Heat sealing unit and method of making same
OwnerLee La Fleurinventor
Life of this patent
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Abstract
A heat sealing unit for producing a heat sealed seam on plastic films wherein a plurality of fins made of thin ductile metal having good heat conducting properties are mounted on a thin flexible heating element. The heating element is in turn mounted on a resiliently compressible back-up pad. The fins are closely spaced and flattened against the heating element in overlapping relation so that they provide a relatively large heat sink and at the same time enable the unit to flex so as to conform to the contour of the plastic films to be heat sealed.
Claims23
A device for heat sealing plastic films comprising an electrical resistance heating unit in the form of an elongated flexible ribbon, a plurality of thin metal fins extending outwardly from one side of the ribbon, means securing the inner ends of said fins to said ribbon so that the individual fins extend transversely of the ribbon in closely spaced relation, all of said fins being flattened in a direction lengthwise of and against the ribbon in overlapping contacting relation, the outer ends of said fins being generally uniformly spaced from said ribbon and defining a heat sealing surface for the device and a resiliently compressible backing strip positioned against and secured to the other side of the ribbon.
The method of making a device for heat sealing plastic films which comprises the steps of folding a thin metal strip transversely along regularly spaced lines to form the strip into a succession of accordian-pleated fins having fold lines extending transversely of the strip, securing the apexes along one side of the pleated strip in closely spaced relation to a strip of flexible electrical resistance heating element, flattening the pleated elements against said heating element in a direction lengthwise of the heating element strip so that the successive fins lie one against the next in partially overlapping relation, mounting said heating element strip with the fins thereon on a relatively rigid backing member and thereafter removing the outer end portions of the fins from the pleated strip along a line generally parallel to the backing member.
Dependencies are inferred from the claim text.