OVER-WRAPPING ENVELOPE FOR FILTER BAGS AND METHOD OF FORMING A PACKAGE WITH OVER-WRAPPING ENVELOPE

Abstract

An over-wrapping envelope containing a filter bag for an infusion product, includes a sheet of over-wrapping paper folded in a “U” shape along a transversal axis around the filter bag to have two parts of over-wrapping material superposed on said filter bag, the sheet having two parallel longitudinal flaps, a bottom flap at the folding and a top flap parallel to the bottom flap, parallel first and second closing tracks formed by grooves along lateral edges of the longitudinal flaps of the folded sheet and where the first and second tracks are obtained by mechanical deformation of the two superposed parts of the sheet (2) at the respective longitudinal flaps; and a third closing track formed by grooves along the transversal top flap obtained by mechanical deformation of the two superposed parts of the sheet at the transversal top flap.

Description

DESCRIPTION

Technical field

This invention relates to an over-wrapping envelope made of paper material for filter bags containing, in particular, tea.

The invention also relates to a method for forming a package with an over-wrapping envelope.

Background art

Products obtained from natural and recyclable materials are currently increasingly requested on the market for tea bag packages.

For this reason, packages with over-wrapping envelopes made of materials such as paper, which is easily recyclable. are increasingly required.

This type of over-wrapping envelope is formed by a sheet of paper folded to form a “U” around the filter bag in such a way as to enclose the filter bag.

The sheet has a flap protruding from one of the sides of the “U” which can be folded towards the outer surface of the other side of the sheet for closing the opening of the over-wrapping envelope.

The two sides of the sheet and the flap are sealed by mechanical deformation (for example by mechanical means) performed on the outer edges of the sheets and of the folded flap.

According to a different solution, the edges are closed by a distribution of cold adhesive on the edges with subsequent pressure on the edges to allow the adhesion with closing of the over-wrapping envelope.

However, both these solutions have drawbacks.

According to the first above-mentioned solution, the presence of the flap folded and sealed only on the lateral edges has the effect of possible loss of product powder during its handling due to the incomplete closing of the opening of the over-wrapping envelope.

The solution of an over-wrapping envelope with the use of cold glue comprises plastic material inherent in the glue product and it is therefore a product which might not be accepted as it is a product which is not completely recyclable.

Aim of the invention

The aim of the invention is to provide an over-wrapping envelope made of paper material for filter bags containing, in particular, tea which overcomes the above-mentioned drawbacks of the prior art.

In particular, the aim of this invention is to provide an over-wrapping envelope made of paper material for filter bags containing, in particular, tea which is able to maintain high sealing characteristics of the package combined with high recyclability and reduced production costs.

A further aim of the invention is to provide a method for forming a package with the over-wrapping envelope which is able to obtain the envelope quickly and safely and without increasing the costs and steps for the machines for forming the production product.

Said aims are fully achieved by an over-wrapping envelope made of paper material for filter bags containing, in particular, tea and a method for forming a package with the over-wrapping envelope according to the invention as characterised in the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The main features of the invention will become more apparent from the following detailed description of a preferred, non-limiting embodiment, illustrated purely by way of example in the accompanying drawings, in which:

FIG. 1 illustrates a front view of an over-wrapping envelope made of paper material for filter bags containing, in particular, tea according to the invention;

FIG. 2 shows a front view of a first variant embodiment of the over-wrapping envelope made of paper material for filter bags containing, in particular, tea;

FIG. 3 shows a front view of a second variant embodiment of the over-wrapping envelope made of paper material for filter bags containing, in particular, tea;

FIGS. 4 to 7 illustrate a corresponding succession of steps for the formation of a package with an over-wrapping envelope of the preceding drawings; FIGS. 4 and 5 are schematic side views, whilst FIGS. 6 and 7 are schematic perspective views.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

With reference to the accompanying drawings, in particular FIGS. 1 to 3, the over-wrapping envelope according to the invention, labelled 100 in its entirety, is used for containing a filter bag 1 for an infusion product, of the powdered or leaf tea type.

The filter bag 1 may be of various types, that is to say, single-or two-lobed with or without string and tag, without thereby limiting the inventive aspect of the solution.

As illustrated, the over-wrapping envelope 100 comprises a sheet 2 of over-wrapping paper folded into a U shape along its transversal axis Y around the filter bag 1 in such a way as to have two parts of the sheet 2 of over-wrapping material superposed with the filter bag 1 interposed between them.

The sheet folded into a “U” has peripherally two longitudinal flaps 3 and 4 parallel to each other, a transversal bottom flap 5 (closed) at the U-shape and a top flap 6 parallel to the bottom flap 5.

Again as illustrated, the envelope 100 comprises a first 7 and a second 8 closing track, parallel to each other, and formed by grooves along the respective longitudinal flaps of the folded sheet 2.

