&lt;title&gt;Injection Molding Of Plastic Optics&lt;/title&gt;

Greis, Ulrich; Kirchhof, Gunther

doi:10.1117/12.934843

Cited by 10 publications

(3 citation statements)

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“…Unido a que el moldeo además permite una alta repetitividad, otros métodos como el torneado o el tallado, más usuales en los vidrios, se utilizan solo en aplicaciones muy concretas. El moldeo es sin embargo una técnica muy compleja y un campo activo de investigación donde el número de parámetros que influyen en el proceso puede ser inusitadamente alto [17]. Dentro del moldeo existen varias modalidades, como el moldeo por inyección, por compresión o técnicas híbridas [18].…”

Section: Fabricaciónunclassified

Optical and physics differential characteristics of optical plastics

et al. 2018

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Optical organic materials, or optical plastics, are raising interest in recent decades thanks to advances in manufacturing processes. It is already common for these materials to be in optical systems, for example in the field of medicine or computer science. However, the characteristics of these compounds have not been as studied as in the case of glasses, and the little available information is widely dispersed. The present revision article tries to compile those most interesting optical and physics differential characteristics of the optical plastics, from the point of view of an optical engineer which must face the design of an optical system.

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Section: Fabricaciónunclassified

Optical and physics differential characteristics of optical plastics

et al. 2018

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“…In the optical field, the use of polymers versus traditional glass is highly desirable since polymers can be easily manufactured into complex shapes, which are lightweight and readily mass-produced via injection molding and other methods [2]. About a hundred years after the first injection molding machines were introduced, the materials and process had advanced sufficiently to allow for the manufacture of precision plastic lenses with qualities that competed with their glass counterparts [3, 4]. This advancement can be credited to several sources, including the development of optical polymers, the improvement of injection molding machines and machine control, the increased understanding of viscoelasticity and rheology of polymers, and the high-quality standards of the injection mold.…”

Section: Introductionmentioning

confidence: 99%

Development of runner reservoir and its effect on optical properties of small high-precision plastic injection molded parts

Shotwell

Lin

Liu

et al. 2023

Plastics, Rubber and Composites

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Adding reservoirs as extensions to a multi-cavity runner-system to regulate cavity fill-rate within small, high-precision optical parts during filling and fill-to-pack switch-over (F/P) was studied with the aid of simulations. This work aimed for a constant melt-front velocity inside the cavities with varying geometries. Three methods of reservoir designs were considered: first, using engineering intuition, second and third, using mass balance and mass and momentum balance equations, respectively. Eight reservoirs were designed and compared to two no-reservoir cases. For each case, 27 runs covering three levels of fill-rate, F/P, and packing pressure were simulated, resulting in 270 simulation runs. The quality variables of flow and thermally induced retardation and the average and standard deviation of volumetric shrinkage were considered and for each parameter, the minimum, best cases, occurred with a reservoir case. Thus, this study offers a proof-of-concept design for using reservoirs to improve molding of small, high-precision optical parts.

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“…[2] About a hundred years after the first injection molding machines the materials and process had advanced sufficiently to allow for the manufacture of precision plastic lenses with optical qualities that competed with their glass counterparts. [3,4] This advancement can be credited to several sources, including the development of optical polymers, the improvement of injection molding machines and machine control, the increased understanding of viscoelasticity and rheology of polymers, and the high-quality standards of the injection molding machine mold. However, there is a limit to the quality improvements that can be obtained in the standard injection molding process due to the inherent properties of the molecular structure of polymers, which cause either geometric or birefringence defects as shown in Figure 1.…”

Section: Introductionmentioning

confidence: 99%

Effect of static mixer on optical properties of plastic injection molded parts

Shotwell

Gim

Yang

et al. 2022

Polymer Engineering & Sci

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The effect of an in‐mold static mixer on the optical properties of polystyrene (PS) parts was explored within the injection molding process. Several mixers were assessed via simulation and molding trials to identify the mixing ability and effect on optical properties including retardation and birefringence. It was found that the static mixers within the runner could successfully mix the polymer and disrupt property distributions including temperature but that there was only a slight improvement in retardation with some of the mixer cases. The experiments and simulations showed relatively good correlation in results although there were slight differences in the trends that could be due to the experimental measurement resolution or unaccounted‐for variables between the experiments and simulations. The retardation was experimentally measured using a custom‐made polariscope using photography and image processing. These experiments indicated that the use of a static mixer within the runner system of a mold could be used for homogenizing the polymer melt after the plasticizing unit. However, its effect on improving the optical performance of injection molded parts could be offset by the melt flow downstream of the static mixer and the potential increase of residual stresses due to flow restriction, suggesting the importance of mixer location and geometry.

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<title>Injection Molding Of Plastic Optics</title>

Cited by 10 publications

References 0 publications

Optical and physics differential characteristics of optical plastics

Optical and physics differential characteristics of optical plastics

Development of runner reservoir and its effect on optical properties of small high-precision plastic injection molded parts

Effect of static mixer on optical properties of plastic injection molded parts

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