Technical Field The present invention relates to a method at the manufacture of a carton bottle, comprising a sleeve-shaped main body of a carton material and a plastic top injection- molded thereon, the main body being formed of a longitudinally heat-sealed, sleeve- shaped blank, for improving the plastic molding conditions at the junction between the main body and the top. Background of the Invention

A so-called carton bottle can thus in essence be manufactured by injection- molding a plastic top on a main body, comprising a blank cut from a carton material web and formed into a sleeve or cylinder and subsequently longitudinally heat-sealed. An injection-molding tool may be provided with a notch for accommodating the double-thickness material at the longitudinal heat-seal.

The width of the carton material web may vary with as much as ±1 mm from the factory, which may lead to unsatisfactory results at the injection-molding of the top on the tool. Especially, excess plastic material may flow out at the injection-molding in the junction area to the heat-seal of the main body at its inside and/or outside. The main object of the invention is thus to improve the molding conditions at this junction, so that the above drawback is removed. The Invention

This is according to the invention accomplished in that a scrap piece of blank material is removed in the junction area, so that a nominal width of the blank in the junction area is accomplished irrespective of the greater real width thereof.

This nominal width is accordingly chosen to be less than any expected real width of the blank, and the dimensioning of the notch in the injection-molding tool is chosen so as to obtain optimal results with the nominal width. In practice a scrap piece width of some 2 mm may be suitable. The scrap piece is preferably removed in conjunction with the cutting of the blank from a carton web.

The scrap piece is preferably removed by punching.

By the method according to the invention it may be possible to bring down the width tolerance of the blank from +1 mm to ±0.1 mm, so that the desirable result may be obtained. Brief Description of the Drawings

The invention will be described in further detail below under reference to the accompanying drawings, in which Fig 1 is an isometric view of a so-called carton bottle,

Fig 2 is an isometric view of an injection-molding tool for the top of the bottle shown in Fig 1,

Fig 3 is a schematic view of a carton web for accomplishing a carton bottle of Fig 1, and Fig 4 schematically illustrates a processing step for the carton web shown in

Fig 3.

Detailed Description of an Embodiment

The present invention relates to a so-called carton bottle, shown in Fig 1. The bottle has a main body 1 of a carton material and a plastic top or lid 2, which is preferably provided with a screw-on cap 3.

In a known way, the manufacturing and filling process for this bottle may comprise the following main steps: from a carton web, one blank 4 (Fig 3) at a time with a suitable length is cut, - the blank is formed into a mainly cylindrical shape or into a sleeve around a mandrel and heat sealed along its longitudinal edge,

- the formed carton cylinder or sleeve is placed on a tool 5, as shown in Fig 2, the tool being part of an injection-molding machine,

- the plastic top 2 is injection-molded on the carton sleeve so as to form an integrated unit therewith,

- the cap 3 is optionally added to the top 2,

- the formed bottle is filled with a suitable fluid from its bottom end, and

- the bottle bottom is heat-sealed, preferably to form a flat surface, on which the package or bottle may stand. The invention is concerned with the step of injection-molding the top 2 on the carton sleeve.

For accommodating the longitudinal double material thickness of the overlapping heat seal of the carton sleeve, the tool 5 is provided with a corresponding longitudinal notch 6 at its lower part. The width of the carton web, from which the blank 4 is cut, may in practice differ rather considerably from its nominal width. If such a width, difference occurs, there is a tendency for excess plastic material to form at the double material thickness area or overlap area on the inside and/or outside of the carton sleeve at the junction to the top 2 at the injection-molding.

The main object of the invention is to obviate this negative forming of excess plastic material. This object is accomplished in the following way.

A nominal width for the carton web is determined, which is less than the lowest experienced width, in practice, and the position and dimensioning of the tool notch 6 is adapted to this nominal width for accomplishing an optimal injection- molding result but also an overlap in the longitudinal heat-sealing with good tolerances. Preferably in conjunction with the cutting of the carton web into a blank 4 a narrow scrap piece 7 is removed, preferably by punching, from one edge portion of the blank in the area intended for positioning in the mold notch 6, so that the blank width 8 in this area becomes the nominal width. The width of the scrap piece 7 may be in the order of 2 mm. Modifications are possible within the scope of the appended claims.