Isg Technologies Inc.

Weirton Steel Corporation

John A Sinsel

Mark Vincent Loen

Michael S Bailey

Lowell W Austin

Tony Georgetti

Ralph Wilkerson

Kenneth H Speckhals

Eugene J Chelen

Methods and apparatus for producing composite-coated rigid flat-rolled sheet metal substrate in which thermoplastic polymeric materials are selected and combined for dual-layer molten-film extrusion presenting a first-contacting tie-layer and an externally-located finish-layer which are simultaneously extruded for a single substrate surface at-a-time; in which tie-layer selection includes an ethylene-glycol modified PET, requiring a substrate-surface temperature between 230&#xb0; F. and 300&#xb0; F., and a maleic-anhydride modified polyethylene free of any substrate-surface heating requirement; the tie-layer provides sufficient green-strength-adhesion for a finish-layer selected from PBT, PET, and a combination of PBT and PET; each substrate-surface is separately activated for desired adhesion and separately polymeric coated; dual-surface finishing-processing is carried-out by remelting the coated polymeric materials for completing bonding of the dual polymeric layers on each inorganic-metallic protectively-coated surface of the substrate.

Methods and apparatus for production of composite-coated rigid flat-rolled sheet metal substrate

Processes and apparatus for manufacturing an engineered-composite combining rigid flat-rolled sheet metal continuous-strip and selected polypropylene thermoplastics, which are formulated into dual polymeric coating layers for extrusion deposition, as distinct layers, on a single surface at a time, of continuous-strip, traveling in-line at ambient temperature. Steps for forming a uniform thickness of polymeric layers across strip width, and attraction to an activated metallic surface which provides enhanced adhesion. Solidification of the polymeric layers is augmented by strip temperature during continuous-in-line travel; final dual-surface finishing provides for complete bonding of the polymeric layers on both metallic surfaces.

Methods and apparatus for surface preparation and dual polymeric layer coating of continuous-strip flat-rolled sheet metal, and coated product

Method steps and apparatus combinations for continuous in-line polymeric coating of rigid corrosion-protected flat-rolled sheet metal continuous-strip substrate utilizing a thermoplastic polymeric material having adhesive characteristics, capable of molten thin-film extrusion for chemical-bonding with an activated-surface of the flat-rolled sheet metal substrate, and substantially-simultaneously bonding with a solid-film polymeric material, establishing a work-product embodiment with multiple-polymer-layers traveling with the single activated surface; and, on which the solid polymeric film is selected to provide strength, hardness and other desired surface mechanical properties which also provide for external surface coloration, design, weather-proofing, and fabricating capabilities. A second embodiment provides dual-surface multiple-polymeric layer coating carried on by activating and polymeric coating one surface, at a time, of rigid corrosion-protected flat-rolled sheet metal continuous strip substrate.

Extruded molten polymeric film bonding of solid polymeric film to flat-rolled sheet metal continuous strip

A process is provided for making a composite work article suitable for fabricating rigid sheet metal can components. A steel sheet having first and second surfaces is pre-treated to enhance reception and retention of a multi-layer polymer coating on the pre-treated first surface. The multi-layer polymer coating is melt extruded on the pre-treated first surface and beyond opposite lateral edges of the work article to establish overhang portions, then solidified. The multi-layer polymeric coating has a tie polymeric layer contacting the pre-treated first surface, and a finish-surface polymeric layer. The solidified overhang portions are trimmed, and the extruded multi-layer polymeric coating is subjected to finish-treatment, involving heating the extruded multi-layer polymeric coating at least to a melt temperature thereof, then cooling the multi-layer polymeric coating through glass-transition temperature thereof at a sufficiently rapid rate to establish amorphous non-directional characteristics in the polymeric coating.

Polymeric coating formulations and steel substrate composites

Engineered composite coated flat-rolled steel strip is produced in continuous line operations, in which flat-rolled steel strip, free of surface iron oxide, having a metallic corrosion-protective coating, is polymer coated in continuous-line operations in which a plurality of adherent thin-film layers of polymeric material are deposited on a strip surface. In a dual-surface polymeric coating embodiment, each surface is separately-pretreated for surface adhesion, solidified, and polymeric overhang is removed. Finish processing re-melts the polymer coating and rapidly cools that coating through glass-transition temperature to establish amorphous characteristics in the polymeric coating materials. An anhydride-modified polypropylene, first contacts the strip, an intermediate layer can include about fifteen to twenty five percent, by weight, polybutylene with the balance polypropylene; an outer surface polymeric layer includes about five to ten percent, by weight, polybutylene with the balance polypropylene.

Surface preparation and polymeric coating of continuous-strip flat-rolled steel and coated product

Flat-rolled steel strip, free of surface iron oxide, is provided with a corrosion-protection metallic coating on both surfaces, followed by continuous-line polymeric coating operations in which a single surface is pre-treated so as to activate that surface for adhesion of molten extruded thin-film polymeric material for in-line travel. Polymeric materials are formulated to provide maleic-anhydride modified polypropylene, which is melted and pressurized for extrusion as a molten thin-film tie-layer for first contacting that activated surface; and, thin-film intermediate and finish layers are each formulated to contain a selected percentage of polybutylene; which are extruded as molten films in overlaying relationship to said first contacting tie-layer. Polymeric finish-processing re-melts the polymeric materials; and, following a selected interval of in-line travel in that re-melted condition, rapidly cools those polymeric materials through glass-transition temperature so as to establish amorphous characteristics throughout said materials. End-usage product comprise flat-rolled mild steel can stock for fabricating one-piece drawn, and drawn and ironed, can bodies with interior polymeric coating and an exterior corrosive-protection metal coating, such as matte-finish electrolytic tin plate.

Methods and apparatus enabling simultaneous electrolytic tinplating of bottom and top surfaces of continuous-strip flat-rolled steel substrate while moving in the direction of its length, are disclosed. Both surfaces are plated in a first cell of a multi-cell horizontally-oriented tinplating line. The stannous ion plating source and the source of electrical power, for each surface, differ. Tin pellets for an upper surface anode are confined in a solution-permeable material confined, within an electrically-conductive lining. Dissolution of surface iron from the steel strip is substantially eliminated, improving the stannous ion plating solution quality, eliminating requirements for harmful additives, and increasing the variety of electrolytically tinplated continuous-strip steel products and processes.

Electrolytic tinplating of steel substrate and apparatus

A new combination of steel strip electrolytic plating process steps which eliminate iron ion dissolution from continuous-strip steel substrate into chemically-corrosive plating solutions, such as Halogen-bath or methylsulphonic acid plating solutions, of horizontal passline electrolytic tin plating means which plate a single strip surface at a time. The previous use of a cyanide in Halogen-bath tin plating operations which formed a hazardous precipitant (prussian blue) is eliminated by eliminating iron ion dissolution from the steel strip substrate. And conversion of stannous ions to stannic ions, which formed additional Halogen-bath precipitant, is substantially eliminated. Also, new electrolytic plated product, with improved corrosion-prevention characteristics, is provided in which a flat-rolled steel substrate strike-coat of tin and/or nickel is plated simultaneously with electrolytic pickling of such cleansed substrate; pickle-plating is carried out prior to finish-surface electrolytic tin plating in such a horizontal passline electrolytic tin plating means.

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Weirton, WV, United States of America

John A Sinsel