Formvar

Formvar refers to any of several thermoplastic resins that are polyvinyl formals, which are polymers formed from polyvinyl alcohol and formaldehyde as copolymers with polyvinyl acetate. They are typically used as coatings, adhesives, and molding materials. 'Formvar' used to be the registered trade name of the polyvinyl formal resin produced by Monsanto Chemical Company in St. Louis, Missouri. That manufacturing unit was sold and formvar is now distributed under the name 'Vinylec'.Formvar is used in many different applications, such as wire insulation, coatings for musical instruments, magnetic tape backing, and support films for electron microscopy. Formvar is also used as a main ingredient for special adhesives in structural applications such as the aircraft industry.Formvar resin has a high softening point and strong electric insulation properties. It is also very flexible, water-insoluble, and resistant to abrasion. Formvar is also halogen free. Formvar resins are combustible and can cause dust explosions. For this reason exposure to heat, sparks, and flame should be avoided. Formvar is most commonly dissolved in ethylene dichloride, chloroform, and dioxane.