Modelling of an innovative liquid rotational moulding process

2017 ◽  
Vol 11 (2) ◽  
pp. 257-267
Author(s):  
Yao Agbessi ◽  
Yves Béreaux ◽  
Jean-Yves Charmeau ◽  
Ronan Le Goff ◽  
Jordan Biglione
Keyword(s):  
Rotational Moulding ◽  
Moulding Process

Rotational Moulding of Liquid Polymers

1996 ◽  
Vol 210 (5) ◽  
pp. 437-447 ◽  
Author(s):  
E Harkin-Jones ◽  
R J Crawford
Keyword(s):  
Ring Opening ◽  
Material Handling ◽  
Bubble Formation ◽  
Rotational Moulding ◽  
Polymer Systems ◽  
Moulding Process ◽  
Cycle Times ◽  
Liquid Polymer ◽  
Liquid Polymers ◽  
Rotationally Moulded

The vast majority of rotationally moulded articles are produced from powdered polymers. However, the moulding process developed originally from the use of liquid polymers and nowadays there is a renewed interest in such systems because of some unique advantages that they offer. This paper compares the behaviour of three different liquid polymer systems—nylon 6 by ring-opening caprolactam, polyvinyl chloride plastisol and polyurethane. The flow behaviour of each material is examined with particular reference to wall thickness distributions and bubble formation in the product. On the basis of this, criteria for the production of fault-free mouldings have been established. The interrelationships between mould shape and resin viscosity are also examined and an ideal viscosity—time—temperature profile is proposed for liquid polymer systems. Finally, a general comparison of the materials is made with regard to material handling, safety, cycle times, etc.

Development of reactive rotational moulding process

2004 ◽  
Vol 33 (1) ◽  
pp. 37-42 ◽  
Author(s):  
N. Corrigan ◽  
E. Harkin-Jones ◽  
E. Brown ◽  
P.D. Coates ◽  
R.J. Crawford
Keyword(s):  
Rotational Moulding ◽  
Moulding Process

Hybrides Rotational-Moulding-Verfahren/Hybrid rotational moulding process – Cost-efficient manufacturing of lightweight components by intrinsic hybridization

2020 ◽  
Vol 110 (07-08) ◽  
pp. 517-520
Author(s):  
Paul Ruhland ◽  
Jonas Nieschlag ◽  
Sven Coutandin ◽  
Jürgen Fleischer
Keyword(s):  
Fibre Composite ◽  
Rotational Moulding ◽  
Lightweight Construction ◽  
Moulding Process ◽  
Hybrid Fibre ◽  
Wide Range ◽  
Hybrid Fibre Composite ◽  
Process Cost ◽  
Cost Efficient ◽  
Efficient Manufacturing

Hybride Faserverbund-Metall-Bauteile für Anwendungen als Antriebswellen, Achsen oder Zug-Druck-Stangen besitzen aufgrund ihres hohen Leichtbaugrades ein enormes Potenzial in den unterschiedlichsten Branchen. In diesem Beitrag wird das Rotational-Moulding-Verfahren vorgestellt, mit welchem derartige Bauteile schnell und kostengünstig hergestellt werden können.   Hybrid fibre-composite metal components for applications as drive shafts, axles or tension-compression rods have enormous potential in a wide range of industries due to their lightweight construction properties. This article presents the rotational moulding process to produce such components quickly and economically.

Effect of Cooling Medium on Fracture Toughness of Rotomoulded Product

2016 ◽  
Vol 852 ◽  
pp. 85-90
Author(s):  
P.L. Ramkumar ◽  
D.M. Kulkarni ◽  
Vikas V. Chaudhari
Keyword(s):  
Fracture Toughness ◽  
Testing Machine ◽  
Compact Tension ◽  
Vital Role ◽  
Point Of View ◽  
Body Parts ◽  
Rotational Moulding ◽  
Agricultural Industry ◽  
Moulding Process ◽  
Cooling Medium

In day-to-day life, usage of plastics is numerous. It offers variety of benefits compared to other materials in various sectors like house hold applications, agricultural industry, and packaging, etc. There are numerous methods for processing plastics. These include: blow moulding, injection moulding, rotational moulding, transfer moulding and thermoforming. Rotational moulding is a competitive alternative to other plastic manufacturing process, since it offers designers an opportunity to achieve an economic production of stress free products. Many products made by rotational moulding process using linear low density polyethylene (LLDPE) are widely used in outdoor applications such as boats, over head tanks, and car body parts etc. In such applications, fracture properties are considered to be critical from the quality characterization point of view. Selection of appropriate cooling medium plays vital role to enhance the quality of rotomolded products. In this paper, an attempt has been made to investigate the effect of cooling medium on fracture toughness of the rotationally moulded products. Fracture tests are carried out on a compact tension (CT) test specimens prepared as per the ASTM D 6068 (2012). The tests are performed on a universal testing machine. R-curve method is used to determine the fracture toughness (JIC) of rotomoulded products. From the experimental results it is found that rapid cooling method favours better fracture toughness of rotomoulded products. Therefore, it is recommended to use faster cooling aids like water cooling in rotational moulding process to achieve highest fracture toughness.

