Coatings applicator rolls

Roller Coaters and Sheet Coaters. These arc often used in coil coating where very large, flat surface areas need to be painted quickly. In these methods, the objects to be painted are passed between a doctor blade and applicator rolls. These methods arc suitable only for coatings that arc to be baked. 

An alternative method to apply starch to paper, especially to paperboard grades, is to use a water box at the calender. Water boxes are used for wet-finishing of paper-board prior to coating application. Use of starch in the water box will increase surface strength and lessen fiber reswelling after coating application. Dilute dispersions of oxidized starch are used, frequently in conjunction with a lubricant to prevent calender roll picking. 

The most common coating application method is the knife over roll system (Fig. 2.16). The shape and angle of the coating blade, the gap between the blade and the fabric and the viscosity of the coating all affect the amount of coating applied and the penetration into the fabric. 

In roll coating arrangements of the sort shown in Figure 1, liquid is carried by the pick-up roll into the nip region between it and the applicator roll. Beyond the nip the liquid is, in effect, stretched and split into two films, each carried off... 

Two-Roll Coating - Any coating technique in which two rolls are involved can be generally called two-roll coating. One roll is in contact with the liquid coating and transfers the liquid to a web that is wrapped around the second roll. The first roll is called the applicator roll and the second roll is called the back-up roll. 

For purposes of compliance with section 5 and section 13, OTS will consider items being imported as articles if they are manufactured in a specific shape or design for a particular end use application, and this design is maintained as an essential feature in the finished product. Thus, materials such as metal or plastic sheets, wire, coated fabric, rolled carpet, sheets of plywood and other similar materials will be viewed as articles by OTS, even if, for example, subsequent to import they are rolled or drawn thinner, cut, printed, laminated, or thermo-... 

MAJOR APPLICATIONS Acrylonitrile copolymers are used extensively in textile fiber manufacture and in nitrile rubber. Copolymers are used in gaskets, grommets, hoses, printing roll surfaces, diaphragms, and in plumbing accessories. They also are used in adhesive and coating applications. 

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