| Water entangling process is a kind of nonwovens processing technology, by which staple fibers go through opening, carding, web-laying and finally entangling with each other under the act of high-pressure fine water columns (diameter: 0.08mm~0.12mm, pressure: 0Bar~600Bar) to form a kind of nonwovens with high density and strength, called spunlaced nonwovens. The technology consists of three parts, i.e. web-laying process, water entangling process and water treatment process. Water entangling technology originated in the 1970s, and was introduced into China in the end of the 21st century. Since its inception, it has experienced 30 years of development. Especially in the latest period, it developed rapidly over the worldwideand and its output increased 16%. Both domestic and foreign manufacturers and researchers have been devoting to the research on the technology. However, since the water entangling technology only has a short period of development, its market and the properties of its end products are far from mature. Those leading manufacturers who have been providing the relevant equipments to China have constantly upgraded their production equipments, and the equipment users are devoting to the production domesticization of raw materials and equipments, and constantly modify and upgrade their equipments according to their actual needs with a view of improving product quality, increasing production capacity and yielding benefits. The research on water entangling technology covers a wide range of areas and is systematic and sophisticated.The water entangled nonwovens, serving as a material, offers such features as softness, good breathability, hygiene, good moisture absorbency, good drapability and barrier etc. and is always the top choice for medical and hygienic material both in and abroad. Innovation of equipment and development of raw material is proceeding worldwide, with domestic participants showing more brisk. Some have made a certain achievements, but still have a long way to go regarding technology innovation and product innovation. As a new technology that has large room for development, it is very important to research on the water entangling technology. The research on raw materials used in this technology and its performance targets, web-laying system and its configuration of process parts, the relationship between water entangling and production quality, performance and requirement of water neilsbed and its water treatment system are introduced in this paper, and the authors opinions on technology innovation are put forward and the results of innovations are verified. Research on this topic started from the end of 2000, and the following conclusion are drawn through reviewing numerous data and conducting a lot of tests, practices and analysis:1. The performance and quality of fiber materials exerts critical effect on production process and product quality. The performance requirements are high than the prevailing textile fiber quality standards and exceed the requirements of top quality product. This topic has formulated the quality standards for the special fibers for water entangling technology; for medical and hygiene products, the writer has put forward his opinions on the relationship between the decrease of whiteness of rayon product after high-temperature sterilization and the PH value.2. The interaction between rollers of carding machine contributes plays a critical role in carding of fibers and on the web quality, and the type of wire varies according to different rollers of the carding machine used to meet different process requirements The raw materials are important toweb-laying process and the carded web sets requirements to the type and length of fibers. This topic of research holds that the optimum length of chemical fiber is 38mm~51mm and that of natural fibers no less than 21mm; Random carded web can change the direction of fiber arrangement in the web; the effect of carding is directly tied to the evenness of web. Cross-laid web is the most rational process in the dry-laying processes, and it can meet the requirements on performance targets of the special MD/CD<1.5 spunlaced nonwovens.3. The pressure of the water needles have little effect on the strength of fiber web, while the distance between the needle holes and the fibers, spunlacing grades, production speed and the density of needle hole exert critical effect on the strength and appearance of the web. The distance between the needle holes and the fibers also moderately impacts the MD curve and rigidity, MD shrinkage and MD expansion rate. The energy of spunlacing is tied to the density of needle hole, the pressure of inner chamber, water flow of needle hole, web-laying speed, weight of web and number of needle.4. Water entangling belt is an important part to realize the entangling of fiber. Its structure parameters and materials have certain relation with the performance and the style of nonwovnes, which affects the congregating status and the product performance of quality.5. The strip shall be made of anti-corrosive stainless steel, of which the rigidity shall be in line with the requirements of sufficient strength of water needle to realize extruded forming of web; when the streamline is used as the shape of water-spraying; the energy of the water column is more concentrative; the processing accuracy of water-spraying hole has critical effect on the concentration of the fine spraying flows.6. Traditional water treatment technology can not solve the problems of completely and partly clogging of hole of needle of strip, which will critically impact the product quality and consume energy and labor. Water treatment technology has become a bottleneck that constrains the development of water entangling technology.
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