Abstract:
A polybutylene terephthalate laminate film having excellent shape memory and high-temperature dimensional stability obtained by (1) subjecting a laminate film comprising a polybutylene terephthalate film and another film or film laminate to a shaping treatment at a temperature T1 equal to or lower than the glass transition temperature of said polybutylene terephthalate while maintaining a first shape; (2) deforming the shaped laminate film to a second shape at a temperature T2 higher than said glass transition temperature; and (3) cooling said laminate film to a temperature T3 equal to or lower than said glass transition temperature.
Abstract:
A plastic film is provided having one or more longitudinal bands with a thickness of 3 μm-50 μm thicker than the main portion of the film. Each thicker band is formed integral with the main portion of the film. Each band is in the form of a single ply. A method for producing the film includes that a molten polymer or polymer composition is extruded in a single ply and cooled, so that a film is formed. The polymer ply is cooled in one or more narrow areas before the main portion of the film is cooled. The narrow cooled areas correspond to the width and position of the thicker longitudinal band or bands. Some typical uses of the film include wrapping pallets and packaging agricultural produce.
Abstract:
A method for manufacturing a film that is provided with markings and is based on a thermoplastic plastic. The thermoplastic plastic is melted in an extruder and emerges from an extrusion die in the form of a melt web. The melt web is conveyed away over a surface of at least one cooling roller and cooled to produce the film. In subregions of the surface of the at least one cooling roller corresponding to the markings, the melt web and/or the film being produced from it is acted on with a different cooling action than in a remainder of the surface.
Abstract:
A method of producing a resin sheet particularly suitably used for a light guide plate positioned on the backside of various display devices or various optical devices, which can give a desired cross-sectional shape when producing a resin sheet with a wide thickness distribution in the width direction upon molding is provided. A sheet-shaped resin material extruded from a die and a backup sheet fed to one side of the resin material are pressed by an emboss roller and a nip roller positioned against the emboss roller in such a manner that the resin material is on the side of the emboss roller and the backup sheet is on the side of the nip roller, thereby transferring projections and depressions on the surface of the emboss roller to the resin material, and the laminate of the resin material and the backup sheet after transfer is wound on a releasing roller positioned against the emboss roller to be released from the emboss roller.
Abstract:
An extrusion die for forming polymeric foam sheets includes a first die body, a second die body, and a manifold within the first die body and the second die body, wherein the manifold includes an inlet to receive polymeric material. The extrusion die further includes a die exit formed by opposing die lips in fluid communication with the manifold and a temperature control zone adjacent the die lips. The extrusion die further includes two generally planar shaping surfaces in proximity to the die exit and place one above and one below the die exit. Adjustable shoes are disposed in proximity to the die exit on each side of the die exit and between the planar shaping surfaces.
Abstract:
A method for producing a tube section from thermoplastic material, in which a tube section is extruded by means of an extruder which is provided with an extruder die having an inner core, which inner core defines an axial hollow space in the tube section, the tube section coming out of the extruder die downstream of the extruder die being internally cooled by means of an internal cooling member and externally cooled by means of an external cooling device. Immediately after the tube section leaves the extruder die, the internal cooling member brings about internal cooling of the tube. The external cooling device is positioned downstream of the internal cooling member, so that the external cooling of the tube section is brought about after the internal cooling.
Abstract:
A blown-film extrusion apparatus for manufacturing a tubular polymer film comprises an extruder; a solidification ring for solidifying a tubular element produced by the extruder and for forming the film by delivering cooling air on the tubular element at a given cooling height, and a film conveyor for conveying the film upwards. The apparatus also comprises a delivery device for projecting correction air on the tubular element, in order to locally correct the thickness of the film, comprising a distribution chamber; a plurality of air delivery members with delivery channels whose delivery mouths are arranged about said axis of the apparatus for projecting correction air partial streams on respective angular correction positions, between the die and the cooling height; flow control elements between the distribution chamber, and the inlet of respective air delivery members, configured for adjusting the flowrate of the respective correction air stream according to an adjustment signal. According to an aspect of the invention, a plurality of separate radial ducts is provided defining respective delivery channels and spaced apart, at an own end portion, by separation spaces, so that the correction air partial streams, after hitting the tubular element in the respective angular correction positions, can flow away from the tubular element through said separation spaces. According to another aspect of the invention, the distribution chamber is defined by an upper ring and by a lower ring connected to each other by means of tight fixed joints with a first substantially cylindrical wall and with a second substantially cylindrical wall arranged around the first cylindrical wall, wherein possible separate radial ducts of the air delivery members protrude from the first cylindrical wall.
Abstract:
A device for cooling products (12) that include an adhesive material that is packaged in a non-adhesive envelope, includes at least one sloped pipe (13) into which flows a cooling liquid that can transport the products, at least one element (20) for evacuating at least a portion of the cooling liquid that is provided in the pipe (13) so as to split the pipe (13) into at least two segments (14, 16), an upstream segment (14) and a downstream segment (14, 16), and at least one element for supplying the downstream segment (16) with cooling liquid.
Abstract:
The present invention provides a process for producing a thermoplastic resin sheet with controlled warpage, the process including extruding a thermoplastic resin sheet, while giving mechanically controlled warpage to the sheet at a position where a temperature of the sheet extruded becomes around a grass transition temperature (Tg) of a thermoplastic resin constituting the sheet. In this production process, the sheet is preferably allowed to pass through a pair of warpage-controlling upper and lower rolls at the position, and the mechanically controlled warpage is preferably given to the sheet by selecting shapes of the warpage-controlling rolls and/or by disposing the warpage-controlling rolls on an upper side or a lower side of a height where a flat sheet is obtained. According to this production process, a thermoplastic resin sheet with controlled warpage can be produced simply and easily with high efficiency.
Abstract:
An optical film composed of a thermoplastic resin film obtained by using a melt extruding machine, characterized in that said thermoplastic resin film satisfies a relation of the formula below over the whole surface of the film when an angle made by the extruding direction of the thermoplastic resin film from the melt extruding machine and a slow phase axis at each point is α, and a retardation amount at each point is Re, is provided. [sin2 2α]×[sin2(π·Re/550)]≦4.0×10−5. According to the present invention, an optical film wherein there is no problem on a residual solvent, optical distortion is small, and there is no problem of color unevenness and color absence of a liquid crystal display obtained by using the optical film as a protective film of a polarizer is provided.