New approach for the dimensional control of plastic gears manufactured by injection molding in the automotive industry

This paper was aimed at finding out the solution to the problem of insufficient dimensional accuracy caused by non-linear shrinkage deformation during injection molding of small module plastic gears. A practical numerical approach was proposed to characterize the non-linear shrinkage and optimize the dimensional deviation of the small module plastic gears. Specifically, Moldflow analysis was applied to visually simulate the shrinkage process of small module plastic gears during injection molding. A 3D shrinkage gear model was obtained and exported to compare with the designed gear model. After analyzing the non-linear shrinkage characteristics, the dimensional deviation of the addendum circle diameter and root circle diameter was investigated by orthogonal experiments. In the end, a high-speed cooling concept for the mold plate and the gear cavity was proposed to optimize the dimensional deviation. It was confirmed that the cooling rate is the most influential factor on the non-linear shrinkage of the injection-molded small module plastic gears. The dimensional deviation of the addendum circle diameter and the root circle diameter can be reduced by 22.79% and 22.99% with the proposed high-speed cooling concept, respectively.

Download Full-text

New approach for the efficient attainment of flame retardancy using multi component injection molding

10.1063/1.5084851 ◽

2019 ◽

Cited By ~ 1

Author(s):

Dorothea Schneider ◽

Christof Hübner ◽

Serge Bourbigot

Keyword(s):

Injection Molding ◽

Flame Retardancy ◽

New Approach

Download Full-text

Diamond Machinable Sol-Gel Silica Based Hybrid Coatings for High Precision Optical Molds

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.438.65 ◽

2010 ◽

Vol 438 ◽

pp. 65-72 ◽

Cited By ~ 6

Author(s):

Andreas Mehner ◽

Ju An Dong ◽

Timo Hoja ◽

Torsten Prenzel ◽

Yildirim Mutlugünes ◽

...

Keyword(s):

Injection Molding ◽

High Precision ◽

Sol Gel ◽

Processing Parameters ◽

Hybrid Coatings ◽

Optical Elements ◽

Optical Components ◽

New Approach ◽

Free Silica ◽

Gel Processing

The demand for high precision optical elements as micro lens arrays for displays increases continually. Economic mass production of such optical elements is done by replication with high precision optical molds. A new approach for manufacturing such molds was realized by diamond machinable and wear resistant sol-gel coatings. Crack free silica based hybrid coatings from base catalyzed sols from tetraethylorthosilicate (TEOS: Si(OC2H5)4) and methyltriethoxysilane (MTES: Si(CH3)(OC2H5)3) precursors were deposited onto pre-machined steel molds by spin coating process followed by a heat treatment at temperatures up to 800°C. Crack-free multilayer coatings with a total thickness of up to 18 µm were achieved. Micro-machining of these coatings was accomplished by high precision fly cutting with diamond tools. Molds with micro-structured coatings were successfully tested for injection molding of PMMA optical components. The wear resistance of the coatings was successfully tested by injection molding of 1000 PMMA lenses. Hardness and elastic modulus of the coatings were measured by nano indentation. The chemical composition was measured by X-ray photo electron spectroscopy (XPS) as a function of the sol-gel processing parameters.

Download Full-text

Experimental Analysis of Process Parameters to Manufacture Micro-Cavities by Micro-Milling

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.498.91 ◽

2012 ◽

Vol 498 ◽

pp. 91-96 ◽

Cited By ~ 1

Author(s):

J. Gomar ◽

A. Amaro ◽

E. Vázquez ◽

J. Ciurana ◽

C. Rodríguez

Keyword(s):

Automotive Industry ◽

Micro Milling ◽

Geometric Features ◽

Milling Machine ◽

Machining Processes ◽

New Approach ◽

Biomedical Field ◽

Dimensional Errors ◽

Conventional Machining ◽

Potential Opportunity

The use of conventional machining processes has been subject to important decline probably due to the increment in the use of emerging technologies. Therefore, the main applications of these traditional processes, such as automotive industry, are in crisis. In order to have a chance to compete successfully in the new trends, the machining industry must meet the needs of alternative sectors such as biomedical field. The aim of this study is to prove the capacity of micro-milling, by machining complex micro-cavities on aluminum workpiece using a conventional milling machine. Results are obtained by evaluating accuracy and geometric features. This study finds that the feed per tooth is a significant factor in order to obtain better results. The use of coolant increases the tool wear and therefore dimensional errors. This scope is a potential opportunity to reutilize the conventional machines from a new approach.

Download Full-text

A New Approach to Conformal Cooling Channels in Injection Molding Process

DAAAM International Scientific Book 2008 ◽

10.2507/daaam.scibook.2008.50 ◽

2008 ◽

pp. 587-602

Author(s):

H. Park ◽

N. Pham

Keyword(s):

Injection Molding ◽

Injection Molding Process ◽

Molding Process ◽

Conformal Cooling ◽

New Approach ◽

Cooling Channels ◽

Conformal Cooling Channels

Download Full-text

Computer aided design of sequencing problem – the concept of Paint Shop 4.0

Mechanik ◽

10.17814/mechanik.2018.7.74 ◽

2018 ◽

Vol 91 (7) ◽

pp. 529-531

Author(s):

Jolanta Krystek ◽

Sara Alszer ◽

Szymon Bysko

Keyword(s):

Automotive Industry ◽

Computer Aided Design ◽

Industry 4.0 ◽

Paint Shop ◽

Actual Structure ◽

New Approach ◽

Digital Factory ◽

Sequencing Problem ◽

Car Body ◽

Aided Design

Presented is the concept of paint shop operation for the automotive industry – Paint Shop 4.0, based on the ideas of Industry 4.0 and Digital Factory. A new approach to the issue of car body sequencing, taking into account the actual structure of the paint shop department with buffers, has been presented. In the created application, proprietary car body sequencing algorithms were implemented.

Download Full-text

Performance of Injection-Molded Plastic Helical Gears Finished by Hot Rolling

Volume 8: 11th International Power Transmission and Gearing Conference; 13th International Conference on Advanced Vehicle and Tire Technologies ◽

10.1115/detc2011-47426 ◽

2011 ◽

Author(s):

Morimasa Nakamura ◽

Atsushi Katayama ◽

Ichiro Moriwaki

Keyword(s):

Injection Molding ◽

Hot Rolling ◽

Load Capacity ◽

Transmission Error ◽

Tooth Profile ◽

Test Rig ◽

Helical Gears ◽

Injection Molded ◽

Injection Molded Plastic ◽

Plastic Gears

A hot-roll finishing was proposed as a simple finishing method for plastic gears. In the hot-roll finishing, plastic work gears are finished by meshing with a heated copper die wheel. In the previous study, a hot-roll finishing rig for plastic gears was developed, and it was confirmed that tooth profiles of hobbed plastic gears are improved by the finishing. Thus, the hot-roll finishing could also be effective for injection-molded plastic gears. In the present paper, appropriate hot-roll finishing procedures for injection-molded polyoxymethylene (POM) helical gears were pursued. In the injection molding, an inadequate mold easily allows large slope deviations on a tooth profile and trace. The hot-roll finishing can reduce the slope deviations, but induces form deviations especially on the profile. Tests of injection-molded and hot-roll-finished plastic gears were performed on a self-produced gear roller test rig and a self-produced fatigue rig, and a transmission error and load capacity were estimated. Compared with injection-molded gears, hot-roll-finished plastic gears showed small transmission error, while a load capacity was at the almost same level. As a result, the hot-roll finishing is effective for improving a transmission error of injection-molded plastic gears.

Download Full-text