GB2371791A

GB2371791A - A self-sealing sachet for packaging and dispensing liquid, gel or paste like products

Info

Publication number: GB2371791A
Application number: GB0201688A
Authority: GB
Inventors: Jean-Paul Pige
Original assignee: Pige SA
Current assignee: Pige SA
Priority date: 2001-01-26
Filing date: 2002-01-25
Publication date: 2002-08-07
Also published as: FR2820119A3; GB0201688D0; DE20201546U1; FR2820119B3

Abstract

A self sealing sachet for packaging and dispensing liquid, gel or paste like products comprises two sheets (2,3) constituting the faces of the sachet which are welded together to form a chamber (V) for receiving and storing a product. An S-shaped evacuation channel (Z<SB>2</SB>) for dispensing the product is formed between the two sheets (2,3) of the sachet so that when pressure (F<SB>2</SB>) is exerted on the sachet the contents is dispensed. When the pressure (F<SB>2</SB>) is released the channel (Z<SB>2</SB>) closes by surface adhesion between the two sheets (2,3) so that the sachet does not leak. Preferably weld zones (Z<SB>5</SB>, Z'<SB>5</SB>) are formed in the vicinity of the longitudinal edges (L<SB>1</SB>,L<SB>2</SB>), these weld zones (Z<SB>5</SB>, Z'<SB>5</SB>) may have a rounded profile, with the concavity of the boundary (C5,C'5) facing the adjacent longitudinal edge(L<SB>1</SB>, L<SB>2</SB>). The sachet is preferably made from multi-layer transparent or translucent plastics material comprising a core (101) made of polyamide coated on one face with a layer of heat-sealable polyethylene (102) and on its opposite face with a finish(103). A flexible tie (6) maybe attached for suspending the sachet.

Description

The present invention relates to a supple sachet for packaging, to the use

made thereof and to a method for packaging a product by means of such a sachet. In the domain of packaging fluid products, it is known to use sachets 5 made of plastics material as described, for example, in US-A-3 380 646. Such sachets present the advantage of allowing long-term storage of the products that they contain, while taking up relatively little room. Such sachets are composed of two principal faces substantially parallel to each other and a [ace forming a gusset constituting the bottom of the sachet.

10 When it is desired to used the product contained in such a sachet, it is known to cut a corner thereof, possibly along a cut-out line, in order to create an opening through which the product contained in the sachet can flow out. Once open, such a sachet can no longer be closed and the product that it contains must be consumed relatively quickly, otherwise it is likely to spoil. In addition, 15 a sachet which is already open cannot be transported easily and must be held at such an orientation that its opening lies uppermost, failing which the product that it contains would flow outside the sachet, causing total or partial loss of the product and pollution of its environment.

It is for this reason that the use of such supple sachets has, up to the 20 present time, been limited to products used all at once or used within a short lapse of time, such as animal food.

In other domains, such as the packaging of cosmetic or hygiene products, it is known to use packagings of semi-rigid plastics material, of the bottle, tube or pot type, provided with a removable stopper allowing each packaging to be 25 opened several successive times. The dimensions of such packagings are relatively large, including when they are only partially full, and it is difficult to

empty them completely. For example, a tube of dentifrice or a bottle of shampoo is generally discarded while it still contains some product. Such packagings may be of relatively high cost price and are relatively bulky, taking up a non ne21igible amount of space in household rubbish.

5 It is a particular object of the present invention to overcome the drawbacks set forth hereinabove, by proposing a supple sachet for packaging a product of the liquid, paste or gel type, which allows fractionated use of this product over a relatively long period, without presenting the limitations of the state of the art packagings incorporating a stopper.

10 To that end, the invention relaters to a supple sachet for packaging a product of the liquid, paste or gel type, this sachet comprising two sheets constituting the principal faces of the sachet and welded together along the edges of the sachet so that they define therebetween a principal volume for receiving and storing the product. This sachet is characterized in that it 15 comprises a channel for evacuation of the product from its principal volume, the channel being Snide between the afore-mentioned two sheets and formed by a zone in which the two sheets are not welded, whereas they are welded together in the vicinity of this channel, this channel being substantially in the shape of an S and presenting a width such that, when no effort of squeezing is exerted on 20 the principal faces of the sachet, the channel closes by surface adhesion between the sheets.

