The Natural Weathering Exposure Evaluation Method Of Automobile Plastic Parts

The automobile natural exposure test is an important method to assess the automobile weatherability, the main means of the evaluation is subjective evaluation. The existing subjective evaluation methods in the automotive industry are not suitable for the evaluation of the weather resistance of automotive plastic parts. This paper is based on Hainan Automobile Co. Ltd. "tropical test vehicle project plastic weatherability subjective evaluation method, the main purpose is to evaluate the aging behavior of car plastic parts, to get the comprehensive evaluation value, determine the level of automotive plastic weatherability.Car plastic parts is very much, each model of the plastic parts is different. In order to make the lateral comparability, the paper made a selection and division of the automobile plastic parts which participated in the evaluation. Exterior plastic parts is divided into front, side and rear, the top four positions of 22 s pecific components. Interior plastic parts are divided into the upper, middle and lower three directions, incorporate 29 specific components. Including the plastic parts of the engine compartment and luggage compartment, each car evaluation 57 kinds of plastic parts. According to the degree of attention to these pieces of plastic in the car,which is divided into two layers respectively give weight will be divided into plastic parts of automobile engine compartment parts, exterior parts, interior parts, luggage Parts and other parts, the weights were 10%, 40%, 40% and 10%,especially.The evaluation index of the weather resistance of plastic parts is the aging phenomenon appearing on the macroscopic. The index loss of light, color, stain, mildew, spots, precipitates, and sticky powder, cracking, blistering, peeling, light transmittance decreased, hardening, deformation etc. 14 evaluation. Quantitative scoring method was used to divide the evaluation indexes into 5 gr ades, and the aging degree of grade 0 t o 4 gr adually increased.Integrate evaluation object and evaluation index, fill in the corresponding aging degree, and calculate the comprehensive evaluation value according to the comprehensive evaluation principle. The calculation method of the comprehensive evaluation value is the sum of each single evaluation index grade multiplied by the weight.Because the number of natural light vehicle restrictions, this paper selects 30 vehicles for nearly ten years in the Hainan area of the natural exposure test sample, the plastic parts of aging were statistically calculated 30 car plastic weatherability comprehensive evaluation value, the comprehensive evaluation value in 0 ~ 10. According to the experience of the evaluation value is divided into four levels, the comprehensive evaluation value is less than 2 grade, the comprehensive evaluation value between 2 t o 4 f or the good l evel, the comprehensive evaluation value between 4 t o 6 for the intermediate, the comprehensive evaluation value is greater than 6 for the poor.Finally, this paper takes a test vehicle as an example, a d etailed description of the automobile natural exposure test, comprehensive evaluation value is calculated to verify the feasibility of the method. The method is easy to operate, and the error between the test personnel is small, and the weather resistance of the automobile plastic parts can be evaluated, the comparison among different automobile products can be applied.