阅读说明：本技术 一种汉麻织物喷墨印花预处理剂及预处理方法 (China-hemp fabric ink-jet printing pretreating agent and pretreating method ) 是由 刘秀明 张敏 房宽峻 于 2021-09-10 设计创作，主要内容包括：本发明提供了一种汉麻织物喷墨印花预处理剂及预处理工艺,预处理剂包括0～3％黄原胶、0～14％尿素、0～5％碳酸氢钠,余量为水；预处理工艺特征在于,恒温25～30℃下将预处理剂搅拌均匀,通过浸轧的方式施加在织物上,然后烘干。用活性染料墨水对经过表面预处理的汉麻织物进行喷墨印花,然后经过汽蒸等工艺得到汉麻织物的喷墨印花产品。用此预处理剂处理过汉麻织物得到的喷墨印花产品,具有更高的颜色深度、图案更加清晰。同时本发明流程简单、易于操作,处理过程成本低能耗少,而且对纤维损伤小。(The invention provides a pretreatment agent for ink-jet printing of hemp fabrics and a pretreatment process, wherein the pretreatment agent comprises 0-3% of xanthan gum, 0-14% of urea, 0-5% of sodium bicarbonate and the balance of water; the pretreatment process is characterized in that the pretreatment agent is uniformly stirred at the constant temperature of 25-30 ℃, is applied to the fabric in a padding mode, and is dried. Carrying out ink-jet printing on the hemp fabric subjected to surface pretreatment by using reactive dye ink, and then carrying out steaming and other processes to obtain an ink-jet printing product of the hemp fabric. The ink-jet printing product obtained by treating the hemp fabric by using the pretreatment agent has higher color depth and clearer pattern. Meanwhile, the method has the advantages of simple flow, easy operation, low cost and energy consumption in the treatment process, and small damage to the fibers.)

1. The pretreating agent for the ink-jet printing of the hemp fabric is characterized by being prepared from 0-3% of polymer, 0-14% of moisture absorbent, 0-5% of alkaline agent and water in a proportioning manner.

2. The pretreating agent for inkjet printing of hemp fabrics according to claim 1, wherein the natural polymer is at least one of sodium alginate, xanthan gum, guar gum and starch.

3. The pretreating agent for inkjet printing of hemp fabrics according to claim 1, wherein the alkaline agent is at least one of sodium carbonate, sodium bicarbonate and sodium hydroxide.

4. The pretreating agent for inkjet printing of hemp fabrics according to claim 1, wherein the moisture absorbent is at least one of glycerol, ethylene glycol, polyethylene glycol and urea.

5. A preparation method of a hemp fabric ink-jet printing pretreating agent is characterized by comprising the following steps: stirring and dissolving 0-14% of urea and 0-5% of an alkaline agent in distilled water at a constant temperature of 25-30 ℃, slowly adding an aqueous solution of a water-soluble polymer under stirring, wherein the mass of the water-soluble polymer accounts for 0-3% of the total mass of the pretreatment solution, and continuously stirring until the water-soluble polymer and the aqueous solution are uniformly mixed to obtain the China hemp fabric ink-jet printing pretreatment agent.

6. A process for pretreating hemp fabric by ink-jet printing as claimed in claim 5, comprising the steps of:

(1) the pretreatment liquid is applied to the surface of the hemp fabric by a two-dipping and two-rolling method,

(2) and (3) drying the hemp fabric subjected to the step (1).

7. The method for pretreating the hemp fabric by ink-jet printing according to claim 6, wherein the padding liquor ratio in the step (1) is 90-110%. In the step (2), the dried hemp fabric has a water content of 5-20%.

8. The pretreatment method of the pretreatment agent for inkjet printing of hemp fabrics according to claim 6, wherein the hemp fabrics pretreated with the polymer are subjected to inkjet printing with reactive dye ink, and then subjected to drying, steaming, washing and drying to obtain inkjet printed products of hemp fabrics.

Technical Field

The invention belongs to the technical field of digital ink-jet printing of textiles, and particularly relates to an ink-jet printing pretreating agent and a pretreating method for hemp fabrics.

