Preparation of microfibers by using a carbon dioxide laser and analysis of superstructure for obtained microfibers

我们succeeded in producing microfibers， such as poly(ethylene terephthalate) (PET), nylon 6isotactic polypropylene (i-PP), poly(L-lactic acid) (PLLA), poly(glycolic acid) fibers，by a continuous thinning method using a carbon dioxide (co_2) laser. a laser-thinning apparatus tocontinuously prepare the microfiber was developed in our laboratory and consists of fiber supplyingwinding spools, a continuous wave co_2 laser emitter, a supplying system of fibers，and a traverse. The laser-thinning apparatus could produce The microfiber in The range of 100m . min^<-1> to 2,500 m . min^<-1>. The diameter of The laser-thinned microfiber decreased withincreasing a winding speed，及其生物生物increased with increasing the winding one. When the nylon 6 microfiberobtained by irradiating the laser operated at a power density of 19.8 W cm <-2> to the undrawn nylon6 fiber supplied at 0.32 m·min^<-1> was wound up at 848 m·min^<-1>，obtained microfiber had a diameter of 3.2 μm and…More a birefringence of 47 x 10 . The draw ratio calculated from The supplying and The draw ratio calculated from The supplying and Thewinding speeds was 2650 times. The SEM showed that The microfiber obtained by The laser-thinningapparatus had a smooth surface without a surface roughened by a laser-ablation and is uniform indiameter. The developed apparatus could more easy produce The microfiber when compared with Theconventional technology such as a conjugate spinning, an islands-in-a-sea type fiber spinning，a melt blowing，a flash spinning. a zone-drawing and zone-annealing method应用于PET microfiber使用co_2 laser-thinning in order to develop its mechanical properties. themicrofiber used for the zone-drawing and the zone-annealing was prepared by winding at 1,386 m/minthe microfiber that was obtained by irradiating the laser at 18.1 W/cm^2 and had a diameter of 2.8μm and a birefringence of 0.097. The zone-drawing was carried out at a drawing temperature of 105℃under an applied tension of 53 MPa，and the zone-annealing at 155℃under 195 MPa. the zone-drawing and the zone-annealing were carriedout at a treating speed of 0.21 m/min. The zone-annealed microfiber finally obtained had a diameter2 μm, a birefringence of 0.234, a tensile modulus of 17.9 GPa，and a tensile strength of 1.1 GPa.The co_2 laser-thinning method应用于PET fiber to producePET microfiber. The apparatus used for The preparation of microfiber web consists offiber supplying spool, a continuous wave co_2 laser emitter, air gun，and a net conveyor to collect the microfiber web. the diameter of microfiber web was depended on asupplying speed the air supply to the air gunand laser power. Nonwoven fabrics were obtained by heating the collected microfiber web at 190℃under constant length and obtained nonwovens were formed by continuous filament with a uniformdiameter . less

We succeeded in producing microfibers, such as poly(ethylene terephthalate) (PET), nylon 6, isotactic polypropylene (i-PP), poly(L-lactic acid) (PLLA), and poly(glycolic acid) fibers, by a continuous thinning method using a carbon dioxide (CO_2) laser. A laser-thinning apparatus to continuously prepare the microfiber was developed in our laboratory and consists of fiber supplying and winding spools, a continuous wave CO_2 laser emitter, a supplying system of fibers, and a traverse. The laser-thinning apparatus could produce the microfiber in the range of 100 m・min^<-1> to 2,500 m・min^<-1>. The diameter of the laser-thinned microfiber decreased with increasing a winding speed, and its birefringence increased with increasing the winding one. When the nylon 6 microfiber obtained by irradiating the laser operated at a power density of 19.8 W・cm^<-2> to the undrawn nylon 6 fiber supplied at 0.32 m・min^<-1> was wound up at 848 m・min^<-1>, the obtained microfiber had a diameter of 3.2 μm and … More a birefringence of 47 x 10^<-3>. The draw ratio calculated from the supplying and the winding speeds was 2650 times. The SEM showed that the microfiber obtained by the laser-thinning apparatus had a smooth surface without a surface roughened by a laser-ablation and is uniform in diameter. The developed apparatus could more easily produce the microfiber when compared with the conventional technology such as a conjugate spinning, an islands-in-a-sea type fiber spinning, a melt blowing, and a flash spinning.A zone-drawing and zone-annealing method was applied to the PET microfiber obtained by using the CO_2 laser-thinning in order to develop its mechanical properties. The microfiber used for the zone-drawing and the zone-annealing was prepared by winding at 1,386 m/min the microfiber that was obtained by irradiating the laser at 18.1 W/cm^2 and had a diameter of 2.8 μm and a birefringence of 0.097. The zone-drawing was carried out at a drawing temperature of 105 ℃ under an applied tension of 53 MPa, and the zone-annealing at 155 ℃ under 195 MPa. The zone-drawing and the zone-annealing were carried out at a treating speed of 0.21 m/min. The zone-annealed microfiber finally obtained had a diameter of 2 μm, a birefringence of 0.234, a tensile modulus of 17.9 GPa, and a tensile strength of 1.1 GPa.The CO_2 laser-thinning method was applied to PET fiber to produce web formed by PET microfiber. The apparatus used for the preparation of microfiber web consists of fiber supplying spool, a continuous wave CO_2 laser emitter, air gun, and a net conveyor to collect the microfiber web. The diameter of microfiber web was depended on a supplying speed the air supply to the air gun, and laser power. Nonwoven fabrics were obtained by heating the collected microfiber web at 190 ℃ under constant length and obtained nonwovens were formed by continuous filament with a uniform diameter. Less