Development and Performance Study of CaCO_3 Modified PP Spun-Bonded Nonwovens

The manufacturing process of CaCO3 modified Polypropylene (PP) spun-bonded nonwovens was studied. Then the effect of the additive amount of CaCO3 on mechanical properties of the product was analyzed, and a compatible mechanism between CaCO3 particles and the main component of PP was established. In the end, the mechanical performance of the products was studied when the natural light degradation was changed. The experiment results show that after adding CaCO3 to the PP spun-bonded nonwovens and through the application of complex coupling agent and organic modification, hardcore of rigid particles and polymer composite elastomers can be combined together tightly and disperse rapidly and evenly in the main part of PP. In addition, CaCO3 can catalyze the light degradation of PP spun-bonded nonwovens. The larger the content of CaCO3 is, the faster the light degradation will be.

MELT-BLOWN NONWOVEN FOR AIR FILTRATION

The technical parameters and the structural factors of melt-blown nonwovens used as filteringmedium are analysed,the orientation of particles filtered in a filter is described,and the optimalparameters for air filtration are obtained.The results are shown as follows:the ratio of tenacity oflongitudinal to cross direction has a close agreement with the random coefficient of fiber arrange-ment in practice;large particles are most likely trapped on the surface of a filter,and smaller parti-cles are filtered throughout the depth of a filter,and the deeper,the smaller;moreover,higher fil-tering efficiency and lower pressure drop can be effected through the optimization of parameters.

INVESTIGATION OF PARAMETERS OF NONWOVEN FILTER USED IN WHITE CELLS REMOVING

This paper is concerned with the relation between the parameters of nonwoven filter and removing of white cells. Melt-blown polypropylene nonwovens are used as filtration materials of white cells filter. According to the combination of different fiber diameter, different product density and different weight, optimized combination of parameters of nonwoven filter with more effective removing of white cells is obtained. The result is that removing of white cells is 96.90 percent; recovery of red cells is 92.27 percent.

Investigation of Atmospheric Pressure Plasma Discharge and Its Application to Surface Modification of Blood-Filtering Material

Melt-blown polybutylene terephthalate (PBT) nonwoven materials treated by usingplasma is regarded as one of the excellent materials to filter white blood cells (WBC) from blood.In this paper, dielectric barrier discharge (DBD) plasma source at an improved quasi-stable at-mospheric pressure is achieved when discharge voltage, discharge current, and gap between theelectrodes are carefully controlled. This plasma source has been used to modify the surface ofPBT melt-blown nonwoven materials. Experimental results indicate that both the wettablity andpermeation of treated PBT melt-blown nonwoven materials are greatly improved.

Researches on preparation and properties of polypropylene nonwovens containing rare earth luminous materials

Polypropylene composite nonwovens containing rare-earth strontium aluminates Sr Al2O4：Eu2＋,Dy3＋ and functional additives were fabricated by the spun-bonded technique.The optical properties, morphology and mechanical properties of the samples were characterized.Results from scanning electron microscopy photographs（SEM） indicated that the surface of the fiber was destroyed by the addition of rare earth luminescent materials lightly but the thickness of the fiber was uniform.Differential scanning calorimetry results showed that pure polypropylene has the double crystallization peak at 162.3 and 165.1 °C.Studies from X-ray diffraction showed that the nonwoven prepared with the luminescent materials contained the α-monoclinic crystal and β crystalline phase.Furthermore, the afterglow properties were tested, which showed that the afterglow curve of the luminous nonwoven was similar to that of strontium aluminate, and the intensity was more intensive than luminous nonwoven at the beginning.The nonwoven fabricated with the luminescent material did not affect the crystal lattice of the polymer making the materials have potential applications in fluorescent lamps and field emission displays（FEDs）.