃, add 3g / L-4g / L oxalic acid to neutralize residual oxides, shape after centrifugal dehydration;

[0019] Fixing treatment: spray water-based polyurethane adhesive, drying temperature, form wear-resistant protective layer.

[0020] Preferably, the environmentally friendly anti-reflective coating is a nano-zinc oxide dispersion liquid with a concentration of 5%-8%.

[0021] Preferably, the wavelength of CO2 laser is 10.6μm, and the wavelength of fiber laser is 1.06μm; the range of gray scale adjusting laser energy density is 1J / cm 2 -5J / cm 2 ; the frequency range of pulse mode is 50kHz-500kHz.

[0022] Preferably, the range of adjusting laser path and overlap rate is 10%-30%.

[0023] Preferably, the focal length range of dynamic focusing mirror is 100mm-300mm, which adapts to the concave-convex surface of denim, ensures the consistency of engraving depth, and the range is 0.1mm-0.5mm.

[0024] Preferably, the temperature range of shaping after centrifugal dehydration is 150℃-160℃, and the speed range is 20 / min-30m / min.

[0025] Preferably, the fixing treatment: spray water-based polyurethane adhesive 30 parts by mass-35 parts by mass, drying temperature 100℃-105℃, form wear-resistant protective layer.

[0026] Preferably, the S1, denim pretreatment also includes base cloth modification, that is, before the base cloth selection, the cotton fiber is pretreated by using a cationic modifier, that is, a long-chain quaternary ammonium salt compound, at a concentration of 6 g / L-8 g / L, the binding force of the fiber and the dye is enhanced through electrostatic action, the Zeta potential is increased from-22.1 mV to +8.7 mV, and the adsorption rate of indigo dye is increased by more than 80%.

[0027] Preferably, the S1, denim pretreatment also includes multi-color step-by-step dyeing after the base cloth modification, different color series dyes, that is, indigo, phthalocyanine green, quinacridone red, are impregnated in stages, and after each dyeing, the surface dye is vaporized by laser positioning to form a color superposition effect, when the first dyeing is indigo 1.2 g / L, the second dyeing is phthalocyanine green 0.8 g / L, and the specific color layer is vaporized by 1064 nm and 980 nm dual-wavelength lasers.

[0028] Preferably, the fixing treatment, spraying a water-based polyurethane-silane coupling agent composite adhesive, 30 parts by mass, is dried at 100-105 DEG C to form a nano protective film.

[0029] Compared with the prior art, the beneficial effects of the present application are:

[0030] Environmental advantage: no chemical reagents throughout, only dye vaporization by laser, wastewater discharge is reduced by 95%.

[0031] Precision improvement: numerical control path error <0.05 mm, supporting complex patterns (such as Chinese style ink gradient, geometric vector patterns).

[0032] Cost control: single piece energy consumption 0.05 kWh, comprehensive cost reduced by 30% compared with traditional process. BRIEF DESCRIPTION OF DRAWINGS

[0033] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the drawings needed in the specific embodiments or prior art description will be briefly introduced below. Obviously, the drawings in the following description are some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without creative labor.

[0034] Figure 1 The present application is a denim laser dyeing process flow chart. DETAILED DESCRIPTION

[0035] With reference to the drawings of the embodiments of the present application, the technical solutions in the embodiments of the present application will be described clearly and completely. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments of the present application, all the other embodiments obtained by a person of ordinary skill in the art without creative work belong to the scope of protection of the present application.

[0036] Please refer to Figure 1 The present application provides a technical solution:

[0037] A jean fabric laser dyeing process, comprising the following steps:

[0038] S1, jean fabric pretreatment:

[0039] Base fabric selection: select pure cotton or cotton blended jean fabric with a grammage of 8-14 oz / yd 2 , i.e. 271-475 g / m 2 , pre-wash to remove floating color, and control the moisture content at 6%-8%;

[0040] Coating treatment: spray environmentally friendly anti-reflective coating to enhance laser absorption efficiency, coating thickness 10-15 μm, drying temperature 80-90℃;

[0041] S2, laser parameter optimization:

[0042] Equipment configuration: use CO2 laser and fiber laser, power range 20W-200W, scanning speed 300mm / s-1200mm / s, focused spot diameter 0.1mm-0.3mm;

[0043] Gradual change control: adjust laser energy density through grayscale image to achieve gradual change effect from light to dark, i.e. light blue to white transition;

