Geometric Influence of a Molded Part on the Draw Direction Range and Parting Line Locations

1996 ◽  
Vol 118 (1) ◽  
pp. 29-39 ◽  
Author(s):  
M. Weinstein ◽  
S. Manoochehri
Keyword(s):  
Heuristic Rules ◽  
Design Features ◽  
Molded Part ◽  
Draw Direction ◽  
Cavity Design ◽  
Injection Molded

This paper presents a methodology based on the geometry of the injection molded part to identify the draw direction range and parting line locations. These parameters are shown to be a function of the interaction of the outward normals of the surfaces that have been divided into concave and convex regions of the part. This approach can also be applied incrementally to determine these mold parameters for a part as design features are added. The designer can then select from the choices provided to find the optimum parting line location and draw direction using heuristic rules. An absence of an allowable draw direction indicates the presence of an undercut that complicates the mold by requiring a side action so that the mold cost increases. The designer can either redesign the part or accept the undercut by specifying a side core or cavity. Design examples are provided which illustrate the effectiveness of the developed approach.

Geometric Influence of a Molded Part on the Draw Direction Ranges and Parting Line Locations

1994 ◽  
Author(s):  
Marc Weinstein ◽  
Souran Manoochehri
Keyword(s):  
Heuristic Rules ◽  
Design Features ◽  
Molded Part ◽  
Draw Direction ◽  
Cavity Design ◽  
Injection Molded

Abstract This paper presents a methodology based on the geometry of the injection molded part to identify the draw direction range and parting line locations. These parameters are shown to be a function of the interaction of the outward normals of the surfaces which have been divided into concave and convex regions of the part. This approach can also be applied incrementally to determine these mold parameters for a part as design features are added. The designer can then select from the choices provided to find the optimum parting line location and draw direction using heuristic rules. An absence of an allowable draw direction indicates the presence of an undercut which complicates the mold by requiring a side action so that the mold cost increases. The designer can either redesign the part or accept the undercut by specifying a side core or cavity. Design examples are provided which illustrate the effectiveness of the developed approach.

Defect Minimization of an Injection Molded Plastic Component Using Conformal Cooling Channels

2021 ◽  
Vol 1019 ◽  
pp. 205-210
Author(s):  
Deepika S. Singraur ◽  
Bhushan T. Patil ◽  
Vasim A. Shaikh
Keyword(s):  
Performance Parameters ◽  
Cooling Process ◽  
Conformal Cooling ◽  
Cooling Channels ◽  
Molded Part ◽  
Cooling Method ◽  
Conformal Cooling Channels ◽  
Differential Shrinkage ◽  
Injection Molded ◽  
Injection Molded Plastic

The cooling process is an essential aspect while designing for uniform heat transfer between the mold and the molded part. Improper design and placement of cooling channels result in non-uniform cooling and thus results in differential shrinkage and warpage on the final product. The installation of the channels yet plays a crucial role in the cooling of the part. Conforming channels that are placed at an optimum distance from the part to enhance the cooling process. In this paper, the performance parameters of straight drilled channels are compared with the conformal cooling channels for an electric alarm box. The analysis indicates that the conformal cooling method improved and enhanced the cooling process and reduced the defects like warpage and differential shrinkage by 25.5% and 28.0% respectively.

Cavity design method for injection-molded spur gears

2000 ◽  
Vol 14 (1) ◽  
pp. 65-71 ◽  
Author(s):  
Choong Hyun Kim ◽  
Sung-Chul Lee ◽  
Hyo-Sok Ahn ◽  
Tae Hyong Chong
Keyword(s):  
Design Method ◽  
Spur Gears ◽  
Cavity Design ◽  
Injection Molded

Viscoelasticity Effects of Polymeric Material in Micro Injection Molding

2008 ◽  
Author(s):  
Peiman Mosaddegh ◽  
David C. Angstadt
Keyword(s):  
Oscillation Mode ◽  
Polymeric Materials ◽  
Elastic Response ◽  
Cavity Pressure ◽  
Molded Part ◽  
Molded Parts ◽  
Filling Phase ◽  
Injection Molded ◽  
Poly Ethylene ◽  
Peak Value

An experimental study has been carried out to determine the effect of viscoelasticity in comparison to viscosity on micro-injection molded parts. In this study, two different polymeric materials — Polystyrene (PS) as a viscous material and High Density Poly-Ethylene (HDPE) as a viscoelastic material — have been selected to observe the effect of melt elasticity on the filling phase of micro molding based on cavity pressure of molded part. All process parameters except temperature are the same for both polymers. Process temperatures have been selected in order to match the viscosity for both polymers used. Polymer viscosity was characterized at different shear rate and temperature. Viscoelasticity of both polymers were investigated using rotational rheometry in the oscillation mode. The mold geometry with high aspect ratio has been used and the effect of viscoelasticity on cavity pressure has been discussed. It was observed that there is retardation on the response of pressure because of elastic response of material during filling. Despite the differences in slope, peak value, area, and cycle time between two curves, they share similar trends. The only difference is their response during solidifying because of material property.

Effect of Size and Spatial Distribution of Titania Pigments in Injection Molded Parts on Surface Reflectance

2007 ◽  
Author(s):  
B. R. Dantal ◽  
A. Saigal ◽  
M. A. Zimmerman
Keyword(s):  
Spatial Distribution ◽  
Statistical Significance ◽  
Average Diameter ◽  
Area Fraction ◽  
Light Emitting ◽  
Molded Part ◽  
Molded Parts ◽  
Injection Molded ◽  
The Difference ◽  
New Applications

Titania pigments are used in molding compounds as a means to improve opacity by increasing the scattering efficiency of the medium and to develop new applications such as liquid crystal displays (LCD) and light emitting diodes (LED). The characteristics of the injection molded products are a function of molding parameters such as gate location and shear rate. In this study, quantitative measures of the particle distribution of titania pigments in polymer composites have been experimentally determined, including area fraction, average diameter, and diameter volume. A 2 × 3 × 3 ANOVA test has been conducted to assess the statistical significance of these parameters. This study deals with the size and spatial distribution of the particles. The important parameters calculated based on the Feret’s diameter are diameter-volume (dv), diameter-number (dn), and area fraction (AF). The term diameter-volume (dv) has been used to give greater significance to the large particles and thus ‘large’ indicates more and/or larger particles. The parameters have been calculated by using Image-J image processing software. MINITAB has been used to assess the statistical significance of these parameters. The results show that titania particles are not uniformly distributed within the final molded parts and they vary along the molding (longitudinal) and transverse directions of plastic flow. The difference of pigment area fraction and diameter volume at different locations within a final molded part has a significant effect on the percentage reflectance of the surface.

The application of modified PVT data on the warpage prediction of injection molded part

2016 ◽  
Vol 23 (5) ◽  
Author(s):  
Xianjun Sun ◽  
Xuming Su ◽  
Patricia Tibbenham ◽  
Jianghui Mao ◽  
Jie Tao
Keyword(s):  
Molded Part ◽  
Pvt Data ◽  
Injection Molded

The application of fuzzy theory for the control of weld line positions in injection-molded part

2008 ◽  
Vol 47 (1) ◽  
pp. 119-126 ◽  
Author(s):  
Mei-Yung Chen ◽  
Huan-Wen Tzeng ◽  
Yi-Cheng Chen ◽  
Shia-Chung Chen
Keyword(s):  
Fuzzy Theory ◽  
Weld Line ◽  
Molded Part ◽  
Injection Molded ◽  
Line Positions
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