Iso- and variothermal injection compression moulding of polymer micro- and nanostructures for optical and medical applications
Iso- and variothermal injection compression moulding of polymer micro- and nanostructures for optical and medical applications
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DOI：
10.1088/0960-1317/25/6/065008
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发表时间：
2015-06-01
影响因子：
2.3
通讯作者：
Neyer, A.
中科院分区：
文献类型：
--
作者：
Rytka, C.;Kristiansen, P. M.;Neyer, A.
医疗和光学聚合物产品的表面越来越多地使用大量复制方法（如注塑成型）用微米和纳米结构进行功能化。我们比较了填充行为和复制质量的结构，使用四种不同的成型工艺与两种不同的粘度和润湿行为的聚合物。为了这个目的，我们复制了三个代表性的二维和三维微米和纳米结构到聚甲基丙烯酸甲酯和无定形聚酰胺的等温和varieries注射成型与压缩和不压缩，分别使用相同的模具。平行压缩阶段降低了型腔中的内部压力，导致更少的脱模问题，但对复制保真度没有显著影响。模具的可变加热与低粘度和良好润湿行为的聚合物的组合特别有利于高纵横比结构的填充。对于微观结构复制，熔体粘度和无流动温度明显比润湿更相关，因为流动阻力和冷冻层形成是在此长度范围内不完全填充的主要原因。在纳米结构中，取决于聚合物的表面能，毛细管效应变得越来越占主导地位。
The surfaces of medical and optical polymer products are being increasingly functionalized with micro- and nanostructures using mass replication methods like injection moulding. We compared the filling behaviour and replication quality of such structures using four different moulding processes with two polymers of different viscosity and wetting behaviour. For this purpose, we replicated three representative 2D and 3D micro- and nanostructures into polymethylmethacrylate and amorphous polyamide by isothermal and variothermal injection moulding with and without compression, respectively, using the same mould. The parallel compression phase reduced the internal pressure in the cavity, leading to fewer demoulding issues but without significant influence on the replication fidelity. Variothermal heating of the mould in combination with a polymer of low viscosity and good wetting behaviour was favourable especially for filling of high aspect-ratio structures. For microstructure replication, melt viscosity and no-flow temperature were clearly more relevant than wetting as flow resistance and frozen layer formation are the main reasons for incomplete filling at this length scale. In nanostructures, the capillary effect becomes increasingly dominant depending on the surface energy of the polymer.