Inventor
SPEAR DEAN M
US6 patents
Patents
6 patentsUS4644623AFeb 24, 1987
Method of making a rotatable molding element for selectively aperturing thermoplastic film
ETHYL CORP28 citations91
US4636161AJan 13, 1987
Screen for selectively perforating thermoplastic film
ETHYL CORP29 citations91
US4604156AAug 5, 1986
Method of fabricating a cylindrical multilayer screen
ETHYL CORP22 citations81
US4585156AApr 29, 1986
Screen fabrication
ETHYL CORP9 citations72
US4543299ASep 24, 1985
Laminated, seamless, cylindrical metal screen for vacuum perforation of thermoplastic film
ETHYL CORP19 citations72
US4541794ASep 17, 1985
Apparatus for producing perforated plastic film
ETHYL CORP18 citations72