METHOD FOR FORMING THERMOPLASTIC RESIN FILM

• Main Authors: KURIHARA MASATOSHI, OOTAKI TOSHIHIRO, YANAGA SUSUMU
• Format: Patent
• Language: English
• Published: 07.11.1984
• Subjects: AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING; MAKING GRANULES OR PREFORMS; PERFORMING OPERATIONS; PREPARATION OR PRETREATMENT OF THE MATERIAL TO BESHAPED; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIALCONTAINING PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDEDFOR; SHAPING OR JOINING OF PLASTICS; TRANSPORTING; WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE, IN GENERAL

PURPOSE:To form a sheet that is free from bubble traces and is excellent in flatness, by bringing an extruded thermoplastic resin film in firm contact with a cooling roll under pressure by a static electricity application method. CONSTITUTION:A thermoplastic resin is made in the melted state, and is extruded from a mouthpiece 2 having a slit into a film 10. Then it is cooled on a cooling roll 6 to be solidified. During the period from the extrusion to the cooling and solidification, the film is exposed to a pressurized atmosphere in the pressurized chamber 4 that is at or over a gauge pressure of 0.2kg w/cm . The cooling roll 6 is electrically insulated from the earth, the pressurized chamber 4 and the mouthpiece 2, and a high voltage is applied onto the surface of the cooling roll 6 with which the film is brought in firm contact to be cooled. Then the cooled and solidified film is led by nip rolling rubber rolls 9 from the pressurized chamber 4 and is taken out as a film 11.