Production of expanded polyolefin beads
AssigneeBASF SE
InventorsJurgen Schweinzer, Joachim Fischer, Isidoor De Grave, Wolfram Kogel
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Abstract
The invention relates to a process for the production of expanded polyolefin beads by impregnating polyolefin particles with volatile blowing agents in a fluidized bed.
Claims7
A process for the production of expanded polyolefin beads by impregnating polyolefin particles with volatile blowing agents at a temperature at most 50.degree. C. below and at most 30.degree. C. above the crystallite melting point of the polyolefin, the crystallite melting point being the maximum of the DSC curve obtained by heating from 3 to 6 mg of the polyolefin granules to 220.degree. C. at a heating rate of 20.degree. C./min, by means of a differential calorimeter, which comprises fluidizing particulate propylene or ethylene polymers under pressure in a fluidized bed and at the same time impregnating them with a blowing agent which is gaseous at the selected temperature, and expanding the impregnated polyolefin particles by decompression.
Dependencies are inferred from the claim text.