IL31300A - A method of simultaneously producing a number of strips of laminate material - Google Patents

Description

31300/4 Tan© ταιη o»ono isoa τχ·»ν ΠΘ»Β? A method of simultaneously producing a number of stripe of laminate material 31300/2 m This invention relates to the production of 3trip material, such as used for example, to make containers for packaging.

The invention contemplates the simultaneous production of a number of strips of laminated material, each consisting of a carrier layer having on at least one side a coverin layer of a material applied to it.

Strips of material, which consist of a carrier layer and one or more layers of coating material, e.g. plastic or metal foil, are often used e.g. in packaging.

The stripe of laminated material converted into packages in the packaging machines are of selected width appropriate to the completed package, which in most cases does not correspond to the width of the web treated li a coating machine ¾o produce the lai-unate.

Frequently, the web of laminate produced in a laminating machine is several times as wide as the s"trips of packaging material needed for use in the packaging machines, and the original web of laminate must be divided to form a number of narrower strips of suitable width.

In the case of packages containing a liquid, which are made froa a strip, the edges of a 3trip are often united by an overlap joint. In this case a raw cut edge of the strip is exposed inside the package, and ia thus liable to come into contact with the liquid inside the completed package* When the oarrier layer of the packaging laminate consists of a fibrous material, such as paper, which will absorb the liquid, steps need to be taken in making such 31300/2 m packages with overlap joints* in order to prevent such liquid absorption into the carrier layer of the laminate.

With a view to providing strip material suitable for this problem the invention consists in a method of producing, from a web of packaging material, narrower strips of laminate material* wherei the web is longitudinally divided into a plurality of strips, and the severed strips slightly separated from one another in transverse directio * whereafter a coating material is applied to one face of the divided web in order to form' a covering layer over the surfaces of the severed stripe, which also overlaps the gap or gaps between the separated stripe, t he layer extending across the* or each, gap being longitudinally cut to leave an overhangin edge zone of the coating layer projecting beyond the edge of each strip.

The invention further consists in apparatus adapted to carr into effect the method set out in the next preceding paragraph comprising cutting means for longitudinally severing a web of material into strips, and means for relatively displacing said strips laterally to leave a gap between adjacent strips.

The invention also consists in laminate strip material, or an article made therefrom, whenever produoed in accordance with the aforesaid method or using the aforesaid apparatus* The invention will now be more fully described with reference to the attached diagrammatic drawings, of which: Fig* 1 shows a simplified layout diagram of laminating equipment incorporating the invention! Fig. 2 shows the same equipment from aboveί Fi sh w 31300/2 sides: Pigi 5 shpws a section through the edge zones of the striib shown in Figure 4 after this has been divided up into independent strips: and Fig. 6 shows different types of overlap joint« For the sake of clarit the arrangement shown in Figs. 1 and 2 will first be described, after which an account will be given of the way in which the actual method Is carried out* The laminator and strip-outting arrangement shown in Figs. 1 and 2 consists of a stand supporting a large roll 1 of a material which is to constitute the carrier layer 2 in t^he complete laminate. One example of such a material is paper.

The cutting means whereby the strip of carrier layer is divided into suitable widths comprise rotatable knives 3 adapted to work against a counter-roller 3a. Beyond the ftnlves 3 and roller 3a the web is received by one or more spreade rollers 5» (also in trade circles sometimes called a "Mount Hope Roll") which is substantially spool-shaped, double-cone or barrel-shaped roller, i.e. has a diameter which is greater at the middle of the roller and progressively decreasing towards the ends of the roller. An extruder device 15 for the extrusion of thermoplastic material is provided by which hot plastics material is forced out at high pressure through a slit-shaped orifice to form a continuous film applied to the carrier layer. There is provided a set of laminating rollers 8, viz two interacting rollers of which at least one is preferably a cooling roll. Another support carries a roll 6 of a material which can be laminated to the carrier layer* Another cutting device 11 which may be constructed in the same way as the first cutting 3 is provided, but in some 31300/2 - be heated in order that a sealing operation can be carried Out at the same time as a cutting operation.

A winder 12 is provided on to which the complete* / strips of laminate can be rolled.

When the method in accordance with the invention < is carried out, a roll 1 of the carrier layer material 2 is first placed on its stand. The web of carrier material is generally too wide for use as the final strip of mater- ial from which paokages are to be made and is therefore cut into a number of strips of the desired width. In order to carry out this cutting operation, the web 2 is fed to the cutters to be divided longitudinally by the rotatable knives 3 working against the counter roller 3a over which the web is fed. After the web 2 is thus divided into a number of separate strips 4» these strips are fed over one or more spreader rollers 5 in which the strips (which after the cutting operation remain hard against one another side-by-side) are spread and separated as shown in Figure 2» The spread which is to be achieved is in general not large, and may conveniently result in a space between the strips of between 2 and 10 mm.