[0044] Virtual bamboo joint: use pulse mode, interval scanning to form irregular stripes, simulate bamboo joint texture, pulse width 4ns-20ns;

[0045] S3, dynamic path programming:

[0046] Texture simulation: import digital texture template, i.e. twill, herringbone, adjust laser path and overlap rate, form three-dimensional texture by multiple scanning and superposition;

[0047] 3D positioning system: use dynamic focusing mirror, adapt to the concave-convex surface of jean fabric, ensure the consistency of engraving depth;

[0048] S4, post-processing technology:

[0049] Water washing and setting: using continuous rope washing machine, water temperature 50-55℃, adding 3-4g / L oxalic acid to neutralize residual oxides, setting after centrifugal dewatering;

[0050] Fixing treatment: spraying water-based polyurethane adhesive, drying temperature, forming a wear-resistant protective layer.

[0051] Specifically, the environmentally friendly anti-reflective coating is a nano zinc oxide dispersion liquid with a concentration of 5%-8%.

[0052] Specifically, the wavelength of the CO2 laser is 10.6μm, and the wavelength of the fiber laser is 1.06μm; the gray scale adjustment laser energy density range is 1J / cm 2 -5J / cm 2 ; the frequency range of the pulse mode is 50kHz-500kHz.

[0053] Specifically, the adjustment range of the laser path and the overlap rate is 10%-30%.

[0054] Specifically, the focal length range of the dynamic focusing mirror is 100-300mm, which adapts to the concave-convex surface of the denim and ensures the consistency of the engraving depth in the range of 0.1-0.5mm.

[0055] Specifically, the setting temperature after centrifugal dewatering is 150-160℃, and the vehicle speed range is 20-30m / min.

[0056] Specifically, the fixing treatment: spraying water-based polyurethane adhesive 30-35 parts by mass, drying temperature 100-105℃, forming a wear-resistant protective layer.

[0057] Specifically, the S1, denim pretreatment also includes base cloth modification, that is, before the base cloth is selected, the cotton fibers are pretreated by using a cationic modifier, i.e. a long-chain quaternary ammonium salt compound, with a concentration of 6-8g / L, to enhance the fiber-dye binding force through electrostatic action, so that the Zeta potential is increased from-22.1mV to +8.7mV, and the indigo dye adsorption rate is increased by more than 80%.

[0058] Specifically, the S1, denim pretreatment also includes multi-color step-by-step dyeing after base cloth modification, i.e. different color series dyes are impregnated in stages, namely indigo, phthalocyanine green and quinacridone red, and after each dyeing, the surface dye is vaporized by laser positioning to form a color superposition effect. When the first dyeing is indigo 1.2g / L, the second dyeing is phthalocyanine green 0.8g / L, and 1064nm and 980nm dual-wavelength lasers are used to vaporize specific color layers respectively.

[0059] Specifically, the color fixing treatment, spraying water-based polyurethane-silane coupling agent composite adhesive, 30 parts by mass, drying at 100-105°C to form a nano protective film.

[0060] Example 1: Gradual snowflake washing effect:

[0061] Parameters: laser power 80W, scanning speed 600mm / s, energy density 3J / cm 2 , gray scale gradient 0-255 linear distribution.

[0062] Effect: The cloth surface presents natural snowflake mottling texture, color difference ΔE≤1.5 (CIE Lab standard), color fading rate <2% after washing.

[0063] Environmental protection: Compared with the traditional potassium permanganate spraying process, the wastewater COD is reduced by 90%.

[0064] Example 2: Virtual bamboo joint texture:

[0065] Parameters: pulse frequency 200kHz, pulse width 8ns, interval scanning path simulates irregular segments of bamboo joints.

[0066] Effect: Bamboo joint spacing 2-5cm, depth 0.2mm, tear strength retention rate ≥85% (ASTM D1424 standard).

[0067] Efficiency: Processing time of a single pair of jeans is 40 seconds, which is 50 times more efficient than manual rubbing.

[0068] Example 3: Imitation weave three-dimensional effect:

[0069] Parameters: import twill template, laser overlap rate 20%, three times scanning superposition, total energy density 4.5J / cm 2 .

[0070] Effect: Texture clarity up to 1200dpi, obvious concave-convex feeling (roughness Ra=12-15μm).

[0071] Comparative reference example: traditional chemical washing process:

[0072] Process: spraying 47g / L potassium permanganate solution, manual rubbing, washing with oxalic acid after washing.

