Estudo experimental do processo de rotomoldagem de PELBD: efeitos sobre a morfologia e estabilidade dimensional
| Autor: | Tiago Boni Comisso, Benjamim de Melo Carvalho, Carlos Alberto Silva de Lima |
|---|---|
| Jazyk: | portugalština |
| Rok vydání: | 2013 |
| Předmět: |
Materials science
Organic Chemistry Mineralogy polietileno linear de baixa densidade Rotomoldagem Rotational molding law.invention Linear low-density polyethylene Cross section (physics) Crystallinity Differential scanning calorimetry Optical microscope Flexural strength law Chemical Engineering (miscellaneous) empenamento Composite material Melt flow index |
| Zdroj: | Polímeros v.23 n.1 2013 Polímeros (São Carlos. Online) Associação Brasileira de Polímeros (ABPol) instacron:ABPO |
| Popis: | In the present study the warpage of rotationally molded parts of a linear low density polyethylene (LLDPE) was investigated. The effect from different processing factors such as part thickness, cooling condition and diameter of the venting tube was evaluated. In addition to the rotational molding experiments, an alternative experimental technique, referred to as "Hot Press", was also applied to investigate the warpage of two different grades of LLDPE under typical rotational molding conditions, which means slow cooling from only one side. The crystallinity and spherulitic morphology along the thickness of the rotationally molded parts were studied by Differential Scanning Calorimetry and Polarized Light Optical Microscopy. It is shown that the warpage increases with increasing cooling rate. The increase in diameter of the venting tube is more effective in reducing the warpage of rotationally molded parts, especially for lower cooling rates. In hot press experiments the grade of LLDPE with lower melt flow index and higher flexural strength presented lower warpage. The part thickness affects the warpage in hot press experiments only for faster cooling rates. In general, crystallinity and spherulitic diameter are lower in positions along the cross section of the rotationally molded part where the cooling rate is faster. |
| Databáze: | OpenAIRE |
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