Mold pressurization as a method to reduce warpage in rotational molding of polyethylene

1990 ◽  
Vol 30 (23) ◽  
pp. 1523-1528 ◽  
Author(s):  
Chih Hung Chen ◽  
James L. White ◽  
Yasuhiko Ohta
Keyword(s):  
Rotational Molding

Computer Controlled Rotational Molding of Liquid Silicone Polymer

1993 ◽  
Vol 8 (2) ◽  
pp. 178-181
Author(s):  
S. H. Teoh ◽  
K. W. Guan ◽  
N. H. Lee ◽  
Y. S. Wong ◽  
A. Y. C. Nee ◽  
...  
Keyword(s):  
Rotational Molding ◽  
Liquid Silicone ◽  
Computer Controlled ◽  
Silicone Polymer

scholarly journals Morphological, thermal and mechanical properties of recycled HDPE foams via rotational molding

2021 ◽  
pp. 0021955X2110137
Author(s):  
Yao Dou ◽  
Denis Rodrigue
Keyword(s):  
Cell Density ◽  
Morphological Analysis ◽  
Mechanical Characterization ◽  
Gradual Increase ◽  
Thermal And Mechanical Properties ◽  
Rotational Molding ◽  
Average Cell Size ◽  
Average Cell ◽  
The Impact ◽  
Recycled Hdpe

In this study, foamed recycled high density polyethylene (rHDPE) parts were produced by rotational molding using different concentration (0 to 1% wt.) of a chemical blowing agent (CBA) based on azodicarbonamide. From the samples produced, a complete morphological, thermal and mechanical characterization was performed. The morphological analysis showed a gradual increase in the average cell size, while the cell density firstly increased and then decreased with increasing CBA content. As expected, increasing the CBA content decreased the foam density as well as the thermal conductivity. Although increasing the CBA content decreased both tensile and flexural properties, the impact strength showed a similar trend as the cell density with an optimum CBA content around 0.1% wt. Finally, neat rHDPE samples were also produced by compression molding. The results showed negligible differences between the rotomolded and compression molded properties indicating that optimal rotomolding conditions were selected. These results confirm the possibility of using 100% recycled polymers to produce rotomolded foam parts.

scholarly journals Valorization of Invasive Plants from Macaronesia as Filler Materials in the Production of Natural Fiber Composites by Rotational Molding

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2220
Author(s):  
Zaida Ortega ◽  
Francisco Romero ◽  
Rubén Paz ◽  
Luis Suárez ◽  
Antonio Nizardo Benítez ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Invasive Plant ◽  
Natural Fiber ◽  
Ricinus Communis ◽  
Local Level ◽  
Natural Fibers ◽  
Fiber Composites ◽  
Filler Materials ◽  
Natural Fiber Composites ◽  
Rotational Molding

This paper compares the mechanical properties of different natural fiber composites produced by rotational molding as a way of waste valorization from campaigns to control invasive plant species in Macaronesia. Rotomolded parts produced with polymeric matrices (polyethylene) and filled with up to 20% by weight of cellulosic fibers obtained from Arundo donax L., Pennisetum setaceum, and Ricinus communis plants were characterized in terms of tensile, flexural, and impact strength. It was found that the sieving of natural fibers allowed for their introduction in higher loadings, from 10 (for un-sieved material) to 20%; fiber size greatly affected the mechanical properties of the final parts, although some combinations were proven not to reduce the mechanical properties of the neat resin. This study is a first approach to the valorization of residues obtained from periodic campaigns of the control of invasive species performed by public authorities, usually at the local level. It is important to highlight that the main objective of this research did not focus on economically profitable activity; instead, it was focused on the reduction of wastes to be disposed from ecosystem maintenance actions and the investment of potential income into preservation policies.