Optimization of the rotational moulding process for polyolefins

2003 ◽  
Vol 217 (3) ◽  
pp. 323-334 ◽  
Author(s):  
M C Cramez ◽  
M J Oliveira ◽  
R J Crawford
Keyword(s):  
Process Control ◽  
Oxidative Degradation ◽  
Antioxidant Systems ◽  
Automatic Process ◽  
Processing Temperature ◽  
Processing Conditions ◽  
Rotational Moulding ◽  
Moulding Process ◽  
Manufacturing Methods ◽  
Plastic Parts

Hollow plastic parts can be made by a number of manufacturing methods, but only rotational moulding offers the ability to create one-piece, stress-free parts with attractive economics. However, the fundamental nature of rotational moulding is such that cycle times are long. Consequently, the plastic is subjected to relatively high temperatures, in the presence of air, for excessive periods of time. This can lead to thermal and oxidative degradation at the inner free surface of the plastic, resulting in a deterioration in the performance of the moulded part. The industry relies heavily on the experience of operators to establish the best processing conditions to avoid degradation, but this is problematic and inefficient. Unfortunately, automatic process control is difficult owing to the complex rotation of the mould. Recent developments highlighting the importance of the peak air temperature inside the mould have been an important step forward, but ever-increasing technical demands on moulders make it clear that more sophisticated process control is needed. It is known that the processing conditions that lead to degradation vary with factors that affect the heating rate, such as the type of mould used and the thickness of the end-product. In the work reported here, a method is proposed for predicting the onset of degradation, on the basis that this occurs when the concentration of antioxidant in the polymer reaches zero. Good agreement has been obtained between the experimental and predicted optimum processing temperature for polyethylenes stabilized with different antioxidant systems. A procedure is described for identifying the best rotational moulding conditions so that more efficient manufacturing methods can be achieved.

A comparative study of mechanical, dynamic mechanical and morphological characterization of tampico and coir fibre-reinforced LLDPE processed by rotational moulding

2020 ◽  
pp. 152808372092936
Author(s):  
SS Abhilash ◽  
D Lenin Singaravelu
Keyword(s):  
Mechanical Properties ◽  
Natural Fibres ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Linear Low Density Polyethylene ◽  
Rotational Moulding ◽  
Polyethylene Matrix ◽  
Moulding Process ◽  
Dynamic Mechanical ◽  
Coir Fibre

Natural fibres find their application as a reinforcing agent for polymer composites to obtain parts with improved mechanical properties. Manufacturing of non-metallic products is incorporated with natural fibres for better strength and to reduce cost. Rotational moulding is a process used for the manufacturing of hollow plastic products, especially water tanks, plastic fuel tanks, barrels, kayaks, refrigerated panels, etc. Incorporation of natural fibres to reinforce polymers in rotational moulding process is a tedious task; since there is no control over fibre and polymer powder mixture, which is rotating bi-axially, it may lead to fibre agglomeration. The present work investigates the mouldability of linear low density polyethylene composites with tampico and coir fibre as the reinforcement agents using a bi-axial rotomoulding machine. NaOH-treated fibres with 5, 10 and 15% by weight have been added to the linear low density polyethylene matrix, and the composites were prepared by rotational moulding process. Mechanical properties such as tensile strength, flexural strength, impact strength and hardness have been investigated. Dynamic mechanical behaviour such as storage modulus, loss modulus and tan  δ of the different composites has been investigated with dynamic mechanical analyser. Fractured surfaces were examined qualitatively with the help of a scanning electron microscope for determining the interfacial properties and fibre adhesion between the fibres and the linear low density polyethylene matrix.

Computer Modelling of the Rotational Moulding Process

1998 ◽  
Vol 17 (14) ◽  
pp. 1307-1318 ◽  
Author(s):  
M. T. Attaran ◽  
E. J. Wright ◽  
R. J. Crawford
Keyword(s):  
Computer Modelling ◽  
Rotational Moulding ◽  
Moulding Process
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