Spray fillers

For a complete panel replacement, the refinisher starts with a panel preprimed in the appropriate stoving primer. For spot repairs or larger repairs without replacement of metal, there will be areas which have to be rubbed through to clean metal. Any indentations then have to be filled with a stopper or spray filler, probably based on unsaturated polyester resins and styrene, with cure initiated by mixing in an organic peroxide. After sanding, remaining bare metal areas are sprayed with a two-pack etch primer. 

UV curing is carried out at a conveyor speed of approximately 3 m/min. The conveyor speed is usually calculated on the basis of a high-pressure mercury vapour lamp with an output of 80 W/cm. Conventional curing of spray fillers in a circulating air oven takes 10 min at 80 °C. These systems provide virtually ideal substrates for a number of top coats as, unlike other systems, they have good hold-out. 

Knifing, Spot and Spray Fillers for Metal and Marble (here also coatings). Knifing and spot fillers are especially suited for filling large areas of unevenness in just a few operations in quick succession. Knifing resins (hard to flexible) are mixed to a paste-like consistency with the extenders described. Benzoyl peroxide and tertiary aromatic amine are used as the hardener system (the latter is usually a component of the resin supply form). 

Chem. Descrip. Highly reactive unsat. polyester resin (69%) in styrene Uses Binder for highly filled primer surfaces, e.g., knifing and spray fillers for automotive refinishing Features Produces hard films... 

Chem. Descrip. Unsat. polyester resin (65%) in styrene Uses Flexibilizer for wax-free polyesters and amine-accelerated resins used in formulation of knifing and spray fillers, and in primers for wood and furniture coatings... 

Eor some appHcations the powder is suspended in an aqueous medium or a solvent with the help of emulsifying agents and then sprayed onto the substrate. The powder is also used as a filler to prepare sprayable compositions of PTEE dispersions, which then can be used to coat various substrates (36). 

Extra-Fine Precipitated Hydroxide. Very fine (< 1 /im-diameter) particle size hydroxide is produced by precipitation under carefully controlled conditions using specially prepared hydroxide seed. Precipitation is usually carried out at low (30 —40°C) temperatures causing massive nucleation of fine, uniform hydroxide particles (Fig. 5). Tray or tumiel Ape dry ers are used to dry the thorouglily washed filter cake to a granular product wliich is easily pulverized to obtain the fine hydroxide. Alternatively, the washed product is spray dried. Precipitation from an organic-free aluniinate Hquor, such as that obtained from the soda—sinter process, fields a very wliite product. Tlie fine precipitated hydroxide is used by the paper and plastic industries as fillers. 

Other uses for coal-tar pitch include production as a binder for foundry cores, as a sealant for dry batteries, and in the manufacture of clay pigeons. PeUeted pitch used as the binder in foundry cores is a hard pitch suppHed as spherical granules which are formed by a spray-cooling process. Clay pigeons consist of disks molded from a mixture of hard pitch and a mineral filler such as clay or limestone dust. 

Adhesives (qv) used to make plywood are classified as either the exterior adhesive or the lesser quaHty interior adhesive. The terms relate to the abUity of the adhesive to survive exposure to moisture and weather. PhenoHc resins (qv) are commonly used as adhesives to make plywood. The difference between interior and exterior phenoHc resin adhesive is the filler level. Exterior rated plywood uses higher resin content adhesives. Interior rated plywood uses either highly extended (below 24% resin soHds) or protein-based adhesives. The adhesive is appHed to the veneer by roU coating, spraying, curtain coating, or foam extmsion. 

Tn comparing the content of drug extract in the final product, teas in granule form are usually very much inferior to instant teas which arc prepared from spray-dried extracts teas in granular form, in addition to 97 -98% filler and carrier substances often contain only 2-3% dry extract, while in spray-dried products almost ten times as much, viz on average 20%, drug extract is present. 

The selection of mix ingredients may depend heavily on the type of adhesive applieation equipment used. The main types of equipment for plywood and LVL are roll coaters, spray systems, eurtain coaters, and foam extruders. When foam extruders are used, animal blood and surfactants are usually added to the mill mix. For other application systems, resin producers typieally supply the non-filler additives as part of the resin eomposition. 

Insulation dry mixed in factory with inorganic fillers and binders for application by wet spraying. Usually mineral... 

Base product produced as a granular loose fill, which can be bonded to form boards or dry mixed with fillers and binders for spray application. 

Powder coating is a solventless coating system that is not dependent upon a sacrificial medium such as a solvent, but is based on the performance constituents of solid TP or TS plastics. It can be a homogeneous blend of the plastic with fillers and additives in the form of a dry, fine-particle-size compound similar to flour. The three basic methods are the fluidized bed, electrostatic spray, and electrostatic fluidized bed processes (9). 

Commercial coated samples were obtained. Coating thickness was nominal 2 mils for organic-metal filled coatings (approximately 50% metal filler). Zinc metal coatings were zinc arc spray and were thicker, 5 mils, but normal for that process. Test results for each fire parameter are given as follows ... 

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