Background

The ink-jet printing technology for textile is also called digital ink-jet printing, and is characterized by that it utilizes various digital input means to input pattern into computer, after the colour separation treatment of computer, the various information can be stored in computer control centre, then the action of every colour ink nozzle can be controlled by computer, the required printed pattern can be sprayed on the surface of the fabric, and then the dye or pigment can be fixed on the fabric by means of after-treatment processes of fixing colour, etc. so as to obtain the invented textile with printed pattern. The ink-jet printing process can creatively produce differentiated high-quality fabrics with excellent color expression and high resolution, and can meet the ever-increasing demand of small-batch order markets; and can remarkably improve the phenomenon of resource waste caused by direct printing, so that the development of the ink-jet printing process is very rapid. As a printing mode without contacting with fabrics, the digital ink-jet printing machine ejects micro ink drops with different colors through a control nozzle according to instructions, and then the micro ink drops collide and mix on the surfaces of the fabrics to form a required printing pattern. Therefore, the interaction between the ink droplets and the fabric is critical, and the impact, spreading and absorption of the ink droplets on the fabric affect the quality and fineness of the printed pattern.

The hemp fiber is a green, environment-friendly and healthy textile raw material, has a plurality of excellent performances such as good moisture absorption and dispersion, mildew and bacteria resistance, heat resistance, sun resistance and corrosion resistance, and also has the functions of shielding ultraviolet rays, dissipating sound waves and light waves and the like. China hemp can be used as antibacterial textile, and also as raw material for military clothing and high-grade textile, and has great development prospect. However, hemp fibers have high pectin and lignin contents and are difficult to remove, and the crystallinity and orientation degree of the hemp fibers are high, so that dyeing and printing of the hemp fibers are always difficult, and the application of the hemp fibers in textile is influenced.

In patent CN105239381A, hemp fabric treated by sodium hydroxide is treated in finishing liquid of silane quaternary ammonium salt cationic modifier, and then the modification is completed by baking, washing and drying, so that the dye uptake of the modified fabric is improved, but the modification by using sodium hydroxide can cause certain damage to the fiber. The patent CN102733189A uses the ionic liquid 1-butyl-3 methylimidazolium chloride ionic liquid to modify the hemp, the treated hemp fabric has higher dyeing property, the processing process is simple, the ionic liquid is safe and nontoxic during treatment, and the ionic liquid can be recycled after treatment, but the modification process can damage the strength of the fiber. The patent CN102899926A relates to a method for applying alkali modified xanthan gum to traditional textile printing, the invention has the advantages of good reproducibility, low equipment requirement and simple and convenient method, the modified gum is easier to transfer to the textile through meshes, and the printed textile has higher surface color yield. Patent CN110306364A provides a starch composite thickener, which comprises starch polymer, carboxymethyl cellulose, water-based bentonite, xanthan gum, polyethylene glycol and preservative, and the composite has the characteristics of high paste forming rate, high color yield and environmental protection as the thickener for flat screen scraping. The xanthan gum has obvious advantages when being used as a thickening agent of the traditional printing, and the xanthan gum can also enable the fabric to obtain good printing effect when being used as a pretreatment agent of the digital printing. In patent CN110195361A, xanthan gum, sodium polyacrylate and citric acid are dissolved in deionized water, then chitosan/nano montmorillonite composite material is added, and after mixing, softening agent and defoaming agent are added to be used as pretreating agent for digital printing of polyester fabric. The digital printing product obtained by the polyester fabric pretreated by the pretreating agent has the characteristics of good printing effect and more beautiful and delicate pattern, and the process flow is simple and the cost is low.

In conclusion, the reported patents propose reagents and processes capable of improving the performance of the hemp fabric dye in combination with the fiber, but cause the reduction of fabric strength, and part of the processes do not meet the theme of green environmental protection. In ink jet printing, the interaction of ink droplets with the fabric door is critical, and the impact, spreading and absorption of ink droplets on the fabric all affect the quality and fineness of the printed image. The fabric is pretreated by using the polymer, and the microstructure of the surface of the fabric is changed, so that the aim of improving the ink-jet printing quality of the fabric is fulfilled. Xanthan gum has obvious advantages when used as a thickener for traditional printing, and can also be used as a pretreating agent for digital printing to obtain good printing effect on fabrics.

The application provides a China hemp fabric ink-jet printing pretreating agent and a treatment process, and an ink-jet printing product of the pretreating agent has good color depth and definition.

Disclosure of Invention

The invention aims to research and explore related processes suitable for the pretreatment of the inkjet printing of the hemp fabric and provide technical and theoretical bases for further solving the problem of light color after the inkjet printing of the hemp fabric; improves the ink-jet printing effect of the hemp fabric and also has the advantage of environmental protection.

In order to solve the problems, the invention adopts the technical scheme that: a pretreating agent for ink-jet printing of hemp fabrics is characterized in that the pretreating agent is prepared by proportioning a water-soluble polymer, an alkaline agent, a moisture absorbent and water; the pretreatment solution is characterized by comprising the following components in percentage by mass: 0-3% of a polymer: 0-5% of an alkaline agent; 0 to 14% of a moisture absorbent; the balance being water.

