Polyester, scientific name polyester fiber. Polyester fiber refers to polyethylene terephthalate (PET) fiber, its excellent performance, easy to obtain raw materials, widely used. After half a century of development, has become the largest synthetic fiber varieties, and domestic and foreign researchers in the continuous chemical modification of PET at the same time, but also developed with different performance of polyester fibers, such as good elasticity Polybutylene terephthalate (PBT), polybutylene terephthalate (PTT) with low wear resistance and less static electricity, poly (ethylene oxide) p-benzoate (PEB) ; High strength, high modulus, low boiling water shrinkage of poly naphthalate (PEN), etc., so that the application of PET continue to expand, the amount is also growing. It has been reported that since the twenty-first century, China's polyester industry has developed rapidly, polyester fiber production from 2000 to 516.5 million tons to the end of 2004 reached 11.38 million tons, 4 years increased by 6,155,000 tons, production than four years ago turned Fan more, the average annual growth rate of more than 20%. China's polyester fiber production in 2004 accounted for 45% of the world's total polyester fiber, accounting for more than 50% of all fiber consumption in China, accounting for 80% of all chemical fiber production. The next five years, will maintain a 15% growth rate, by 2010, China's polyester production will reach 20 million tons. The application of polyester fiber has been involved in all aspects of clothing, decoration, home textiles, industrial textiles, industrial engineering and other people's livelihood. But as a textile material, polyester also has the following shortcomings: poor dyeing. Therefore, the choice of scientific, efficient, high-quality, energy-saving, environmentally friendly coloring technology, to adapt to and promote the polyester industry, polyester fiber high-speed sustainable development is essential.
1 polyester spun before coloring and masterbatch applications
Polyester, its structure is as follows: molecular arrangement closely, and less hydrophilic groups, and thus poor color is always a major problem that people are troubled. In order to improve the dyeing of polyester, people have studied cationic dyeable polyester, that is, in the molecular structure of polyester by adding cationic dye modifier, the modified agent in the process of polyester synthesis, the result is in the polyester molecular chain The introduction of the cationic dye can be combined with the group, thereby improving the polyester fiber at high temperature and pressure or boiling at room temperature when the dyeing rate, but also changed the polyester spinnability, dyeing saturation, fiber Heat resistance, etc., have a certain adverse effect on fiber performance. Polyester conventional dyeing method is in high temperature, high pressure or additive dyeing, and can only be more than polyester glass transition temperature (81 ℃) fiber expansion after adding disperse dyes, dyeing is possible. In fact, conventional polyester dyeing is generally carried out at 130-140 ℃, 0.3-0.4MPa pressure, after suspension, pad dyeing and drying, baking and other steps. Some blended fibers are difficult to withstand such high temperatures, but also need to use carrier-assisted dyeing. According to statistics, the production of 1,000 tons of polyester colored wool need to invest 2.5 million yuan, 1,300 square meters plant, water 100,000 tons, the use of gas 165,000 cubic meters, power consumption 560,000 degrees. It can be seen that this dyeing method energy consumption, low efficiency, serious pollution. At present, China's polyester fiber production of about 12 million tons, of which one-third need to use coloring, the use of dyeing methods, will bring 40 million tons of colored wastewater discharge each year. Disperse dyed fabrics or the development of national imports of textiles limit the mouth, they believe that the use of disperse dyes in dyeing can lead to cancer, harmful to health. Dyeing fastness, washing, perspiration, ironing and other fastness are much lower than the pre-spinning coloring. Has not adapted to the needs of social development and people's living standards. Polyester spinning before the coloring is to dissolve or disperse the colorant in the polyester spinning solution for melt spinning, the direct preparation of colored polyester fiber is a new technology, is the most effective way to solve the polyester dyeing, the process characteristics are as follows:
(1) easy to use
      Spinning before the color of polyester production, fiber use without any special requirements, the original spinning equipment, the existing production process. Especially when the polyester and other fibers blended intertwined, the use of polyester fiber does not only reduce the dyeing process, so that is not suitable for high temperature, high pressure dyeing conditions of fiber and polyester blended intertwined and easy to achieve the fabric pre-designed style. So before the spinning color to a certain extent, it can be said that no investment in the dyeing plant, is to use advanced technology to solve the dyeing and finishing "bottleneck" one of the shortcuts.
