Plastisol
Encyclopedia
Plastisol is a suspension of PVC
particles in a plasticizer
; it flows as a liquid and can be poured into a heated mold. When heated to around 177 degrees Celsius, the plastic and plasticizer mutually dissolve each other. On cooling the mold below 60 degrees C, a flexible, permanently plasticized product results. Aside from molding, plastisol is commonly used as a textile ink for screen-printing
and as a coating, particularly in outdoor applications (roofs, furniture) and dip-coating
.
for screen-printing
on to textile
s. Plastisols are the most commonly used inks for printing designs on to garments, and are particularly useful for printing opaque graphics on dark fabrics.
Plastisol inks are not water-soluble. The ink is composed of PVC
particles suspended in a plasticizing emulsion
, and will not dry if left in the screen for extended periods. Because of the convenience of not needing to wash a screen after printing, plastisol inks can be used without a source of running water. Plastisol inks are recommended for printing on colored fabric. On lighter fabric, plastisol is extremely opaque and can retain a bright image for many years with proper care.
Plastisol inks will not dry, but must be cured. Curing can be done with a flash dryer, or more inexpensively, a home oven. Most plastisols need to reach a temperature of about 180 degrees celsius (350 Fahrenheit) for full curing. Plastisol tends to sit atop the threads instead of soaking into them, giving the print a raised, plasticized texture. Other inks can produce a softer feel.
that is more complex than relatively simple resin casting
, but less expensive and less sophisticated than the injection molding
used for most plastic products. It involves metal molds that are filled with liquid plastisol. When the open mold cavities are filled, the mold is spun on a heavy duty, high speed centrifuge to force the liquid vinyl into all of the fine detail on the interior of the mold. Then the metal mold is placed into a heating solution, usually an industrial salt heated to about 400 degrees. The liquid vinyl cooks for a few seconds. The mold is then removed from the heating solution and the remaining liquid is poured out. This leaves a thin skin of vinyl on the interior of the metal mold. The mold is then placed back into the heating solution for three to four minutes to cure. After curing, the mold is again removed from the heating solution, cooled with water, and placed on a rack. While the vinyl part is still warm in the mold, it is very flexible and can be removed from the mold with pliers. When the parts cool, they become rigid and are ready for assembly.
The metal molds can produce an unlimited number of castings. Unlike the flexible molds used for resin casting, metal molds are not adversely affected by heat. The metal molds allow grouping of several parts in one mold cavity and several mold cavities in one mold for faster production.
Polyvinyl chloride
Polyvinyl chloride, commonly abbreviated PVC, is a thermoplastic polymer. It is a vinyl polymer constructed of repeating vinyl groups having one hydrogen replaced by chloride. Polyvinyl chloride is the third most widely produced plastic, after polyethylene and polypropylene. PVC is widely used in...
particles in a plasticizer
Plasticizer
Plasticizers or dispersants are additives that increase the plasticity or fluidity of the material to which they are added; these include plastics, cement, concrete, wallboard, and clay. Although the same compounds are often used for both plastics and concretes the desired effects and results are...
; it flows as a liquid and can be poured into a heated mold. When heated to around 177 degrees Celsius, the plastic and plasticizer mutually dissolve each other. On cooling the mold below 60 degrees C, a flexible, permanently plasticized product results. Aside from molding, plastisol is commonly used as a textile ink for screen-printing
Screen-printing
Screen printing is a printing technique that uses a woven mesh to support an ink-blocking stencil. The attached stencil forms open areas of mesh that transfer ink or other printable materials which can be pressed through the mesh as a sharp-edged image onto a substrate...
and as a coating, particularly in outdoor applications (roofs, furniture) and dip-coating
Dip-coating
thumb|A schematic of the continuous dip coating process.Dip coating is a popular way of creating thin films for research purposes. Uniform films can be applied onto flat or cylindrical substrates...
.