Thanks to the invention, a supple sachet may be used for packaging products consumed over a relatively long period of time, without risk of the product spoiling, since the evacuation channel is closed by adherence of the 25 sheets which define it, without using a stopper or other closure means. The sachet of the invention can be emptied completely by being squeezed and, when

it is empty, can be discarded without taking up room in a rubbish bin.

According to advantageous but non-compulsory aspects of the invention, the sachet incorporates one or more of the following characteristics: - The opening of the channel is made at the level of a first edge of the 5 sachet, while, near the edges adjacent this fast edge, the sheets are welded together over zones extending towards the centre of the receiving volume with respect to these adjacent edges, the distance between these zones being less than the distance between the edges adjacent the first edge on either side of these zones, with the result that a constriction is created between these zones, which 10 constricts circulation of the product. The fact of creating a constriction induces a convergentldivergent movement of the product when an effort of squeezing or of crushing is exerted on the principal faces of the sachet, which allows optimum distribution of the product towards the opening of the evacuation channel. This facilitates extraction of the product from the sachet. These zones 15 of welding of the sheets may be provided to present a rounded section, the concavity of their boundaries with the volume for receiving the product facing the closest adjacent longitudinal edge.

- The sheets are each made of a multi-layer plastics material comprising a core made of polyamide coated, on one face, with a layer of heat- sealable 20 polyethylene and, on its opposite face, with a finish. This finish is advantageously formed by a central layer based on polypropylene coated, on its face oriented towards the core of the sheet, with a layer of heat-sealable bonding material and, on its opposite face, with a layer of material of malt appearance. 25 - The sheets are made of transparent or translucent materials. Information relative to the contents of the sachet may, of course, be affixed on these sheets,

particularly in the form of printed legend or labels. The transparent or translucent character of the sheets makes it possible to visualize the interior of the sachet in order to know the quantity of product remaining in the sachet after it has been opened, or the nature thereof.

5 - The sachet comprises a bottom interposed between the afore-mentioned sheets, opposite the evacuation channel with respect to the centre of the volume for receiving the products. This bottom, which is not compulsory, allows the sachet to stand upright, in accordance with the technical teaching of US-A-3 380 646.

10 The afore-mentioned sheets and possibly the bottom are each pierced with at least one orifice for passage of a flexible tie for suspending the sachet.

This allows the sachet to be suspended with the evacuation channel lowermost, with a view to being used by squeezing, the product flowing in the lower part of the sachet. The fact that the evacuation channel in that case lies in the lower part 15 of the sachet is not a drawback since this channel is efficiently closed thanks to the surface adhesion of the sheets which delimit it.

The invention also relates to the use of the sachet described hereinabove for packaging cosmetic or hygiene products, dnnks, food for animals, or glue.

Other uses of this sachet may, of course, be envisaged.

20 Finally, the invention relates to a method for packaging a product which may be effected thanks to the sachets described hereinbefore. In this method, two sheets intended to constitute the principal faces of the sachet are welded over the major part of the periphery, with the possible interposition of an additional sheet intended to form the bottom of the sachet. This method 25 comprises the following steps of: - forming, by localized welding of the sheets, a non-rectilinear channel

connecting a volume for receiving the product to the outside, while leaving an opening for access to this receiving volume free, independently of this channel; - filling the said volume with a desired quantity of product via said opening, and - closing said opening by welding the sheets.

The first step mentioned above may be camed out in the workshop of the custom-moulder preparing the sachets, while the second and third steps are earned out in the premises of the firm producing the products which are immediately bagged.

10 The invention will be more readily understood on reading the following description of two forms of embodiment of a sachet in accordance with its

principle and of a method for packaging by means of one of such sachets, given solely by way of example and with reference to the accompanying drawings, in which: 15 Figure 1 is a view in perspective of a sachet according to the invention.

Figure 2 is a section along line II-II of Figure 1.

Figure 3 is a section along line III-m of Figure 2.: Figure 4 schematically shows a first step of using the sachet of Figure 1.

