Properties and physical structure of cellular PVC coatings
Artykuł w czasopiśmie
MNiSW
15
Lista A
| Status: | |
| Autorzy: | Garbacz Tomasz |
| Rok wydania: | 2014 |
| Wersja dokumentu: | Drukowana |
| Język: | angielski |
| Numer czasopisma: | 2 |
| Wolumen/Tom: | 33 |
| Strony: | 71 - 90 |
| Bazy: | Index Copernicus | SCOPUS | Web of Science |
| Efekt badań statutowych | NIE |
| Materiał konferencyjny: | NIE |
| Publikacja OA: | NIE |
| Abstrakty: | angielski |
| The production of cellular coatings made of polymeric materials by the extrusion process differs from solid coating extrusion in that the polymer produced by the process based on the application of blowing agents has a diphase structure (gas-polymer) with small and evenly distributed gas bubbles. The research described in the paper was conducted using blowing agents with endothermic and exothermic decomposition behaviours, dosed as pellets in the range from 0.4% to 0.8% by weight relative to the weight of the polymer being processed. The extrusion process for modified PVC was conducted using the technological line for the production of electrical cable coatings. The content of the blowing agents applied in the tests in the amount of up to 0.8 wt% was selected in such a way as to produce cables with a solid coating and center coating. The appearance of the produced cable coatings, their thickness and dimensions comply with the current norms. In the investigated range of the blowing agent content, the temperature of the extrudate leaving the head decreased by approximately 7%, which can probably be attributed to the endothermic blowing agent decomposition behaviour in the extruder head. The mechanical properties of cellular products, including their hardness, are affected by the macromolecular shape, orientation and bond. A lower number of cross-linkages in the cellular polymeric material means decreased strength properties of such product. The results of the cellular coating resistance to water and oil absorption have demonstrated considerably increased absorption of the coatings produced, depending on the residence time in the aggressive environment and type of blowing agent applied. Analyzing the results of density, porosity and optical examination of the physical structure of thin-walled cellular coatings, it has been determined that the favourable content of the blowing agent in the polymer should amount to 0.6-0.8 wt%, which leads to density decrease by approximately 40%. |
