Polyester Button Transfer Printing Technology Discussion II

Second, the choice and preparation of transfer printing ink

Transfer printing ink is an important part of the transfer printing process, and it is also one of the key factors of transfer printing technology. General transfer printing inks can be divided into alcohol-soluble, oil-soluble and water-soluble three major categories. Due to the high cost of the first two inks and the serious environmental pollution, although the disadvantage of water solubility is that they easily cause deformation of the transfer paper, considering that the button products are small, the print pattern is smaller and the small pattern will not cause the paper to be deformed. . Therefore, I will only introduce the preparation methods and auxiliaries of the water-soluble transfer ink and the process requirements:

1. Disperse dye screening methods Disperse dyes are not only simple in molecular structure, but also do not contain ionizable groups, so there is a certain vapor pressure sublimation phenomenon. The rate of sublimation is proportional to the temperature, and this sublimation phenomenon of disperse dyes is used by transfer printing. In the disperse dye system, azo dyes and lanthanide series which have a small molecular weight and a small amount of polar groups are dyes that are easily sublimated. The criteria for disperse dyes selected for transfer printing should meet the following requirements:

1) High vapor pressure and diffusion coefficient are required, and it is usually selected from 170 to 210°C.
2) The molecular weight is less than 400.
3) The consistency of the dye sublimation property is required when used together, and the level of fastness is met.

According to the introduction of relevant data, the screening work for disperse dyes can be divided into two stages: universal selection and testing. First, the low-temperature type (E) or medium-temperature type (SE) disperse dyes that can be purchased can be transferred into a paste with a thickener. The screen printing method is printed on the paper, and then it is transferred onto the buttons. The selection is determined according to whether the color concentration is rich or not, and the selected dye is further screened as follows. Although there are many methods for screening dyes suitable for transfer printing, in addition to focusing on the molecular weight, chemical structure, and selection from the vapor pressure and differential thermal analysis curves of the dyes, the transfer rate method should also be selected: the measurement before and after transfer The change in the dye weight of the dye is determined by the percentage of dye removed and the screening method based on the color depth of the buttons after printing. This method can be directly linked with the quality of the product and the process performance of the dye, and has a direct guiding role in production. In order to achieve good reproducibility of transfer color when transferring buttons, the dye selection requires an approximate sublimation performance in the transfer temperature range. In general, the dyes generally include: disperse red 3B, disperse red FB, disperse yellow 6G, disperse yellow 5G, disperse yellow 2GC, disperse blue 2BLN, and disperse yellow RGFL. Small button patterns can be tried), dispersed fluorescent yellow 2, disperse red E-4B, disperse yellow E-3R, disperse brilliant blue E-4R and other dyes. The disperse dyes imported from abroad are used for transfer printing. It is not introduced here one by one. In thermal transfer printing, two or more disperse dyes are often required for the design according to the design of the color tone of the flower, and the compatibility of the dye should be paid attention to in the mixed use. For example, the sublimation point of the dye can not be too different, so as to avoid difficulties in determining the control of the pressing temperature, resulting in different colors and shades of the product. According to the domestic past selection of low-temperature three primary colors disperse red 3B, disperse blue 2BLN and disperse yellow RGEL; and now selected domestic disperse dye low-temperature disperse yellow E-3R, red E-4B, brilliant blue E-4R, as long as the factory reserves Trichromatic dyes and several dyes, including black, can be easily formulated with a variety of chromatograms to minimize the amount of factory dye stock.

2. The selection of thickeners can be used as a thickener for printing inks. There are only a few suitable thickeners for water-soluble transfer inks. The requirements for them are to make the papers nice, and the transfer patterns should be clear; The affinity for disperse dyes is small; at room temperature there is a good thickening effect and the suitability for printing, and when deuterium temperature (220°C) does not decompose, good stability; there is a certain solubility in water. According to the introduction and screening of relevant data, it is generally appropriate to use methyl cellulose, sodium alginate, etc. as the base material of water-soluble transfer ink. In order to improve the dispersion of the ink, a small amount of a surfactant such as Pingping plus O is added, and if necessary, a small amount of an organic solvent such as ethanol, methylamine aqueous solution, etc. is added to adjust the ink's printability. In recent years, Liaoning Textile Chemistry Research Institute (Dandong Hengxing Fine Chemicals Co., Ltd.) has introduced a series of thickeners in order to meet the requirements of various special printing. Among them, FS-60 series thickener can replace sodium alginate by 100% for dispersion. Dye printing.

