Button Covering Process
button covering dies wrap material around the shell, and crimp the shell over the sides of the back. drawing "a" shows the fabric in place over the shell in the top die.
Drawing "b" shows the fabric wrapped under the shell by die action as the top die plunger moves down toward the bottom die.
Drawings "c" and "d" show the assembly and clinching of the fabric wrapped shell against the back. the bottom die curls the shell and fabric against the back, making the button solid and secure.