Studies On Process Technology And Property Of PE/PET Bi-component SMS Nonwoven Composite Materials

Bi-component nonwoven composite materials was a new-type nonwoven composite materials,which was produced via thermal-bonding both bi-component spunbond processing(bi-component spunmelt)and melt-blown technology,and which was featured by high strength,great hydrostatic pressure resistance,fine aperture,soft hand feel,and so on. These materials could be used in different kinds of field such as health care,outside protective products,packaging.At present,a lot of bi-component even polycomponent spunbond nonwoven composite materials have been developed,and a lot of patents have been applied in overseas.But there are merely bi-component spunbond products and single component SMS nonwoven composite materials at home,their bi-component counterpart research has not been initiated.PE/PET bi-component nonwoven composite materials were studied in this paper.The processing and equipment of PE/PET bi-component SMS nonwoven composite materials,the interfacial bonding mechanism of bi-component SMS nonwoven composite materials,the influence of processing on PE/PET fiber's property in the composite materials,the relations of thermal-bonding technology and products properties,the properties and applications of bi-component SMS composite materials were systematically analyzed in this thesis.The purpose is providing systematic and detailed experimental basis for research and development of SMS bi-component composite materials at home in the future.The interfacial bonding mechanism of bi-component SMS composite materials was analyzed;the analysis indicated that the interfacial bonding conforms to the absorption diffusion and mechanical bond theory in the interfacial bonding principle.Since the PE constituents in bi-component spunbond materials is structurally similar to their PP counterpart in melt-blown materials,macromolecular segment diffusions and interlacements happened between them,and these are the main reasons why the SMS composite materials could effectively interfacial cohered.By means of single factor analysis,the influence of temperature and velocity of lateral blow,and the pressure of attenuating blast on the linear density and crystallinity of PE/PET fiber in the composite materials.The analytic results indicated that the crystallinity of PE/PET fiber increased if the lateral blow temperature rose,and their linear density increased as the increasing of cooling air temperature and slit width of extension apparatus,and it decreased when the lateral blow temperature and the pressure of attenuating blast increased.Via single factor analysis,the relations of hot rolling and property of bi-component SMS composite materials were analyzed,in order to enhance the racking strength,the technological parameters were optimized via orthogonal experiments.The experiment results showed that the crystallinity was increasing when the temperature and pressure rose,the breaking tenacity of composite materials would became largest if the temperature pressure and velocity of thermal-bonding reached to the critical value,the elongation rate increased as the velocity mount up, while decreased as the temperature and pressure growth.So did the softness.The factors may affect the racking strength are as follow: temperature velocity and pressure of thermal-bonding.The adhered area ratio was different because of the diversity of hot roller pattern,so did the elongation and softness.The materials,which have a small area proportion,would have a great strength and elongation rate in the MD direction,but the items in the CD direction would be smaller,and the softness is excellent.The properties of bi-component SMS composite materials,like stretching,softness,impermeability,light fastness, aperture,and ventilation property,were compared with single component SMS composite materials,finally found that the above properties of bi-component ones is superior than to the single component.So,the bi-component SMS composite materials were more competitive than single component ones in health care,packaging,outside protective products and filter bags industry.