초록 ▼

An electric heating element for sterilely cutting and welding together a pair of thermoplastic tubes transversely of the axis of each tube includes as an outer layer a folded sheet of a metal, such as copper, aluminum, silver or gold, having a thermal conductivity of at least about 173 watts/m°K at

An electric heating element for sterilely cutting and welding together a pair of thermoplastic tubes transversely of the axis of each tube includes as an outer layer a folded sheet of a metal, such as copper, aluminum, silver or gold, having a thermal conductivity of at least about 173 watts/m°K at a thickness of 0.10 mm and a tensile yield strength of at least 34×104 kPa at a 0.10 mm thickness. A resistance heating element, preferably having a positive thermal coefficient of resistance (PTC), in the form of a resistor of stainless steel or the like is disposed inside the fold of the metal sheet and a layer of dielectric adhesive, such as an epoxy or acrylic adhesive, stable to about 260°C., is disposed between the inner surfaces of the metal sheet and the resistor to insulate the resistor from the folded sheet and bond the resulting structure together. The folded edge of the metal sheet forms the melting edge of the heating element. The heating element has a thickness of from about 0.13 mm. to about 0.76 mm.

대표청구항 ▼

A heating element for sterilely welding first and second thermoplastic tubes together transversely of the axis of each tube consisting essentially of as an outer layer, a folded sheet of metal having a thermal conductivity of at least about 173 watts/m °K. at a 0.10 mm thickness and a tensile yield

A heating element for sterilely welding first and second thermoplastic tubes together transversely of the axis of each tube consisting essentially of as an outer layer, a folded sheet of metal having a thermal conductivity of at least about 173 watts/m °K. at a 0.10 mm thickness and a tensile yield strength of at least about 34×104 kPa at a 0.10 mm thickness, a resistor disposed inside the fold of said folded sheet of metal; a layer of dielectric adhesive, stable to about 260°C., between inner surfaces of said folded sheet of metal and surfaces of said resistor, thereby electrically insulating the resistor from the folded sheet and bonding the resulting structure together; said resistor having exposed terminals for reception of electrical current and the folded edge of said metal sheet being the melting edge of the heating element.