Counter-die cylinder blanket of die cutting machine and blanket manufacturing process

Abstract

Counter-die cylinder blanket of die cutting machine comprising a band (3) of soft plastic material provided with a key (4), and an insert (5) of stiffening material housed in the key (4), wherein the insert (5) additionally comprises separating ribs (11) which extend from the top face (8) and/or from a bottom face (9) to facilitate the positioning of the insert (5) in the key (4) during the forming by moulding of the band (3) inside of a mould (16), and it preferably incorporates separating ribs (11) which extend from its side faces (10).

Claims

1. A counter cylinder blanket for a die cutting machine comprising: a key seat defined on a surface of the counter-die cylinder; a band of soft plastic material designed to completely surround the counter-die cylinder including the key seat to provide therein a key of the band; a sheet of stiffening material incorporated in the band of soft plastic material and outlining the counter-die cylinder blanket; and an insert of stiffening material housed inside the key of the band, the insert comprising a body having a front end, a rear end, a top face, a bottom face and side faces, wherein insert disposed inside of the key of the band is surrounded by the band of soft plastic, the body of the insert has a parallelepiped configuration and wherein the insert additionally comprises separating ribs which extend from the bottom face and/or the top face of the body of the insert, grooves that extend longitudinally along a length of the body, and a plurality of striations defined in the body of the insert to increase adherence between the insert and the band of soft plastic material.

2. The counter-die cylinder blanket according to claim 1, comprising separating ribs which extend from the side faces.

3. The counter-die cylinder blanket according to claim 1, wherein the grooves are defined in the top face of the body and/or the bottom face of the body of the insert, which extend longitudinally between the front end and the rear end.

4. The counter-die cylinder blanket according to claim 1, wherein the the plurality of striations defined in the top face and/or the bottom face of the insert.

5. The counter-die cylinder blanket according to claim 1, wherein in the plurality of striations have a saw tooth pattern.

6. The counter-die cylinder blanket to claim 1, wherein the plurality of striations have an undulated shape.

7. The counter-die cylinder blanket according to claim 1, wherein the insert additionally comprises a handling area defined in the front end designed to be manipulated during handling of the insert during introduction of the insert in the key seat, which is provided with lines of identification.

8. The counter-die cylinder blanket according to claim 1, wherein the sheet of stiffening material is made of fiber glass.

9. The counter-die cylinder blanket according to claim 1, wherein the soft plastic material of the band is polyurethane.

10. The counter-die cylinder blanket according to claim 1, wherein the separating ribs have a rounded tip.

11. The counter-die cylinder blanket according to claim 1, wherein the separating ribs have the same height.

12. A manufacturing process of the counter-die cylinder blanket according to claim 1, which makes use of a mould of essentially cylindrical geometry, comprising: an inner mould, an outer mould concentric to the inner mould, a cavity defined between the inner mould and the outer mould, and a mould key seat defined in the surface of the inner mould, designed to create the key of the band, comprising the stages of: introducing the insert in the mould key seat, by means of the use of the separating ribs for an introduction and guiding parallel to the faces of the mould key seat, and to achieve a centred positioning of the insert inside of said mould key seat, pouring inside the cavity of the mould the plastic material constituting the band in fluid state, until filling the inner volume of said cavity, including the mould key seat and the insert introduced, curing the plastic material poured, and extracting the band from the mould, and producing a band with cylindrical cortex geometry, with the key provided with an insert embedded inside.

13. The manufacturing process of the counter die cylinder blanket according to claim 12, further comprising the additional previous stage of positioning of a sheet of stiffening material inside of the cavity of the mould in a position adjacent to the surface of the inner mould.

14. The manufacturing process of the counter-die cylinder blanket according to claim 12, wherein after the curing the cutting is performed of the handling area of the insert.

Description

DESCRIPTION OF THE DRAWINGS

(1) To complement the description being made and in order to aid towards a better understanding of the characteristics of the invention, according to a preferred example of practical embodiment thereof, a set of drawings is attached as an integral part of said description wherein, with illustrative and non-limiting character, the following has been represented:

(2) FIG. 1.Shows an elevational view of a detail of a cross-section made in an assembly formed by the counter-die cylinder and the blanket according to a first preferred embodiment of the blanket, wherein the separating ribs defined in the insert are observed.