The strips 4 thus separated laterally, are fed over a plain roller of constant diameter which arrests the spreading, and the strips again travel forward in the same plane, with the desired spacing* The strips 4 are now fed forward to a laminating station consisting of a set of rollers 8 and an extruder 15· A film of plastics material 9 is forced out of the extruder 15 in a hot and fluent condition and is spread onto the strips 4 in such a wa that it covers all the stri s of carrier material 31500/2 the outer strips of carrier material.

For the purpose of illustration, a description of another lamination onto the stripe of carrier mater» ial, of a strip of pre-produced material will now be mentioned.

The width of this strip 7 of material, which may be a metal foil and which is unwound from the second storage roller 6, corresponds substantially to the width of the extruded film of plastics, and it is laminated with the strips 4 of carrier material as illustrated. This exampl shows that the method in accordance with the invention may be applied using both extrusion lamination, and lamination by applying pre-produced foils, as well as by a combination of both these procedures.

The strips 4 of carrier material, the ex*truded film 9 of plastics material and the strip 7 of preformed material, if applied, are brought together and compressed between the rollers 8, which preferably incorporates* at least one cooled roller by which the extruded plastics layer is cooled to such an extent that it is solidified.

The laminate 10 described thus consists of the strips 4 of carrier material, separated from one another, and of continuous layers 9 and 7 consisting of plastics and metal foil respectively, laminated onto the strips of carrier mater* ial. This laminate 10 is fed past the cutting device 11 by which it is divided into separate strips by means of cuts in plastics zones 13 between the spread-out strips.

The separate strips of laminate no formed, consist of a carrier layer and of one or more layers laminated onto ti 31300/2 carrier layer, (at least one of which, in the example now being described, is a plastics layer). In each case the plastics layer extends beyond the edge of the carrier layer strips and forms overhanging edge zones 16. The separated strips of laminate are wound up onto storage ralHec means 12. In some cases it is desirable that both sides of the strips of carrier material be coated with a plastics layer, and in this case tho first cutting and spreading of the strip by means of cutting device 3 is carried out in the above described way. The, first coating of the laterally spread strips 4 also takes place ✓ in the manner described above, but the strips 4 are then given a second coating of plastics after the orientation of the strip has been changed by means of rollersΦ This second plastics coating may be effected in the same way as the first application of a plastics coat; After the second application of the plastics coat, the strip formed is cut up by the cutting device 11, and in this case the rotstable knives may be heated, so that the two plastics layers on the carrier layer material are caused to melt together at the same time as they are cut in the spaces between the strip of carrier material. Such melting-together of the plastics coats means that the strip of carrier material is enolosed within the plastics material, (Pig. 5).

Sections of a portion of the strip are shown in Fig. 3 respectively in positions A-A, B-B, C-C, D-D, E-E indicated in Fig. 2..

Section A-A shows the uncut web of carrier material 2 whloh after passing the cutting device 3 has the appearance 31300/2 . shown in Section, Β·Β· When the web of oarrier material 2, cut into separate strips 4, has passed spreader roller 5» the section through a strip will appear as in Section C-C. At the coating and laminating station with its roller 8, the separated strips are coated with an unbroke homogeneous layer 9, 7 which is vrider than the total width of. strips 4 and intervening spaces 13. The coating may be an extrusion coating of plastics film or a lamination of a pre-produced film. The coating layer 18 (Pig. 3) may consist of an extruded plastics layer, or a web of, a plastics film or metal foil, or combinations of these materials. Section D-D shows the separated carrier material strips 4 with a coating layer 18 which in addition to covering the complete width of strips also bridges the spaces 13 between the strips, and extends outside the outer strips 4 in ed e zone portions 16.

The strips 4 united by the coating layer 18 are again separated by the cutting device 11 along a line 17 to form independent stripe 10 each having a coating layer that covers one side of the strip and extends beyond the side edges thereof. In order to obtain this desired shape of strip, separation of the strips 4, is effected by cutting through the coating layer 18 where it extends across the spaces 13 between the strips of carrier material as shown in Figure 2, and the result achieved after this second cutting operation is shown in Section E-E in Fig. 3, As previously indicated a web may be turned over after one side of the separatedstrips of carrier material has been coated, and the opposite side of the web ooated in the 31300/2 same way. After such a double coating operation, a strip of the kind shown in Pig* 4 is obtained* If one or each of the coatings 18 of this strip contains a layer of a thermoplastics material, e.g. polyethylene, a sealing of the cut edge 20 of the strip of carrier material may be effected e.g. during the cutting operation carried out by a heated cutter* which cuts through both the coating layers 18 in areas 13 and weld them together in the area of the cute as shown in a aone 19 of the type shown in, Fig.

„ If it is desired that the portions which project beyond the outer edges of the outer strips shall also be joined, this may be effected by passing the edges of the outer strips between two hoated pressure rollers, which compress and weld together the coating layers.

