Polyethylene expansion material.
US 2,835,634
Polyethylene expansion material. - May. 20, 1958
cl.252/4
POLYETHYLENE
EXPANSIBLE MATERIAL
SWITCH
VALVE
US 2,835,634
Polyethylene expansion material. - May. 20, 1958
cl.252/4
POLYETHYLENE
EXPANSIBLE MATERIAL
SWITCH
VALVE
US 2,835,634