IMPORTANCE OF PRINT TECHNIQUE
The process of creating a pattern with the printing technique is superior to creating a pattern with the weaving and knitting technique in terms of ease and cheapness.
According to the weaving technique, white threads must first be dyed and then woven on the loom to obtain colored patterns. Dyeing the yarns is not easy in many cases, and the weaving efficiency of some looms is low. In addition, many patterns that can be obtained with the printing technique are difficult and in some cases impossible to obtain with the weaving technique.
Repression is a regional coloring or a regional color etching. In dyeing, all sides of the fabric are dyed with the same color (uni dyeing), whereas in printing, the areas where the pattern is found are dyed. The whole feature of printing provides this regional coloring.
Devices and methods used in dyeing cannot be used in printing, and dyeing liquors with low viscosity prepared with water are not suitable for printing.
The most obvious difference between dyeing and printing is that dyes and chemicals are dispersed in low concentrations in a printing paste. Printing paste containing printing ink is transferred to textile surfaces with the help of a suitable machine with rollers or templates. Thus, pattern effects with precise boundaries are achieved on the fabric.
Textile first emerged as weaving products created with the fibrous materials found around in order to meet the need of people to cover and protect themselves from natural conditions. Later, the human being, who colored these products with the dyes obtained from nature, was not satisfied with this, he shaped his feelings and thoughts on these weavings with the instinct of self-expression. These regional dyeings, which are made to obtain colorful patterns on textile products, are called printing.
It is claimed that textile printing was first made in the Far East by the Indians and the Chinese. In the researches carried out in recent years, pieces of fabric colored with different methods than dyeing have been found in the Egyptian Pyramids and tombs.
Coloring on textile surfaces is done by weaving, knitting and printing techniques. In weaving and knitting techniques, the printing technique is more preferred due to the low production speed, the difficulty of application, the less variety of patterns and color variations.
Coloring the fabric with weaving and knitting techniques is more laborious and expensive than the printing technique. Because the yarns are first dyed to the desired colors and then they are produced in weaving or knitting machines. However, the production speed is high and the cost is low in printing technique. In this technique, a viscous paste is first prepared with thickening agents. Dyestuffs are added to this paste to color it and auxiliary chemicals are added to provide the desired printing environment. This viscous solution prepared is transferred to the fabric with the help of suitable printing machines.
The printing technique actually consists of coloring a certain area of the textile surface or abrasion of the dyestuff in this area. While the entire textile material is dyed in the dyeing process, certain areas of this material are colored in the printing process.
Coloring a Textile Material and Creating Patterns
Textile printing is an interesting and important part of the textile finishing industry. Printing is one of the rare branches of industry where art and technique go hand in hand. Two main techniques are applied to obtain one- or multi-colored patterns on fabrics.
1-Weaving and knitting technique
Textile printing can be narrowly defined as a regional dyeing. Single or multi-colored patterns on fabrics can also be obtained by weaving and knitting techniques. However, the printing technique is superior to the weaving and knitting technique in terms of convenience and cheapness.
In order to obtain colored patterns according to the weaving technique, first white threads must be dyed and then they must be woven on looms with pattern equipment (jacquard machines). The dyeing of threads is not easy in many cases, and as the patterning possibilities of the looms increase, their speed decreases. On the other hand, many patterns obtained with the printing technique are difficult to obtain compared to the weaving technique, and in some cases it is impossible.
Machinery and methods used in dyeing cannot be used in printing, and aqueous dyestuff solutions are not suitable for printing. The dyestuff solution applied on the fabric will spread due to the absorption feature of the fabric and a limited shape, ie pattern, cannot be obtained. In order to prevent the dye solution from spreading, it is necessary to resist the absorbing power of the fabric. For this purpose, dyestuff solutions are thickened and put into a form called paste.
Printing is essentially a zonal monochrome or a zonal color etching. In dyeing, each side of the fabric is dyed a color, whereas in printing, certain parts of the fabric are dyed. The concept of Textile Printing means painting limited areas that allow one or multi-colored patterning. Prints according to material condition;
1-Fix or tops (Vigur print) print
2-Thread (thread and warp) printing
3-Weaving and knitting fabric printing
4-Carpet print, in the form
5-Finished textile product printing
1. Penetration of the dissolved dyestuff into the fiber,
2. Permanent bonding of dyestuffs to fibers
3. It covers the steps of fixing the dyestuffs to the fibers.
The dyestuff is locally limited in printing and transferred to certain parts of the textile surfaces.