Figure 5 is a view similar to Figure 4 during a subsequent step of using 20 the sachet.

Figure 6 is a view similar to Figure 4 during a step of subsequent storage of the sachet.

Figure 7 is a view similar to Figure 4 showing another possibility of storage of the sachet.

25 Figure 8 is a section on a larger scale, and along line IV-IV in Figure 2, of a sheet of plastics material used for making the sachet of Figures 1 to 7.

Figure 9 schematically shows a first step of manufacture of the sachet of Figures 1 to 8.

Figure 10 is a view similar to Figure 9 during a subsequent step of packaging a product.

5 Figure 11 is a view similar to Figure 10 during a second subsequent step of packaging the product, and Figure 12 is a view similar to Figure 6 for a sachet in accordance with a second form of embodiment of the invention.

Referring now to the drawings, the sachet 1 shown in Figures 1 to 11 is 10 formed by assembling two sheets 2 and 3 of plastics material, with the interposition of a sheet 4, in the form of an upturned V, constituting the bottom of the sachet 1. Sheets 2 to 4 are welded on the periphery of the sachet 1 and define therebetween a volume V for receiving a product which, in the example shown, is a liquid bath/shower soap L. 15 In Figure 3, the zones in which the sheet 2 is welded by heat-sealing to the sheet 3 or to the bottom 4 are hatched. In Figure 1, these zones are represented by cross hatchings corresponding to the superposition of the zones in question with those of the sheet 3, these zones being seen by transparency through sheet 3.

20 The sheet 2 is substantially rectangular in shape, with two large sides Lit and L2 and two small sides 1 and 1,, these small sides being shown respectively at the top and bottom of Figure 3.

As shown at the top and to the right in this Figure, sheets 2 and 3 are welded over a substantially rectangular zone Zag, while, in a central part Z2 of 25 this zone Zig, the sheets 2 and 3 are not heat-sealed. This central zone constitutes a channel in which the liquid L can penetrate as represented by arrow Fl. This

channel Z2 has a substantially constant width l and is divided into a first part Z3 forming a curve with a centre of curvature facing the inside of the sachet 1, and into a second zone Z4 forming a curve whose centre of curvature lies on the side opposite the centre of curvature of the preceding zone Z3, i.e. towards the 5 outside of the sachet 1. In this way, the channel Z2 iS in the form of an S. As is more particularly visible in Figure 8, the sheet 2 comprises a core 101 made of polyamide which constitutes an efficient barrier to the migration of gases from or towards volume V. This core is also tight with respect to the liquid L. On its face 101_ oriented towards the volume V, the core 101 is coated 10 with a layer 102 of polyethylene improving tightness of the sheet 3 and allowing it to be welded or sealed with one of the sheets 2 or 4.

On its face 101b opposite face 101_, the core 101 is coated with a complex 103 rendering the sachet 1 pleasant to the touch and to the eye. This complex, or finish, comprises a central layer 103a made of polypropylene and 15 an inner layer 103b interposed between the layer 103a and the core 101 and allowing adhesion by heat-sealing of the coating 103 on the core 101. The central layer 103g is coated, opposite the layer 103b, with an outer layer 103c made of heat-sealable material of mall appearance.

The structure of sheet 3 is identical to that of sheet 2.

20 In the hatched part of zone Zig in Figure 3, sheets 2 and 3 are sealed by fusion of layers 102 and equivalent which are in contact. In zone Z2, the layer 102 of the sheet 3 and the equivalent layer of sheet 2 are in surface contact without being welded together and, taking into account their respective surface tensions, they adhere to each other by default.

25 Before the sachet 1 is first used, the volume V is completely surrounded by the hatched zones in Figure 3 in which the sheets 2, 3 and 4 are sealed.

When the liquid L is to be used, sheets 2 and 3 can be cut along a predetermined line 5 shown in broken lines in Figure 3.

It is then possible to force the liquid L out of the volume V by exerting on the sheets 2 and 3 an effort F2 of crushing or of squeezing shown in Figure 4.

5 If the user releases the effort F2 as shown in Figure 5, the liquid L is no longer subjected to a pressure tending to cause it to penetrate in the channel Z' via its opening Z'2.