The first track 7 and the second track 8 are obtained by mechanical deformation of the two parts of the sheet 2 (knurls) at the respective longitudinal flaps 3 and 4.

Again as illustrated, the envelope 100 comprises a third closing track 9 formed by grooves along the transversal flap 6 and obtained by mechanical deformation of the two superposed parts of the sheet 2 at the transversal top flap 6 (knurling).

As illustrated in FIG. 3, for example, the first and the second closing tracks 7 and 8 intersect the third closing track 9 in at least one respective joining zone between the lateral flaps and the top flap.

On the other hand, as illustrated in FIGS. 1 and 2, the first and the second closing tracks 7 and 8 may extend along the entire extension of the lateral flaps to the top flaps, whilst the third closing track 9 extends for a length less than the distance between the first 7 and the second 8 track, in such a way as to not intersect with at least one between the first and the second tracks 7 and 8.

Preferably, the third track 9 does not intersect both the first and the second tracks 7 and 8.

As illustrated in FIG. 1, the first and second closing tracks 7 and 8 have a respective orientation of the mechanical deformation grooves parallel to the transversal folding axis Y of the envelope 100.

It should be noted in FIG. 1 that the third closing track 9 has an orientation of the mechanical deformation grooves perpendicular to the orientation of the mechanical deformation grooves of the first 7 and second 8 closing tracks.

According to an alternative embodiment not illustrated, the first and second closing tracks 7 and 8 may have a respective orientation of the mechanical deformation grooves transversal to the transversal folding axis Y of the envelope 100.

As illustrated in FIGS. 2 and 3, the third closing track 9 may have an orientation of the mechanical deformation grooves parallel to the transversal folding axis Y of the envelope.

It should be noted that the sheet 2 of over-wrapping material which forms the over-wrapping envelope 100 is obtained from recycled paper.

The envelope 100 comprises at least one weakening notch 10 for opening the envelope 100 made on the first 7 and/or on the second 8 track.

The envelope 100 shown FIGS. 1 to 3 comprises a notch 10 on the first 7 and on the second 8 track.

In FIG. 3, with a dashed line, the envelope 100 illustrated comprises one or more notches 10 also made on the third track 9 (intersected on the first and second tracks 7 and 8).

It should also be noted that the sheet 2 of over-wrapping material is in direct contact with the filter bag 1, without any other material being interposed.

The invention also provides a method for forming a package with an over-wrapping envelope 100 of a filter bag 1 for an infusion product, of the type such as tea in powder or leaf form.

The method comprises the following steps:

• • preparing a sheet 2 of over-wrapping material made of paper (FIG. 4);
  • folding the U-shaped sheet 2, along its transversal axis Y, around the filter bag 1 in such a way as to have two parts of the sheet 2 of over-wrapping material superposed with the filter bag 1 interposed between them; the sheet 2 folded in a U-shape has peripherally two longitudinal flaps 3, 4 parallel to each other, a transversal bottom flap 5 at the folding of the U-shaped sheet and a transversal top flap 6 parallel to the bottom flap 5. (FIG. 5);
  • making a first 7 and a second 8 closing track, parallel to each other, forming grooves along lateral edges of the two longitudinal flaps 3 and 4 of the folded sheet 2; the first and second tracks 7 and 8 being obtained by mechanical deformation of the two superposed parts of the sheet 2 at the respective longitudinal flaps 3 and 4 (FIG. 6);
  • making a third closing track 9 formed by grooves along the transversal top flap 6; the third track 9 is obtained by mechanical deformation of the two superposed parts of the sheet 2 at the transversal top flap 6 (FIG. 7).

The step of making the first 7 and second 8 track and the step of making the third 9 track occur in terms of time in two separate moments through separate deformation means (for example, opposite knurling heads for the pair of lateral tracks and a pair of heads for the head track).

Alternatively, the step of making the first 7 and second 8 tracks and the step of making the third track 9 occur simultaneously through, by way of non-limiting example, a single deformation element 11 composed of two opposite rollers each with knurling heads for the lateral tracks 7 and 8 and a transversal bar, rotating with the respective rollers, and able to form the third track 9, in a single passage, according to a predetermined step of feeding the pairs of rollers relative to the length of the folded sheet 3 (see FIGS. 6 and 7).

The step of making the first 7 and second 8 closing tracks is achieved with a mechanical deformation configured for making repeated grooves having orientation parallel to or transversal to the axis Y.

Similarly, the step of making the third closing track 9 is achieved with a mechanical deformation configured for making repeated grooves having an orientation perpendicular to the orientation of the grooves of the first 7 and second 8 tracks.

The orientation of the grooves is given by the shaping of the knurling heads.

It should be noted that the step of making the first 7 and the second 8 closing tracks comprises the formation of grooves along the entire respective lateral edge of the two longitudinal flaps 3, 4 of the folded sheet 2, until striking the top flap 6.

