K2 . dip coating (hot dipping) and dip molding - When a heated object is immersed in plastisol and withdrawn, and the material remaining on the object fuses, a useful coating can be provided. The object is heated to a temperature high enough to cause the plastisol to gel. The thickness of the coating depends on the temperature of the part to be dipped, its shape, the length of time it remains in the plastisol, the characteristics and temperature of the plastisol and the rate of withdrawal. The coating can be as thin as 0.005 in (0.13 mm) and as thick as 0.25 in (6 mm). The process constitutes an easy method for coating tool handles, glass bottles and other objects to provide easier grasping, electrical insulation or cushioning. Dish drying racks are another application A typical sequence involves priming the part to provide improved adhesion, reheating the part, immersing it in the plastisol, withdrawal, additional heating to complete fusion, and then cooling. The operation can be done on a batch basis or can be conveyorized to be continuous and automatic.

If this operation is performed with a shaped mandrel or mold, from which the coating is stripped after the coating cools, the operation is referred to as dip molding. One common application is the manufacture of medical gloves as illustrated in Fig. 4K2. Another application, using a collapsible mold, is the molding of flexible bellows. Closures and caps are also made with this method. Although vinyl plastisol is the prime material used in dip molding, it is possible to dip mold objects of nylon, silicone and polyurethane.

Fig. 4K2 Dip molding of medical gloves. The plastisol coats the heated mold and fuses. After the mold is withdrawn, the solidified coating is stripped from the mold. The thickness of the coating depends on the time of immersion, the temperature of the mold, and the rate of withdrawal.

K2a. cold dipping - with the part or mold to be dipped at room temperature, is sometimes used when the part to be coated cannot retain enough heat to gel the plastisol or has limited resistance to high heat levels. It may also be used when the surface detail desired may not be achievable when the plastisol gells rapidly on a hot mold. Cold dipping is somewhat slower than hot dipping. The procedure is as follows: The cleaned part is dipped into the liquid plastisol at a uniform rate of immersion. The immersion is held for a few seconds and the part is withdrawn at the same slow and steady rate. The part is then suspended in an oven at 365 to 500 ° F (185 to 260 ° C) until the plastisol fuses. Coating cloth work gloves is a common application.

K3. slush molding - is a casting process for vinyl plastisol and is identical to dip molding except that the plastisol material contacts the inside of a hollow mold instead of the outside of a male mold. The hollow mold is filled with plastisol and heated sufficiently to gel the material in contact with the inner surface of the mold. The liquid material in the mold is poured back into the source container, leaving a shell of gelled material in the mold. The higher the mold temperature and the longer the plastisol is contained in the mold, the greater the thickness of the fused material. Further heat applied to the mold fully fuses the plastisol. The mold is cooled and the hollow finished part is removed. The process is useful for making products such as beach balls, dolls, boots, hollow toys, and the surface of automotive head and arm rests. The process is suitable for hand operation for making prototypes and for short run production but can be automated for mass production situations. For products with fine surface detail, two or more fills of the mold may be employed, the first one with the mold cold to allow the plastisol to contact all surface details before gelling. Excess material from the first fill is poured out and the mold is heated to gel the first-coat material. The mold is then filled again while hot, with the same plastisol or sometimes with a cellular plastisol in order to provide a soft, thicker lining to the product.

K4. cavity, in-place, and low-pressure molding - are all essentially casting operations to produce solid parts from plastisol. With cavity molding, a mold is filled with plastisol and heated until the part has fused. The mold is then cooled so that the part can be removed. In place molding is simply the casting of a soft plasticised vinyl as a seal and adhesive in some other part. Examples are the seals for jar and bottle caps where plastisol is metered into the inverted cap which is then heated to fuse the plastisol. A similar approach is used in the manufacture of automotive air cleaner filters, to bond and seal the filter material to the steel frame of the device.Clay sewer pipe sections are also sealed together with this approach. Low-pressure molding is a somewhat mechanized version of cavitymolding, wherein metered amounts of plastisol are pumped into closed molds which are then heated to fuse the plastisol. The molds are then cooled and opened. Shoe soles and printing plates are made with this method. The process is also used to encapsulate electronic components.

K5. strand coating, using plastisols and organisols - Wire, filaments and cords can be coated with vinyl plastisol. The operation is performed by running the strand through a plastisolreservoir or by pumping the plastisol over the strands which then may pass through a circular small-diameter die to control the amount of material covering the strand. The die wipes off any excess material that may be on the strand. In some cases, no die is needed and a low-viscosity organisol leaves only a thin layer of coating on the strand. Multiple passes may then be made. With a die, there are two approaches. In the floating die method, the die is loosely held and it tends to center itself on the strand. Low-viscosity organisol or plastisol is used with this approach. In the set-die method, the die is securely mounted and the strand is guided to pass through the center of the die to insure a concentric application. The strand must be under some tension if concentricity is to be controlled. In all these process variations, the coated wire is subjected to heat after coating, to fuse the plastisol. Coated strands are used in the manufacture of fiberglass screening, electrical wire, rope, thread, and woven cords.

K6. spray coating - Plastisols and organisols can be sprayed to apply decorative or protective coatings to various objects. The process is used for outdoor furniture, appliances and building components, and is particularly useful if the item to be coated is irregular in shape and too large in size or otherwise unsuitable for dip coating. Essentially conventional spray painting equipment can be used. After the coating has been allowed to level, oven baking at a temperature of 350 to 400 ° F (175 to 200 ° C) follows to fuse the coating. Organisols are more commonly sprayed than plastisols since spraying works best with low viscosity fluids. The process is used for tank and drum linings and automotive anti-corrosion sealants.

K7. extrusion of plastisol - is another coating method. The liquid plastisol is fed to a heated barrel of the extruder where its PVC particles absorb plasticizer and fuse. The resulting compound is extruded as film through a die that has a slot opening. It is fed onto and adheres to, a fabric or other substrate. One application, in addition to coated fabrics, is the manufacture of battery separators, where the extrudate is fed to a fiberglass sheet where it forms spacer ribs on the fabric.