Abstract
In rotational moulding of plastics, improving the mechanical properties without sacrificing the processibility is a challenging task. In this paper, an attempt has been made to investigate the effect of oven residence time on the mechanical properties of the rotationally moulded products made using linear low density polyethylene. Simulation studies were conducted using ROTOSIM software to analyze thermal transitions and phase changes during the process. Degree of curing of the polymers was also assessed and correlated with mechanical properties. Experiments were further conducted to obtain favourable oven residence time to obtain highest mechanical properties. Experimental investigation revealed that there exist regions where the part was ‘under-cured’ and mechanical properties were found to be inferior. It was also found that when parts were ‘over-cured’, the mechanical properties were severely affected. A regime of favourable processing window was identified where the highest tensile, flexural and impact properties were noticed.
Similar content being viewed by others
References
Antonio G and Alfonso M 2004 Powder shape Analysis and sintering behavior of high-density polyethylene powders for rotational molding. J. Appl. Polym. Sci. 92: 449–460
Bharat I C, Elizabeth T and John V 2001 Processing enhancers for rotational molding of polyethylene. Polym. Eng. Sci. 41: 1731–1742
Brent Strong A 2006 Plastics materials and processing. 3rd edn, New jersey, United States: Pearson Education Inc
Crawford R J and James L T 2002 Rotational molding technology. England Norwich: William Andrew Publishing
Crawford R J 1996 Recent advances in the manufacture of plastic products by rotomoulding. J. Mater. Process. Technol. 56: 263–271
Crawford R J 2003 Vision 2020 through 2002. Rotation. 12: 16–19
Crawford R J 1994 Causes and cures of problems during rotomoulding. Rotation 3: 10–14
Run SU, Wang K E, Qin Zhang, Feng Chen and Qiang Fu 2010 Effect of melt temperature on the phase morphology, thermal behavior and mechanical properties of injection-molded PP/LLDPE blends. Chinese J. Polym. Sci. 28: 249–255
Amara Aissa, Carl Duchesne and Denis Rodrigue 2012 Characterization of polymer powder motion in a spherical mold in biaxial rotation. Polym. Eng. Sci. 954–963
Ramkumar P L, Kulkarni D M and Chaudhari V V 2014 Parametric and mechanical characterization of linear low density polyethylene (LLDPE) using rotational moulding technology. Sadhana – Acad. Proc. Eng. Sci. 39: 625–635
Spence A G and Crawford R J 1996 The effect of processing variables on the formation and removal of bubbles in rotationally moulded products. Polym. Eng. Sci. 36: 993–1009
Louise Therese Pick and Eileen Harkin-Jones 2003 An investigation in to relationship between the impact performance of rotationally moulded polyethylene products and their dynamic mechanical properties. Polym. Eng. Sci. 43: 905–918
Marcilla A and Garcia-Quesada J C 2007 Cross linking of rotational molding foams of polyethylene. Polym. Eng. Sci. 47: 1804–1812
Alejandro Benítez, Sanchez J J, Arnal L M and Mülle A 2013 Abiotic degradation of LDPE and LLDPE formulated with a pro-oxidant additive. Polym. Degrad. Stabil. 98: 490–501
Sachin Waigaonkar, Babu B J C and Amit Rajput 2011 A case study of rotational moulding process. Int. J. Six Sigma Compet. Advant. 6: 256–277
Banerjee S, Yan W and Bhattacharyya D 2008 Modeling of heat transfer in rotational molding. Polym. Eng. Sci. 48: 2188–2197
Glomsaker T, Hinrichsen E L, Larsen A, Doshev P and Ommundsen E 2009 Warpage—Crystallinity relations in rotational molding of polypropylene. Polym. Eng. Sci. 49: 523–530
Alongkorn Kanokboriboon 2009 Computer simulation and internal air temperature assist in moulding multi-layer rotationaly moulded parts. Rotation. 5: 66–71
Tan S B, Hornsby P R, McAfee M B, Kearns M P and McCourt M P 2011 Internal cooling in rotational molding—A review. Polym. Eng. Sci. 51: 1683–1692
Abdullah M Z, Bickerton S and Bhattacharyya D 2007 Rotational molding cycle time reduction through surface enhanced molds: Part A—Theoretical study. Polym. Eng. Sci. 47: 1406–1419
Abdullah M Z, Bickerton S, Bhattacharyya D, Crawford R J and Harkin-Jones E 2009 Rotational moulding cycle time reduction using combination of physical techniques. Polym. Eng. Sci. 49: 954–963
Liu S J and Fu K H 2008 Experimental investigation and numerical simulation of the heating/cooling process in rotational molding enhanced with fins. J. Appl. Polym. Sci. 108: 1696–1705
Yan W, Lin R J T, Bickerton S and Bhattacharya D 2003 Rotational moulding of particle reinforced polymeric shell structures. Mater. Sci. Forum 235–238
Crawford R J, Spence A G, Cramez M C and Oliveira M J 2004 Mold pressure control as a tool in rotational molding. Proc. Inst. Mech. Eng. B – J. Eng. 218: 1683–1694
Khouri R M 2004 Reducing cycle time in rotational moulding of plastics. PhD thesis, Queens University of Belfast UK
Crawford R J and Nugent P J 1992 A new process control system for rotational moulding. J. Plast. Rubber Compos. Process. Appl. 7: 23–27
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Ramkumar, P.L., Waigaonkar, S.D. & Kulkarni, D.M. Effect of oven residence time on mechanical properties in rotomoulding of LLDPE. Sādhanā 41, 571–582 (2016). https://doi.org/10.1007/s12046-016-0489-4
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s12046-016-0489-4