| With the increase of the amount of glass fiber, glass fiber reinforced PA66 will be difficult to generate, easy to fiber floating, surface roughness and other shortcomings, which seriously affect the appearance of products and limit its application. The connecting seat of the automobile rearview mirror, as the car exterior decoration, should denote the good surface quality, no fiber floating accident and be weather resistance. So 60% glass fiber reinforced PA66 composite material is required.According to the requirement of The connecting seat of the automobile rearview mirror, researching group use the twin screw extruder for preparing GF / PA66 composite material, research the amount of glass fiber, viscosity nylon and its varieties, auxiliaries and amount of anti-fiber-exposure, different anti UV additive systems and amount of the mechanical properties of the GF / PA66 composite material and surface quality; the researching group also research the influence of the tensile strength, color and surface morphology in the xenon lamp accelerated aging conditions, different anti UV additive system of GF / PA66 composite material.It was found that when the mechanical properties and heat resistance of glass fiber amount was increased from 10% to 60%, the tensile strength would be increased from 115 MPa to 210 MPa. It is also found that when the thermal deformation temperature was increased from 205℃ to 260℃. Both factors enjoy 1.8 times and 1.26 times increase respectively. And at the same time, the surface quality would be poorer. Moreover, the gloss will be decreased from 71% to 12%. With the decrease of the viscosity of nylon resin, the mechanical properties of GF/PA66 composites material are basically the same, but the surface quality is gradually increased, with matrix resin based on mixture of PA66 24FE2 and PA6 XC030 and glass fiber content of 30%,the gloss can reach 48.2%. When the anti- exposed fiber master batch is added in, it can improve the surface quality of GF / PA66 composite material. when amount of anti- exposed fiber master batch content of increase from 0 to 2.5%,the surface fiber floating phenomenon would be gradually reduced,At the same time, the gloss will be increased from 12% increased to 34%;Mechanical properties, tensile strength, impact strength and bend strength are with an overall upward trend. When its amount reaches 1.5%, there appears the maximum figure and decrease slightly thereafter. When the amount of the anti-fiber-exposure master batch is 2%, composite material has the best overall performance.Under xenon lamp accelerated aging, as the aging time goes, the tensile strength of GF / PA66 composite material will be decreased gradually, and the color gap is gradually increased. Revealed by SEM, the surface of this material gradually cracks and the situation continues to intensify. Anti ultraviolet additives can improve the aging resistance of GF/PA66 composite materials, and delay its aging. When mass percentage of 0.5% of anti UV additive uv-5 is added and 1000 h of xenon lamp irradiation, The color difference of GF/PA66 is(△E)2.8, it will meet the weather resistant requirements of the automotive rearview mirror connecting seat.After analyzing the influence of molding parameters on the surface quality of the connecting seat of the automobile rear view mirror, the research shows that the surface quality of the products is improved gradually with the increase of the temperature, the temperature of the mold, the injection speed and the injection pressure, and the phenomenon of fiber floating is gradually reduced. At the same time, the gloss is increased from 5% to 30%, which obtains the optimal forming process.Based on the analysis above, the GF/PA66 composite material meets the requirements of the automobile rear view mirror connecting seat, and solves the surface quality and weather resistance of the product, so as to realize the product mass production. |
PDF Full Text Request