Abstract: A blow extruder for producing hoses made of plastic material has, at the outlet of its nozzle arrangement for producing hoses, a cooling air nozzle ring which encompasses hoses exiting from the nozzle arrangement and to which air is delivered from a blower. An apparatus for cooling air delivered to the cooling air nozzle ring includes a direct evaporator provided with a refrigeration plant and arranged between the blower and the cooling air nozzle ring. The direct evaporator includes a plate fin element and an injection device for a cooling agent and hot air. The cooling apparatus further includes a regulation device for controlling the temperature of the cooling air by controlling operation of the cooling apparatus.

Abstract: An apparatus for highly intensive cooling of biaxially oriented films from high- and medium-molecular weight thermoplastics using a long neck on a blown film line is described, including: a plastics extruder, a die for forming a tube neck from the extruded plastic, means positioned adjacent the die for externally cooling the tube neck, an expansion zone where the tube neck becomes a bubble, a drag mandrel positioned immediately before the expansion zone for internally contacting, stabilizing and guiding the tube neck, means for continuously providing cool air internally of the tube neck at the expansion zone immediately after the contact, the means including a first tube in communication with a cool air source, and means for continuously removing the cool air that has been heated.

Abstract: A feed bushing for single-screw extruders for the plasticizing extrusion of plastics under a high inertia resistance comprising an outer casing, a grooved bushing enclosed in the outer casing, and a cooling system. The groove bushing is assembled from a tubular grooved inset and a tubular reinforcement surrounding the grooved inset, the inset being shrink-fitted into the reinforcement with such a high shrinkage allowance that the inset is prestressed for pressure by the reinforcement for withstanding the maximum forces of inertia of the screw received in the grooved bushing. The grooved inset of the grooved bushing is made of cemented carbide, a metal oxide or other extremely hard and wear-resistant material. The reinforcement element is made of high-strength ductile steel.