GB2172245A - Creasing matrix strips and matrix assemblies - Google Patents

Abstract

Matrix strips for use in a platen press for producing creases in card carton blanks comprise a metal strip (6) with an adhesive layer (7) on one face thereof for fixing the strip (6) to a platen. On the other face of the strip (6) are formed two longitudinal spaced strips of synthetic resin material (9, 10) to define a channel between their adjacent edges (11, 12). In order to avoid difficulties in feeding card across a platen provided with such creasing matrix strips, due to the height of the matrix strip, the outer edges of the synthetic resin strips are inclined or rounded so as not to present a vertical side surface. <IMAGE>

Description

SPECIFICATION Improvements in or relating to creasing matrix strips and matrix assemblies This invention relates to creasing matrix strips and matrix assemblies for use in the production of creases along which material is to be folded to form boxes, cartons, folders or the like.

The card or like material is normally cut and creased ready for folding by means of a cutting and creasing platen press. To produce the desired pattern of cuts and creases, a cutting and creasing forme is prepared from cutting and creasing rules. In addition a creasing matrix is applied to the platen, said matrix comprising a number of channels corresponding to the edges of the creasing rules. Thus, when the press is closed with a piece of card resting on the matrix, the creasing rules force the card into the channels to produce the desired creases.

It is known to produce, the creasing matrix on the platen by temporarily attaching lengths of channelled strip to the creasing rules and causing these lengths to adhere to the platen in register with the creasing rules.

Each of the matrix strips may comprise a metal strip having two mutually spaced apart strips of synthetic resin material on its upper surface. The lower surface of the metal strip is provided with an adhesive layer so that it will adhere to the upper surface of the platen.

In order to produce the temporary attachment of the matrix strips to the creasing rules, each of the matrix strips may be provided with a location strip which releasably grips the sides of the creasing rules and which is removably secured on the matrix strip.

When the matrix strip consists of a metal strip having strips of synthetic resin material on the upper surface to form the channel, it is usual for both the inner and outer edges of the two synthetic resin strips to be substantially perpendicular to the metal strip, for example, as shown in United Kingdom Patent Specification No. 909331.

When the card is to be fed into the platen press automatically, the upright ridges at the sides of the matrix strips may cause difficulties in the feeding, and accordingly it is an object of the present invention to provide a creasing matrix strip which does not suffer from this disadvantage.

From one aspect the invention consists in a creasing matrix strip comprising a metal strip having an adhesive layer on its underside, the upper surface of the strip being formed with two longitudinal spaced strips of synthetic resin material which define a channel between their adjacent sides, the outer sides of the synthetic resin strips extending downwardly and outwardly.

It will be understood that matrix strips in accordance with the invention present an inclined surface to the leading edge of card being fed into the platen press and accordingly do not impede the feeding of the card.

It will also be understood that, if the metal strip extends for the full width of the two synthetic resin strips, there will still be a slight step in the path of the card corresponding to the thickness of the metal strip and the thickness of the adhesive layer beneath it. In some circumstances even this very small step may cause feeding problems, and accordingly it is preferred that the metal strip is narrower than the overall width of the matrix strip and that the metal strip is recessed into the two synthetic resin strips.

Even the arrangement defined in the preceding paragraph still leaves a step equal to the thickness of the adhesive layer. Accordingly in a futher preferred embodiment of the inventioe adhesive layer is recessed into the synthetic resin strips as well as the metal strip. Preferably the recess provided for the adhesive layer is wider than the recess provided for the metal strip. However, in another form of the invention the adhesive layer has the same width as the metal strip and the two are accommodated in the same recess.

In yet a further embodiment, the upper surfaces of the synthetic strips are curved to extend downwardly and outwardly to terminate in edges situated in or below the plane of the undersurface of the adhesive layer.

From another aspect the invention consists in any features of novelty, taken singly or in combination, of the four embodiments of the invention illustrated in the accompanying diagrammatic drawings, in which: Figure 1 is a perspective view of a matrix assembly in accordance with the invention; Figure 2 is a perspective view of a modified form of matrix assembly in accordance with the invention; Figure 3 is a perspective view of a further modified form of matrix assembly in accordance with the invention; and Figure 4 is a perspective view of a further modified form of matrix assembly in accordance with the invention.

The assembly illustrated in Fig. 1 includes a location strip 1 made of a synthetic resin material and formed with a channel 2 designed to enable the assembly to be fitted to a creasing rule of a creasing platen press. The location strip 1 is also provided with two lines of tacky adhesive 3 and 4, by means of which the location strip can be temporarily secured to the matrix strip 5.

