Patent ID: 8820871

Claim:
A valve jet printer comprising: a solenoid coil; a plunger rod having a magnetically susceptible shank with a first end and a second end at opposite ends thereof, the first end and at least a portion of the shank received within a bore of the solenoid coil; a nozzle including an orifice extending therethrough; and a spring configured to bias the second end of the shank toward the nozzle, wherein the second end of the plunger rod comprises a tip formed of perfluoroelastomer (FFKM), wherein the tip has one or more of the following properties: a Shore A hardness between 65 and 95, a tensile strength of approximately 2,000 lb/in 2 , a maximum continuous service temperature of approximately 325° C., a 50% modulus of 15.5 MPa, a tensile strength at break of 22.75 MPa, surface smoothness between 20 and 50 micro inches, a thickness between 0.3 and 0.6 mm, an elongation at break of 75%, and a compression set of 12% for 70 hours at 204° C., or 23% for 70 hours at 260° C.