Printing paste preparation: As commercial disperse dyes usually contain more anionic dispersant, it has obvious solubilizing effect on disperse dyes. When disposing printing materials, most of dissolvable water is dispersant. The fine dye particles are simply surrounded by a water-soluble dispersant, and the aggregation of the dye particles does not occur close to each other. In the preparation, the slurry is firstly adjusted with water at 40° C. which is twice the amount of dye, and diluted with water under high-speed stirring, and the printing paste (ink) is blended with the original paste (thickener).

Third, the preparation of transfer printing paper General buttons enterprises will not have their own printing equipment, transfer printing paper printing methods, generally can use gravure printing, offset printing and screen printing, transfer printing an important material flower paper, according to today's society Different industry divisions, button manufacturers can commission the printing plant to produce transfer printing paper. If the factory adopts self-printing, screen printing is recommended because of less screen printing investment and quicker results. Of course, the button enterprises set up a printing shop to print on their own, which can prevent imitation of counterfeit products because the imitation of counterfeit products is more serious nowadays. The requirements for printing paper: the paper must have a certain strength, and it should not be brittle or deformed under high temperatures. . The dye has a low affinity for paper so that the dye gas can be fully transferred to the button. The printing material on the paper has no obvious blocking effect on dye transfer.

A three important materials, transfer printing paper prepared <br> <br> Typical coin business he would not have the printing apparatus, the printing paper transfer printing method, may generally be gravure printing, lithographic printing and screen printing, transfer printing According to the division of labor in today's society, button manufacturers can entrust printing companies to produce transfer printing paper. If the factory adopts self-printing, screen printing is recommended because of less screen printing investment and quicker results. Of course, the button enterprises set up a printing shop to print on their own, which can prevent imitation of counterfeit products because the imitation of counterfeit products is more serious nowadays. The requirements for printing paper: the paper must have a certain strength, and it should not be brittle or deformed under high temperatures. . The dye has a low affinity for paper so that the dye gas can be fully transferred to the button. The printing material on the paper has no obvious blocking effect on dye transfer.

Fourth, button transfer printing equipment and technology

Most of the transfer printing equipment currently on the market is designed for fabric printing, and individual products are designed for special products such as cups, plates, and so on. It is difficult to find a set of special equipment suitable for the use of buttons. There are mainly two types of transfer printing equipment on the market: one is an intermittent flat ironing machine, and the other is a continuous hot roller ironing machine. According to the pressurization mode, it can be divided into two types: pressurized type and negative type (vacuum type). Both models are produced in China, but they are not suitable for the button transfer printing machine. According to the characteristics of button production, the company develops its own pressing equipment or designs and manufactures it with a printing machine manufacturer. Here, the author designs a soil method for reference only. Buttons are small in size, complicated in variety, and varied in form and size. From the production point of view, they cannot be pressed one at a time. The surface of buttons and hot presses will appear flat, convex, concave and other states, these will cause a lot of difficulties for the button printing, this to take a flat hot flower machine as an example, according to the layout of the flower paper plate layout , will be printed in batches of buttons, arranged in a mold made of plaster paste, the pressure nest positioning, this pressure nest and floral paper plate is consistent. When the plaster is hardened and solidified, the position of the button printing arrangement is basically positioned. This positioning mold can be used for several sets of rotation to avoid affecting the speed of flowering. According to the size of the button, each dozen or hundreds of hot flowers can be completed. The use of thermal transfer glue (such as 3M spray glue) sold on the current market can be used to bond the paper and button securely. The two hot plates of the flat ironer are hard (hot plate) soft (cold plate) and soft (hot plate) hard (cold plate). The purpose of doing so is to adapt to the complexity of the button burnt surface, also taking into account the basic conditions of the printing process there are two: First, temperature, and second, time, these can be tested by the method to find the best parameters. Only the size of hot pressure, has little effect on the printing effect. If the transfer printing using vacuum ironing machine, then the effect will be even more ideal.

As a button product, it is a special shape of the substrate, the shapes vary widely, to achieve printing must be fixed in accordance with certain requirements, in order to make the printing surface and the position of the imprinted parts consistent with the requirements of the printing process, this The device that allows the printing surface of the substrate to meet the requirements of the printing process is called a positioner. The button printing positioner is complicated and time-consuming if manufactured by a mechanical processing method, and the cost is relatively high. If a resin casting method using a plastic industry is used, it is simple and quick to manufacture, low in cost, and convenient to use. This kind of casting method is not a good thing for button companies, and it will be more difficult for screen printers. You can try out some of the information by referring to the relevant materials. Because of the lack of space, you cannot introduce more.