| Abstract [eng] |
Rotational moulding is used to obtain hollow plastic products. By this method it is possible to obtain relatively large volume (> 2 m3) one – piece plastic products (tanks, pontoons, kayaks, outdoor furniture, etc.) with low internal stress values. Linear low density polyethylene (LLDPE) is most popular material to be used in rotational moulding process. This method is widely used in company UAB ,,ENEKA“ for molding LLDPE undergound tanks, manhole covers. Black colored products are the most popular in the market. For this purpose an active filler – black carbon is used. It is mixed with pure LLDPE powder by dry blending method. The LLDPE composition formulations for rotational moulded products is selected according to existing standarts. However, very often moulded parts has defects, such as recesses, cracks, blisters, which are caused by black carbon susceptibility to aggregation and agglomeration. The aim of this work – to determine effective black carbon amount in LLDPE composition for manufacturing of rotational molded products without defects and high mechanical properties. It was determined that LLDPE behavior under tensile, flexural and compressive loading and rheological properties of depend on the black carbon content. Effective filler content is not higer than 1 ppm. In this case the increase in 10 % of mechanical properties is obtained. Simulation of performance conditions for underground tanks showed that 1 ppm of black carbon increases LLDPE tanks resistance to buckling and safety factor increases in 1.5 times. The work was carried out by order UAB ,,ENEKA”. |
