白车身发泡材料膨胀性能研究

Research on Expansion Properties of Body-In-White Foam Part

通过某高端车型车身使用的以乙烯-醋酸乙烯酯共聚物为基材的发泡材料测试,获取其在温度时间下的膨胀性能曲线。试验表明,该发泡材料产生膨胀的门槛温度为120℃,当<120℃时,发泡材料不产生膨胀。随着温度升高,膨胀至临界状态所需的时间降低。达到相同膨胀率,间隔加热比连续加热所需的时间更长。基于试验制定热循环曲线,为烤箱停机时制定维修策略和判断过烘烤车身是否合格提供数据依据。

Through the foam material test based on ethylene-vinyl acetate copolymer used in the Body-In-White(BIW)of a high-end model,the expansion performance curve of ethylene-vinyl acetate was obtained.The test shows that the threshold temperature for expansion of the foam material is 120°C,and when it is lower than 120°C,the foam material does not expand.As the temperature increases,the time required to expand to a critical state decreases.To achieve the same rate of expansion,interval heating takes longer than continuous heating.The thermal cycle curve is formulated based on the test,which provides a data basis for formulating a maintenance strategy and judging whether the over-baked BIW is qualified when the oven is stopped.