Object of the invention.
[0001] The object of the present invention is a container pre-cutting device, in particular
for containers formed with multilayer materials, comprising a die plate and a punch
holder plate provided with blades for making an upper and lower precut, in the multilayer
material of the containers positioned on the die plate.
Field of application of the invention.
[0002] This invention is applicable in the field dedicated to the manufacture of containers
and preferably containers for food use, such as yogurt packs or the like.
State of the art.
[0003] In the manufacture of containers and in particular containers for the food industry,
packs are commonly formed with a variable number of packages which, once filled and
closed, are subjected to cutting and pre-cutting operations in which a portion of
the contour of the mouths of the containers is cut and precut lines which facilitate
the subsequent breaking and separation of the containers from the pack are marked
in the remaining portions of the contour.
[0004] These cutting and pre-cutting operations are commonly performed by a die provided
with a die plate, and a punch plate which incorporates for making the precuts blades
which partially project from said punch holder plate and make a crease or precut line
on the upper face of the container.
[0005] In containers formed with single-layer or double-layer plastic, making the precut
line in the upper area of the container is sufficient to allow the subsequent breaking
and separation of the containers from the pack by the user. However, today it is common
to use in the manufacture of these containers multilayer plastics incorporating more
than three layers, using up to nine plastics, which have up to more than 30 layers.
[0006] With the use of these multilayer plastics, the pre-cutting devices used today are
unable to leave the marking or impression of the precut line in the lower layers of
the multilayer material, which constitutes an important problem since it generates
defects in the breaking and separation of the containers from the pack.
[0007] Therefore, the technical problem that is considered is the development of a container
pre-cutting device of the type mentioned above which allows the problems set forth
above to be solved in a satisfactory manner.
Description of the invention.
[0008] The container pre-cutting device object of this invention, comprising a die plate
and a punch holder plate provided with blades for marking a precut line in the upper
area of the multilayer material of the containers positioned on the die plate, presents
features aimed at defining two precut lines in opposition on opposite faces of the
multilayer material of the containers, preventing the defects of breaking and separation
of the containers, known to all manufacturers of cutting tools for Form, Fill & Seal
(FFS) lines.
[0009] To that end, and according to the invention, this pre-cutting device has an essential
feature consisting of the incorporation in the die plate of a lower blade, in opposition
to the upper blade of the punch plate, such that this pre-cutting device simultaneously
makes in the container two precut lines on opposite faces of the container, whereby
achieving said double precut line affecting both the upper face and the lower face
of the multilayer material, assuring correct breaking and separation of the containers
from one and the same pack.
[0010] Both the upper blade of the punch holder plate and the lower blade of the die plate
are formed in a high mechanical strength material, for example metal carbide, assuring
a long duration of the edges of the blades.
[0011] This device achieves the precut lines defined on opposite faces of the multilayer
material affecting both the upper layers and the lower layers of the multilayer material,
preventing defects in the breaking and separation of the containers.
Description of the figures.
[0012] As a complement to the description provided herein, and for the purpose of helping
to make the characteristics of the invention more readily understandable, the present
specification is accompanied by a set of drawings which, by way of illustration and
not limitation, represent the following:
- Figure 1 shows a top perspective view of a container cutting and pre-cutting die provided
with the pre-cutting device of the invention.
- Figure 2 shows a partially cross-sectioned elevation view of two portions of the die
plate and the punch holder plate in which the upper blade and the lower blade, fixed
respectively to the punch holder plate and to the die plate, and a portion of multilayer
material of a pack of containers with the two upper and lower precut lines defined
by said blades can be observed.
Preferred embodiment of the invention.
[0013] The embodiment shown in Figure 1 depicts a die provided with a die plate (1) and
a punch holder plate (2) which, as schematically shown in Figure 2, incorporates upper
blades (3) for defining a precut line on the upper face of the multilayer material
of the containers positioned on the die plate (1).
[0014] According to the invention, and as shown in the mentioned Figure 2, the die plate
(1) incorporates, in a position in opposition to the upper blades (3), lower blades
(4) which form, together with the former, the pre-cutting device of the invention.
[0015] When the punch holder plate (2) is brought closer to the die plate (1), the upper
blades (3) and the lower blades (4) define in the multilayer material (5) of the container
two precut lines: an upper precut line (51) and another lower precut line (52), which
affect both the upper layers and the lower layers of the multilayer material of the
containers, assuring correct breaking and separation of the containers from a pack.
[0016] As can be seen in Figure 2, the punch holder plate (2) has, on one side of the upper
blades (3), a protrusion (21) for pushing the multilayer material (5) against the
lower blade, assuring both upper and lower cutting.
[0017] Having sufficiently described the nature of the invention, in addition to a preferred
exemplary embodiment, it is hereby stated for the relevant purposes that the materials,
shape, size and layout of the described elements may be modified, provided that it
does not imply altering the essential characteristics of the invention claimed below.