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Kim D, Ahn S, Lee KH, Nambiar R, Chung SW, Park SJ, German RM. Gas-assisted powder injection molding: A study about residual wall thickness. POWDER TECHNOL 2013. [DOI: 10.1016/j.powtec.2013.02.032] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Liu SJ, Hsieh MH. Residual Wall Thickness Distribution at the Transition and Curve Sections of Water-assisted Injection Molded Tubes. INT POLYM PROC 2013. [DOI: 10.3139/217.0130] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Abstract
Water-assisted injection molding technology has been used to manufacture plastic tubes in recent years, due to its light weight, relatively lower resin cost per part and faster cycle time. The residual wall thickness around dimensional transitions and curved sections can significantly affect the strength of molded parts and is of great concern. This research investigated the uniformity of the residual wall thickness distribution in water-assisted injection molded circular tubes with dimensional variations and curved sections. Experiments were carried out on an 80-ton injection-molding machine equipped with a lab scale water injection system, which included a water pump, a pressure accumulator, a water injection pin, a water tank equipped with a temperature regulator, and a control circuit. The material used was semi-crystalline polypropylene. It was found that the wall thickness was not uniform near transitions. With the addition of fillets with proper angles around transitions, the uniformity of residual wall could be greatly improved. The residual wall thickness in curved sections was thick around the outer wall and thin around the inner wall. In addition, the experimental results suggest that water-assisted molded parts exhibit a more uniform thickness distribution at transition and curved sections than in gas-assisted molded parts.
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Affiliation(s)
- S.-J. Liu
- Polymer Rheology and Processing Lab., Department of Mechanical Engineering, Chang Gung University, Tao-Yuan, Taiwan
| | - M.-H. Hsieh
- Polymer Rheology and Processing Lab., Department of Mechanical Engineering, Chang Gung University, Tao-Yuan, Taiwan
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Yang JG, Zhou XH. Numerical simulation on residual wall thickness of tubes with dimensional transitions and curved sections in water-assisted injection molding. J Appl Polym Sci 2012. [DOI: 10.1002/app.38394] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Lee K, de Hoyos M, Ahn S, Nambiar R, Gonzalez MA, Park SJ, German RM. Gas-assisted powder injection molding: A study on the effect of processing variables on gas penetration. POWDER TECHNOL 2010. [DOI: 10.1016/j.powtec.2010.02.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Polynkin A, Pittman J, Sienz J. Gas assisted injection molding of a handle: Three-dimensional simulation and experimental verification. POLYM ENG SCI 2005. [DOI: 10.1002/pen.20353] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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