On This Day

Tuesday 21st November 1843

176 years ago

Vulcanised rubber was patented in England by Thomas Hancock, 8 weeks before Charles Goodyear in the US (30 January 1844). Thomas Hancock founded the rubber industry in Great Britain. He was born at Marlborough in Wiltshire, England, the third of twelve children of a lumber merchant and cabinet maker. Around 1815 Hancock went into the stagecoach business with one of his brothers in London, England. The need for an effective waterproofing agent--for coaches, drivers, and passengers--drew Hancock's attention to rubber. In April 1820 he patented India-rubber springs for various types of clothing such as gloves and suspenders. The Hancock brothers then started an "elastic works" to manufacture items using the rubber springs. Searching for a more effective way to process his raw material and use rubberremnants, Hancock in 1820 invented his most important device: the rubber masticator. He designed a machine with revolving teeth that tore up rubber scraps. To Hancock's surprise, the shredded bits adhered into a solid mass of rubber that could then be pressed in molds into solid blocks or rolled into sheets. Hancock's masticator, which was perfected in 1821, made rubber manufacturecommercially practical and gave birth to the rubber industry. (Hancock called his machine a "pickle" and kept the masticating process a secret for 10 years). The advantages of the Hancock rubber masticator caught the interest of Charles Macintosh (1766-1843), who in 1823 had patented a process for waterproofingfabrics with naphtha-treated rubber. Hancock in turn applied for a license in 1825 to use Macintosh's naphtha process. The two men eventually became partners in the manufacture of waterproofed items. Although the rubber industry was prospering, rubber still suffered from the defects of becoming brittle or gummy with temperature variations. About 1840,Hancock developed a slicer, which was to play an important role in John Wesley Hyatt's (1837-1920) production of celluloid sheets. Around 1842 Hancock acquired a sample of rubber that had been vulcanized by the Goodyear process. Hestudied the sample and discovered the effects on it of sulphur under heat. In November 1843 Hancock took out a British patent for his variation of vulcanization--a patent that blocked Charles Goodyear's (1800-1860) efforts to secure a British patent for his invention of vulcanization. (Although both Hancock and Goodyear claimed to be the inventors of sulphur-modified rubber, they were both probably predated by Lüdersdorf, Bergius, Leuchs, van Geuns, and others.} The addition of sulphur under heat was termed vulcanization by Brockedon, and Hancock later patented his discovery that if up to 30 percent ofsulphur is added to the rubber, a hard, rigid, thermoplastically moldable product results. Termed vulcanite, ebonite, or hard rubber,the material would soon be used as an insulating solid in the electrical industry. In the decorative arena, vulcanite was molded to produce brooches and pipe stems. Hancock was granted a total of 16 patents relating to rubber between 1820 and1847. In 1822 he developed rubber tubing that could be cut into rubber bandsand life-belt tubes. He devised many medical uses for rubber, and promoted the use of rubber rather than leather fire hoses. He made many improvements inthe manufacture of rubber and thought of a multitude of ways in which this remarkable new product could be used. Hancock died in 1865 at Stoke Newington,London.