Different types of overla joint which may be made use of when a strip of packaging material is formed into a tube by means of the longitudinal edges of the strip being joined to one another are shown in Figure 6.

An overlap joint of conventional type is shown in Fig, 6a, in which a separate strip 21 is placed over the joint to cover the cut edges 25 of the carrier layer. Joints produced using coating materials produced in accordance with the invention are shown in Figures 6b and 6c· Figure 6b shows an overlap joint using a strip of packaging material as described above, one side of which 3s coated with coating material. The coating layer constitutes the inner surface of the tube formed by rolling up the strip and the edge 23 of the coating ¾>hioh projects from the edge of the carrier material is sealed, to the coating layer at the opposite edge zone of the stri of material. The coating layer is of material which, does not absorb liquid, and at least the outer layer of the coating consists of a material capable of being sealed, so that it is possible to construct a watertight and durable seal, A tube joint, wherein opposite sides of a strip of material which- has ,been coatad on both sffles, in accordance with the invention are Joined together in an overlap joint, is shown in Figure 60· Since the cut edge of the carrier layer in this strip of material is completely enclosed and sealed by virtue pf the fact that the projecting coating layers have been joined to one another in a watertight seal , no additional measures need be taken in order to render the cut odge of the carrier material waterproof.

It is within the scope of the invention to modify both the apparatus which has been diagrammatically described abov and the material which is produced by this process within the terms of the appended claims.

Alternative compositions of the coating layer and alternative forms of apparatus used to apply the coating layer and to spread out the strips may be employed, to ensure the production of a number of narrower strips from a wider web of carrier material, which are then collectively covered with a coating layer that extends beyond the outer edges of the narrower strips. 31300/2

Claims (3)

1. , A method of producing, froa a web of packaging material, narrower strips of laminate material, -iherein the web is longitudinally divided into a plurality j of strips, and the severed strips slightly separated from one another in transverse direction, whereafter a coating material is applied to one face of the divided web in order to form a covering layer over the surface of the several strips, and aleo overlaps the gap or gaps between the separated strips, the layer extending across the, or each, gap being longitudinally cut to l/save an overhanging edge zone of the coating layer projecting beyond the edge of each strip*

2. # A method as claimed in Claim 1 wherein the covering layer on each strip is a plastics filn, or a metallic foil, or both in superposed relation on the strip*

3. * A method as claimed in Claim 1 or 2 wherein mater«» ial for a caering layer is drawn as a web from a roll, and laminated with the strips of the firstmentioned divided web. 4» A method as claimed in any preceding claim wherein plastics material is applied by extrusion to the spaced strips to form the covering layer. 5· A method as claimed in any preceding olaim wherein both sides of the spaced strips are coated with plastics material* 6» A method as claimed in Claim 5 wherein the plastic coating on each side of a strip has an overhanging edge zone projecting beyond the cut edge by which the strip was separated from the adjacent wt?b areas, 7; A method as claimed in Claim 6 wherein the two overhanging edge zones along the edges of a strip are sealed together, 8. Apparatus incorporating means for carrying into effect the various steps of the method as claimed inany of Claims.1 - 7 comprising cutting means for longitudinally severing a web of material into strips, and means for relatively displacing said strips laterally to leave a1 ap between adjacent strips. 9· Apparatus as claimed in Claim 8 wherein the cut ing means comprise a rotatable knife. 10· Apparatus as claimed in Claim 8 or 9 wherein said strip-displacing means comprise a double-cone or barrel-shaped roller. 11. Apparatus as claimed in Claim 8, 9 or 10 comprising means for delivering material to form a covering layer on one face of the web after severance into spaced strips, said covering material extending across the gap or gaps between strips. 12. Apparatus as olalmed in Claim 11 wherein said covering-applying means comprise extrusion means for delivery of fluent plastics material to the cut web. 13· Apparatus as claimed in Claim 11 wherein said covering-applying means comprise a roll of web of covering mater-ial, means for drawing said covering material off its web, and applying, and bonding it to the spaced strips of said 31300/2 ^ longitudinally divided web. 14» Apparatus as claimed In Claim 11, 12 or 13 comprising second cutter means for longitudinally severing the strip of covering material extendlt^ across a gap between the spaced strips of the longit dinally divided web. 15· Apparatus as claimed in Claim 14 wherein said second cutter means comprise a rotating knife. 16» Apparatus as claimed in Claim 14 or 15 wherein said second cutter means are adapted to be heated, 17· A method of producing laminated strip material sub-, st ntlally as described herein with reference to the accompanying drawings* 18· Apparatus for manufacture of laminated strip material substantially as described herein with reference to the accompanying drawings* 19· ¾aminated strip material, or an article made therefrom whenever produced in accordance with a method as claimed in any of Claims 1 - 7 or 17» or by use of apparatus as claimed In any of Claims 8 - 16 or 18· RTHERS