A blown film line and process for making blown film, including an annular extrusion or coextrusion die, a plurality of nip rollers at a location remote from the annular die, a blown film bubble extruding from the annular die and traveling toward the nip rollers along a traveling path, an air cooling apparatus in the vicinity of the annular die, and a water cooling apparatus located downstream from the air cooling apparatus along the traveling path. The water cooling apparatus includes a wet porous material in direct contact with the blown film bubble and surrounding an outer circumference of the blown film bubble. The wet porous material continuously wipes the blown film bubble with water as the blown film bubble moves along the traveling path.

A plastic film of a thermoplastic synthetic resin is made in a film-making system by extrusion from a die of an extruder. First the plastic is melted and extruded from the die as a tube or web that is, typically after cooling and stretching, formed into a package. At least one reference parameter is provided, and, during continuous operation of the system, two input parameters different from the reference parameter are measured by respective measuring devices An output is determined from these reference parameters and is compared with the reference parameter.

A plastic film of a thermoplastic synthetic resin is made in a film-making system by extrusion from a die of an extruder. First the plastic is melted and extruded from the die as a tube or web that is, typically after cooling and stretching, formed into a package. At least one reference parameter is provided, and, during continuous operation of the system, two input parameters different from the reference parameter are measured by respective measuring devices An output is determined from these reference parameters and is compared with the reference parameter.

A strip-shape softened resin sheet (S) which is continuously extruded from a molten resin extruder is cut to a unit resin sheet and a press molded product is manufactured by press-molding the unit resin sheet in a press-molding machine. Prior to cutting the continuously extruded strip-shape softened resin sheet (S) to the unit resin sheet (U) , the slits C.sub.1, C.sub.2, C.sub.3, C.sub.4 and C.sub.5 which promote the molding to the press molded part from the unit resin sheet (U) (improve an inflow property of the material) are formed by a cutter which is upwardly and downwardly driven by an air cylinder at a portion P.sub.3 in which the material therein is out of a range of the press molded products P.sub.1 and P.sub.2 obtained by press-molding the press molded product by using the press molding machine and becomes a scrap. The inflow property of the resin material for vertical walls and embossment portions when press-molding is improved and the defects of the product can be prevented.

A strip-shape softened resin sheet (S) which is continuously extruded from a molten resin extruder is cut to a unit resin sheet and a press molded product is manufactured by press-molding the unit resin sheet in a press-molding machine 20. Prior to press-molding the unit resin sheet (U) by the press-molding machine, the unit resin sheet (U) is heated by a heating machine 16. The heating machine 16 comprises a first heating furnace 84 and a second heating furnace 86. The first heating furnace 84 includes a series of heaters 84-3 and 84-4 whose heat source is infrared ray in a far-infrared region and the second heating furnace 86 includes a series of heaters 86-3 and 86-4 whose heat source is the infrared ray in a middle-infrared region. In the first furnace 84, the unit resin sheet (U) is continuously conveyed with a low velocity and is gradually heated by the far-infrared ray up to temperature which is slightly lower than the temperature which is suitable for press-molding the unit resin sheet (U). In the second furnace 86, the unit resin sheet (U) is stopped and is rapidly heated by the middle-infrared ray. By efficiently heating the unit resin sheet (U), a cycle time can be shortened and the production speed can be improved.

An extrusion system (10) is provided that has first and second extruders (12,14) with first and second extrusion barrels (50,52). First and second extruded components (24,26) are transferred through the barrels (50,52) to a die (22) to coextrude tire tread (20) from the first and second extruded components (24,26). A horizontal plane (70) is located above ground in a vertical direction (40) and extends through both the first extrusion barrel (50) and the second extrusion barrel (52).

An extrusion system (10) is provided that has first and second extruders (12,14) with first and second extrusion barrels (50,52). First and second extruded components (24,26) are transferred through the barrels (50,52) to a die (22) to coextrude tire tread (20) from the first and second extruded components (24,26). A horizontal plane (70) is located above ground in a vertical direction (40) and extends through both the first extrusion barrel (50) and the second extrusion barrel (52).

A production line for manufacturing extruded plates, comprises a conveyor for conveying a semifinished product, an edge cutting device for cutting off an edge area of the semifinished product to present a plate-shaped endless base profile, and a separating device for separating individual plates from the endless base profile. A distance (D) between the separating device and the edge cutting device in the conveying direction is dimensioned such that, between an average temperature T.sub.1 of the semifinished product during cutting of the edge area in the edge cutting device and an average temperature T.sub.2 of the endless base profile during separation, there is a temperature difference T.sub.1−T.sub.2 of 2 K≤T.sub.1−T.sub.2≤15 K. Due to distance (D) within an optimum temperature range, further processing of the cut off edge areas is essentially neutral in terms of installation space.

A production line for manufacturing extruded plates, comprises a conveyor for conveying a semifinished product, an edge cutting device for cutting off an edge area of the semifinished product to present a plate-shaped endless base profile, and a separating device for separating individual plates from the endless base profile. A distance (D) between the separating device and the edge cutting device in the conveying direction is dimensioned such that, between an average temperature T.sub.1 of the semifinished product during cutting of the edge area in the edge cutting device and an average temperature T.sub.2 of the endless base profile during separation, there is a temperature difference T.sub.1−T.sub.2 of 2 K≤T.sub.1−T.sub.2≤15 K. Due to distance (D) within an optimum temperature range, further processing of the cut off edge areas is essentially neutral in terms of installation space.

A method for starting up a production line for manufacturing extruded plates, wherein an extruded semi-finished product comprising a free end is pressed towards a conveying device, wherein the conveying device is configured to pull the semi-finished product to a separating device, wherein a conveyor belt extending in the conveying direction is placed on the conveying device, the free end of the semi-finished product is pressed onto the conveyor belt, the conveyor belt is pulled together with the semi-finished product towards the separating device, and the free end of the semi-finished product arriving at the separating device is introduced into the separating device, while the conveyor belt is pulled away from the semi-finished product upstream of the separating device. This enables a cost-effective production of panels made from the plates.