2.2 Effect of Nano-SiO2 Concentration on Printing Effect
The printing effect is based on the outline sharpness of the flowers, the fineness of the lines (fine stems), and the texture of the fabric. The details are:
a. Flower outline definition and line fineness
High-mesh screens are printed on high-value-added textiles with fine patterns, clear lines, smooth lines, no bleeds, and bright colors.
b. Effect on fabric feel
Printed textiles are soft to the touch. Similar to material printing.
From Table 2, it can be seen that the nano-SiO2 concentration has a great influence on the print's outline definition, line interface fineness and feel. The printing effect mainly depends on the outline definition, handle and color fastness, and the excellent characteristics of the nano-powder material, the quantum size effect, the small size effect, the surface and interface effects greatly improve the color paste printing effect. The quantum size effect and small size effect make the distribution of coating particles in the color paste more uniform, and the viscosity of the color paste is more suitable for printing, especially for patterns with higher fineness of printing, the effect is very obvious. The surface and interface effects make the color paste and the fabric adhere more firmly, thereby improving the color fastness, and at the same time improving the elasticity and flexibility of the dry and solid color paste, and improving the hand feeling after printing.
2.3 Effect of curing temperature on printing fastness
The effect of curing temperature on print fastness is shown in Table 3.
From Table 3, it can be seen that the baking temperature is the first external factor that affects the color fastness. The baking temperature mainly affects the effect of the binder. The temperature is low, the adhesive cannot be well combined with the surface of the fabric, the cross-linking of the adhesive is not sufficient, the fastness is reduced, and the printing effect is not achieved; if the temperature is too high, the adhesive cross-linking is damaged, and the adhesive becomes hard and yellow. , Feeling worse, poor fastness. From the results of the experimental tests, it can be seen that the temperature is too high to meet the printing requirements, wasting a lot of energy, and increasing production costs. In the past, the printing temperature of cotton fabrics was around 150°C. According to this experiment, the best baking temperature was 130°C. This is due to the nanomaterial SiO2 surface and interface effects, the small size effect and the macroscopic quantum tunneling effect reduces the fixing temperature of the binder crosslinking in the colorant. At the temperature of 130°C, the fastness and the scrubbing fastness of the roasted fabrics were also the best. The contour definition, the hand feeling and the line of the printing reached the purpose of the experiment.
2.4 Effect of baking time on printing fastness and printing effect
The effect of baking time on the printing fastness and printing effect is shown in Table 4 and Table 5.
The effect of baking time on printing is basically the same as the baking temperature, and the main influence and role are the crosslinking fastness of the adhesive and the vividness of the printing color. Printing requirements for baking time are also very strict, the baking time is short, printing paste can not fully cross-linked with the fiber, printing fastness is reduced; baking time is too long, the adhesive crosslinking has been damaged, and The sharpness, color and feel of the printing effect are seriously affected. After adding the nano-material SiO2, the test results show that the printing fastness is the best when the baking time is 4 minutes, and the printing effect is the best.
3. in conclusion
3.1 According to the test of print fastness, it is known that the concentration of nano-SiO2 is 0.3%.
3.2 The baking temperature is very important for the printing effect and color fastness. According to the actual Ij test results, the optimum baking temperature was 130°C.
3.3 The best time for baking is 4 min.
The basic concept of the color tone printed fabric: China Information Center, published in the dyeing industry: 2005-12-15 has been read 31 times
Basic concept of color tone printing on knitted fabrics
At present, knitted fabric printing products are increasingly favored by consumers. For this reason, a considerable number of knitting companies have invested a lot of energy in printing new items and developing new printing techniques.
The printing of knitted fabrics is divided into garment printing, garment printing and knitted grey fabric printing. From the point of view concerning the number of knitting and printing enterprises, the majority of companies are clothing and garment printing. The printing method is mainly based on lithographic screen printing. In addition to lithographic screen printing, the printing of knitted grey fabrics can also use rotary screen printing.
With the continuous development of printing technology, people are increasingly demanding the printing of knitted fabrics. From the point of view of the effect of the printed pattern, the means of expressing the pattern of the flower cloth by using only the color patches and lines has been far from satisfying the demand. Computer technology is applied to the color printing of printing, creating a very convenient condition for the rich expression of printing patterns. Halo, moiré, water stains and silk and other special effects can be printed in the printing pattern. Halftone and color tone printing techniques in printing are also used in textile printing.
At present, color tone printing technology is mainly applied to the printing of knitted garments and garments, and the printing effect for knitted fabrics is not ideal.
The technique of color tone printing on knitted fabrics comes from printing. Color tone printing is the use of four or six printing plates capable of printing colorful colors. Printed color photographs of paper and various artistic paintings are printed using such techniques.
Computer prepress software is the pre-press processing tool necessary to achieve color tone printing. For medium and small-sized knitted printing companies that only print clothing and ready-to-wear garments, there is no need to use professional printing color separation software. Adobe's Photoshop graphics software can fully meet the requirements for printing color tone patterns.
Decompose continuously changing patterns such as photographs, various artistic paintings and other images into many small, pixel-by-density pixel nodes whose eyes cannot be resolved at a certain viewing distance, and achieve continuous tone visual effects within the observation distance. . The image expressed in this way is called a tone image. The printed floral version of the printed tone image is called a halftone printing pattern. The halftoning image has a distinction between monochrome and color halftones, and monochrome is called halftone. Continual changes in the depth and intensity of any continuous tone original pattern can be divided into three levels: high, medium, and low. The shallow and bright levels are called high-profile, and the deep and dark levels are called dark lines. The middle tone between the two is called middle tone. The technique of converting continuous tone images into tonal images is called tonal network technology. Tone-tone screening technology is to express continuous tone images using different light and dark spatial points, ie, tones. Thanks to the use of computers, the screening process has become very convenient.
There are two types of expressions for different light and dark spatial nodes: one is that the density of spatial dots with equal density express the shade of light by the diameter of the dot; the other is the size of the dot with the same diameter, and the hue is expressed by the distribution density of the dots. Bright and light. The screens for the isobaric space outlets are used for printing. The screen density is expressed as the number of lines in units of lines/cm. Smaller dot areas are bright, known as high-profile areas, and larger diameter dot areas are dark and dark, called low-key areas, and areas between low-key areas and high-profile areas are called midtone areas. The change from high to medium to low-key is called tonality.
Color tone is the use of space color mixing (including the subtraction of the overlapping parts of the color mixing) to achieve the tone of the tone effect, so that tone has a color effect. Color tones are generally obtained through four monotone halftone screens (halftones), namely Cyan, Magenta, Yellow, and Black. Cyan, magenta, yellow, and black are summarized as CMYK, which is called the color separation printing.