In light of this, the step of making the third closing track 9 comprises the formation of grooves along the entire top flap 6 until striking the longitudinal flaps 3, 4, in such a way that the first 7 and the second 8 closing tracks intersect the third closing track 9 in at least one respective joining zone between the longitudinal flaps 3, 4 and the top flap 6.

Alternatively, the step of making the third closing track 9 may extend for a length less than the length of the top flaps, not intersecting with the first 7 and the second 8 tracks.

After the step for making the third track 9 a single or pair of notches 10 is made on the lateral edges of the envelope 100.

It should be noted that the sheet 2 of over-wrapping material is wrapped around the filter bag 1 without any interposing of other material, so as to be directly in contact with it.

The over-wrapping envelope thus obtained fully achieves the preset aims thanks to the use of a sheet of paper with three closing tracks which allow a high level of sealing of the filter bag.

The absence of a folding of the top flap allows material to be saved in order to obtain the over-wrapping envelope.

This product as a whole is fully recyclable and can also be obtained with recycled paper without the need for operational changes on existing packaging machines.

Claims

1. An over-wrapping envelope containing a filter bag for an infusion product, of the type such as tea in powder or leaf form, the over-wrapping envelope comprising: a sheet of over-wrapping material made of paper folded into a “U” shape along its transversal axis around the filter bag in such a way as to have two parts of the sheet of over-wrapping material superposed with interposed said filter bag, said sheet folded into a “U” shape having peripherally two longitudinal flaps parallel to each other, a transversal bottom flap at the folding of the “U” shape sheet and a transversal top flap parallel to the bottom flap; characterised in that it also comprises:a first and a second closing track, parallel to each other, formed by grooves along the respective lateral edges of the two longitudinal flaps of the folded sheet, said first and second tracks being obtained by mechanical deformation of the two superposed parts of the sheet at the respective longitudinal flaps; anda third closing track formed by grooves along the transversal top flap, said third track being obtained by mechanical deformation of the two superposed parts of the sheet at the transversal top flap.

2. The envelope according to claim 1, wherein the first and the second closing tracks intersect the third closing track in at least one joining zone between the lateral flaps and the top flap.

3. The envelope according to claim 1, wherein the first and second closing tracks have a respective orientation of the mechanical deformation grooves parallel to or transversal to the transversal folding axis of the envelope and wherein the third closing track has an orientation of the mechanical deformation grooves perpendicular to the orientation of the mechanical deformation grooves of the first and second closing tracks.

4. The envelope according to claim 1, wherein the sheet of over-wrapping material is made of recycled paper.

5. The envelope according to claim 1, comprising at least one weakening notch for opening the envelope made on the first and/or the second track and/or on the third track.

6. The envelope according to claim 1, wherein said sheet of over-wrapping material is in direct contact with the filter bag, without any other material being interposed.

7. A method for forming a package with an over-wrapping envelope of a filter bag for an infusion product, of the type such as tea in powder or leaf form, comprising the steps of: preparing a sheet of over-wrapping material made of paper;folding the U-shaped sheet, along its transversal axis, about the filter bag in such a way as to have two parts of the sheet of over-wrapping material superposed with interposed said filter bag, said sheet folded in a U-shape having peripherally two longitudinal flaps parallel to each other, a transversal bottom flap at the folding of the U-shaped sheet and a transversal top flap parallel to the bottom flap;making a first and a second closing track, parallel to each other, forming grooves along the respective lateral edges of the two longitudinal flaps of the folded sheet, said first and second tracks being obtained by mechanical deformation of the two superposed parts of the sheet at the respective longitudinal flaps;making a third closing track formed by grooves along the transversal top flap, said third track being obtained by mechanical deformation of the two superposed parts of the sheet at the transversal top flap.

8. The method according to claim 7, wherein the step of making the first and second tracks, and the step of making the third track occur in terms of time in two separate moments.

9. The method according to claim 7, wherein the step of making the first and second tracks, and the step of making the third track occur simultaneously.

10. The method according to claim 7, wherein the step of making the first and second closing tracks is obtained with a mechanical deformation configured for making repeated grooves having an orientation parallel to or transversal to the transversal axis and wherein the step of making the third closing track is obtained with a mechanical deformation configured for making repeated grooves having an orientation transversal to or parallel to the orientation of the grooves of the first and second tracks.

11. The method according to claim 7, wherein the step of making the first and second closing tracks comprises the formation of the grooves along the entire respective lateral edge of the two longitudinal flaps of the folded sheet, until striking the top flap, and wherein the step of making the third closing track comprises the formation of the grooves along the entire top flap until striking the longitudinal flaps, in such a way that the first and the second closing tracks intersect the third closing track in at least one respective joining zone between the longitudinal flaps and the top flap.

12. The method according to claim 7, wherein said sheet of over-wrapping material is wrapped around the filter bag without any interposing of other material, in such a way as to be directly in contact with it.