Diagnosis of injection-molded weld lines in ABS thermoplastic by polarized terahertz reflective imaging. (September 2021)

• Record Type: Journal Article
• Authors: Zhai, Min; Ahmed Mohamed, Esam T.; Locquet, Alexandre; Schneider, G.; Kalmar, R.; Fendler, M.; Declercq, N.F.; Citrin, D.S.
• Is Part Of: NDT & E international. Volume 122(2021)
• Publication Date: 2021-09
• Subjects: Nondestructive testing -- Terahertz radiation -- Ultrasonic imaging -- Injection-molded weld lines -- Birefringence; Nondestructive testing -- Periodicals; Contrôle non destructif -- Périodiques; Electronic journals; 620.1127
• DOI: 10.1016/j.ndteint.2021.102497
• Languages: English
• ISSNs: 0963-8695

Abstract

Abstract: We carry out a nondestructive study of injection-mold weld lines in an acrylonitrile butadiene styrene (ABS) thermoplastic electrical receptacle plate. Terahertz techniques show morphological features at the weld lines and reveal terahertz birefringence properties localized around the welds, indicating frozen-in molecular orientation and stress proximate to the welds. Surface acoustic microscopy corroborates the morphological features at the welds shown by terahertz imaging and also reveals anomalous mechanical properties at the weld lines. These results indicate that THz-based techniques provide nondestructive reliability assessment and quality control for injection-molded thermoplastic products. Highlights: THz imaging and SAM were applied to characterize the injection-molded weld lines in an ABS electrical receptacle plate. V-shaped notches are found in both SAM and THz results. Spatially dependent THz birefringence resulting from the fountain flow in the melt is highly correlated with the weld-line location. THz imaging, in conjunction with SAM, serves as an effective approach for quality control of injection-molded thermoplastics nondestructively.