Intaglio (Roll) Printing
In intaglio (roll) printing, the motifs were prepared by carving or burning on copper cylinders. Rollers (rollers) are painted with paint rollers (feed rollers). A separate roller is used for each color of the pattern. Scrape blades scrape excess paint from the glossy surface of the printing cylinder. Thus, the ink remains only inside the engravings (pattern cavities in the printing cylinder) and is transferred to the fabric during the printing process. Intaglio machines have a high production speed. Up to sixteen colors can be printed. The engraving depth is different according to the fabric quality. This printing technique requires making separate cylinders for each color of each pattern, as well as making separate cylinders for each fabric type. The engraving of cylinders is very expensive. Therefore, the roll printing technique can only be efficient when used for large volumes. On the front of the fabric, patterns and colors are distinct and clear. On the reverse side, it is indistinct and faint.
Hand Stencil Printing
The pattern to be applied in hand stencil printing is cut from a cardboard. While the paint does not penetrate the cardboard covered areas, it penetrates the woven fabric from the empty places.
Spray printing: In spray printing, the template is placed on the fabric. With a spray gun, the paint is sprayed onto the fabric. A coarse-grained pattern is formed on the fabric. This method is also used for prints on carpets.
Plain Film Printing (Screen Printing)
In flat film printing, thin gauze (silk fabric) through which the dye can pass is used. The areas that cannot be patterned are covered with a water-soluble lacquer layer on both sides so that the paint does not pass. A separate template is required for each color to be printed. Templates are prepared by photochemical means. Printing ink is pressed onto the fabric with a rubber squeegee or a roller from the dye-permeable parts of the stencil. Flat film printing is especially used for large patterns and small quantities. The disadvantage of this technique is the high space requirement.
Rotation Film Printing (Rotation Screen Printing)
In cases of more than twenty colors, the flat film printing technique is not economical. Rotation film printing (rotation screen printing) is an improved form of flat film printing. The advantage is that the production flow is continuous. This was achieved by shaping flat templates into an engraved cylinder. Ink is pumped into the printing rollers. Then, it reaches the fabric by passing through the perforated rollers. With rotational film printing, 4000 m of fabric can be printed per hour. It is suitable for production in large quantities and can be printed in twenty-four colours. Cylinders can be prepared more quickly and cheaply.
Rotation Film Printing
Laser Stencil Preparation, The most advanced form of stencil preparation is laser stencil preparation. In this technique, the chemical layer on the stencils is burned using a laser. The burned sheet particles are then vacuum suctioned, collected and discarded. Laser stencil preparation technique is cheaper than conventional methods in the following ways. Film negatives are saved. There is no development of templates. The time to prepare the templates is shorter.
The difference of the spray printing technique, which at first glance seems to be the same as the spray printing technique in stencil printing, is that no template is used. Only plaids and borders can be printed with this method. Pattern edges are not sharp and clear; it is a little faded and intertwined. It is used in knitting and flexible weaving. (For example, t-shirts, swimsuits, etc.) As many colors as desired can be used with the spray printing technique.
In transfer printing, a special paint paste is printed on a single-use transfer paper tape on a copper gravure cylindrical press. Paper tape and fabric are passed through a heated calender. The paper tape is contacted with the dyed side on the front of the fabric. With heat and pressure, the dye moves from the paper to the fabric. In the new techniques, an additional fixation process is not required. With this printing technique, as many colors as desired can be used in a seamless transition. Thus, pattern drawings can be extremely fine. Textile manufacturers do not need to use expensive printing machines. The pattern is developed on paper in printing machines with its many colors. In other words, the textile business only needs a calender (hot roller used in transfer printing). The risk in storage is reduced. Fabrics are printed as they are ordered or not unless the pattern sells well. The colors used in this method only appear on the front of the fabric. The back side remains in the fabric's own ground color. When the knits are stretched, the inner parts of the loops appear lighter.
By using cylindrical hot molds, a permanent and fluffy pattern is created on the fabric surface. For non-thermoplastic fabrics, an artificial resination process is carried out first. Thus, the fabric can be permanently formed.