In the absence of such a pressure, the sheets 2 and 3 stick together again by superficial adherence of the layers 102 and equivalent, with the result that 10 the channel Z2 iS closed, without the use of a stopper, and the liquid L present in the volume V is isolated from the outside atmosphere and there is no risk of its flowing out.

This surface adhesion of the sheets 2 and 3 at the level of channel Z2 iS an unexpected result. In particular, the liquid might have been expected to enter the 15 channel Z2 by gravity, separating the sheets 2 and 3. This is not the case, as the surface tension of the material used is sufficient to seal the channel Z2 efficiently. The sachet 1 may then be kept in either of the positions shown in Figures 6 and 7.

20 For storage in the position of Figure 6, the sachet 1 is provided with a small cord 6 passing through orifices 7 made in the sheet 2 and 3 and in the bottom 4. The cord may be replaced by a ribbon or any other flexible tie, the choice of this tie being made as a function of the nature of the product contained in the sachet 1.

25 On the longitudinal edges Lit and L2 of the sachet 1 along which the sheets 2 and 3 are welded together, there are provided two zones Z5 and Z's in

which the sheets 2 and 3 are likewise welded together, this having the effect of creating a constriction since the distance do between these zones is shorter than the distance d' between the edges Lo and L2 on either side of these zones This constriction induces a convergentldivergent movement of the liquid 5 L in the Volume V when an effort F2 is exerted, this convergent movement being represented by arrows F3 and F'3 In Figure 3. This convergent/divergent movement ensures that a sufficient quantity of liquid is directed, with a sufficient pressure, towards the opening Z'2 of the chapel Z2 when the egos F2 is exerted.

10 Zones Z5 and Z's are parts of discs of which C5 and C'5 denote the circumferences, the centres of these circumferences lying respectively at the level of edges L' and L2. In this way, the concavity of the circumferences Cat and C2 faces the edges Lo and L2 while zones Z5 and Z'5 present a rounded profile. 15 According to a variant embodiment of the invention (not shown), the zones Zs and Z'5 might be offset with respect to each other over Me length of the edges Lo and L2, as long as a constriction creating a convergent/divergent movement of the liquid L towards the opening Z'2 can be created.

As is more particularly visible in Figures 9 to 11, when it is desired to 20 package a product in the sachet 1, the sheets 2, 3 and 4 are welded essentially over the zones shown hatched in Figure 3. In Figure 9, only the constitution of zone Zen is represented, this zone being obtained using two tools S 1 and 52 which are heated and brought together as represented by arrows F4 and P'4. Tool 52 comprises a zone 52_ intended to be heated with a view to a superficial 25 fusion of the sheets 2 and 3 in order to create zone Zen, while a hollow zone 52b is not heated, so as to create the channel Z2- Tool 51 is constituted in the same

manner. Dunng the operation shown in Figure 9, the sheets 2 and 3 are not welded together in a zone Z6 adjacent to zone Zoo.

After the sachet 1 has been prepared as shown in Figure 9, it may be 5 conducted to a station where it is filled with the product L, this being represented by arrow F5 in Figure 10. The product L in that case transits through an opening O made between sheets 2 and 3 at the level of zone Z6 When the sachet 1 has been filled, it suffices to heat the sheets 3 locally to produce a zone Z7 of additional weld of the sheets 2 and 3, this closing the 10 opening O (Figure 11).

In the second form of embodiment of the invention shown in Figure 12, elements similar to those of the first form of embodiment bear identical references increased by 200. The sachet 201 shown in this Figure differs from the previous one essentially in that it comprises a single series of orifices 207, 15 traversing sheets 202 and equivalent which constitute it, for the passage of a small cord 206 for suspending the sachet 201.

This sachet has no bottom, the sheets 202 and equivalent being directly welded together in the upper part of the sachet 201 shown in Figure 1. The bottom 4 of the first form of embodiment can, in effect, be dispensed with.

20 As previously, a channel Z2 in the form of an S is provided to connect the principal volume V of the sachet 201 to the outside, this channel being able to be closed in the absence of a squeezing effort exerted on the principal faces of the sachet 201.

