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介绍了压印聚合物材料在不同温度下的力学状态,运用粘弹性材料模型解释了压印材料PMMA在玻璃化温度附近的力学性质及PMMA冷却到玻璃化温度以下时的材料模型。在热压印过程中,PMMA的应力发生了复杂的变化。压印产生的应力在保压阶段不断松弛,随着温度的降低不仅会产生热应力,同时应力松弛时间也会变长,脱模时候的应力状态是由压印、冷却以及材料多种因素决定的。通过粘弹性材料模型分析热压印过程中PMMA的应力变化,运用响应面法拟合应力与工艺参数的数学模型,分析温度对PMMA应力的影响。
The mechanical properties of imprinted polymer at different temperatures are introduced. The viscoelastic material model is used to explain the mechanical properties of PMMA near the glass transition temperature and the material model when PMMA is cooled below the glass transition temperature. During hot stamping, the stress of PMMA undergoes complex changes. The stress generated during stamping is continuously relaxed during the dwell phase. As the temperature decreases, not only the thermal stress but also the stress relaxation time will be longer. The stress state at the time of demolding is determined by embossing, cooling, and material factors of. The viscoelastic material model was used to analyze the stress changes of PMMA. The response surface method was used to fit the mathematical model of stress and process parameters, and the influence of temperature on PMMA stress was analyzed.