9732306 Development of injection molding process by molding. Surface coating for heat insulation - appearance quality improvement of injection molding parts by mold surface coating Chikara Tanaka, Chiaki Asano, Hiraku Hayashi, Shinya Takimura (Mazda Motor Corporation)

JSAE Review ◽  
1998 ◽  
Vol 19 (1) ◽  
pp. 99
Keyword(s):  
Quality Improvement ◽  
Injection Molding ◽  
Surface Coating ◽  
Heat Insulation ◽  
Injection Molding Process ◽  
Mold Surface ◽  
Molding Process ◽  
Appearance Quality

scholarly journals Surface Homogeneity of Injection Molded Parts

2018 ◽  
Vol 62 (4) ◽  
pp. 284-291 ◽  
Author(s):  
László Zsíros ◽  
József Gábor Kovács
Keyword(s):  
Injection Molding ◽  
Evaluation Method ◽  
Solid Phase ◽  
Color Space ◽  
Processing Parameters ◽  
Injection Molding Process ◽  
Mold Surface ◽  
Molding Process ◽  
Molded Parts ◽  
Injection Molded

In this paper we are presenting a novel method for color inhomogeneity evaluation. We proved that this method has a higher than 95 % linear correlation coefficient if results are correlated with human visual evaluations.We applied this evaluation method to analyze the homogenization in the injection molding process, therefore we measured the homogenization properties of various solid phase masterbatches on injection molded parts. We tested the effects of the processing parameters of injection molding and analyzed various dynamic and static mixers as well. We have also measured the influence of the mold surface texture on the sensation of inhomogeneities on the part surface.We have carried out our tests on an injection grade ABS material using various masterbatches. The method was based on the digitization of the molded flat specimens. The images of these specimens were evaluated with an own developed formula using the CIELAB color space resulting high correlation with human visual inspections.

scholarly journals Study on External Gas-Assisted Mold Temperature Control for Improving the Melt Flow Length of Thin Rib Products in the Injection Molding Process

2019 ◽  
Vol 2019 ◽  
pp. 1-17 ◽  
Author(s):  
Phan The Nhan ◽  
Thanh Trung Do ◽  
Tran Anh Son ◽  
Pham Son Minh
Keyword(s):  
Injection Molding ◽  
Temperature Control ◽  
High Efficiency ◽  
Mold Temperature ◽  
Injection Molding Process ◽  
Thin Wall ◽  
Mold Surface ◽  
Melt Flow ◽  
Molding Process ◽  
Flow Length

In the injection molding process, mold temperature control is one of the most efficient methods for improving product quality. In this research, an external gas-assisted mold temperature control (Ex-GMTC) with gas temperature variation from 200°C to 400°C was applied to thin wall injection molding at melt thicknesses from 0.2 to 0.6 mm. The melt flow length was evaluated through the application of this system to the mold of a thin rib product. The results show that the heating process achieves high efficiency in the initial 20 s, with a maximum heating rate of 6.4°C/s. In this case, the mold surface reached 158.4°C. By applying Ex-GMTC to a 0.2 mm flow thickness, the flow length increased from 37.85 to 41.32 mm with polypropylene (PP) material and from 14.54 to 15.8 mm with acrylonitrile butadiene styrene (ABS) material. With the thin rib mold and use of Ex-GMTC, the mold temperature varied from 112.0°C to 140.8°C and the thin rib height reached 7.0 mm.

scholarly journals Hierarchical Structure of iPP During Injection Molding Process with Fast Mold Temperature Evolution

Materials ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 424 ◽  
Author(s):  
Vito Speranza ◽  
Sara Liparoti ◽  
Roberto Pantani ◽  
Giuseppe Titomanlio
Keyword(s):  
Injection Molding ◽  
Surface Temperature ◽  
Hierarchical Structure ◽  
Flow Fields ◽  
Electrical Heating ◽  
Cavity Surface ◽  
Injection Molding Process ◽  
Mold Surface ◽  
Molding Process ◽  
Injection Molded

Mold surface temperature strongly influences the molecular orientation and morphology developed in injection molded samples. In this work, an isotactic polypropylene was injected into a rectangular mold, in which the cavity surface temperature was properly modulated during the process by an electrical heating device. The induced thermo-mechanical histories strongly influenced the morphology developed in the injection molded parts. Polarized optical microscope and atomic force microscope were adopted for morphological investigations. The combination of flow field and cooling rate experienced by the polymer determined the hierarchical structure. Under strong flow fields and high temperatures, a tightly packed structure, called shish-kebab, aligned along the flow direction, was observed. Under weak flow fields, the formation of β-phase, as cylindrites form, was observed. The formation of each morphological structure was analyzed and discussed on the bases of the flow and temperature fields, experienced by the polymer during each stage of the injection molding process.

scholarly journals Effect of Femtosecond-Laser-Structured Injection Molding Tool on Mechanical Properties of the Manufactured Product

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2187
Author(s):  
Krisztián Kun ◽  
Zoltán Weltsch
Keyword(s):  
Mechanical Properties ◽  
Injection Molding ◽  
Femtosecond Laser ◽  
Polymer Surface ◽  
Processing Parameters ◽  
Injection Molding Process ◽  
Mold Surface ◽  
Molding Process ◽  
Melt Temperature ◽  
Polymer Product

During the injection molding process, the melt travels with a flow due to friction. As the velocity of the layers next to the wall is less than that of those flowing in the middle of the channel, a fountain flow is formed at the melt front. The temperature of the polymer surface decreases from the melt temperature to the contact temperature after contacting the mold surface. Based on all this, a complex shell–core structure is formed in injection-molded products, which can be influenced by the processing parameters and the surface of the tool insert. This paper focuses on investigating the effect of the microstructures replicated from the insert to the polymer product on its mechanical properties. During the research, two microstructured surfaces were created, with different effects on the melt flow formed by the femtosecond laser. These were compared with a ground insert to analyze the effects. For examining the effect of technological variables on the mechanical properties, an experimental design was used. The structure created by the femtosecond laser on the surface of the tool influenced the mechanical properties of the polymer products. Recognizing the effect of microstructures on the melt front and, through this, the change in mechanical properties, a predefined polymer product property can be achieved.

scholarly journals Injection Molding of Rubber Compound Influenced by Injection Mold Surface Roughness

2014 ◽  
Vol 1025-1026 ◽  
pp. 283-287 ◽  
Author(s):  
Michal Stanek ◽  
David Manas ◽  
Miroslav Manas ◽  
Martin Ovsik ◽  
Vojtech Senkerik ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Injection Molding ◽  
Flow Characteristics ◽  
Mold Cavity ◽  
Cavity Surface ◽  
Injection Molding Process ◽  
Mold Surface ◽  
Technological Parameters ◽  
Molding Process ◽  
Melt Temperature

Delivery of polymer melts into the mold cavity is the most important stage of the injection molding process. This paper shows the influence of cavity surface roughness and technological parameters on the flow length of rubber into mold cavity. The fluidity of polymers is affected by many parameters (mold design, melt temperature, injection rate and pressures) and by the flow properties of polymers. Results of the experiments carried out with selected types of rubber compounds proved a minimal influence of surface roughness of the runners on the polymer melt flow. This considers excluding (if the conditions allow it) the very complex and expensive finishing operations from the technological process as the influence of the surface roughness on the flow characteristics does not seem to play as important role as was previously thought. Application of the measurement results may have significant influence on the production of shaping parts of the injection molds especially in changing the so far used processes and substituting them by less costly production processes which might increase the competitiveness of the tool producers and shorten the time between product plan and its implementation.

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