Pre Seal Time delay between press being closed and seal time coming on to ensure proper compression. Usually between 1/2 to 1 sec. Seal Time that r.f. is on and material is being sealed. Generally you want less time to seal, try more power and less time. It saves wear on the oscillator tube plus you can produce more. Some materials have to be sealed at lower power with more time. Cool or Dwell Time for material to cool while still under pressure, preventing tearing of hot material. Generally cool time is 1/2 the seal time.