A pretreatment method of a hemp fabric ink-jet printing pretreatment agent is characterized by comprising the following steps:

(1) the pretreatment liquid is applied to the surface of the hemp fabric by a two-dipping and two-rolling method,

(2) and (3) drying the hemp fabric subjected to the step (1).

Preferably, the polymer is at least one of xanthan gum, sodium alginate, guar gum and starch.

Preferably, the alkaline agent is at least one of sodium carbonate, sodium bicarbonate and sodium hydroxide.

Preferably, the moisture absorbent is at least one of glycerol, ethylene glycol, polyethylene glycol, and urea.

Preferably, the preparation method of the hemp fabric ink-jet printing pretreating agent is characterized by comprising the following steps of: and stirring and dissolving 10% of urea and 2% of an alkaline agent in percentage by mass in distilled water, slowly adding an aqueous solution of a water-soluble polymer under stirring, wherein the mass of the water-soluble polymer accounts for 0-2% of the total mass of the pretreatment solution, and continuously stirring until the water-soluble polymer and the pretreatment solution are uniformly mixed to obtain the hemp fabric ink-jet printing pretreatment agent.

Preferably, the mangle ratio of padding is 90-110%. In the step (2), the dried hemp fabric has a water content of 5-20%.

The hemp fabric pretreated by the polymer is subjected to ink-jet printing by using reactive dye ink, and then the ink-jet printing product of the hemp fabric is obtained through the steps of drying, steaming, washing, drying and the like.

The beneficial effect that uses above-mentioned technical scheme to produce lies in: the pretreatment liquid is used for pretreating fabrics, so that the hemp ink-jet printing fabrics have clearer patterns, and the ink-jet printing products have higher color depth. In addition, the method has the advantages of short treatment time, simple and convenient process flow and small damage to the fabric.

Detailed Description

The technical solutions in the embodiments of the present invention are described more clearly below, and it is obvious that the described embodiments are only a series of embodiments of the present invention, and all other embodiments obtained by those skilled in the art without making any inventive step belong to the protection scope of the present invention.

In the following description, specific details are set forth in order to provide a thorough understanding of the present invention, which may be practiced otherwise than as described, and thus is not intended to be limited to the specific embodiments disclosed below.

In the following examples, the main materials involved:

the hemp fabric is hemp plain fabric with a gram weight of 188g/m²Purchased from textile, llc, shanxi oasis;

the printing and dyeing grade sodium alginate is industrial grade and purchased from Qingdao Mingyue seaweed group Limited company;

the xanthan gum is of industrial grade and is purchased from Zhengzhou Puer chemical products Co.Ltd;

sodium bicarbonate was analytically pure and purchased from Tianjin Kemi European chemical reagent, Inc.;

urea was analytically pure and purchased from Tianjin Kemiou chemical reagents, Inc.;

the reactive dye ink is of industrial grade and purchased from Hangzhou Honghua digital science and technology, the dye structure of the ink is monochlorotriazine type, and the viscosity range of the ink is 15-40 mPa & s;

the ink-jet printing effect of the invention is verified by the color data and the anti-seepage performance of the ink-jet printed fabric.

Since all experiments cannot be performed in the same batch due to practical limitations of inkjet printing equipment and production, the following examples are performed in batches according to variable factors, and different batches of printed fabrics have different inkjet performance detection results due to fluctuations of inkjet amount, printing patterns and other process conditions, so that there is no comparability between data obtained by inkjet printing of different batches.

Example 1

The formula of the ink-jet printing pretreatment liquid suitable for the hemp fabrics comprises the following components in percentage by mass: 2% of xanthan gum, 10% of urea, 2% of sodium bicarbonate and the balance of water.

The pretreatment method comprises the following steps: the polymer was slowly added to a certain amount of water at a stirring speed of 500r/min using a stirrer RW20 to obtain a 4% polymer raw paste, left overnight, the above-mentioned amounts of urea and sodium bicarbonate were weighed and stirred uniformly with a certain amount of water, and then 50% raw paste (the amount of the polymer was 2%) was weighed and then stirred at a stirring speed of 500r/min until mixed uniformly to obtain a surface pretreating agent.

