Fiber coater

An assembly drawing and photograph of a continuous fiber coater appear in Figures... 

At the current time, liquid precursor (solution/sol/slurry) coating techniques have been the most successful for the deposition of oxides, such as monazite (LaP04) and porous oxides (carbon-oxide mixtures) onto oxide fiber tows [178, 179, 191, 192]. Atypical fiber coater is shown in Figure 10a [193]. In the coating process, a lighter, immiscible liquid is floated on the surface of the coating precursor. The immiscible liquid is used to remove excess sol from the coated tow and it allows for the coating of individual filaments with... 

The primary substrates or support iaclude many types of paper and paperboard, polymer films such as polyethylene terephthalate, metal foils, woven and nonwoven fabrics, fibers, and metal cods. Although the coating process is better suited to continuous webs than to short iadividual sheets, it does work very well for intermittent coating, such as ia the printing process. In general, there is an ideal coater arrangement for any given product. 

Spin coater Fiber spinner Crystallizer Conveyer Kiln... 

Taking, for instance, Al, with a melting point of 660 °C and a web substrate temperature of 50 °C, zone I formations will be created (porous structure, pointed crystallites, large voids) and up to 250 °C, formations in the transitional area (densely packed fibers) will appear. Up to 450 °C zone II (pillar-shaped crystallites), and above this temperature zone III (conglomerate-type crystallites) formations will be seen. Because of the relatively low maximum thermal stress that may be applied to polymer webs, the growth in metallized layers on polymer webs mainly occurs in Zone I or in the transitional zone. The different growth is also evident from comparison of cooling drum and free-span coater methods. 

Chemical products used for mold-proofing can be applied to the surface of the paper or board at the size press, coater, water box or some other surface treatment. The obvious advantage here is 100% retention of the moldproofing agent onto the product and better efficiency. The disadvantage is exposure to biocide and in some cases no such feed point exists. Biocides may also be added to the pulp slurry. In this case, the product or blend of products must adhere to the fibers. This is referred to as the product s substantivity. 

Sputter coating is a particrrlarly convenient means of decorating the surface of fibers. A DC sputter coater using a high-prrrily silver target, for instanee. 

The size press is a type of coater that applies a light coating of a particular additive to one or both sides of the sheet. Materials run on a size press inelude starch and surface size. Starch is used to prevent picking-out of fibers when the sheet is typed on. Surface sizing with materials such as styrene maleic anhydride or cellulose gmn serve to increase the resistance to penetration by aqueous fluids such as ink. Surface sizes can also be used to achieve erasability of bond papers by keeping ink from penetrating into the paper. 

---