Method of sealing thermoplastic materials by dielectric heating

Claim 1

A METHOD OF JOINING TWO PORTIONS OF A THERMOPLASTIC MATERIAL HAVING A LOW DIELECTRIC LOSS FACTOR INCLUDING THE STEPS OF PLACING SAID PORTIONS TOGETHER; PLACING A BUFFER MATERIAL BETWEEN AN ELECTRODE AND THE PORTIONS AND IN CONTACT THEREWITH, SAID BUFFER MATERIAL BEING A REINFORCED PLASTIC MATERIAL WITH A DIELECTRIC LOSS FACTOR OF AT LEAST 0.1 AND A SOFTENING POINT NOT ABOVE A TEMPERATURE SUBSTANTIALLY EQUAL TO THE SOFTENING POINT OF THE MATERIAL TO BE SEALED SO THAT THE BUFFER MATERIAL AND THE THERMOPLASTIC MATERIAL BOTH SOFTEN TO ABOUT THE SAME DEGREE WHEN THE TWO MATERIALS ARE PRESSED TOGETHER AND A GIVEN HIGH FREQUENCY ELECTRIC FIELD IS IMPRESSED ACROSS THEM, SAID BUFFER MATERIAL HAVING THE PROPERTY OF NOT STICKING TO SAID THERMOPLASTIC MATERIAL WHEN SAID MATERIALS ARE PRESSED TOGETHER AND SAID BUFFER MATERIAL IS HEATED TO THE SOFTENING POINT OF THE THERMOPLASTIC MATERIAL; PLACING A HEAT RESISTANT INSULATING MATERIAL BETWEEN THE COUNTER-ELECTRODE AND SAID PORTIONS AND IN CONTACT THEREWITH, SAID INSULATING MATERIAL HAVING A RELATIVELY LOW DIELECTIC LOSS FACTOR; PRESSING AN AREA OF THE BUFFER MATERIAL, THE INSULATING MATERIAL AND SAID PORTIONS AGAINST EACH OTHER, AND IMPRESSING A HIGH FREQUENCY ELECTRIC FIELD AFTER THE BUFFER MATERIAL AND THE THERMOPLASTIC MATERIAL HAVE SOFTENED, AND SUBSEQUENTLY DISCONTINUING PRESSING THE SAID AREA AFTER THE THERMOPLASTIC MATERIAL HAS BECOME SELF-SUSTAINING.

Claim 2

A METHOD OF JOINING TWO PORTIONS OF A THERMOPLASTIC MATERIAL HAVING A LOW DIELECTRIC LOSS FACTOR INCLUDING THE STEPS OF PLACING SAID PORTIONS TOGETHER; PLACING A BUFFER MATERIAL BETWEEN AN ELECTRODE AND THE PORTIONS AND IN CONTACT THEREWITH, SAID BUFFER MATERIAL BEING A REINFORCED PLASTIC MATERIAL WITH A DIELECTRIC LOSS FACTOR OF AT LEAST 0.1 AND A SOFTENING POINT NOT ABOVE A TEMPERATURE SUBSTANTIALLY EQUAL TO THE SOFTENING POINT OF THE MATERIAL TO BE SEALED SO THAT THE BUFFER MATERIAL AND THE THERMOPLASTIC MATERIAL BOTH SOFTEN TO ABOUT THE SAME DEGREE WHEN THE TWO MATERIALS ARE PRESSED TOGETHER AND A GIVEN HIGH FREQUENCY ELECTRIC FIELD IS IMPRESSED ACROSS THEM, SAID BUFFER MATERIAL HAVING THE PROPERTY OF NOT STICKING TO SAID THERMOPLASTIC MATERIAL WHEN SAID MATERIALS ARE PRESSED TOGETHER AND SAID BUFFER MATERIAL IS HEATED TO THE SOFTENING POINT OF THE THERMOPLASTIC MATERIAL; PLACING A HEAT RESISTANT INSULATING MATERIAL BETWEEN THE COUNTER-ELECTRODE AND SAID PORTIONS AND IN CONTACT THEREWITH, SAID INSULATING MATERIAL HAVING A RELATIVELY LOW DIELECTIC LOSS FACTOR; PRESSING AN AREA OF THE BUFFER MATERIAL, THE INSULATING MATERIAL AND SAID PORTIONS AGAINST EACH OTHER, AND IMPRESSING A HIGH FREQUENCY ELECTRIC FIELD AFTER THE BUFFER MATERIAL AND THE THERMOPLASTIC MATERIAL HAVE SOFTENED, AND SUBSEQUENTLY DISCONTINUING PRESSING THE SAID AREA AFTER THE THERMOPLASTIC MATERIAL HAS BECOME SELF-SUSTAINING.