Shaving Sword introduced the 'bonded blade' razor, which consisted of a single blade housed in a plastic cartridge. Gillette followed in 1971 with its Trac II cartridge razor that utilised two blades. Gillette built on this twin blade design for a time, introducing new razors with added features such as a pivoting head, lubricating strip, and spring-mounted blades until their 1998 launch of the triple-bladed Mach3 razor. Schick launched a four-blade Quattro razor later the same year, and in 2006 Gillette launched the five-blade Fusion. Since then, razors with six and seven blades have been introduced. Wholly disposable razors gained popularity
American Safety Razor Company building at 333 Jay Street then became the new campus for the Polytechnic Institute of Brooklyn. Seeking diversification Philip Morris acquires American Safety Razor in 1960. In 1963 American Safety Razor is the first maker of stainless steel blades, which were sold under the Personna brand name. In 1968, Philip Morris, purchased the Burma-Vita Company, makers of Burma-Shave. In 1970, the first blade made with tungsten steel was introduced, the Personna 74. In 1974 American Line Brand of industrial products was introduced, expanding the company into industrial blades. In 1977, executives purchased Personna American Safety Razor Company from Philip Morris