Development Of High Quality Eyeliner Brushes Made Of PBT Fibers

Synthetic fibers are widely used in many modern industrial areas, such as aviation, construction, automobile and public facilities. Eyeliner Pen is one kind of the make-up products, which will be used to write on human skin directly. Therefore chemical synthetic fiber’s applying into eyeliner has a high requirement on safety and performance.An eyeliner brush is usually made of natural fibers and animal hair, because of the poor durability and tendency of adhesion, which are partially replaced by chemical synthetic fibers. In fact, chemical fiber like polyamide has already been introduced to eyeliner brushes, such as nylon6, nylon66. But the nylon fiber curls easily, and has low rigidity, dimensional stability and the moisture regain rate is relatively high, which will lead to unstable ink outlet and adhering easily. In the case of polyester fiber, it has low moisture regain but its high initial modulus will make users uncomfortable, which is not suitable for eyeliner brushes. Polybutylene terephthalate (PBT) fiber is turned out to be an excellent choice for eyeliner brushes and meets the very requires.Polybutylene terephthalate fiber was first developed by the German scientist P.Schlack in1942, which is made from high purity terephthalic acid (TPA) or terephthalic acid methyl ester (DMT) and1,4BDO esterification polycondensation of linear polymer through melt spinning fiber. PBT fiber has merged the excellent mechanical properties of polyester and the softness and abrasion resistance of polyamide, turning out to be very ideal material for eyeliner brushes.Raw material for an eyeliner brush, is usually mixed up by fibers of different length, diameter, taper degree and cross-section shape, which will directly affect the quality of the final products. In this paper, on the premise of a full understanding of eyeliner brush material selection and process, eyeliner brushes were developed by PBT fiber as raw material, and then comprehensive performance tests were carried out under different blending degree and different fiber proportions, including electron microscope observation of cross-section, rigidity evaluation, ink maintenance evaluation and the defective rate evaluation. Results showed the rigidity, ink maintenance and the defective rate were greatly affected by the mixing degree. The higher the mix degree is, the better and more stable properties the brushes get. In addition, with the weight ratio of the fiber with bigger diameter increased, the rigidity of brush also increased.Carrying out comprehensive performance test of mixing degree, rigidity, ink maintenance and the defective rate on the eyeliner brushes may contribute to the development of high-quality eyeliner brushed made of synthetic fiber.