The matrix strip includes a metal strip 6, on the underside of which is a double-sided adhesive tape 7 which is normally protected by a paper strip 8. On the upper side of the metal strip 6 are two strips of synthetic resin material 9 and 10. The adjacent sides 11 and 12 of the strips 9 and 10 are perpendicular to the surface of the metal strip 6 and between them define the channel which will cooperate with the creasing rule to produce the required creases.

The outer edges of the two strips 9-and 10 are inclined as shown at 13 and 14.

When the creasing matrix is to be made up, the assemblies are cut to the required length and fitted to the creasing rules by inserting the rules in the channels 2. The paper strip 8 is removed from the adhesive tape 7 and the press is closed. As a result, the matrix strips 5 adhere to the platen and the location strips 1 are detached from the creasing rules. Since the location strips are secured to the matrix strips only by tacky adhesive, the location strips can thereafter be removed from the matrix. Preferably a hot melt adhesive is used for the tacky adhesive and it is found-that this adheres preferentially to the location strip and does not leave any residue on the matrix strips.

It will be seen from Fig. 1 that, when the matrix is in position on the platen, the only impediment to feeding of the card across the platen is the very thin upright step constituted by the thickness of the metal strip 6 and the adhesive tape 7. Since even this small step may sometimes cause feeding problems, the modified form of matrix strip illustrated in Fig.

2 may be preferred.

The assembly illustrated in Fig. 2 is identical to that illustrated in Fig. 1 except that the metal strip 6 is recessed in the two synthetic resin strips 9 and 10. It will be seen that in this case the only step presented to the card being fed is constituted by the thickness of the adhesive tape 7.

If even the thickness of the tape 7 causes feeding- problems, the arrangement illustrated in Fig. 3 may be used. In this case, it will be seen that both the metal strip 6 and the adhesive tape 7 are recessed in the synthetic resin strips 9 and 10. Consequently the inclined sides 13 and 14 of the matrix strip present no step at all to the card being fed. As illustrated, the adhesive tape 7 is wider than the metal strip 6 and is accommodated in its own recess. However, as previously mentioned, the metal strip may be the same width as the adhesive tape and in this case both the strip and the tape can be accommodated in the same recess.

As an alternative to the inclined side surfaces 13 and 14, the synthetic resin strips may be rounded in profile, provided that they present no vertical side surface portion.

The embodiment shown in Fig. 4 also presents no vertical step to impede the feeding of the card. In this embodiment the synthetic strips 9, 10 extend laterally beyond the metal strips 6 and are smoothly curved downwards and tapered in thickness so that when in position on the platen no vertical discontinuity is apparent. The matrix strip may also be so formed that the extreme edges of the synthetic strips form lips 9a, 10a, which, in their unstressed condition, are situated in a plane below that of adhesive layer 7. This will ensure that intimate contact of these edges and the platen is maintained at all times due to the resilience of the synthetic strips 9, 10.

It will also be noted that the recess accommodating the metal strip 6 and adhesive layer 7 does not conform exactly to the outline of the combined strip 6 and layer 7. It is to be understood that no necesssity for exact conformity of the recess to the metal strip 6 and layer 7 exists, even in the earlier embodiments, although such conformity is shown in Figs. 1 to 3.

To assist in cutting the matrix strips to the correct length before attaching them to the creasing rules it is preferred that markings should be provided on the exposed side of the paper strip 8 to indicate length. Markings may consist, for example, merely of transverse lines spaced at 5 mm intervals.

However any other convenient form of marking may be used as an alternative.

Claims (7)

1. A creasing matrix strip comprising a metal strip having an adhesive layer on its underside, the upper surface of the strip being formed with two longitudinal spaced strips of synthetic resin material which define a channel between their adjacent sides, the outer sides of the synthetic resin strips extending downwardly and outwardly.

2. A creasing matrix strip according to claim 1, in which the outer inclined sides of the synthetic resin strips extend below the upper surface of the metal strip.

3. A creasing matrix strip according to claim 2, in which the side portions of the metal strip are received in recesses formed in the synthetic resin strips.

4. A creasing matrix strip according to claim 1 or claim 2, in which the outer inclined sides of the synethetic resin strips extend downwardly to the plane of the adhesive layer.

5. A creeasing matrix strip according to claim 4, in which the side portions of the metal strip and of the adhesive layer are received in recesses formed in the synthetic resin strips.

6. A creasing matrix strip in accordance with claims 1, 2 or 3, in which the synthetic resin strips extend laterally beyond the adhesive layer and are tapered in thickness and curved to terminate in lips situated in or below the plane of the adhesive layer.

7. A creasing matrix strip according to any preceding claim, substantially as shown in Fig.

1, 2, 3 or 4 of the drawings.