The prepared pretreating agent is padded on the hemp fabric by a horizontal padder P-B0 through a two-padding and two-rolling procedure, and the pressure at two sides of a press roll is 0.1kg/cm²In the process, the mangle squeezing rate is controlled to be 90-110%, and the hemp fabric padded with the pretreating agent is placed in a 60 ℃ drying oven to be flatly dried, so that the pretreated hemp fabric is obtained. And (3) carrying out ink-jet printing on the treated fabric by using reactive dye ink, drying the printed fabric in an oven at 60 ℃, steaming for 10min, and drying after a water washing process (cold water washing → warm water washing → soaping (2g/L soap chips) → warm water washing → cold water washing) to obtain the ink-jet printed hemp fabric.

Comparative example 1

The pretreatment agent was prepared and the hemp fabric was treated according to the method of example 1, and then ink jet printing was performed, except that hydroxypropyl starch, guar gum, sodium polyacrylate, sodium alginate, carboxymethyl hydroxypropyl cellulose, nonionic polyacrylamide, and anionic polyacrylamide were used instead of xanthan gum in this comparative example. And (3) carrying out ink-jet printing on the treated fabric by using reactive dye ink, drying the printed fabric in an oven at 60 ℃, steaming for 10min, and drying after a water washing process (cold water washing → warm water washing → soaping (2g/L soap chips) → warm water washing → cold water washing) to obtain the ink-jet printed hemp fabric.

The hemp fabrics pretreated in the experimental example 1 and the comparative example 1 were subjected to ink-jet printing, drying, steaming and water washing in the same batch, and the color data of the hemp fabrics subjected to ink-jet printing were measured, and the results are shown in table 1.

TABLE 1 influence of different pretreatments on the color index of inkjet printing of hemp fabrics

Testing color data by using a Datacolor SF-600plus, measuring the inkjet printing color block of the hemp fabric under a D65 light source and a 10-degree visual angle, folding the monochromatic color block to be measured four times, placing the folded monochromatic color block in front of a color measuring hole of a color measuring instrument, fixing, and randomly taking 8 points to measure the color data, so that the error is less than 0.1. The calculation formula of the apparent color depth K/S value of the fabric is as follows:

K/S＝(1-R)²/(2×R)；

where K represents the absorption coefficient of the fabric for light, S represents the scattering coefficient, and R represents the reflectance at the wavelength of maximum absorption of the dye.

According to the data in table 1, taking black as an example, the brightness value L of the inkjet printed hemp fabric after the polymer treatment is reduced compared with that of the untreated hemp fabric, which indicates that the color of the fabric is dark; the absolute values of a and b of the hemp fabric treated by the partially water-soluble polymer are reduced; meanwhile, the color saturation C is reduced, which shows that the black color light is purer; the K/S value of the fabric treated by the partial water-soluble polymer is larger than that of the fabric not treated by the polymer, wherein the K/S value of the color depth of the fabric obtained in example 1 is the largest, which shows that the pretreatment provided by the invention can obviously improve the apparent color depth of the reactive dye ink-jet printed fabric.

Example 2

The pretreatment solution was prepared in the same manner as in example 1 to pretreat hemp fabric, and then the pretreated fabric was subjected to post-treatment such as ink-jet printing.

Comparative example 2

The pretreatment solution was prepared according to the method of comparative example 1 to pretreat hemp fabric, and then the pretreated fabric was subjected to post-treatment such as inkjet printing, and the polymer used in comparative example 2 was sodium alginate instead of xanthan gum.

The hemp fabrics pretreated in the experimental example 2 and the comparative example 2 were subjected to subsequent treatments of ink-jet printing, drying, steaming and water washing in the same batch, and the anti-seepage performance of the hemp fabrics subjected to ink-jet printing was characterized, and the results are shown in table 2.

TABLE 2 influence of different pretreaters on the parameters of the width of the warp and weft lines of a cyan ink jet printed fabric

The width of the printed lines is measured by using an RH-2000 biological phase optical microscope to represent the anti-seepage performance of the fabric, the average value of the lines subjected to ink-jet printing on the hemp fabric is obtained through multiple measurements, and the thinner the width of the lines is, the better the anti-seepage performance of the fabric is.

The data in table 2 show that the line width of the hemp fabric pretreated with the water-soluble polymer in the warp and weft directions is reduced compared with the line width of the fabric not treated with the polymer, wherein the line width of the fabric obtained in example 2 is the smallest, the anti-seepage performance of the fabric is better, and the inkjet printing pattern has higher definition.

Example 3

The pretreatment solution is prepared according to the method in the example 1 to pretreat the hemp fabric, and then the treated fabric is subjected to post-treatment such as ink-jet printing, and the amount of the polymer in the example 2 is different from that in the example 1, wherein the mass percentages of the xanthan gum are respectively 0%, 0.5%, 1%, 1.5% and 2%.