Simplified Version of Polymer Rotational Molding Manufacturing Method

2016 ◽  
Vol 699 ◽  
pp. 97-103 ◽  
Author(s):  
Laurenţiu Slătineanu ◽  
Oana Dodun ◽  
Margareta Coteaţă ◽  
Gheorghe Nagîţ ◽  
Irina Beşliu
Keyword(s):  
Liquid Phase ◽  
Rotation Speed ◽  
Rotational Molding ◽  
Slow Speed ◽  
Molding Process ◽  
Manufacturing Method ◽  
Polyurethane Resin ◽  
Liquid Material ◽  
Complex Equipment ◽  
Plastic Parts

Rotational molding is a manufacturing method which supposes the rotation of the mold, during the solidification of the liquid phase material, so that finally a part having a hollow could be obtained. The method could be applied in manufacturing of metallic and nonmetallic parts. Usually, the equipment for rotational molding ensures slow speed rotating of the mold around two axes placed perpendicularly each other and this fact led to relatively complex equipment for achieving rotational molding. The capacity of the liquid material to entirely cover the internal walls of the mold depends essentially on the liquid material viscosity, on the rotation speed and on the movements applied to the mold. Simplified equipment including a single rotation movement could be materialized. In order to test such a solution, a preliminary experiment was designed and materialized, by using a device adapted on universal lathe. Thus, the objective of the research presented in the paper was to study if it is possible to achieve plastic parts made by rotational molding using a single rotation movement. A polyurethane resin obtained from two liquid components was used in order to obtain the liquid material that could be introduced in the mold. The research results proved the possibility to use simplified equipment for achieving a rotational molding process, at least in certain cases and with some technological limits.

scholarly journals Chemorheological study of DGEBA/IPD system for reactive rotational molding (RRM)

2010 ◽  
Vol 116 (2) ◽  
pp. 969-976 ◽  
Author(s):  
E. Mounif ◽  
V. Bellenger ◽  
P. Mazabraud ◽  
F. Nony ◽  
A. Tcharkhtchi
Keyword(s):  
Rotational Molding ◽  
Reactive Rotational Molding

New models for rotational molding of plastics

1998 ◽  
Vol 38 (9) ◽  
pp. 1387-1398 ◽  
Author(s):  
G. Gogos ◽  
L. G. Olson ◽  
X. Liu ◽  
V. R. Pasham
Keyword(s):  
Rotational Molding ◽  
New Models

MECHANICAL PROPERTIES OF ROTATIONALLY MOLDED PET MICROFIBRIL REINFORCED COMPOSITES

2006 ◽  
Vol 20 (25n27) ◽  
pp. 4613-4618 ◽  
Author(s):  
R. J. T. LIN ◽  
D. BHATTACHARYYA ◽  
S. FAKIROV
Keyword(s):  
Mechanical Properties ◽  
Manufacturing Industry ◽  
Polymer Processing ◽  
Raw Material ◽  
Medium Density ◽  
Reinforced Composites ◽  
Rotational Molding ◽  
Commercial Scale ◽  
Strength And Stiffness ◽  
Set Up

Being a fast growing plastic manufacturing industry, rotational molding has been using the linear polyethylenes extensively as the raw material. As these materials have shown insufficient mechanical properties for certain applications where strength and stiffness of the products are the main concerns, worldwide rotational molders have expressed a need for stronger and stiffer materials to be available for rotomolding. A possible attractive solution may be the recently developed microfibril reinforced composites (MFCs). Blends of linear medium density polyethylene/polyethylene terephthalate (LMDPE/PET) with an MFC structure are manufactured on a commercial-scale set-up and thereafter used in rotational molding. The samples are characterized morphologically and tested mechanically. The results obtained show that the MFC-concept has good application opportunities in the polymer processing including rotational molding.

Rotational molding of compatibilized PA6/LLDPE blends

2020 ◽  
Author(s):  
Rosa Gabriela López GonzalezNúñez ◽  
Roberto Carlos Vázquez‐Fletes ◽  
Pedro Ortega‐Gudiño ◽  
Milton Oswaldo Vázquez‐Lepe ◽  
Denis Rodrigue ◽  
...  
Keyword(s):  
Rotational Molding
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