Rotary Screen Printing

This is a clever modification of flat silk screen printing. The paste adhesive is fed in the center of a rotary perforated drum, it is pumped through a hollow doctor blade into the rotating screen stencil and then through the holes in the drum and applied onto a web or fabric (Fig. 64). The web or fabric is running over a counter roller coated with rubber. 

This technique is used mostly for hot melt adhesives now (Microprint machines from Graco, Varidot applicator from Loctite (Fig. 66) for instance). 

The fluid adhesive is pumped into a trough or a slot die, and it flows as a vertical curtain from this trough, on the panels or sheets to be coated, which move on a horizontal conveyor (Fig. 67). The excess of adhesive, on the sides or between two successive panels or sheets, is recycled in the adhesive tank. The top tank is V-shaped, with an adjustable slot orifice at the bottom. 

In some modem curtain coaters, the top tank is a small volume chamber equipped with a rotating double knife. It may apply a thin film of adhesive, with reduced entrapment of air and an electronic control of thickness. With this closed application system there is no evaporation of solvents, it may work with both solvent based or water based adhesives and even the moisture curing polyurethanes. 

Refer to Fig. 67. To ensure a perfect shut down, the coating is automatically bypassed to a circulating system as the knives close. 

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Fig. 8. Print bonding methods where (a) is gravure and (b) is rotary screen printing.

Figure 112 A six-station, non-stop rotary screen printing machine (Courtesy Stork X-cel BY)...

Foam printing compositions have been devised which can he applied on conventional roller print or rotary screen print machines (12). These systems are not yet commercial. 

Figure 7. Rotary screen printing (left) foam (right) conventional...

Fig. 13.27. Rotascreen V Rotary Screen Print Machine. (Courtesy of Zimmer Machinery Co.)...

Fiber flock binder dry cleaning and washing resistant. Suitable for screen printing and rotary screen printing machines. 

Ecco Fast Binder. [Eastern Color Chem.] Pigment binder for machine and rotary screen printing. 

Blanket Adhesive H-98. [Catawba-Charlab] Blanket adhesive for flat bed and rotary screen print machines. 

Dur-O-Tron . at l. Starch Chem.] Polymeric pigment btndets for roller and rotary screen printing. 

Other rotogravure flexognq>hy, rotary screen, (n inting, laminating or varnishing units (>15) rotary screen (muting on textile/caid-board (>30) 15-25 >25 >30 100 100 100 25 20 20 Threshold for rotary screen printing [Pg.1210]

Figure 32. The schemes of (a) gravure printing and (b) rotary screen printing processes used in the roll-to-roll OLED processing [4]...

Rotary screen printing - A combination of roller and screen printing in which a perforated cylindrical screen is used to apply color. Color is forced from the interior of the screen onto the cloth. 

Figure 65 Examples of pattern available with rotary screen printing (Microprint...

Figure 66 Varidot applicator for rotary screen printing (by courtesy of Loctite).

Krebs PC, Fyenbo J, J0rgensen M (2010) Product integration of compact roll-to-roU processed polymer solar cell modules methods and manufacture using flexographic printing, slot-die coating and rotary screen printing. J Mater Chem 20(41) 8994-9001... 

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