1) Less use and no use of pva Since the establishment of the pulp production and application department of China Cotton Textile Industry Association, it has been put forward that the development direction of China pulp is "high quality, multifunction, less components, serialization, less use and no use of PVA". After several years of practice and the papers of this conference, it is proved to be in line with China's national conditions and production requirements. Because under the guidance of this development direction, it has promoted the development of size and the improvement of sizing technology in China, such as the development and application of acrylic size and grafted starch. Regarding the biodegradation of PVA, everyone thinks that there is no product at present and it needs to be stored. Therefore, according to the current situation in China, the development direction of using less and not using PVA is in line with the actual situation. PVA should be used in combination with different polymerization degrees and alcoholysis degrees on the premise of less use. (2) Acrylic size Acrylic size used to have only amide size and methyl ester size. According to the papers of this conference and the products provided by the participating pulp mills, more than 65,438+00 manufacturers are producing all kinds of acrylic pulp. According to the fabric type and chemical structure, they chose multi-monomer for * * * polymerization. Some use emulsion polymerization and solution polymerization, and the products are mostly liquid; Some companies have developed solid polyacrylate size, and the products have excellent adhesion, flexibility, water solubility and miscibility. Due to the use of ester monomer, the adhesion to polyester fiber is improved, and the hygroscopicity and re-adhesion are low. The application of acrylic fiber size can appropriately increase modified starch to replace part of PVA, so that the yarn hairiness is adhered, the opening is clear, the warp breakage is reduced, and the loom efficiency is improved. It is a good auxiliary size. It is believed that there are many types of acrylic size at present. What kind of units should be used for polymerization and what proportion is appropriate? It is necessary to discuss and provide its mechanism and performance data in order to facilitate production and application. (3) Grafted starch Grafted starch is a new size developed in recent two years. According to the introduction of Jining Green Slurry Company, they adopted a technical route that can break starch granules and carry out grafting reaction inside the granules. After that, the grafting rate increased to more than 20%, the grafting efficiency increased from 40% to more than 70%, the product caking phenomenon was also improved, and the production cost was reduced. This product can replace PVA by about 70% after being applied in related textile mills (but there is still sizing phenomenon). It is believed that the grafting rate and grafting efficiency of grafted starch have been greatly improved than before. However, since the grafted monomer is propylene monomer, the ungrafted monomer and modified starch can still be used as sizing agent together. Therefore, it is considered that the sizing performance of grafted starch size should be compared with that of modified starch mixed size with the same amount of propylene monomer, which shows that the quality of grafted starch size is better than that of mixed size (propylene monomer+modified starch). This opinion was put forward at the Nanchang meeting last year, but there is still no pulp mill to test it. It is hoped that all pulp mills producing grafted starch can carry out this comparative test, which will provide theoretical and practical data for textile mills. (4) Other modified starches At present, modified starch has been widely used by everyone, but according to the characteristics of products, it has not been fully applied. According to the similar compatibility principle, esterified starch is more suitable for polyester-cotton products, but many factories use acid-hydrolyzed starch and oxidized starch, and the production level is equivalent. It is considered that there are two possibilities: first, the pulp mill failed to produce starch with the characteristic quality of esterified starch; Second, there is little difference in the quality of various modified starches. At the meeting, Professor Ye Guozhen of Guangxi University conveyed the planning requirements of modified starch association for textile sizing: by 2000.