Metal Box Corporation

Cmb Packaging (uk) Limited

Mb Group Plc

Mg Group Plc

Andrew P Pavely

Joseph S Taylor

Martin F Ball

Peter J Smith

A plastics collar for retaining a plug lid 45 in a ring 44 double seamed to can body 1, has a peripheral skirt 38 portion having on its interior surface a snap fit bead 41 for entering under the double seam 3; a planar annulus 37 extending radially inwards from the top of the skirt over the seam 3 and at least part of the ring 44 and lid 45; and an annular rib 43 extending down from the planar annulus to hold the lid in the ring. The collar may be provided with a jacking screw 39 to assist removal from interlock with the double seam 3 and progressive removal is facilitated by a radial slit or line of weakness at which the collar first parts from the can.

Lid retaining collar

A method of making a metal can end with a tear-open plastics closure, for a can intended to be resistant to leakage when subject to internal pressures, such as arise from carbonation of a beverage or thermal processing, wherein the undersurface of the can end is provided with a plastics coating, and the can end is pierced to form an aperture with a peripheral downturned flange at an angle of 70.degree. to 110.degree. to the plane of the can end and having a flat end. A one-piece ring pull closure is injection-moulded onto the can end from a plastics material resistant to softening at up to at least 65.degree. C., without additional heating of the metal, so as to fill the aperture, bond with the coating, and enclose the flange, with a residual thickness below the flange of 0.125 to 0.5 mm. The thickness of the plastics material of the closure is such that it can be sheared against the flange when the ring pull is pulled manually. The residual thickness of the plastics material may be varied around the aperture to increase resistance of the closure to creep, and the aperture may be pear-shaped or may be circular with a separate vent hole.

Methods of making metal can ends with plastics closures

Can closure

Container closure

A method of making a metal can end with a tear-open plastics closure, for a can intended to be resistant to leakage when subject to internal pressures, such as arise from carbonation of a beverage or thermal processing, wherein the undersurface of the can end is provided with a plastics coating, and the can end is pierced to form an aperture with a peripheral downturned flange at an angle of 80.degree. to 120.degree. to the plane of the can end and having a flat end. A one-piece ring pull closure is injection moulded on to the can end from a plastics material resistant to softening at up to at least 67.degree. C., without additional heating of the metal, so as to fill the aperture, bond with the coating, and enclose the flange, with a residual thickness below the flange of 0.08 to 0.5 mm. The thickness of the plastics material of the closuure is such that it can be sheared against the flange when the ring pull is pulled manually. The residual thickness of the plastics material may be varied around the aperture to increase resistance of the closure to creep, and the aperture may be pear-shaped or may be circular with a separate vent hole.

Methods of making can ends with plastics closures

A closure for a container such as a can for carbonated beverages comprises a collar which is an easy fit in the opening in the container and a plug which is hingedly connected to the collar and when fitted into the collar causes the collar to be elastically deformed into tight sealing engagement with the opening and with the plug.

Closure for a container

A metal can end with a tear-open plastics closure in which the closure has a plug part fitting into an aperture in the can end, a rim surrounding the plug part, and a pull tab, wherein a groove extends across the plug part and aligned grooves or interruptions extend across the rim to provide a hinge line allowing the tab and the adjacent portion of the plug part to pivot upwardly to provide venting of the can in a first stage of opening before full opening of the closure in a second stage. The closure is of the kind which is moulded on to the can end so as to totally enclose a downturned flange around the periphery of the aperture, and to be capable of being sheared against the flange on opening, and the residual thickness of the plastics material below the flange is greater in the main portion than in the vent portion of the closure to provide a temporary arrest after venting. The plug part is stiffer than the metal of the can end so that doming of the can end under internal pressure is concentrated in the metal and the pull tab extends at an angle to the can end surface, rendering it easier to grasp for opening the aperture. A second hinge line may be provided at the far end of the closure, with a further increase in residual thickness, so that the closure can be retained on the can end while being hinged out of the way for pouring.

Growing community of inventors

Blunsdon, United Kingdom

Andrew P Pavely