Abstract: A heating device having a screw rotatable within a barrel therefor, such as a part of an extruder, especially constructed to circulate and heat a granular or particulate work load of fusible material while still in its particulate condition. The essential purpose is to heat the material to a uniform temperature just under plasticization in preparation for entering melting apparatus, such as a downstream melting section of an extruder. The screw has a core and a main thread defining a main channel in which the portions of the core surface extending side-by-side longitudinally of the channel deviate from an average core diameter throughout the length of the heating device to circulate the work load transversely of the channel and to heat the work load while in a granular condition.

Abstract: Web coating apparatus wherein a liquid coating material is pressure fed upwardly into the nip of rolls rotating in opposite directions through the nip by structure which prevents contact of the coating material with the atmosphere, enables desired temperature control, and enables vacuum degasing of coating material prior to being pressured into a region adjacent to nip. This coating apparatus is particularly suitable for applying molten resinous compositions to webs.