Blowing mandrel for extrusion blow-moulding machines

摘要

The invention relates to a blowing mandrel for extrusion blow-moulding machines, having a mandrel upper part with tubular shank and connections for the feed and removal of cooling water, a calibrating sleeve, a cutting sleeve, a cooling pipe surrounding the shank and the calibrating sleeve at a distance to form a cooling inner jacket on the inside, and a blowing tube leading through the mandrel for feeding the blowing air. The blowing mandrel according to the invention is characterised in that the cutting sleeve is arranged between the shank of the mandrel upper part and the calibrating sleeve and is in direct contact on its inside with the cooling water flowing through the cooling inner jacket. The blowing mandrel according to the invention improves the heat dissipation from the cutting sleeve and thereby permits an increase in the operating rate of the blow-moulding machine. The cutting sleeve can be used on both sides and therefore has, overall, a longer life than cutting sleeves that can be used on only one side.