Determination of Mold Parting Direction Based on Automatic Molding Feature Recognition

1999 ◽  
Author(s):  
Zhengchao Gu ◽  
Zhenyong Zhou ◽  
Shuming Gao ◽  
Jiaoying Shi
Keyword(s):  
Feature Recognition ◽  
Recognition Algorithm ◽  
Injection Mold ◽  
Automatic Design ◽  
Molded Part ◽  
Molded Parts ◽  
Automatic Feature Recognition ◽  
Parting Direction ◽  
Injection Molded

Abstract Mold parting direction is an important factor to verify the moldability of a molded part. The determination of mold parting direction is the first step to achieve automatic design of an injection mold or a casting die. A method using automatic feature recognition is proposed in this paper to automatically determine parting direction of an injection mold. Parting direction determination of a molded part consists of three steps in our approach. First, all features of a molded part are recognized using a universal hint-based feature recognition algorithm, and all candidate and feasible parting directions of each feature are determined according to the type of the feature. Then, all candidate parting directions of the molded part are automatically generated from all recognized features candidate parting directions. The optimal parting direction is finally chosen based on certain criteria. The case studies on several industrial parts show that the proposed method is effective and efficient in determining the optimal parting direction of injection molded parts.

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.

Study of the Structural Characteristics of Mold for Precise Injection Molding

2011 ◽  
Vol 291-294 ◽  
pp. 610-613
Author(s):  
Hong Lin Li ◽  
Zhi Xin Jia
Keyword(s):  
Injection Molding ◽  
Process Parameters ◽  
Structural Characteristics ◽  
Injection Mold ◽  
Industrial Products ◽  
Balance System ◽  
Molded Parts ◽  
Manufacturing Accuracy ◽  
Injection Molded

With the improvement of accuracy requirements for industrial products, the precise injection molding is replacing the traditional injection molding quickly and widely. Many factors influence the quality of injection-molded parts greatly, such as the property of the plastics, mold structure and the manufacturing accuracy, injecting machine and the injecting process parameters. In this paper, the work is emphasized for the influence of mold structure on the quality of injection-molded parts. Eight portions of injection mold are analyzed, including the cavities and cores, the guide components, the runner system, the ejection system, the side-core pulling mechanism, the temperature balance system, the venting system and the supporting parts. The structural characteristics of the above eight portions are presented.

Study on Improving the Life of Stereolithography Injection Mold

2012 ◽  
Vol 468-471 ◽  
pp. 1013-1016 ◽  
Author(s):  
Hua Qing Lai
Keyword(s):  
Injection Molding ◽  
Injection Molding Process ◽  
Injection Mold ◽  
Molding Process ◽  
Molded Parts ◽  
Injection Molded ◽  
Plastic Parts ◽  
Assembly Operations ◽  
Conventional Injection Molding ◽  
Shape And Size

Molding is one of the most versatile and important processes for manufacturing complex plastic parts. It is a method of fabricating plastic parts by utilizing a mold or cavity that has a shape and size similar to the part being produced. Molten polymer is injected into the cavity, resulting in the desired part upon solidification. The injection-molded parts typically have excellent dimensional tolerance and require almost no finishing and assembly operations. But new variations and emerging innovations of conventional injection molding have been continuously developed to offer special features and benefits that cannot be accomplished by the conventional injection molding process. This study aims to improving the life of stereolithography injection mold.

A Region Based Method to Automated Design of Multi-Piece Molds with Application to Rapid Tooling

2002 ◽  
Vol 2 (2) ◽  
pp. 86-97 ◽  
Author(s):  
Yong Chen ◽  
David W. Rosen
Keyword(s):  
Linear Programming ◽  
Programming Problem ◽  
Linear Programming Problem ◽  
Problem Formulation ◽  
Automated Design ◽  
Rapid Tooling ◽  
Mold Design ◽  
Molded Parts ◽  
Parting Direction ◽  
Injection Molded

Particularly for rapid tooling applications, delivering prototype parts with turn-around times of less than two weeks requires fast, proven mold design methods. We present a region-based approach to automated mold design that is suitable for simple two-piece molds (consisting of core and cavity), as well as molds with many additional moving sections. In our region-based approach, part faces are partitioned into regions, each of which can be formed by a single mold piece. The basic elements of our approach are concave regions (generalized pockets) and convex faces since these elements are central to the identification of regions. This paper focuses on the initial steps of automated mold design, including a problem formulation, methods for identifying the basic elements from part faces, and combining them into regions. By seeking to minimize the number of mold pieces, different partitions of faces into regions are explored until the smallest number of regions is found. During this process, a linear programming problem is adopted for finding a satisfactory parting direction of a region. Algorithms are presented for the region generating and combining process. Our approach is illustrated with several examples of industrial injection molded parts.

