|著者||De-Lung Lai; Gwo-Geng Lin; Chao-Tsai (CT) Huang; Chen-Chieh Wang; Yuan-Jung Chang; Rong-Yeu Chang|
|摘要||In modern life, polymeric optical lens has been utilized in many electronic devices, such as camera, mobile phone, tablet, and other optical devices. Although hundred million lenses are produced annually for these devices, the quality is the key to the main suppliers. Indeed, the optical quality can be affected by the geometric features and/or the optical birefringence. However, how the material’s viscoelasticity influences the optical features is still not fully understood yet. In this study, we have investigated the viscoelastic effects on the optical property of a lens made of Zeonex COP 480R material by the traditional injection molding, simulated with n = 0.4 and * = 217,000 Pa in the Cross model. Results show that if the power-law index (n) was varied from 0.1 to 0.6, the total fringed order has no significant difference, but the fringed patterns were varying dominantly in the perpendicular direction, instead of the flow direction for the case at n = 0.4.
This situation was matched with the distribution of the flow-induced residual stresses. Moreover, if the * in the Cross model was varied from 100,000 Pa to 300,000 Pa, the total fringed patterns were apparently changing from being dominated in the flow direction to being in the direction perpendicular to the flow. The influenced width of the fringed patterns was almost linearly increased with the increasing *. The results can be applied as some guideline for either the further material modifications or the new material developments.
|關鍵字||流變學;黏彈性;雙折射;Cross model;White-Metzner model|