Micarta
Encyclopedia
Micarta is a trademark of Norplex-Micarta industrial high pressure laminates and refers to a composite
Composite material
Composite materials, often shortened to composites or called composition materials, are engineered or naturally occurring materials made from two or more constituent materials with significantly different physical or chemical properties which remain separate and distinct at the macroscopic or...

 of linen
Linen
Linen is a textile made from the fibers of the flax plant, Linum usitatissimum. Linen is labor-intensive to manufacture, but when it is made into garments, it is valued for its exceptional coolness and freshness in hot weather....

, canvas
Canvas
Canvas is an extremely heavy-duty plain-woven fabric used for making sails, tents, marquees, backpacks, and other items for which sturdiness is required. It is also popularly used by artists as a painting surface, typically stretched across a wooden frame...

, paper
Paper
Paper is a thin material mainly used for writing upon, printing upon, drawing or for packaging. It is produced by pressing together moist fibers, typically cellulose pulp derived from wood, rags or grasses, and drying them into flexible sheets....

, fiberglass
Fiberglass
Glass fiber is a material consisting of numerous extremely fine fibers of glass.Glassmakers throughout history have experimented with glass fibers, but mass manufacture of glass fiber was only made possible with the invention of finer machine tooling...

, carbon fiber
Carbon fiber
Carbon fiber, alternatively graphite fiber, carbon graphite or CF, is a material consisting of fibers about 5–10 μm in diameter and composed mostly of carbon atoms. The carbon atoms are bonded together in crystals that are more or less aligned parallel to the long axis of the fiber...

 or other fabric in a thermosetting plastic
Thermosetting plastic
A thermosetting plastic, also known as a thermoset, is polymer material that irreversibly cures. The cure may be done through heat , through a chemical reaction , or irradiation such as electron beam processing.Thermoset materials are usually liquid or malleable prior to curing and designed to be...

, originally used in electrical and decorative Koekjes applications. Micarta(R) was developed by George Westinghouse
George Westinghouse
George Westinghouse, Jr was an American entrepreneur and engineer who invented the railway air brake and was a pioneer of the electrical industry. Westinghouse was one of Thomas Edison's main rivals in the early implementation of the American electricity system...

 at least as early as 1910 using phenolic resins invented by Dr. Leo Baekeland
Leo Baekeland
Leo Hendrik Baekeland was a Belgian chemist who invented Velox photographic paper and Bakelite , an inexpensive, nonflammable, versatile, and popular plastic, which marks the beginning of the modern plastics industry.-Career:Leo Baekeland was born in Sint-Martens-Latem near Ghent, Belgium,...

. These resins were used to impregnate paper and cotton fabric which were cured under pressure and high temperature to produce laminates. In later years this manufacturing method included the use of fiberglass fabric, other resin types were also used. Today Micarta high pressure industrial laminates are produced with a wide variety of resins and fibers. The term has been inappropriately used to generically refer to most resin impregnated fibre compounds. Common uses of modern high pressure laminates are as electrical insulators, printed circuit board substrates, and knife handles.

Manufacturing process

Micarta industrial laminates are normally phenolic
Phenol formaldehyde resin
Phenol formaldehyde resins include synthetic thermosetting resins such as obtained by the reaction of phenols with formaldehyde. Sometimes the precursors include other aldehydes or other phenol. Phenolic resins are mainly used in the production of circuit boards...

, epoxy, silicone, or melamine resin
Melamine resin
Melamine resin or melamine formaldehyde is a hard, thermosetting plastic material made from melamine and formaldehyde by polymerization. In its butylated form, it is dissolved in n-butanol and xylene. It is then used to cross-link with alkyd, epoxy, acrylic and polyester resins, used in surface...

 based thermoset materials reinforced with fiberglass, cotton cloth, paper, carbon fiber or other substrates. Micarta industrial laminate sheet is a hard, dense material made by applying heat and pressure to layers of prepreg
Pre-preg
Pre-preg is a term for "pre-impregnated" composite fibres. These usually take the form of a weave or are uni-directional. They already contain an amount of the matrix material used to bond them together and to other components during manufacture. The pre-preg are mostly stored in cooled areas since...

. These layers of laminations are usually of cellulose paper, cotton fabrics, synthetic yarn fabrics, glass fabrics, or unwoven fabrics. When heat and pressure are applied to the layers, a chemical reaction (polymerization
Polymerization
In polymer chemistry, polymerization is a process of reacting monomer molecules together in a chemical reaction to form three-dimensional networks or polymer chains...

) transforms the layers into a high-pressure thermosetting industrial laminated plastic.

Applications

The largest use for Micarta industrial laminates is a high strength electrical insulation in power generating and distribution equipment. Laminates are also used in heavy equipment, aerospace, automotive, office equipment, tabletops, countertops, electronic, electrical insulation between pressure vessels or piping and their supports, decorative applications, including knife handles and gun handles, guitar fingerboards and bridges, pool cues, and safety gear such as hard hats. Between 1935-1945, Westinghouse's Power-Aire desk fans used blades made of Micarta

Micarta is a trademark of Norplex-Micarta Industrial Composites.
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