Effect of melt viscoelastic characteristics on manufacturing precision of in-mold micro assembly molding
Aiming at the functional self-lubricating liquid film assisted in-mold micro assembly molding of the micro univer-sal spherical revolute motion pair,the key technical issue to achieve precise control of its manufacturing accuracy is to clarify the multi field collaborative coupling evolution law among the diameter manufacturing tolerance of the micro as-sembly interface,viscoelastic thermal fluid solid coupling impact load,the thickness of continuous phase transformation evolution zone,thermal viscoelastic plastic stress,and melt viscoelastic characteristics.The research results indicated that the diameter manufacturing tolerance of the micro assembly interface was controlled by the viscoelastic characteristics of the secondary injection molding melt.When the reference viscosity increased from 2 267 to 15 000 Pa·s,the diameter manufacturing tolerance of the micro assembly interface increased by 72.7％from 11 to 19 μm.When the relaxation time increased from 0.05 to 0.25 s,the diameter manufacturing tolerance of the micro assembly interface decreased by 38.7％from 31 to 19 μm.To meet the industry standard of dimensional manufacturing tolerance technical indicators ≤30 μm,it is not advisable to use a high elastic melt with a relaxation time≤0.05 s for the functional self-lubricating liq-uid film assisted in-mold micro assembly molding.
万方数据
维普
