The Researches On Forming Process And Absorption Gel Mechanism Of SAF Non-Woven Material

SAF nonwoven material is a new kind of material containing SAF fiber in its fiber mesh. This material is with good retention capacity and absorbability of water and moisture. Meanwhile, its absorption rate is high and the handle is soft. With such properties, it can be applied as the optical cable and cable waterproof material, medical material, water retention and afforestation materials, etc. Superabsorbent fiber (SAF) is a kind of functional fibers that developed from SAP. It is the extension and expansion of SAP. Due to the mixing of powder and SAP granule tends to be heterogeneous and they are easy to slide, non-woven material strength and properties are affected in a certain degree. So the idea of changing superabsorbent powder into fiber brings SAF fiber into reality. SAF fiber makes up for the weakness of SAP and replaces SAP in many applications. At present, there are three major foreign companies that achieved SAF fiber industrialized production, and they also successively developed some superabsorbent non-woven material. But there is only one domestic company developed SAF fiber and achieved batch production. Comparatively speaking, the domestic researches on SAF nonwoven materials are still fewer.This paper is mainly about experimental designs of the forming process of SAF non-woven material. The forming process absorption and gel mechanism are studied in it. The purpose that we did these researches is to offer accurate experimental data base for future independent research and production of SAF nonwoven materials in China, and to realize early industrial production of SAF nonwoven materials in order to satisfy different demands from many fields.By means of single factor analysis method, the influence of the mixing proportion of SAF fiber, heating temperature and heating time on the forming process and non-woven material properties was investigated. Studies show that, with the increase of SAF fiber content, the water retention rate, deionized water absorption rate and salt-water absorption rates of SAF non-woven material are all increased. And the deionized water absorption rates are all higher than the salt-water absorption rate, besides, the density of SAF non-woven material decreased with the increase of SAF fiber content. The strength of SAF nonwoven material is increased with the heating temperature rise between 130-140℃, and then decreased after 140℃with heating temperature rise, its maximum is got at 140℃. Meanwhile, the strength of SAF nonwoven material is increased with the heating time increase between 15min-25min, and then decreased after 25min with time, its maximum is got at 25min. The maximum crystallinity of SAF non-woven material is achieved at 140℃, and the crystallization rate between 130℃-140℃is higher than that between 140℃-150℃. Crystallinity changes great between 15min-25min and very little between 25min-30min. Though grain size rises with both the increase of heating time and heating temperature, the influence of heating time is inferior to heating temperature.Impact factors of water absorption performance of non-woven material were studied via orthogonal experiments, and the experimental results were analyzed through extreme difference analysis. Through this way, the order of factors we got that affect the water absorption rate of SAF fiber is content of SAF fiber, heating temperature, and heating time. And in general, the optimal process is, SAF content 27%, heating temperature 140℃and heating time 25min.The influences of the different fiber structure, different mesh reinforcement ways on gel state and gel structure, and then water absorption and water holding properties of products are analyzed. Researches show that after absorption, the hot rolling part of SAF nonwoven material produced through hot rolling could not slide like other part in the fiber mesh and this causes break and shift or loss of gel. Thus affecting the absorbing and water holding performance of SAF nonwoven materials. While after absorption, SAF nonwoven materials produced through hot-melting, with its SAF fiber coated by other fibers, avoid the gel sliding. So, even after a long time, SAF gel can still keep evenly distributed this fully exert its excellent water absorbent and holding properties.