(2) low cost:
      The cost of dyeing is the consumption of energy and additives. Spinning before dyeing reduces the dyeing process of dyeing and dyeing equipment and multi-channel fibers or fabrics, removes the dyeing auxiliaries, combines each pigment molecule into the target product, fundamentally eliminates the dye discharge, reduces the consumption of raw materials, To avoid environmental pollution, reducing the cost of dyeing, saving a huge amount of pollution control costs, there are reports, "polyester spinning before coloring and fiber dyeing compared to the production of 100 tons of liquid dyeing polyester staple fiber, can save water 10,000 tons, Gas 16,500 cubic meters, saving electricity 5.6 million degrees. "" Fiber dyeing per 100 kilograms of products, can produce about 10 tons of wastewater. " According to the survey, dyeing average t coloring fee of 4,000 yuan or so, and the use of masterbatch spinning before coloring, the t-coloring fee is only about 1,200 yuan on average, we can see that before spinning color not only saves a lot of pollution charges, and coloring only dyeing Of the third, that is, the cost of dyeing to more than three times the color of the liquid.
(3) high coloring quality
      Conventional dyeing is mainly carried out using high temperature and high pressure conditions as described above using disperse dyes. However, due to the production of fiber and physical and chemical treatment is difficult to ensure that the internal structure of the crystal area and the uniform distribution of the area, the dye crystal, dispersion, dyeing rate and other general are often different, so the dyeing process is often easy to produce Color, stain, color flowers and other dyeing defects. Spinning before spinning is the coloring agent and the true color of the slices before the spinning, evenly mixed, and then by the melt filter, and then spinning, so the fiber dyeing uniform, regardless of batch size, color uniformity can be maintained, batch and The batch will not appear between the unacceptable color. From the structure of the fiber before dyeing, the colorant and the polyester form a consistent uniform solid solution, light fastness, washability, abrasion resistance and other fastness than conventional dyeing.
(4) environmental protection is good, good for health
      The coloring agent used before dyeing is solvent dye, does not contain the structure and composition of the disabled, the human body does not cause harm. At the same time as the dyeing before dyeing can withstand more than 300 ℃ high temperature, spinning process without any gas and wastewater discharge, dye utilization increased to 100%, therefore, masterbatch color can be said to be environmentally friendly, health products.
(5) is conducive to the development of polyester fiber function
      With the development of science and technology and the improvement of people's living standards, the fabric fabrics are becoming more and more functional in the direction of functionalization, diversification and flexibility. The functional fibers have been successfully developed, such as antibacterial, antistatic, flame retardant, far infrared, Thermal underwear, flame retardant, antibacterial, anti-ultraviolet fabric and other functional fabrics on the market, enriching people's lives, all this is achieved through the melt spinning; Therefore, masterbatch not only for polyester fiber color opened up the road, and For the polyester fiber to give new features to open up the road.
