Control of the uniformity of direct electrical heating for Rotational Moulding

Khan, W. A.; Methven, J.M.

doi:10.1007/978-1-84996-432-6_20

Cited by 6 publications

(5 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Thermograms recorded by a thermocouple in the mold cavity (Figure 2) typically show va kink in the heating curve (point 1); which for semi crystalline polymer powders, corresponds to the beginning of melting. From this point the temperature curve is a semi plateau; which continues to rise gradually until a point (2) where it is accelerated. At this stage the powder bed is depleted; however, the melt is in-homogenous with numerous air bubbles.…”

Section: Process Control For Rotational Molding 21 the Rm Cyclementioning

confidence: 97%

“…Once demolding temperatures are achieved, the finished part is removed from the mold (Figure 1). Heating of the mold can be achieved using a number of means including: convective heat transfer through air inside an oven, direct heating by gas combustion, electric heating elements [2], microwave heating [3] and recently by solar energy [4]. At the cooling station, demolding temperatures are achieved either by rotating the mold in quiescent air, directing streams of cold air and towards it, atomized water evaporative cooling [5] or by using internal cooling mechanisms [6].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Rotational molding: A review of the models and materials

Ogila¹,

Shao²,

Yang³

et al. 2017

Express Polym. Lett.

View full text Add to dashboard Cite

This article surveys recent and not so recent literature in the field of rotational molding. The mechanisms of heat transfer, sintering and bubble removal are evaluated; as are degradation and dimensional stability. The parameters that affect the surface finish are highlighted and a number of the control systems available to the rotational molding process are mentioned. Improvements in molds and machinery, and the extent to which they reduce cycle times are also described. Finally, the range of materials available to the rotational molding process is examined and recent developments are highlighted. Of particular interest is the rotational molding of liquid polymer systems; which are shown to possess great potential for fulfilling many of rotational molding's surface quality requirements while simultaneously reducing cycle times.

show abstract

Section: Process Control For Rotational Molding 21 the Rm Cyclementioning

confidence: 97%

Section: Introductionmentioning

confidence: 99%

Rotational molding: A review of the models and materials

Ogila¹,

Shao²,

Yang³

et al. 2017

Express Polym. Lett.

View full text Add to dashboard Cite

show abstract

“…11 that the temperature field around the mold was more uniform compared with the two former designs. The uniform temperature field guaranteed that the plastic powder absorb heat from hot air efficiently, and it was also beneficial for the plastic powder molding process, the plastic articles manufactured under a uniform temperature field would have a even thickness and good mechanical properties [6] .…”

Section: D Numerical Investigation Of Original Oven Structurementioning

confidence: 99%

“…However, most of the rotational molding machines are designed without a proper temperature field analysis in the oven at present, which might lead to an unevenly distributed temperature field, resulting in a low efficiency and time consuming oven structure. Due to the poor heat transfer between the mold and the ambient hot air, the heating process usually takes about 20 minutes [6] .…”

Section: Introductionmentioning

confidence: 99%

A Numerical Investigation on Temperature Field in the Oven of a Rotational Molding Machine

Guan

Peng

et al. 2013

KEM

View full text Add to dashboard Cite

A simplified 3D model of a rotational molding machine oven was built, and a numerical investigation was carried out with the RNG k-ε approach in FLUENT. Since the temperature field in the original oven structure was distributed unevenly, three types of reformed designs were proposed and numerically studied. Results showed that by changing the inclined angle of inlet flow to 30° downward, hot air flowed onto the mold surface directly, the temperature field around the mold became more uniform but temperature in the bottom of the mold was still a little bit low. By changing the inclined angle of hot air to 30° downward and 45° rightward and leftward, or by changing both the cross sectional dimension of the inlet to 900mm×400mm and the inclined angle of hot air to 30° downward, the temperature field became more uniform and the average temperature around the mold remained relatively high, these two reformed designs were effective with good feasibility and economic efficiency, which could be considered in the future design of rotational molding machine.

show abstract

“…They observed that the experimental and projected optimal processing temperatures for polyethylene that had been stabilised using a variety of antioxidant systems agreed with one another quite well. Liu et al [18] reported on the processing of plastic foam for the creation of LLDPE foams by the use of rotomolding. Their findings pointed out that the majority of blowing agent, heating time, and processing temperature performed a key impact in determining the cell shape in rotational foam moulding.…”

Section: Introductionmentioning

confidence: 99%

Investigating the influence of peak internal air temperature (PIAT) on material characteristics of linear low-density polyethylene (LLDPE) during rotational moulding

Umbare,

Arakerimath

2024

Eng. Res. Express

View full text Add to dashboard Cite

In present study, six samples of ICORENE 1613 LLDPE fuel tank with homogeneous composition were analysed for six different PIAT values of 165°C, 170°C, 180°C, 190°C, 195°C and 200°C in the first stage. In the second phase of the study, the samples with optimum PIAT values were considered for the Tensile and Flexural strength study at different temperatures. Peak Internal Air Temperature (PIAT) values were obtained using the rotolog software, while the tensile and flexural tests were performed utilizing the Universal Testing Machine for accurate characterization of the material properties. The tensile and flexural strength were carried out at three different operating temperatures considering the tank will be subjected to variable operating conditions in real world exercise. Since the measured values for flexural strength and flexural modulus fall outside the acceptance criteria's 200°C PIAT threshold, the highest value of 195°C PIAT is used for further investigation. The failure data obtained from these two destructive testing will be helpful to mitigate the defects during the process. The tensile test results indicate that the LLDPE sample exhibits the maximum tensile strength of 17.3 MPa at 23°C and the highest elongation percentage at failure, which is 182.7% at 80°C. Moreover, the sample shows a remarkable flexural strength of 75.97 MPa at 23°C, which is indicative of its superior ability to resist deformation under applied bending stresses.

show abstract

Control of the uniformity of direct electrical heating for Rotational Moulding

Cited by 6 publications

References 7 publications

Rotational molding: A review of the models and materials

Rotational molding: A review of the models and materials

A Numerical Investigation on Temperature Field in the Oven of a Rotational Molding Machine

Investigating the influence of peak internal air temperature (PIAT) on material characteristics of linear low-density polyethylene (LLDPE) during rotational moulding

Contact Info

Product

Resources

About