Simulations of cyclic transient mold cavity surface temperatures in injection mold-cooling process

Abstract Generally, the strength at the weld line of the injection molded part is very weak. The heat transfer coefficient (HTC) between the polymer melt and the mold cavity surface was analyzed to solve this problem. The surface roughness of the mold cavity and the material of the mold insert were changed to adjust the interface environment between the polymer melt and the mold cavity surface. HTC was obtained by combing the experimental measurement with the theoretical calculation. In the current study, the influence of HTC on the tensile strength of the weld line of the molded specimen was investigated. The results show that the weld line strength of the molded specimen increases with the decrease in HTC between the polymer and the mold cavity surface. Meanwhile, the decrease in the surface roughness of the mold cavity or replacing the mold material with lower thermal conductivity can reduce the value of the HTC between the polymer and the mold effectively and can delay the cooling rate of the hot polymer melt. This provides a new idea to solve thin-wall injection molding weld line defects.

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The Effective Measures of Preventing Collapse Angle Problem in Polishing Plastic Mould

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.538-541.1720 ◽

2012 ◽

Vol 538-541 ◽

pp. 1720-1723

Author(s):

Yi Lei Ren ◽

Hong Qi Lin

Keyword(s):

Preventive Measures ◽

Dimensional Accuracy ◽

Machining Process ◽

Mold Cavity ◽

Cavity Surface ◽

Plastic Model ◽

Plastic Parts ◽

Surface Angle ◽

Plastic Mold

Plastic mold polished, in the mold cavity parting collapsed throwing angle appear, which seriously affect the dimensional accuracy and surface quality of the plastic parts, this article proposed two effective preventive measures: (1) cutting the model which having a same size as plastic model of the cavity at the parting surface, sticking the model and cavity parting with 502 glue together, within the required type of alignment, and then thrown together, polished finish will be a model to out; (2) in the plastic model cavity machining process, type in the mold cavity surface set aside allowance 0.5 ~ 1mm, polished until the cavity is completed, the surface of the cavity type 0.5 ~ 1mm rubbed off with a grinding allowance, it will ensure the cavity size and cavity to prevent the collapse of sub-surface angle at the phenomenon.

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Coated Composite Crosstie Mold Structure Design Used for Experiment with Inventor, Moldflow and Ansys

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.561.196 ◽

2013 ◽

Vol 561 ◽

pp. 196-200

Author(s):

Yu Guang Gong ◽

Zhi Wen Zong ◽

Ying Yu ◽

Bai Yuan Lv

Keyword(s):

Simulation Analysis ◽

Displacement Vector ◽

Processing Parameters ◽

Structure Design ◽

Mold Cavity ◽

Von Mises Stress ◽

Process Conditions ◽

Injection Mold ◽

Injection Process ◽

Von Mises

Coated crosstie products and counter mold components are created in 3-D model using Inventor software, preparing for CAE analysis. By using Moldflow software , to determine products gate location, filling, packing, cooling, push-out processing, as well as the injection process conditions optimization of simulation analysis to find possible defects, modify and optimize the design, determine the best processing parameters and conditions. Binding using Ansys11.0 software to analyze rail sleeper mold cavity deformation, structure stress, get distribution of property of von Mises stress and displacement vector sum, in the mold cavity on the contact surface. By changing the cavity wall thickness, and other factors to improve the force which it is subjected, providing references to structure optimization of injection mold design. It has been proven that in collaborative application of these three softwares, the design of the injection mold is a very efficient and easy.

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Computer simulation of the injection mold cavity filling process

Polimery ◽

10.14314/polimery.2002.122 ◽

2002 ◽

Vol 47 (02) ◽

pp. 122-129 ◽

Cited By ~ 2

Author(s):

ELZBIETA BOCIAGA

Keyword(s):

Computer Simulation ◽

Mold Cavity ◽

Injection Mold ◽

Filling Process ◽

Cavity Filling

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Multi-Objective Optimization of the Heating Rods Layout for Rapid Electrical Heating Cycle Injection Mold

Journal of Mechanical Design ◽

10.1115/1.4001529 ◽

2010 ◽

Vol 132 (6) ◽

Cited By ~ 2

Author(s):

