Bakelite ( /ˈbeɪkɨlaɪt/ US dict: bāk′(ə)līt), or polyoxybenzylmethylenglycolanhydride, is an early plastic. It is a thermosetting phenol formaldehyde resin, formed from an elimination reaction of phenol with formaldehyde, usually with a wood flour filler. It was developed in 1907 by Belgian chemist Leo Baekeland.
One of the first plastics made from synthetic components (although phenol can be extracted from biological sources), Bakelite was used for its electrically nonconductive and heat-resistant properties in radio and telephone casings and electrical insulators, and also in such diverse products as kitchenware, jewellery, pipe stems, and children's toys. In 1993 Bakelite was designated a National Historical Chemical Landmark by the American Chemical Society in recognition of its significance as the world's first synthetic plastic.[1]
The "retro" appeal of old Bakelite products and labor intensive manufacturing has made them quite collectible in recent years. Bakelite and Bakelit are registered trademarks of Momentive Specialty Chemicals GmbH.
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Dr. Baekeland had originally set out to find a replacement for shellac (made from the excretion of lac beetles). Chemists had begun to recognize that many natural resins and fibres were polymers, and Baekeland investigated the reactions of phenol and formaldehyde. He first produced a soluble phenol-formaldehyde shellac called "Novolak" that never became a market success, then turned to developing a binder for asbestos which, at that time, was moulded with rubber. By controlling the pressure and temperature applied to phenol and formaldehyde, he found in 1905 he could produce his dreamed-of hard mouldable material (the world's first synthetic plastic): bakelite.[2] [3] He announced his invention at a meeting of the American Chemical Society on February 5, 1909.[4]
The Bakelite Corporation was formed in 1922 (after patent litigation favorable to Baekeland) from a merger of three companies: the General Bakelite Company, which Baekeland had founded in 1910, the Condensite Company founded by J.W. Aylesworth, and the Redmanol Chemical Products Company founded by L.V. Redman.[5]
Bakelite Limited was formed in 1926 from the amalgamation of three suppliers of phenol formaldehyde materials: the Damard Lacquer Company Limited of Birmingham; Mouldensite Limited of Darley Dale and Redmanol Chemical Products Company of London. Around 1928 a new factory opened in Tyseley, Birmingham, England (subsequently demolished in 1998). In 1939 the company was acquired by the Union Carbide and Carbon Corporation.
Phenolics are seldom used in general consumer products today due to the cost and complexity of production and their brittle nature. An exception to this overall decline is their use in small precision-shaped components where their specific properties are required, such as molded disc brake cylinders, saucepan handles, electrical plugs and switches and parts for electrical irons. Today, Bakelite is manufactured and produced in sheet, rod and tube form for hundreds of industrial applications in the electronics, power generation and aerospace industries, and under a variety of commercial brand names, including Garolite.
Phenolic sheet is a hard, dense material made by applying heat and pressure to layers of paper or glass cloth impregnated with synthetic resin. 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) transforms the layers into a high-pressure thermosetting industrial laminated plastic. When rubbed, original Bakelite has a telltale odor.
Bakelite Phenolic sheet is produced in dozens of commercial grades and with various additives to meet diverse mechanical, electrical and thermal requirements. Some common types include:
NEMA refers to the US National Electrical Manufacturers Association[6], and cooperate with IEC.
In its industrial applications, Bakelite was particularly suitable for the emerging electrical and automobile industries because of its extraordinarily high resistance - not only to electricity, but to heat and chemical action. It was soon used for all nonconducting parts of radios and other electrical devices, such as bases and sockets for light bulbs and electron tubes, supports for any type of electrical components, automobile distributor caps, and other insulators. The foremost usage of Bakelite today is in the industrial sector for insulation of wires, construction of brake pads and related automotive components as well as industrial electrical related applications.
In the early 20th Century, it was found in myriad applications including saxophone mouthpieces, whistles, cameras, solid-body electric guitars, telephone housings and handsets, early machine guns, and appliance casings. The thermosetting phenolic resin was at one point considered for the manufacture of coins, due to a shortage of traditional manufacturing material. In 1943, Bakelite and other non-metal materials were tested for usage as a penny in the United States before the Mint settled on zinc coated steel.[7][8]
After WWII, factories were retrofitted to produce Bakelite using a more efficient extrusion process which increased production and enabled the uses of Bakelite to extend into other genres. Jewelry boxes; desk sets; clocks; radios; game pieces like chessmen, poker chips, billiard balls and Mah Jong sets; kitchenware such as canisters and tableware were also made of Bakelite through the 1950s. Beads, bangles and earrings were produced by the Catalin Company which introduced 15 new colors in 1927. The creation of marbled Bakelite was attributed to the Catalin Company. Translucent Bakelite jewelry, poker chips and other gaming items such as chess sets were also introduced in the 1940s under the Prystal Corporation name; however, its basic chemical composition remained the same.
The primary commercial uses for Bakelite today remain in the area of inexpensive board and tabletop games produced in China, India and Hong Kong. Items such as billiard balls, dominoes and pieces for games like chess, checkers, and backgammon are constructed of Bakelite for its look, durability, fine polish, weight, and sound. Common dice are sometimes made of Bakelite for weight and sound, but the majority are made of a thermoplastic such as acrylonitrile butadiene styrene (ABS) which is not as durable as Bakelite.
Bakelite is used to make the presentation boxes of Breitling watches and sometimes as a substitute for metal firearm magazines. Bakelite is also used in the mounting of metal samples in metallography.[9]
Phenolic resins have been commonly used in ablative heat shields. Soviet heatshields for ICBM warheads and spacecraft reentry consisted of asbestos textolite impregnated with Bakelite.[10]
In July 1907, Baekeland filed US patent #942,699: Method of making insoluble products of phenol and formaldehyde, patented on December 7, 1909. His method of producing a hard, compact, insoluble and infusable condensation product of phenols and formaldehyde, marked the beginning of the modern plastics industry.