[0073] Defects: color difference ΔE≥3, wastewater containing Mn 2 exceeding standard (>5mg / L), high risk of skin burns for workers.

[0074] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, and are not intended to limit the present application; although the present application has been described in detail with reference to the above embodiments, those skilled in the art should understand that the technical solutions recorded in the above embodiments can be modified, or some or all of the technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A denim laser dyeing process, characterized by: The steps include: S1. Denim pretreatment: Base fabric selection: Choose a weight of 8-14oz / yd 2 , i.e. 271-475g / m 2 Pure cotton or cotton blended denim, pre-washed to remove loose color, moisture content controlled at 6%-8%; Coating treatment: spraying environmentally friendly anti-reflective coating to enhance laser absorption efficiency, coating thickness 10-15μm, drying temperature 80-90℃; S2. Laser parameter optimization: Equipment configuration: CO2 laser and fiber laser, power range 20W-200W, scanning speed 300mm / s-1200mm / s, focus spot diameter 0.1mm-0.3mm; Gradient control: adjust the laser energy density through the grayscale image to achieve a gradient effect from light to dark, that is, light blue to white transition; Virtual bamboo joint: uses pulse mode and interval scanning to form irregular stripes to simulate the texture of bamboo joints. The pulse width is 4ns-20ns. S3, dynamic path programming: Weave simulation: Import digital weave templates, such as twill and herringbone patterns, adjust the laser path and overlap rate, and form a three-dimensional texture through multiple scans and superposition; 3D positioning system: uses dynamic focusing mirror to adapt to the uneven surface of denim and ensure the consistency of engraving depth; S4, post-processing process: Washing and shaping: Use a continuous rope washing machine, water temperature 50℃-55℃, add 3g / L-4g / L oxalic acid to neutralize residual oxides, centrifuge and dehydrate before shaping; Color fixing treatment: spray water-based polyurethane adhesive and dry at low temperature to form a wear-resistant protective layer.

2. The denim laser dyeing process according to claim 1, characterized in that: The environmentally friendly anti-reflective coating is a nano zinc oxide dispersion with a concentration of 5%-8%.

3. The denim laser dyeing process according to claim 1, characterized in that: The wavelength of the CO2 laser is 10.6μm, and the wavelength of the fiber laser is 1.06μm. The grayscale image adjusts the laser energy density to 1J / cm 2 -5J / cm2; the frequency range of the pulse mode is 50kHz-500kHz.

4. The denim laser dyeing process according to claim 1, characterized in that: Adjust the laser path with the overlap ratio in the range of 10%-30%.

5. The denim laser dyeing process according to claim 1, characterized in that: The dynamic focusing lens has a focal length range of 100mm-300mm, which adapts to the uneven surface of denim and ensures the consistency of engraving depth, ranging from 0.1mm to 0.5mm.

6. The denim laser dyeing process according to claim 1, characterized in that: The temperature range of the shaping after centrifugal dehydration is 150° C.-160° C., and the speed range is 20 / min-30m / min.

7. The denim laser dyeing process according to claim 1, characterized in that: The color fixing treatment comprises spraying 30 parts by mass to 35 parts by mass of a water-based polyurethane adhesive and drying at a temperature of 100° C. to 105° C. to form a wear-resistant protective layer.

8. The denim laser dyeing process according to claim 1, characterized in that: Said S1, denim pretreatment also includes base fabric modification, that is, before the base fabric is selected, the cotton fiber is pretreated by using a cationic modifier, i.e., a long-chain quaternary ammonium salt compound, at a concentration of 6g / L-8g / L, to enhance the binding force between the fiber and the dye through electrostatic action, thereby increasing the Zeta potential from -22.1mV to +8.7mV, and the indigo dye adsorption rate by more than 80%.

9. The denim laser dyeing process according to claim 1, characterized in that: The denim pretreatment step S1 also includes multi-color step-by-step dyeing of the modified base fabric, wherein different color dyes, namely indigo, phthalocyanine green, and quinacridone red, are dipped in stages. After each dip, the surface dye is vaporized by laser positioning to form a color superposition effect. When the first dip is 1.2 g / L indigo and the second dip is 0.8 g / L phthalocyanine green, 1064 nm and 980 nm dual-wavelength lasers are used to vaporize specific color layers respectively.

10. The denim laser dyeing process according to claim 1, characterized in that: The color fixing treatment comprises spraying 30 parts by mass of a water-based polyurethane-silane coupling agent composite adhesive and drying at 100° C.-105° C. to form a nano protective film.

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