Method and device for manufacturing a fibre moulding and a fibre moulding manufactured using these

Abstract

A method and a device for manufacturing a fiber molding for drinks packaging containers having an improved structure and surface quality. The method includes the following steps: dipping of a forming wire arranged on a toolholder into a pulp slurry, lifting of the toolholder in order to move the covered forming wire completely out of the pulp slurry, compressing of the fiber material in an area of the circumferential edge of the forming wire through inflating of a circumferential collar, relaxing of the pressure in the collar, and removing of the fiber molding. A device for manufacturing of a fiber molding is also provided.

Claims

1. A method for manufacturing a head or base element for drinks packaging containers formed from a fibre moulding, the method comprising the following steps: dipping of a moulding screen arranged on a toolholder, said moulding screen extending along an outer contour of a moulding tool, into a fibre-containing pulp slurry in order to cover the moulding screen with fibre material, lifting of the toolholder in order to move the moulding screen covered with fibre material completely out of the pulp slurry, compressing the fibre material in an area of a peripheral edge of the moulding screen through expansion of a sleeve arranged around the moulding tool and going all the way around the moulding screen, relaxing pressure in the sleeve, removing fibre moulding from the moulding screen, transferring the fibre moulding onto a press tool, and mechanically compacting the fibre moulding on the press tool with a geometry corresponding to the fibre moulding.

2. The method according to claim 1, wherein an upper edge of the fibre moulding is sprayed with water before it is removed from the moulding screen.

3. The method according to claim 1, wherein the moulding screen is adapted to have air applied to it from an inside in such a way that both an underpressure, for precipitation of the fibre material, and an overpressure for releasing and removing the fibre moulding can be applied.

4. The method according to claim 1, wherein the fibre moulding is dried after removal.

5. The method according to claim 4, wherein the drying takes place using compressed air.

6. The method according to claim 4, wherein the drying takes place using thermal energy supplied.

7. The method according to claim 1, wherein an inner and an outer surface of the fibre moulding are coated so as to be gas-tight and/or liquid-tight.

8. The method according to claim 1, wherein an edge all the way around the fibre moulding is cut to length and an opening located in the fibre moulding is introduced.

9. The method according to claim 8, wherein the cutting to length of the edge or introduction of the opening take place by die-cutting or by laser cutting.

10. The method according to claim 1, wherein the toolholder with the moulding screen and the sleeve is cleaned by being sprayed with water.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention is described in more detail below using a drawing that depicts only one preferred embodiment.

(2) In the drawing, the following are shown:

(3) FIG. 1 a first vertical section through a device according to the invention

(4) FIG. 2 a plan view of the subject matter of FIG. 1

(5) FIG. 3 a further vertical section through the device according to the invention along the line III-III from FIG. 2 and

(6) FIG. 4 a fibre moulding manufactured using the above-mentioned device, from below and in perspective view.

DESCRIPTION OF THE INVENTION

(7) In FIG. 1 one first discerns a forming wire 1, which extends along the outer contour of a moulding tool 2. The moulding tool 2 is hollow on the inside and has a plurality of channels 3 which in the depicted, and in that respect preferred, embodiment, are designed as drill holes, which extend from the surface of the moulding tool 2 at suitable points up unto the hollow interior of the moulding tool 2. The moulding tool 2 is located on a toolholder 4 and is connected to this from below with screws 5 that can only partially be discerned. Toolholder 4 also has a central supply line 6 which can likewise be designed as a drill hole.

(8) Below the toolholder 4 one discerns a fixing plate 7 which, in turn, has a central supply line for the air supply for moulding tool 2. A seal 8 that is preferably designed as an O ring provides the necessary imperviousness of the contact area between toolholder 4 and fixing plate 7. Around the moulding tool 2 is an inflatable collar 9 which, at its inner end, is clamped by moulding tool 2 with the toolholder 4 and whose outer end is clamped by a retaining plate 10 placed on top. Below the collar 9 there runs a circumferential air channel 11 which corresponds to the shape of collar 9; this is described in more detail further on.

(9) FIG. 2, which shows a plan view of the device according to FIG. 1, clearly shows that the moulding tool 2 is designed asymmetrically and that the rising connector is arranged eccentrically to the vertical axis of the fibre moulding.

(10) FIG. 3 essentially has the same structure as FIG. 1; here, however, the supply channels positioned below the circumferential ring channel 11 for a compressed air connection 12, present in duplicate in the depicted and preferred embodiment, are clearly depicted.

(11) For manufacturing purposes, the whole device is dipped into a pulp slurry, so that the entire forming wire 1 is surrounded by pulp. After lifting the toolholder 4, the forming wire 1 is evenly covered and the fibre moulding detaches itself from the wire structure through the generation of pressure in the interior of the forming wire 1 through the drilled hole 6 and the channels 3. At the same time or directly afterwards, the circumferential collar 9 is inflated through an appropriate supply of compressed air via the connections 12, so that the lower edge of the fibre moulding becomes evenly compressed through the collar that bulges outwards. After relaxation of the pressure in the collar 9, the fibre moulding can be removed, through an increase in the pressure via the channels 3, from the moulding tool 2.

(12) A fibre moulding F thus produced is shown in FIG. 4; for a better depiction of the contour according to forming wire 1 and/or moulding tool 2, the fibre moulding F is upside down. One can clearly recognise a uniform circumferential edge R which is required for the sealing with a tube-shaped drinks container sleeve (not depicted). In addition, one can clearly discern ain this illustration pointing downwardsconnector S, which is suitable for accommodating a screw cap.