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Mechanical properties of rotomolded parts with abaca fiber: effect of manufacturing with 1, 2 or 3 layers

Ortega Zaida, Suárez Luis, Kelly-Walley Jake, McCourt Mark

Composites Theory and Practice

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2023

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R. 23, nr 3

158--166

EN

The range of materials suitable for rotational molding is not as wide as for other polymer processing technologies. An option to reduce the carbon footprint of such materials is to introduce natural fibers, such as abaca. In this work, different loadings of abaca fibers (5 to 20 % by weight) were molded using one, two and three-layer constructions. A comparison of the mechanical behavior (tensile, flexural, and impact properties) with the fiber content, considering the method of obtaining the composite (1, 2 or 3 layers) was performed. The thermomechanical behavior of the matrix was not affected due to the introduction of the fibers; apart from a reduction in the storage modulus, especially at low temperature, the curves have a similar profile. In general terms, the tensile and flexural strength were not affected by the incorporation of the fibers, that is, the composites exhibit similar behavior to neat polyethylene. Significant improvements in the tensile modulus were obtained for the parts manufactured with 2 layers, with 10 wt.% fiber in the internal one. As expected, the impact strength was reduced for all the composites, although the layer of PE on the inner side that coats the fibers counteracts this reduction to a certain extent. An increase in the heating time was observed for all the composites made in different layers; although the incorporation of fibers slightly modifies the course of the curve, the heating time is only significantly increased for loadings over 10%. The higher energy consumption needed to obtain the part in the different layers would only then be justified by an increase in the composite properties, which is not the case of the parts obtained in this work.

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Maszyna do formowania rotacyjnego : konstrukcja, budowa i analiza działania

Scheffler Christian, Skibicki Dariusz

Developments in Mechanical Engineering

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2022

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nr 18(10)

23--29

PL

Formowanie tworzyw to jedna z ważniejszych, ale jednocześnie i nowych technologii stosowanych w przemyśle tworzyw polimerowych. W pracy zaprezentowano realizację procesu formowania tworzywa termoplastycznego metodą rotacyjną. W tym celu wykorzystano maszynę formującą zaprojektowaną i w całości wykonaną przez dyplomanta Wydziału Inżynierii Mechanicznej. W artykule zamieszczono prezentację projektu oraz prezentację maszyny. Przedstawiono także analizę funkcjonalności urządzenia oraz analizę jakości produktu wytworzonego za jego pomocą.

EN

Molding of plastics is one of the important but also new technologies used in the polymer plastics industry. This paper presents the implementation of the rotational molding process of a thermoplastic material. For this purpose, a forming machine was used, designed and entirely made by a graduate of the Faculty of Mechanical Engineering. The work includes a presentation of the project and the presentation of the machine. The article also presents an analysis of the functionality of the device and an analysis of the quality of the product made with it.

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Effect of mould speed on selected properties of moulded parts and energy consumption in rotational moulding

Głogowska Karolina, Longwic Filip, Ludziak Krzysztof

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2022

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Vol. 70, nr 5

art. no. e143106

EN

This paper deals with rotational moulding. The relationship between mould speed and wall thickness in the upper, middle and lower areas of rotational moulded parts is investigated. Young’s modulus of moulded parts is determined via static tensile testing. A static compression test is performed to determine the maximum compressive force causing strain. The test is conducted on the wall of moulded parts, parallel to the main axis of rotation. Also, energy consumption in rotational moulding is investigated for different rotational speeds of the mould. Moulded parts are made of DOWLEX®2629UE linear low-density polyethylene (LLDPE). Experimental results are statistically analysed using STATISTICA 13. Non-parametric statistical tests are used for results analysis. The ANOVA method is employed to determine if there are any significant differences between obtained results. The statistical tests show that the range is much narrower for a speed ratio of 4:1. The narrowest range value is obtained for 12\3 rpm. The highest Young’s modulus values are obtained for the parts moulded at 12\3 rpm (1263.33 MPa) and 16\4 rpm (1263.67 MPa). The highest maximum compressive force is obtained for the parts moulded at 12\3 rpm (10 400 N). An analysis of the results demonstrates that the part moulded at 12\3 rpm has the most advantageous properties. For this mould speed, the power consumption amounts to 8.28 kWh. Experimental results and statistical analyses demonstrate that mould speed affects both moulded part quality and energy consumption in the rotational moulding process.

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Formowanie rotacyjne tworzyw termoplastycznych. Cz. 1 Charakterystyka ogólna metody

Tomanek H.

Przetwórstwo Tworzyw

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1998

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nr 12

289-294

PL

Przedstawiono technikę formowania wyrobów, zwłaszcza zbiorników, pojemników z tworzyw termoplastycznych w postaci proszku. Forma metalowa, na ogół lekka, blaszana z odpowiednią ilością proszku tworzywowego wykonuje ruchy obrotowe względem dwóch prostopadłych do siebie osi i podlega ogrzewaniu do odpowiedniej temperatury. Tworzywo na skutek kontaktu z podgrzaną ścianką formy osiąga temperaturę topnienia, rozlewa się i przywiera do ścianki. Dzięki obrotom względem dwóch osi osiąga się rozłożenie tworzywa w postaci równomiernej warstwy na wewnętrznej powierzchni formy. Po schłodzeniu, wyrób wyjmowany jest z formy, która wykonana jest, najczęściej jako element dwudzielny.