2 polyester spinning before the development and application of the status quo and promote the application of the need to pay attention to the problem
      After the 70 years since the spinning before the color technology research and development, China's dye industry, electronic color technology and masterbatch production technology has developed by leaps and bounds, the annual output reached more than ten million tons, before spinning color by the car interior The development of the embroidery line, sewing thread, apparel fabrics, industrial textiles and other fields, it is worth mentioning in 2004 the People's Liberation Army uniforms to achieve the pre-spinning color, which is the People's Liberation Army since the beginning of the test since the first comprehensive promotion Application, which for the industry before the textile before the ribbon with a color. People's Liberation Army in the island of fiber for the production of high leather for cold boots fabric coloring has also been carried out before the successful dyeing test. However, at present, China's high-grade, high-quality fiber masterbatch production enterprises, bright color, high technical indicators (such as compliance with the German standards of resistance to light fastness, etc.) production there are some difficulties, therefore, The healthy development and the wide application of masterbatch also need the government and industry associations to support, pay attention to solve the following problems:
(1) to strengthen the joint, collaborative operations, improve the technical level of the industry
      As a result of historical reasons, China's masterbatch production enterprises and services for enterprises, chemical fiber, dyes, machinery and so many independent, isolated from each other, seriously restricting the advanced technology and advanced production technology promotion and application, hinder the masterbatch technology Level of improvement. Foreign masterbatches are generally monopolized by a small number of multinational companies, which are usually derived from dyestuff producers, such as Dessa, Klein, Ciba Specialty Chemicals. This approach is conducive to product development, is conducive to improving product quality and reduce production costs. With the international capital into the Chinese market and China's accession to the WTO after the new situation, China's masterbatch industry should establish a dye ♀ masterbatch development, production ┈ application integration joint group, coordinated operations, the Yang Yang, may accelerate the technology Progress, improve the level of masterbatch industry has been promoted.
(2) to increase publicity, change the concept, and vigorously promote the pre-spinning application
      China's dye production and fiber masterbatch production has been close to the international level, some varieties can adapt to the chemical fiber industry spinning requirements, color, fastness, price and other indicators have advantages, and most textile industry is still stick to the traditional first Weaving after dyeing. In order to eliminate the pollution of the environment and reduce the harm to society and health, the government and the industry should increase the propaganda, formulate corresponding policies and measures to encourage the use of color spinning, especially in the textile industry, Color silk, and strive in two or three years, the domestic textile before the color can reach the current developed countries accounted for 40% of the proportion of polyester fiber production.
      At present, the spinning of chemical fiber enterprises agreed that the spinning before the color is good, melt straight spinning enterprises have begun to study the transformation of direct spinning equipment, and strive to develop a certain number of differentiated varieties, but quite a part of the chemical fiber plant did not dare to move, they think Color "hard", "top not net", worried about "rising costs". Practice the truth. Dalian Chemical Fiber Factory began spinning yarn in 2002, the Japanese Teijin test machine, Shanghai production of large spinning machine, are installed on the injection device, the general color change most of the wire handle can transition normal, from the wire handle, from the point of view, from Primary color → white → new color, 20 minutes, 15cm or so. The use of masterbatch palette of each set from the adjustment to a representative of about 20 minutes, in particular, the current masterbatch plant given the amount of access are generally more accurate, Dalian A color Masterbatch Co., Ltd. generally given to the decimal point after the 2, adjust the settings are very convenient. Transition wire small equipment 40-80Kg, large equipment about 200Kg, this part of the wire can be directly wound for the knitting industry for the use of color silk, chemical fiber plant loss is not serious. As the spinning yarn processing costs are generally higher than 2-3 times the white silk, therefore, spinning yarn than the white silk economic benefits higher, which is currently Xiaoshan, Shaoxing most of the chemical fiber plants are one of the reasons. Chemical fiber plant should seize the opportunity to vigorously produce color silk.
(3) with the development of science and technology to promote market development
      The development of differentiated fiber, small batch, multi-species is completely to meet the requirements of fabric processing. With the development of textile technology complex fabric more and more, therefore, to improve the ability of differentiation is an important task of the chemical fiber industry, to expand the pre-spinning market should first increase the intensity of science and technology development, for China's polyester industry in the textile market And the textile industry in the field of market there is a great potential, consumption will continue to expand, export textiles still face South Korea, Japan, Taiwan and Southeast Asia, some countries and challenges and international market instability, export textile limited reality, we must rely on Science and technology development, comprehensive promotion before spinning coloring. Clean the environment, care for health, with environmentally friendly, healthy high-tech products to occupy the international and domestic markets.