The hemp fabrics pretreated in the embodiment are subjected to ink-jet printing in the same batch, and are subjected to subsequent treatment of steaming and water washing, and color data and bleeding property of the hemp fabrics subjected to ink-jet printing are measured. The results are shown in tables 3 and 4.

TABLE 3 influence of Polymer dosage on inkjet printing color index of reactive dyes for hemp fabrics

The data in table 3 show that, taking cyan ink as an example, as the mass concentration of the polymer in the pretreatment agent increases, the brightness of the printed fabric gradually decreases, indicating that the fabric becomes darker, and as a and b in cyan are negative and have increasing absolute values, the color of the cyan fabric is greener and bluer, and meanwhile, the color saturation C of the treated fabric increases, and the vividness also increases with the increase of the mass concentration of the polymer. The apparent color depth K/S value is increased continuously, reaches the maximum value when the concentration is 1.5 percent, and the color depth of the fabric is the maximum.

Example 4

The pretreatment solution was prepared according to the method of example 1 to pretreat hemp fabric, and then the treated fabric was subjected to post-treatment such as inkjet printing, wherein the amount of the polymer in example 1 was 1.5% different from that in example 1, and the amount of sodium bicarbonate was 0%, 1%, 2%, 3%, 4%, and 5% different from that in experimental example 1.

The hemp fabric pretreated in example 4 was subjected to ink jet printing in the same batch, and to subsequent treatments of steaming and washing, and color data measurements were performed on the hemp fabric subjected to ink jet printing, and the experimental results are shown in table 4.

TABLE 4 influence of sodium bicarbonate dosage on inkjet printing color index of reactive dyes for hemp fabrics

As can be seen from the data in Table 4, taking cyan as an example, the addition of the alkaline agent to the pretreating agent can significantly reduce the brightness L of the printed fabric, the values of a and b are negative, the absolute value is increased, the colored light is more blue and more green, the saturation C is increased, and the color is more bright. The apparent colour depth K/S value then decreases slightly with increasing sodium bicarbonate concentration, with the colour of the printed fabric reaching the deepest at a sodium bicarbonate mass fraction of 2%.

Example 5

The pretreatment agent was prepared and the hemp fabric was treated according to the method of example 1, and then ink-jet printing was performed, except that the amount of the polymer used in example 1 was 1.5% as compared with example 1, and the amount of urea was 0%, 2%, 4%, 6%, 8%, 10%, 12%, and 14% as compared with example 1.

The hemp fabrics pretreated in example 5 were subjected to ink jet printing in the same batch, and after the drying and steaming washing steps, different ink jet printed hemp fabrics were obtained, and the color data of the printed hemp fabrics were tested, and the results are shown in table 5.

TABLE 5 influence of Urea dosage on inkjet printing color index of reactive dyes for hemp fabrics

As can be seen from the data in Table 5, taking magenta as an example, the brightness L of the printed color blocks gradually decreases with the addition of urea in the pretreating agent; a is positive and increases and then decreases slightly; b is a negative value, the absolute value of which is continuously increased, and the color of the fabric is more yellow; the saturation C is gradually increased, and the color is more and more bright; the apparent color depth K/S value of the printed fabric gradually increases with the increase of the dosage of the urea and then slightly decreases, and when the mass fraction of the urea is 10%, the color of the printed color block of the hemp fabric is deepest.

Example 6

The pretreatment agent is prepared according to the method in the embodiment 1, and the hemp fabric is treated to complete the ink-jet printing, except that the steaming time of the printed fabric after the ink-jet printing in the embodiment 6 is 0-16 min. The hemp fabrics pretreated in example 6 were subjected to ink jet printing in the same batch, and after the drying and steaming washing steps, different ink jet printed hemp fabrics were obtained, and the color data of the printed hemp fabrics were tested, and the results are shown in table 6.

TABLE 6 influence of steaming time on inkjet printing color index of reactive dyes for hemp fabrics

As can be seen from the data in table 6, taking magenta as an example, the brightness L of the steamed printed fabric is obviously reduced, and the absolute values of a and b are increased, wherein a is a positive value, b is a negative value, the fabric is more blue, the saturation C is increased, and the vividness is improved; the apparent color degree K/S value of the fabric is increased and then reduced along with the increase of steaming time, and when the steaming time is 10min, the color of an ink-jet printing product of the hemp fabric is deepest.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that modifications can be made by those skilled in the art without departing from the principle of the present invention, and these modifications should also be construed as the protection scope of the present invention.