초록 ▼

The invention concerns a tube with a plastic neck and with a cover to be welded over the neck after its cap has been fixed, the cover having at least one projecting portion for pulling it off, with cap holding the cover while it is being sealed over the neck. The cover has one or more projecting tab

The invention concerns a tube with a plastic neck and with a cover to be welded over the neck after its cap has been fixed, the cover having at least one projecting portion for pulling it off, with cap holding the cover while it is being sealed over the neck. The cover has one or more projecting tabs, at least one of which is used to pull off the sealed cover and the cover is deformable and has little or no resilience. The end of the cap has a shoulder to press the cover onto the neck, which shoulder is configured so that it does not bear on the burrs of the neck, and the neck and cap have space between them for the bent back projecting tab or tabs of the cover. The invention also concerns a method of sealing the tube by induction of ultrasonic welding. The invention is used for the packaging of toiletries, cosmetics or food products.

대표청구항 ▼

A method of sealing a tube (2) with a plastic neck (1) using a cap (8) also made of plastic and a cover, comprising the steps of: (a) providing a deformable laminate with little or no springback effect comprising at least 2 external layers based on plastics and a barrier layer, the laminate being fr

A method of sealing a tube (2) with a plastic neck (1) using a cap (8) also made of plastic and a cover, comprising the steps of: (a) providing a deformable laminate with little or no springback effect comprising at least 2 external layers based on plastics and a barrier layer, the laminate being from 0.10 to 0.40 mm thick; (b) cutting a cover (21) out of the laminate, the cover having a circular outline (22) with a diameter between the outside diameter of the end (4) of the neck (1) minus 0.3 mm and that diameter plus 0.5 mm, and comprising a radially projecting tab 23 or a plurality of regularly spaced radially projecting tabs (23), the cover (21) being of a type which can straddle a burr (5) on the neck (1) without any risk of bursting; (C) preparing a tube (2) with a screw thread on the neck (1) and the cap (8), the end (13) of the cap having a peripheral shoulder (14) to bear on the end (4) of the neck (1), the inside diameter of the shoulder (14) being between the inside and outside diameters of the neck (1) and being chosen so that it does not bear on burss (5) not cut off at the end of the neck (1) and hence does not press the cover (21) onto such a burr (5), the outside of the neck and the inside of the cap below that shoulder having a space between them which can contain the tab or tabs (23) projecting from the cover (21); (d) arranging the cover (21) at or near the end (13) of the cap (8), the circular portion of the cover being centered therein and its projecting tab or tabs being bent back towards the inside lateral surfaces (19 and 20) of said cap (8); (e) screwing the cap thus fitted with the cover (21) right down onto the neck (1) of the tube; and (f) welding the cover (21) onto the end (4) of the neck (1) either by induction or by ultrasound, according to the nature of the cover (21).