Numerical Simulation of Compression Molding of UHMWPE

2000 ◽  
Vol 15 (2) ◽  
pp. 194-201
Author(s):  
N. C. Parasnis ◽  
K. Ramani
Keyword(s):  
Numerical Simulation ◽  
Compression Molding

Numerical simulation for flow-induced stress in injection/compression molding

2015 ◽  
Vol 56 (3) ◽  
pp. 287-298 ◽  
Author(s):  
Wei Cao ◽  
Zhiyu Min ◽  
Shixun Zhang ◽  
Tao Wang ◽  
Jing Jiang ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Compression Molding ◽  
Induced Stress ◽  
Injection Compression Molding

Numerical Simulation of Compression Molding of UHMWPE

2000 ◽  
Vol 15 (2) ◽  
pp. 180-193 ◽  
Author(s):  
N. C. Parasnis ◽  
K. Ramani
Keyword(s):  
Numerical Simulation ◽  
Compression Molding

Simulation of Molding Flow of Sheet Molding Compound in Complicated Dies

2008 ◽  
Vol 575-578 ◽  
pp. 422-426
Author(s):  
Qi Lin Mei ◽  
Shi Lin Yan ◽  
Zhi Xiong Huang ◽  
Jian Juan Guo
Keyword(s):  
Numerical Simulation ◽  
Finite Element Method ◽  
Finite Element ◽  
Control Volume ◽  
Compression Molding ◽  
Technological Parameters ◽  
Molding Compound ◽  
Sheet Molding Compound ◽  
Molding Flow ◽  
Control Volume Finite Element

Based on generalized Hele-Shaw(GHS) model, numerical simulation of compression-molding flow of sheet molding compound (SMC) in complicated dies is realized by control volume/finite element method (CV/FEM). Finite element computing and post analysis programs have been written. The flow fronts of SMC charge during compression molding are tracked, and the time needed of mold filling in complicated dies is predicted. The results of simulation are helpful for the placement of SMC charge, the design of mold and the optimization of technological parameters.

Numerical Simulation and Experimental Study of Residual Stresses in Compression Molding of Precision Glass Optical Components

2008 ◽  
Vol 130 (5) ◽  
Author(s):  
Yang Chen ◽  
Allen Y. Yi ◽  
Lijuan Su ◽  
Fritz Klocke ◽  
Guido Pongs
Keyword(s):  
Numerical Simulation ◽  
Residual Stress ◽  
Residual Stresses ◽  
High Volume ◽  
Compression Molding ◽  
Optical Components ◽  
Shape Precision ◽  
Important Quality ◽  
Near Net Shape ◽  
Glass Lenses

Compression molding of glass optical components is a high volume near net-shape precision fabrication method. Residual stresses incurred during postmolding cooling are an important quality indicator for these components. In this research, residual stresses frozen inside molded glass lenses under different cooling conditions were investigated using both experimental approach and numerical simulation with a commercial finite element method program. In addition, optical birefringence method was also employed to verify the residual stress distribution in molded glass lenses. Specifically, optical retardations caused by the residual stresses in the glass lenses that were molded with different cooling rates were measured using a plane polariscope. The measured residual stresses of the molded glass lenses were compared with numerical simulation as a validation of the modeling approach. Furthermore, a methodology for optimizing annealing process was proposed using the residual stress simulation results.

Numerical Simulation Assisted Curve Compensation in Compression Molding of High Precision Aspherical Glass Lenses

2009 ◽  
Vol 131 (1) ◽  
Author(s):  
Fei Wang ◽  
Yang Chen ◽  
Fritz Klocke ◽  
Guido Pongs ◽  
Allen Y. Yi
Keyword(s):  
Numerical Simulation ◽  
High Volume ◽  
Compression Molding ◽  
Quality Parameter ◽  
Experimental Results ◽  
Geometrical Shape ◽  
Molding Process ◽  
Curve Change ◽  
Aspherical Lenses ◽  
Glass Lenses

Compression molding is an effective high volume and net-shape fabrication method for aspherical lenses and precision glass optical components in general. Geometrical deviation (or curve change as often referred to in industry) incurred during heating, molding, and cooling processes is a critically important manufacturing quality parameter. In the compression glass molding process, there are many factors that could lead to curve change in final products, such as thermal expansion, stress and structural relaxation, and inhomogeneous temperature distribution inside the molding machine. In this research, an integrated numerical simulation scheme was developed to predict curve change in molded glass aspherical lenses. The geometrical deviation in the final lens shape was analyzed using both an experimental approach and a numerical simulation with a finite element method program. Specifically, numerical simulation was compared with experimental results to validate the proposed manufacturing approach. The measurements showed that the difference between numerical simulation and experimental results was less than 2 μm. Based on the comparison, the mold curve was revised using numerical simulation in order to produce more accurate lens shapes. The glass lenses molded using the compensated molds showed a much better agreement with the design value than the lenses molded without compensation. It has been demonstrated in this research that numerical simulation can be used to predict the final geometrical shape of compression molded precision glass components. This research provided an opportunity for optical manufacturers to achieve a lower production cost and a shorter cycle time.

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