Textile ink
Plastisol is used as inkInk
Ink is a liquid or paste that contains pigments and/or dyes and is used to color a surface to produce an image, text, or design. Ink is used for drawing and/or writing with a pen, brush, or quill...
for screen-printing
Screen-printing
Screen printing is a printing technique that uses a woven mesh to support an ink-blocking stencil. The attached stencil forms open areas of mesh that transfer ink or other printable materials which can be pressed through the mesh as a sharp-edged image onto a substrate...
on to textile
Textile
A textile or cloth is a flexible woven material consisting of a network of natural or artificial fibres often referred to as thread or yarn. Yarn is produced by spinning raw fibres of wool, flax, cotton, or other material to produce long strands...
s. Plastisols are the most commonly used inks for printing designs on to garments, and are particularly useful for printing opaque graphics on dark fabrics.
Plastisol inks are not water-soluble. The ink is composed of PVC
PVC
Polyvinyl chloride is a plastic.PVC may also refer to:*Param Vir Chakra, India's highest military honor*Peripheral venous catheter, a small, flexible tube placed into a peripheral vein in order to administer medication or fluids...
particles suspended in a plasticizing emulsion
Emulsion
An emulsion is a mixture of two or more liquids that are normally immiscible . Emulsions are part of a more general class of two-phase systems of matter called colloids. Although the terms colloid and emulsion are sometimes used interchangeably, emulsion is used when both the dispersed and the...
, and will not dry if left in the screen for extended periods. Because of the convenience of not needing to wash a screen after printing, plastisol inks can be used without a source of running water. Plastisol inks are recommended for printing on colored fabric. On lighter fabric, plastisol is extremely opaque and can retain a bright image for many years with proper care.
Plastisol inks will not dry, but must be cured. Curing can be done with a flash dryer, or more inexpensively, a home oven. Most plastisols need to reach a temperature of about 180 degrees celsius (350 Fahrenheit) for full curing. Plastisol tends to sit atop the threads instead of soaking into them, giving the print a raised, plasticized texture. Other inks can produce a softer feel.
Slush molding
Plastisol is used for slush molding or slush casting. It is a form of spin castingSpin casting
Spin casting, also known as centrifugal rubber mold casting , is a method of utilizing centrifugal force to produce castings from a rubber mold. Typically, a disc-shaped mold is spun along its central axis at a set speed. The casting material, usually molten metal or liquid thermoset plastic is...
that is more complex than relatively simple resin casting
Resin casting
Resin casting is a method of plastic casting where a mold is filled with a liquid synthetic resin, which then hardens. It is primarily used for small scale production like industrial prototypes and dentistry...
, but less expensive and less sophisticated than the injection molding
Injection molding
Injection molding is a manufacturing process for producing parts from both thermoplastic and thermosetting plastic materials. Material is fed into a heated barrel, mixed, and forced into a mold cavity where it cools and hardens to the configuration of the cavity...
used for most plastic products. It involves metal molds that are filled with liquid plastisol. When the open mold cavities are filled, the mold is spun on a heavy duty, high speed centrifuge to force the liquid vinyl into all of the fine detail on the interior of the mold. Then the metal mold is placed into a heating solution, usually an industrial salt heated to about 400 degrees. The liquid vinyl cooks for a few seconds. The mold is then removed from the heating solution and the remaining liquid is poured out. This leaves a thin skin of vinyl on the interior of the metal mold. The mold is then placed back into the heating solution for three to four minutes to cure. After curing, the mold is again removed from the heating solution, cooled with water, and placed on a rack. While the vinyl part is still warm in the mold, it is very flexible and can be removed from the mold with pliers. When the parts cool, they become rigid and are ready for assembly.
The metal molds can produce an unlimited number of castings. Unlike the flexible molds used for resin casting, metal molds are not adversely affected by heat. The metal molds allow grouping of several parts in one mold cavity and several mold cavities in one mold for faster production.