Preparation And Properties Of Anti-UV Extinction Polyester Fibers And Fabrics

Polyethylene terephthalate（PET）is currently the world’s number one synthetic fiber species.Due to its good mechanical properties and low cost,PET is commonly used in clothing,home textiles,industry,etc.It is also one of the fabrics commonly used for summer clothing.When used as a summer and outdoor fabric,there are certain requirements for UV protection.The PET fiber itself has insufficient UV resistance and harsh luster,which cannot meet the demand for summer and outdoor fabrics.Therefore,the development of UV-resistant matte polyester fiber is necessary to meet the market demand.In this paper,UV-resistant matte chips were prepared by twin-screw blending method,and the spinnability and crystallinity of the chips were investigated.The modified polyester spinning process and fiber properties were also studied by melt spinning.Finally,the fabric was woven on the machine and the taking properties of the fabric were explored.To provide some reference for the anti-UV matting modification of fibers.The main studies are as follows:（1）A composite powder（Ce-Ti）compounded with equal masses of cerium dioxide（CeO₂）and titanium dioxide（TiO₂）is used as the modifier.The modified PET with dissimilar mass fractions（0.5%,1.0%,1.5%,2.0%）was prepared by twin-screw and PET blending.Its melt crystallization properties and isothermal crystallization properties were investigated and found that the melting point（T_m）of the modified chips decreased with the increase of the composite powder,from 252.8℃ to 247.9℃,while the melt crystallization temperature（T_c）increased by18.2%-19.2%.At the same time the crystallization speed is accelerated.The time was reduced from 10-20 min to 1-2 min.The semi-crystallization time(t_1/2)showed a tendency to shorten first and then increase with the increase of the composite powder.The thermal stability properties of the slices were also investigated by thermal weight loss apparatus（TGA）.The initial decomposition temperature(T_5%)of the slices was found to decrease after the addition of the composite powder,from 403℃ to about 389℃.It can still meet the needs of the spinning process.The observation of the modified PET cross-section by scanning electron microscopy（SEM）proved that the grain fineness of the powder in the obtained modified PET remained below 1μm with good dispersion.Finally,the fluidity of the slices was investigated by melt index（MFI）and it was found that the fluidity of the modified slices increased with the increase of the composite powder.Thus the addition of the composite powder was obtained to improve the crystalline properties and flow properties of the slices.（2）FDY fiber was prepared by melt spinning of modified PET.Investigated were the changed fibers’degree of crystallinity,degree of orientation,and mechanical characteristics.With the addition of the modified powder,it was discovered that the crystallinity,orientation,and mechanical qualities of the fibers deteriorated.The mechanical properties of the modified fibers can still be maintained above 3 c N/dtex when drafted 4 times,which can meet the requirements of the serviceability.SEM analysis revealed that as the amount of composite powder increased,the fiber surface become rougher.The fiber has a larger specific surface area.Additionally,the changed fibers’shrinkage in boiling water and rate of rewetting were examined.The results showed that the boiling water shrinkage and moisture return of the fibers were reduced by the low percentage of the composite powder,as well as the fibers’shrinkage and moisture return when placed in boiling water were enhanced by the high percentage of the composite powder.When 2%of the composite powder was added,the boiling water shrinkage of the modified fibers increased to 15%and the moisture return rate increased to 0.61%,which was connected to the modified fibers’specific surface area and crystallinity.The extinction of the fibers was greatly enhanced,according to a study on the subject,and the absorbance of the modified fibers increased by 16.1%-73.5%and the reflectance by 2.2%-5.5%compared to PET fibers.（3）UV-resistant matte plain fabrics were prepared using a small sample loom.The changes in whiteness,UV protection,washing resistance,breathability and moisture permeability,contact coolness,moisture wicking and quick drying properties,and mechanical properties of the modified fabrics were investigated.The results showed that the whiteness of the fabric increased by 7.4%-18.7%with the addition of the composite powder.The UV protection properties of the modified fabrics were investigated.When the compound powder addition amount reaches 1%,UPF>50+,UVA<5%,when the compound powder addition amount is above 1.5%,it can achieve excellent anti-UV effect in both normal and wet condition.After 30 times of washing experiments,it was found that the modified fabric could still maintain excellent UV resistance,and when the powder with a mass fraction of 2%was added,the UPF of the fabric could reach 435 and the transmission rate in the UVA region was reduced to 3.2%.In the fabric breathable and moisture permeable performance research shows that the composite powder has a small effect on the breathable performance of the fabric,but significantly affects the fabric’s ability to wick away moisture.When the composite powder is added,the moisture permeability first decreases at 0.5%and then increases,which is related to the moisture regain rate and surface roughness of the fiber.The contact coolness of the modified fabric was found to decrease as the roughness of the fabric surface increased.In the study of moisture absorption and quick-drying properties and mechanical properties,it was discovered that the addition of the composite powder marginally improved the fabric’s ability to absorb moisture and dry quickly.Although the mechanical qualities were diminished,the taking was unaffected.It demonstrates how well the modified fabric works with summer garment fabrics.