JPWO2021074240A5 - - Google Patents

Claims (12)

A method for producing a sealable biaxially oriented polyester monomaterial film (2) stretched in a first direction and a second direction extending perpendicularly to the first direction, the method comprising: steps, i.e.
a) melt extruding a substrate having at least a first layer and a second layer, the first layer of said substrate being a base layer (2.1) and the second layer being a crystalline layer; a melt-extruding step of co-extruding the base layer and the intermediate layer (2.2);
b) then applying a heat-sealable coating layer (2.3) to said substrate by melt coating;
c) The duration of the first heat supply from the coating layer (2.3) to the intermediate layer (2.2) depends on the length of contact of the substrate to the temperature-controlled roller (8) and the physical properties of said coating layer (2.3) with respect to the adhesion strength between said coating layer (2.3) and said intermediate layer (2.2). (2.3) is applied to the intermediate layer at a temperature higher than the melting point or softening point of the intermediate layer (2.2) melted by the coating layer (2.3) at the contact point; influencing the heat supply carried out to said base layer (2.1) through said intermediate layer (2.2) so that the temperature of said base layer (2.1) of the substrate is below its crystallization temperature; the step of
d) after heating said substrate coated with said coating layer (2.3), subjecting said substrate to transverse stretching from a correspondingly elevated temperature level via a timed second heat supply; and,
including methods. 2. The method of claim 1, wherein at least one of the physical properties is the viscosity of the coating layer (2.3). 3. The method according to claim 1, wherein the monomaterial film (2) comprises a multilayer monomaterial, in particular a polyester-based monomaterial. 3. The method according to claim 1, wherein the intermediate layer (2.2) is made extremely thin compared to the base layer (2.3). The coating layer (2.3) has a viscosity of 0.5 to 20000 Pa·s, especially 1 5. The method according to claim 1, wherein the temperature is in the range from 1 to 10 000 Pa.s. 6. The method as claimed in claim 1, wherein one coating layer (2.3, 2.4) is applied to each side of the substrate. 7. The method according to claim 1, wherein a thickness measurement of the substrate is carried out after the coextrusion and a thickness measurement of the monomaterial film (2) is carried out before drawing. 8. The method according to claim 1, wherein the melt coating of the coating layer (2.3) takes place upstream of a longitudinal stretching machine (5). A film stretching apparatus ( 1), comprising the following equipment components:
a) a casting roller unit (3) for coextruding and joining together at least one base layer (2.1) and an intermediate layer (2.2) as substrates;
b) a longitudinal stretching machine (5) capable of longitudinally stretching the base material consisting of the base layer (2.1) and the intermediate layer (2.2) with a first roller system (4);
c) a nozzle for extruding a coating layer (2.3), which is a sealable layer, welded with said intermediate layer (2.2) according to a controllable contact length on said intermediate layer (2.2); A device (6),
i) said nozzle device (6) cooperates with a second roller system (7) which guides said substrate with a predetermined contact length around a temperature-regulated roller (8);
ii) the temperature-regulated rollers (8) include a supply roller (8.1) and a take-off roller (8.2); the substrate is transferred from the supply roller (8.1) to the take-off roller; (8.2),
iii) The coating layer (2.3) is applied to the substrate between the take-off roller (8.2) and the supply roller (8.1) in contact with the take-off roller (8.2). can be supplied to
iv) the adhesion length of the substrate provided with the coating layer (2.3) is controllably variable, and the physical properties of the coating layer for the monomaterial film are controlled by the intermediate layer (2.3); 2.2) and the coating layer (2.3) through the temperature-regulated roller (8) and the length of the adhesion around the roller (8). can be controlled by
a nozzle device (6);
d) a transverse stretching machine (9) capable of drawing and winding the monomaterial film (2) via a third roller system (10);
A film stretching device (1) having: The adhesion length of the monomaterial film (2) comprising the base layer (2.1), the intermediate layer (2.2) and the coating layer (2.3) 10. Film stretching device (1) according to claim 9, which is extendable or shortenable by means of rollers (11). The nozzle device (6) and the second roller system (7) are movable relative to each other, so that the extruded coating layer (2.3) first passes through the take-off roller (8.2). ) and can be fed with the take-off roller (8.2) to the substrate fed to the feed roller (8.1), thereby removing from the coating layer (2.3) Film stretching apparatus (1) according to claim 9 or 10, wherein the heat transfer to the intermediate layer (2.2) is temperature-regulated and controlled. The thickness of the base material after the coextrusion and the bonding of the base layer (2.1) and the intermediate layer (2.2) and the thickness of the monomaterial film (2) before drawing out are The film stretching device (1) according to any one of claims 9 to 11, which is measurable by a thickness measuring device.