(3) FIG. 2.Shows a perspective view of the stiffening insert inserted in the key seat according to a second preferred embodiment wherein upper, lower and side separating ribs are observed.

(4) FIG. 3.Shows an elevational view of a detail of a cross-section made in an assembly formed by the counter-die cylinder, a stiffening sheet and a blanket according to the second embodiment.

(5) FIG. 4.Shows an elevational view of a detail of the production of the blanket inside of a mould according to the second embodiment.

PREFERRED EMBODIMENT OF THE INVENTION

(6) A detailed explanation is given below of examples of preferred embodiment of the object of the invention with the aid of the aforementioned figures.

(7) FIG. 1 shows a counter-die cylinder blanket of die cutting machine mounted on a counter-die cylinder (1) which has defined on its surface a key seat (2), said counter-die cylinder (1) being completely surrounded by a polyurethane band (3). The band (3) in turn comprises a key (4) housed in the key seat (2) of the counter-die cylinder (1), and inside of the key (4) is housed an insert (5).

(8) The insert (5), shown in FIGS. 1 to 4, is formed by a body of essentially parallelepiped geometry, provided with a front end (6), a rear end (7), a top face (8), a bottom face (9) and side faces (10), and a plurality of separating ribs (11) which emerge from the bottom face (9) and top face (8) in the first embodiment shown in FIG. 1, and which additionally emerge from the side faces (10) in the second embodiment, shown in FIGS. 2 to 4.

(9) The insert (5) incorporates in the top face (8) different grooves (12) which extend longitudinally between the front end (6) and the rear end (7), as observed, for example, in FIGS. 1 and 2. Additionally, the surface of the top face (8) comprised between both grooves (12) has defined a plurality of striations (13) which extend longitudinally from the front end (6) to the rear end (7) of the insert (5).

(10) It additionally contemplates that the insert (5) incorporates an extension or handling area (14) in its front end (6), as observed in FIG. 3, designed to be the place of gripping and handling of the insert (5) during its introduction in the mould (16), delimited by indicative lines (21).

(11) It is also provided that the band (3) additionally comprises a layer of stiffening material (15), as observed in FIG. 3, which in this preferred embodiment is a fibre-glass sheet.

(12) FIG. 4 shows a mould (16) used for the manufacturing of the blanket, which has an essentially cylindrical geometry, and comprising an inner mould (17) and an outer mould (18) concentric to the inner mould (17) between which is defined a cavity (19). On the surface of the inner mould (17) is a mould key seat (20) designed to form the key (4) of the band (3).

(13) In the event one wants to form a blanket with a sheet of stiffening material (15), the manufacturing process starts with the positioning of said sheet of stiffening material (15) inside of the cavity (19) of the mould (16), adjacent to the surface of the inner mould (17).

(14) Subsequently, the insert (5) is introduced in the mould key seat (20), by means of the use of the separating ribs (11) for an introduction and guiding parallel to the faces of the mould key seat (20), and to achieve a centred positioning of the insert (5) inside of said mould key seat (20).

(15) In that moment the plastic material constituting the blanket (1) is poured inside the cavity in fluid state, until filling the inner volume of said cavity (19), including the mould key seat (20) and the insert (5) introduced. Both the grooves (12) and the striations (13) defined in the insert (5) increase their surface and therefore increase the adherence of said insert (5) with the material of the band (3) surrounding it.

(16) Additionally, the separating ribs (11) defined in the top face (8) of the insert (5) prevent the direct contact of this insert (5) with the sheet of stiffening material (15), avoiding contaminations and guaranteeing good adherence as it allows the entry of a layer of plastic material between the sheet of stiffening material (15) and the insert (5), as detailed in FIG. 4.

(17) Then the blanket is extracted from the mould (16), producing a blanket with cylindrical cortex geometry, with the key (4) provided with an insert (5) embedded inside and the handling area of the insert is cut.

(18) In FIG. 1, it is observed that the blanket is connected to the counter-die cylinder (1), covering its outer surface with the key (4) inserted in the key seat (2).