Abstract: A W-shaped frangible seal line separating at least two chambers in a container or securing together two sheets of material. Outer legs of the W-shape preferably describe an angle of 170.degree. or less. Inner legs of the W-shape preferably describe an upside down chevron or V-shape that describes an acute angle.

Abstract: A method of radio frequency sealing attaches a seal member to a cylindrical, hollow, access port of a container. The method uses two sets of spaced apart die elements to generate an axial electric field along a region where the port and seal member overlap. An external peripheral ring is formed about an exterior surface of the port. The method can be used with containers having a sealed periphery as well as those previously filled with a fluid.

Abstract: A flexible thermoplastic pouch having an easy-open tear strip means secured thereto is provided. According to one embodiment of the present invention, a tear strip is secured to an imperforate sidewall of a flexible pouch along two sawtooth securement lines arranged generally in the shape of an ellipse. The point where the two securement lines converge is give a W-shape, which provides two points of high stress concentration. When the user grasps and pulls the tear strip means, the securement lines rupture precisely at these two points of stress concentration and continue along the sawtooth securement lines, thereby providing the pouch with a dispensing opening of predetermined size, shape, and location. A sealing die apparatus for forming sawtooth, notched lines of securement between the tear strip means and the flexible pouch is alos disclosed.

Abstract: The method for bonding a plastic tubing to a metal needle includes the steps of coating the inner end of the needle with a cement, inserting the coated inner end of the needle within the outer end portion of a plastic tubing and applying a radiofrequency current across the plastic tubing around the inner end of the needle to heat seal the plastic tubing to the inner end of the needle.