Poly cold-rolling

Another specialty area is coil coating, which involves coating metal coils by continuous operation. Modern roller systems afford speeds of up to 200 m/min. Most coils are made of cold-rolled and surface treated steel, aluminum, or alloys of the latter with manganese or magnesium. Coating systems are based on alkyd or acrylic resins, oil-free polyester, silicone-modified polyester or acrylic resin, poly(vinylidene fluoride), or poly(vinyl fluoride). Water-reducible systems, mainly based on acrylic resins, have been developed for aluminum as well as for steel coils [21-24], Drying is carried out by continuous operation in gas- or oil-heated multichamber ovens. 

Initial adhesion tests were made with 3.5- X 1- X 0.064-inch specimens of aluminum (Aluminum Associates No. 2024) and cold-rolled steel (polished ASTM A-415). Later tests were made with strips of copper, chrome-coated steel (Weirton Steel Co.), and brass with molded nylon 66 bars and with Mylar 300A poly (ethylene terephthalate) film. Before use, the specimens were washed (scrubbed with a soft bristle brush) with a solution of Alconox detergent, rinsed with water, rinsed with acetone, and dried. 

Pipes, film, profiles, cable insulation, and knot-free nets are produced by extrusion. Extrusion with broad slits, for example to produce 20-100-/Ltni-thick film, is a special case. The film is then chilled by cold rolling or by water baths (melt-molding or chill rolling process). Broad slits are also used in what is called the extrusion coating of paper or cardboard with, for example, poly(ethylene). Papers thus treated can then be heat sealed. 

Although most studies of corrosion protection by conjugated polymers utilize the doped (thus conducting) form of the polymer, several studies have been conducted on neutral (undoped) polymers. Most of these studies have utilized the EB form of polyaniKne and include studies on A1 alloys [70,85,86], stainless steel [87], mild steel [88,89], cold rolled steel [90-92], carbon steel [93], and iron [92,94,95]. An undoped poly(2,5-bis(N-methyl-N-hexylamino) phenylene vinylene) or BAMPPV has been studied for the corrosion control of the A1 alloy AA 2024-T3 [96,97]. Little else appears to have been published on the use of other undoped conjugated polymers for corrosion control. 

Fig. 2.5 Effect of mastication by Brabender plastograph on the MWD of bimodal c/>poly-butadiene (1) original (2) 4 min, hot (3) 20 min, hot (4) 25 min, cold (roll mill). Distributions are from sedimentation coefficients obtained by ultracentrifugation [13].

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