Solid ink (also referred to as hot melt ink) is a type of ink used in

printing Printing is a process for mass reproducing text and images using a master form or template. The earliest non-paper products involving printing include cylinder seals and objects such as the Cyrus Cylinder and the Cylinders of Nabonidus. The ...

. Solid ink is a waxy resin-based polymer that must be melted prior to usage unlike conventional liquid inks. The technology is used most in graphics and large format printing environments where color vividness and cost efficiency are important.

History

Solid ink, Hot-Melt or Phase change ink was introduced in 1962 at Teletype Corporation in the Project 176. Solid ink is the name for ink that is solid at room temperature. Wax was formally introduced in the first Solid ink product introduced with Continuous Inkjets in the Teletype Inktronic Terminal in 1966 but the patent for Hot-melt wax did not issue until Patent US3653932 April 4, 1972. In 1971, a patent, US3596285 was issued for a Liquid Metal Recorder, a printer process that fabricated metal models of symbols, patterns and characters. Liquid metal was referred to as Hot-Melt "type" ink in this patent and it was introduced before the term 3D printing was ever conceived. These are examples of inks that stand off the page ("3-D inks"). In 1982, Robert Howard had the idea to build a small color printer system before he left Centronics Corporation. Two years later he formed a new company, Howtek, Inc., to carry out this mission. The Pixelmaster printer used "Hot melt" Thermoplastic ink jetted by piezo crystals that could spit out millions of small droplets of ink of each of the primary colors (red, green and blue) and black onto a piece of paper. Although its creation was originally credited to Data Products, formerly Exxon, it was also credited to Howtek in 1984. Howtek Solid inks could print thousands of colors by subtractive color deposition (layering). The Pixelmaster, a Howtek product, printed with 32 single nozzle inkjets mounted in a rotating reservoir with 8 nozzles per color. It was designed to print on standard sheet paper in 4 minutes with alpha-numeric or images. The Pixelmaster was manufactured by Juki Corporation and sold by Howtek, Inc., Hudson, NH. Some founders and many former employees of Howtek left and joined 3D printing companies. Richard Helinksi formed C.A.D.-Cast, Inc on October 27, 1989 (renamed to Visual Impact Corporation), a 3D printer company to build the Sculptor but later gave up after receiving a 3D Patent US 5136515A on August 4, 1992 and licensed it to Sanders Prototype, Inc in 1993. Herb Menhennett joined Ballistic Particle Manufacturing (BPM) in 1993 with the Personal Modeler product. Both companies used Howtek style inkjets and thermoplastic materials. No fewer than 3 presidents of 3D companies were former Howtek employees and designers, VP's, engineers ( including the inkjet engineer), chemists, buyers, secretaries and technicians have all gone on to 3D companies. Solid ink is a 3D materi