Guoqun Zhao ◽

Xiping Li ◽

Yanjin Guan

Keyword(s):

Temperature Distribution ◽

Injection Molding ◽

Mold Cavity ◽

Electrical Heating ◽

Cavity Surface ◽

Heating Cycle ◽

Multi Objective Optimization ◽

Heating Efficiency ◽

Multi Objective ◽

Distribution Uniformity

Rapid electrical heating cycle injection molding (ERHCM) technology is a promising green manufacturing technology for plastic parts. By using this technology, the defects that usually appear on the surface of conventionally injected parts, such as weld and flow marks, can be avoided effectively. This paper studies rapid electrical heating cycle injection molding technology and its mold structure design techniques. Temperature distribution uniformity and heating efficiency on the mold cavity surface are considered as the major influencing factors on product quality and production efficiency. A multi-objective optimization model for the heating rods layout in the mold cavity plate is formulated to optimize temperature distribution uniformity and heating efficiency with respect to the heating rods layout. An application to a liquid crystal display TV panel is implemented successfully using a genetic algorithm.

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Optimization and application of temperature field in rapid heat cycling molding

Thermal Science ◽

10.2298/tsci210606291h ◽

2021 ◽

pp. 291-291

Author(s):

Mingliang Hao ◽

Haimei Li

Keyword(s):

Injection Molding ◽

Electric Heating ◽

Heating System ◽

Mold Temperature ◽

Temperature Control System ◽

Cavity Surface ◽

Injection Mold ◽

Molding Process ◽

Molded Parts ◽

Automotive Part

The rapid thermal cycle molding (RHCM) belongs to the injection mold temperature control system which is helpful to improve mold ability and enhance part quality. Despite many available literatures, RHCM does not represent a well-developed area of practice. The challenge is the uneven distribution of temperature in the cavity after heating, which mostly leads to defects on the surface of the products. In order to obtain uniform cavity surface temperature distribution of RHCM, the power of heating rods of the electric-heating system in an injection mold was optimized by the response surface method(RSM) in this work. The proposed optimization result was applied to design a complex RHCM injection mold with side core-pulling, holes and different thickness of an automotive part to verify its effectiveness by injection molding. Compared with initial design, the mold temperature uniformity was remarkably improvedby79%. Based on the optimization and injection molding numerical simulation results, the workable molding process to weaken the weld-lines effects on the quality was suggested and the practical injection molded parts were well produced.

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Structural Optimization of a Dual-Sensing Module for Temperature and Pressure Measurement in Injection Mold Cavity

Volume 9: Mechanical Systems and Control, Parts A, B, and C ◽

10.1115/imece2007-42250 ◽

2007 ◽

Author(s):

Zhaoyan Fan ◽

M. Haris Hamid ◽

Robert X. Gao ◽

Stephen Johnston ◽

David Kazmer

Keyword(s):

Interaction Analysis ◽

Polymer Melt ◽

Mold Cavity ◽

Injection Molding Process ◽

Optimized Design ◽

Injection Mold ◽

Molding Process ◽

Optimal Dimension ◽

Fea Model ◽

Sensor Module

This paper presents the design and optimization of a temperature-pressure sensing module that is structurally integrated into an injection mold. The sensor extracts energy from the polymer melt pressure differential during the injection molding process and uses ultrasonic pulses as the wireless information transmission carrier. The dimension of the piezo ceramic rings that scavenge energy from the mold pressure change is optimized to minimize the volume of the sensor while maintaining the minimum Signal-to-Noise Ratio (SNR) required for reliable signal reception. An analytical expression of the optimal dimension is presented. Based on the optimized design, the sensor module package, together with the injection mold steel and the polymer melt that flows over the sensor into the mold cavity, was modeled using the finite element method. To quantify the behavior of polymer melt and its effect on sensors output, a coupled fluid-structure interaction analysis was performed to examine the mold-melt interface, by using the solution-looping and mesh-morphing techniques. A case study of the sensor design for a 40 mm thick injection mold was investigated by using the presented optimization method and FEA model. Results show that the volume of the piezo stack can be reduced to 0.7 cm3 while meeting the minimum SNR requirement. The minimum insulator thickness of 1 mm is presented by the FEA model to maintain the thermal induced error below 0.5%.

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