Roll coating arrangements

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... 

Different roll coating methods and roll arrangements S = steel roll, R = rubber-covered roll, E = engraved roll. (Courtesy of Faustel Corporation.)... 

Tensile strength of radiation-cured purified natural rubber Tensile strength of radiation-cured purified natural rubber Examples of industrially important acrylated prepolymers The arrangement for direct roll coating Different types of cells on the surface of a gravure roll Reverse roll coating... 

Different roll coating methods and roll arrangements... 

The canonical jelly roll barrel is schematically illustrated in Figure 16.13. Superposition of the structures of coat proteins from different viruses show that the eight p strands of the jelly roll barrel form a conserved core. This is illustrated in Figure 16.14, which shows structural diagrams of three different coat proteins. These diagrams also show that the p strands are clearly arranged in two sheets of four strands each P strands 1, 8, 3, and 6 form one sheet and strands 2, 7, 4, and 5 form the second sheet. Hydrophobic residues from these sheets pack inside the barrel. 

The calender was developed over a century ago to produce natural rubber products. With the developments of TPs, these multimillion dollar extremely heavy calender lines started using TPs and more recently process principally much more TP materials. The calender consists essentially of a system of large diameter heated precision rolls whose function is to convert high viscosity plastic melt into film, sheet, or coating substrates. The equipment can be arranged in a number of ways with different combinations available to provide different specific advantages to meet different product requirements. Automatic web-thickness profile process control is used via computer, microprocessor control. 

CPMV particles have an icosahedral symmetry with a diameter of approximately 28 nm (Figure 9.2), the protein shell of the capsid is about 3.9nm thick [72], The structure of CPMV is known to near-atomic resolution (Figure 9.3) [73], The virions are formed by 60 copies of two different types of coat proteins, the small (S) subunit and the large (L) subunit. The S subunit (213 amino acids) folds into one jelly roll P-sandwich, and the L subunit (374 amino acids) folds into two jelly roll P-sandwich domains. The three domains form the asymmetric unit and are arranged in a similar surface lattice to T = 3 viruses, except they have different polypeptide sequences therefore the particle structure is described as a pseudo T = 3 or P = 3 symmetry [74]. 

A typical coating line consists of fabric pay-off, the tower, and a take-up for the coated goods. Some lines also include a festoon (accumulator) to avoid the need for stopping the line if the web is being spliced or if the take-up has to be stopped for roll change or a problem. The take-up may be arranged as a turret for a faster roll change. 

A stainless-steel dip tank is on the bottom of the coating tower. Inside the tank is a submerged roll, sometimes called dip bar, which may be made from stainless steel or PTFE.8 The roll may be locked or rotated. A rotating bar most frequently has sleeve bearings, which are lubricated by the liquid in the tank. Some designs use multiple rolls (typically three, see Figure 6.2) this arrangement reduces differences in pickup between the two sides of the web. 

The roll mill system consists of a pair of heatable counter-rotating metal cylinders arranged parallel to one other with an adjustable gap, or nip, between them. A pre-mixed feedstock is dropped on these rolls and is drawn into the gap between the two rolls where high-shear mixing occurs. One roll normally turns faster than the other, and because of this speed difference (friction ratio) the shear force is amplified. The feedstock usually forms a coating around the slower roll. 

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