Adhesive bonding and miscellaneous chemical manufacture – Methods – Surface bonding and/or assembly therefor
Reexamination Certificate
1998-11-13
2001-03-13
Sells, James (Department: 1734)
Adhesive bonding and miscellaneous chemical manufacture
Methods
Surface bonding and/or assembly therefor
C156S308200, C156S322000, C156S324000, C156S499000, C156S555000
Reexamination Certificate
active
06200409
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a method and an apparatus for manufacturing a thermoplastic resin coated metal sheet (hereinafter referred to simply as a resin coated metal sheet), which can effect high speed production thereof. More particularly, it relates to a method and an apparatus for manufacturing a resin coated metal sheet, which make it possible to reduce bubbles generated in a laminate when a thermoplastic resin film (hereinafter referred to simply as a resin film) is laminated onto a metal sheet at high speed, and also make it possible to manufacture a resin coated metal sheet having excellent adhesion after forming of a laminated resin film to a metal sheet at high speed.
BACKGROUND OF THE INVENTION
Recently, an increasing amount of material which is prepared by laminating a thermoplastic resin film such as polyester resin film to both surfaces of a metal sheet has been used for heavily formed cans such as drawn cans and drawn and stretch-formed cans. A resin coated metal sheet used for such heavily formed cans is manufactured by a method of heat bonding a resin film to a metal sheet or a method of laminating a resin film into a metal sheet by means of a thermosetting adhesive therebetween. There arises no particular problem in both methods as far as the resin film is laminated on the metal sheet at low speed. However, when the resin film is laminated onto the metal sheet at a high speed of at least 200 m/min., the resultant resin coated metal sheet has bubbles included between the laminated resin film and the metal sheet and a ratio of the thus included bubbles to the resin coated metal sheet comes to about 10 to 30% by an area ratio. Such inclusion of bubbles not only causes decrease in the adhesion after forming of the laminated resin film but also causes surface roughness of the resin coated metal sheet, which results in flaws of the resin coated metal sheet at the time of forming. Therefore, the lamination speed at the time of laminating a resin film to a metal sheet has been limited to a low speed form the view of reducing bubbles at present.
In the method of continuously laminating a resin film onto a metal sheet, various techniques for preventing bubbles from being included between the laminated resin film and the metal sheet have been proposed as follows.
(1) Japanese Patent Laid-open Publication No. HEI-5-269857 discloses a method in which the surface roughness of a metal sheet is set to 0.5 &mgr;m or less, and a space defined by an intermediate roll and a seal roll which are disposed before a pressure roll is conditioned under a reduced pressure of 50 Torr or less.
(2) Japanese Patent Laid-open Publications Nos. HEI-6-8335 and HEI-6-8336 disclose a method in which the diameter of a laminating roll, the thickness of a rubber lining of the laminating roll, and the hardness of the rubber roll are respectively fixed, and a backup roll having a larger diameter than the laminating roll is further provided.
(3) Japanese Patent Laid-open Publication No. HEI-6-270363 discloses a method in which a first pressure roll is a steel roll by which a laminate material is roller with a reduction ratio of 0.5 to 2.0% and a second pressure roll is a rubber lining roll, and the laminate material is press-bonded with a nip width of 10 m or more.
(4) Japanese Patent Laid-open Publication No. HEI-7-186353 discloses a method in which a seal roll for nipping a metal sheet strip is disposed on an upstream side of a pressure roll, and intermediate roll is further provided in contact with these rolls, and a space defined by these rolls is conditioned under a reduced pressure, and a resin film is laminated on the metal sheet strip under such conditions.
(5) Japanese Patent Laid-open Publication No. HEI-7-214724 discloses a method in which a gas is blown from a gas jet nozzle against a surface of a metal sheet, which is advancing, in the opposite direction to the advance direction of the metal sheet directly before a resin film is laminated onto the metal sheet.
Considering the case of laminating a resin film to a metal sheet continuously at high speed, these methods (1) to (5) are not sufficiently suitable as the method of manufacturing a resin coated metal sheet for cans which requires excellent formability.
Therefore, it is the object of the present invention to solve the above mentioned problems in the manufacture of a resin coated metal sheet for cans. That is, the object of the present invention is to provide a method and an apparatus for manufacturing a resin coated metal sheet, which make it possible to reduce bubbles included between a laminated resin film and a metal sheet when the resin film is continuously laminated onto the metal sheet at a high speed of at least 200 m/min. and which make it also possible to impart excellent adhesion after forming to the laminated resin film of the resin coated metal sheet thus manufactured.
DISCLOSURE OF THE INVENTION
The present invention comprises a method of manufacturing a thermoplastic resin coated metal sheet, which includes the steps of heating a metal sheet strip, which advances continuously, to a temperature of or higher than a melting point of a thermoplastic resin film, bringing the thermoplastic resin film into contact with at least one surface of the metal sheet, and nipping the metal sheet and the thermoplastic resin film by a pair of laminating rolls to laminate them, wherein the thermoplastic resin film, which is heated to a temperature of at least a surface temperature of the laminating rolls and below a softening temperature of the thermoplastic resin film, is brought into contact with at least one surface of the metal sheet and the metal sheet and the thermoplastic resin film are nipped by the laminating rolls to be laminated to each other.
The method is characterized in that when said heated thermoplastic resin film is brought into contact with said metal sheet and both are nipped to be laminated to each other by said laminating rolls, said heated thermoplastic resin film and said laminating rolls are made to contact with each other within 0.1 second.
The present invention comprises an apparatus for manufacturing a thermoplastic resin coated metal sheet, which includes metal sheet supplying means for continuously feeding a metal sheet strip, a heating means for heating the metal sheet to a temperature of a least a melting point of a thermoplastic resin film, a pair of laminating rolls, and a thermoplastic resin film supplying means for continuously feeding a thermoplastic resin film between the laminating rolls and the metal sheet, the apparatus further including a thermoplastic resin film heating means for heating the thermoplastic resin film to a temperature of at least a surface temperature of the laminating rolls and below a softening temperature of the thermoplastic resin film directly before the thermoplastic resin film is made to contact with the metal sheet.
The apparatus is characterized in that a first deflector roll is provided between the thermoplastic resin film supplying means and the laminating rolls so as to come into contact with one surface of the thermoplastic resin film and it is movably, disposed so as to permit a winding angle of the thermoplastic resin film around the laminating roll to be changed.
It is further characterized in that the thermoplastic resin film heating means is a heating roll which is disposed between the thermoplastic resin film supplying means and the laminating rolls so as to come into contact with one surface of the thermoplastic resin film.
It is still further characterized in that the heating roll also serves as a deflector roll which is disposed movably in the direction perpendicular to the advance direction of the metal sheet so as to permit the winding angle of the thermoplastic resin film around the laminating roll to be changed.
It is still further characterized in that a second heating means for heating the thermoplastic resin film is provided between the heating roll and the laminating rolls.
It is still further characterized in that the se
Kaguma Noriaki
Sakamoto Yoshiki
Tanaka Atsuo
Browdy and Neimark
Sells James
Toyo Kohan., Ltd.
LandOfFree
Method and apparatus for manufacturing metallic sheet... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and apparatus for manufacturing metallic sheet..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and apparatus for manufacturing metallic sheet... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2547029