Warpage Characterization of Thin and Centrally-Gated Injection Molded Part by Applying Cavity Pressure Measurement

2013 ◽  
Vol 446-447 ◽  
pp. 1099-1103 ◽  
Author(s):  
H. Zamani ◽  
S. Azmoudeh ◽  
K. Shelesh-Nezhad
Keyword(s):  
Radial Flow ◽  
Mold Temperature ◽  
Cavity Pressure ◽  
Injection Speed ◽  
Molded Part ◽  
Pressure Time ◽  
Molded Parts ◽  
Injection Molded ◽  
Thin Disks

Two types of injection molded parts including parts with thin shell feature and parts molded with radial flow pattern are highly susceptible to the warpage. In this research, the warpage performance of a thin and centrally-gated disk was experimentally investigated. The melt pressure-time traces of two different locations inside the mold cavity were monitored by employing piezoelectric transducers. The results indicated that the pressure difference magnitude of melt at two locations along the radial flow path is related to the extent of molded part deformation. Moreover, it was pointed out that the high magnitude of warpage is because of two conflicting actions in the molded part comprising expansion as a result of viscoelastic recovery in the central region, and thermal contraction in the edge region of the thin disk. The molding variables encompassing injection speed, holding pressure, back pressure, mold temperature and screw rotational speed affected the thin disks deformation in order of significance.

scholarly journals The use of IR thermography to show the mold and part temperature evolution in injection molding

2016 ◽  
Vol 36 (1) ◽  
pp. 40-43 ◽  
Author(s):  
Karol Bula ◽  
Leszek Różański ◽  
Lidia Marciniak-Podsadna ◽  
Dawid Wróbel
Keyword(s):  
Injection Molding ◽  
Isotactic Polypropylene ◽  
Infrared Camera ◽  
Mold Temperature ◽  
Temperature Evolution ◽  
Injection Mold ◽  
Ir Thermography ◽  
Molded Parts ◽  
Injection Molded

Abstract This study concerns the application of infrared camera for injection molding analysis by measuring temperatures of both injection molded parts and injection mold cavities in a function of injection cycles. The mold with two cavities, differing in thickness (1 and 3 mm), and a cold direct runner was used. Isotactic polypropylene homopolymer was utilized to produce parts. Mold temperature was set at 22°C and controlled by a water chiller. Five measuring points were determined: SP1, SP2 (placed in the 3 mm cavity), SP3, SP4 (located in the 1 mm cavity) and SP5 around an injection molding gate. Our investigations showed that the highest temperature is localized around SP2 point and the lowest at SP4. Also, it was proved that even after 62 injection molding cycles, temperatures of cavities were not stable, revealing their further increase with each cycle.

Study on the Optimization of Conformal Cooling Channels for Plastic Injection Mold

2012 ◽  
Vol 591-593 ◽  
pp. 502-506
Author(s):  
Ying Ping Qian ◽  
Yong Wang ◽  
Ju Hua Huang ◽  
Xi Zhi Zhou
Keyword(s):  
Injection Mold ◽  
Conformal Cooling ◽  
Cooling Channels ◽  
Conformal Cooling Channels ◽  
Complicated Process ◽  
Molded Parts ◽  
Injection Molded ◽  
Popular Subject ◽  
Plastic Injection

The cooling process of injection molding is a complicated process related to thermodynamics and hydrodynamics, and it has a direct impact on quality and productivity of injection molded parts. With increasing requirements on high quality of injection molded parts, the research on the design of conformal cooling channels of injection mould gradually becomes a popular subject. The paper introduced the process of heat transfer for plastic injection mold with conformal cooling channels and its feature; analysed the optimization of conformal cooling channels; A new set of design methodology and rules is developed.

Study of the effect on conductivity and its uniform distribution in injection molded composite polymer bipolar plate

e-Polymers ◽  
2007 ◽  
Vol 7 (1) ◽  
Author(s):  
Chen Shia-Chung ◽  
Shih Ming-Yi ◽  
Lin Yi-Chang
Keyword(s):  
Flow Direction ◽  
Mold Temperature ◽  
Bipolar Plate ◽  
Surface Conductivity ◽  
Temperature Control System ◽  
Melt Flow ◽  
Molded Part ◽  
Molded Parts ◽  
Fluid Channel ◽  
Injection Molded

AbstractIn this study, PPS blended with as high as 50 wt% carbon fiber were injection molded. Effects of molding conditions as well as the melt flow condition parallel and perpendicular to fluid channel on the surface conductivity was investigated. It was found that mold temperature affects the surface conductivity of molded parts significantly. Using a variable mold temperature control system based on electromagnetic induction heating, the conductivity of the molded part increase by about 152% when the peak mold temperature increases from 120 °C to 210 °C. The channel layout also helps the fiber to orient more randomly leading to an increase in the conductivity. The channel design parallel to melt flow increases the conductivity by 152% and when it is perpendicular to melt flow, the conductivity increases by 95%. Channel layout perpendicular to melt flow direction provides more influence on the fiber reorientation than that of the parallel design.

Sign in / Sign up

Export Citation Format

Share Document