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http://dx.doi.org/10.7473/EC.2012.47.4.336

A Study on the Stress Measurement in a Plastic Product using Chemical Cracking Method  

Won, S.T. (Department of Mechanical System Design Engineering, Seoul National University of Science and Technology)
Kim, T.B. (Department of Mechanical System Design Engineering, Seoul National University of Science and Technology)
Lee, S. (Department of Mechanical System Design Engineering, Seoul National University of Science and Technology)
Won, J.M. (Department of Mechanical System Design Engineering, Seoul National University of Science and Technology)
Cha, K.H. (Department of Mechanical System Design Engineering, Seoul National University of Science and Technology)
Lyu, M.Y. (Department of Mechanical System Design Engineering, Seoul National University of Science and Technology)
Publication Information
Elastomers and Composites / v.47, no.4, 2012 , pp. 336-340 More about this Journal
Abstract
Residual stress in the injection molded part is originated from thermal shrinkage and shear stress during injection molding process. There are many measurement methods of residual stress in the plastic part. Residual stress in opaque products can be measured by chemical cracking test. This method enables the solvent and specimen to react and to cause cracks. Cracks developed according to the level of residual stress. Thus the stresses in plastic part can be quantitatively measured by counting the number of cracks or measuring the size of cracks. Relationship between stress and number of cracks in a plastic specimen has been investigated in this study. Bergen jig was used to give a strain in the specimens those were molded using PC/PBT and PC/ABS. Solvent for the chemical cracking test was prepared using tetrahydrofuran and methyl alcol with the ratio of 1 to 3. Stresses in the specimen can be calculated by strains those were imposed by Bergen jig. Cracks were developed for stress higher than certain level. The number of cracks increased by second order function for stress.
Keywords
residual stress; injection molding; chemical cracking testing; PC/PBT; PC/ABS;
Citations & Related Records
Times Cited By KSCI : 3  (Citation Analysis)
연도 인용수 순위
1 J.S. Hong, S. R. Park, and M.-Y. Lyu, "Measurement of residual stress using photoelasticity and computer simulation of optical characteristics in a transparent injection molded article", Polymer(Korea), 35, 1 (2011).   과학기술학회마을
2 S. H. Cho, J. S. Hong, and M.-Y. Lyu, "Investigation of the molding conditions to minimize residual stress and shrinkage in injection molded preform of PET bottle", Polymer(Korea), 35, 467 (2011).   과학기술학회마을
3 Chaehwan Kim, Sungho Kim, Hwajin Oh, and Jae Ryoun Youn, "Measurement of residual stresses in injection molded parts", Annual conference of the Korean society of automotive engineers, pp. 1982-1985 (2005).
4 Sun-Ho Bang, Sun-Woo Kim, and Eon-Seok Lee, "Measurement of residual stress in polycarbonate using hole-drilling strain gage method", Proceedings of the KSME 2006 fall annual meeting, pp. 7-10 (2006).
5 H. Aben, L. Ainola, and J. Anton, "Integrated photoelasticity for nondestructive residual stress measurement in glass", Optics and lasers in engineering, 33, 49 (2000).   DOI   ScienceOn
6 C.-H. Ma, J,-H. Huang, and Haydn Chen, "Residual stress measurement in textured thin film by grazing-incidence X-ray diffraction", Thin solid films, 418, 73 (2002).   DOI   ScienceOn
7 Jr. R. L. Bergen, "Stress cracking of rigid thermoplastics", SPE Journal, 8, 667 (1962).
8 J. H. Cho, S. R. Park, H. Kim, and M.-Y. Lyu, "Investigation on the residual stress relaxation according to annealing condition for transparent injection molded part", Polymer(Korea), 36, 131 (2012).   과학기술학회마을   DOI   ScienceOn