In practice, the shape of the sachet 201 may be preferred for relatively 25 small packagings.

A sachet according to the invention may be used for cosmetic or hygiene

products, such as shampoo, washing cream, hand-cream, liquid soap, dentifrice or washing-up liquid. It is also possible to use such a sachet for energy drinks, for example adapted to be canted by a sportsman taking part in a bicycle- or orienteering race. Domestic applications may also be envisaged, particularly for 5 the packaging of fertilizers for plants, fish food or glue, such as wood glue or paste. In any case, fractionated use of the product contained in these sachets can be envisaged.

Whatever the form of embodiment, the sachet 1 or 201 may carry technical or commercial information relative to its content. Such information 10 may be printed directly on the sheets 2, 3, 202 or equivalent, or affixed in the form of a label 8 or 208.

Claims

1. A supple sachet for packaging a product of the liquid, paste or gel type, this sachet comprising two sheets constituting the principal faces of the sachet and welded together along the edges of the sachet, so that they define 5 therebetween a principal volume for receiving and storing the product, wherein it comprises a channel (Z2) for evacuation of said product from said principal volume (V), said channel being made between said two sheets (2, 3; 202) and formed by a zone (Zen) in which said two sheets are not welded, whereas they are welded together in the vicinity (Zag) of said channel, said channel being 10 substantially in the shape of an S and presenting a width (1) such that, when no effort (F2) of squeezing is exerted on the principal faces of the sachet, the channel closes by surface adhesion between the sheets.

2. A sachet as claimed in Claim 1, wherein the opening (Z'2) of said channel

(Z2) is formed at the level of a first edge (1) of said sachet and, in the vicinity of 15 the edges (Lo, I') adjacent said first edge, said sheets are welded together over zones (Zs, Z'5) extending towards the centre of said receiving volume (V) with respect to said adjacent edges (L', 2), the distance Ad) between said zones being less than the distance (O between said edges adjacent to-said first edge on either side of these zones, with the result that a constriction is created 20 between these zones for the circulation 3, F'3) of said product.

3. A sachet as claimed in Claim 2, wherein said zones (Z5, Z's) of weld of said sheets in the vicinity of the longitudinal edges (Lo, L2) have a rounded profile, the concavity of their boundary (C5, C'5) with the volume receiving the product, facing the closest adjacent longitudinal edge (Lo, L2).

25 4. A sachet as claimed in one of the preceding Claims, wherein said sheets (2, 3; 202) are each made of a multi-layer plastics material, comprising a core

(101) made of polyamide coated, on one face (101), with a layer (102) of heat sealable polyethylene and, on its opposite face (lOlO with a finish (103).

5. A sachet as claimed in Claim 4, wherein said finish (103) is formed by a central layer (103a) based on polypropylene coated, on its face oriented towards 5 the core (101) of said sheet (2, 3, 202), with a layer (103O of heat-sealable bonding material and, on its opposite face, with a layer (103) of material of - matt appearance.

6. A sachet as claimed in one of the preceding Claims, wherein said sheets (2, 3; 202) are made of transparent or translucent materials.

10 7. A sachet as claimed in one of the preceding Claims, wherein it comprises a bottom (4) interposed between said sheets (2, 3) opposite said channel (Z2) with respect to the centre of said volume (V) for receiving the product (L).

8. A sachet as claimed in one of the preceding Claims, wherein said sheets (2, 3; 202) and possibly said bottom (4) are each pierced with at least one 15 orifice (7; 207) for passage of a flexible tie (6; 206) for suspending said sachet (1; 201).

9. Use of a sachet (1; 201) as claimed in one of the preceding Claims for packaging cosmetic or hygiene products, clanks, food for animals or glue.

10. A method for packaging a product of liquid, paste or gel type, in which 20 two sheets (2, 3; 202) intended to constitute the principal faces of a supple sachet (1; 201) are welded over the major part of their periphery Hi, k, Lo, L2), with the possible interposition of an additional sheet (4) intended to form the bottom of the sachet, wherein it comprises the steps consisting in: - forming, by localized welding of said sheets, a non-rectilinear channel 25 (Z2) connecting a volume (V) for receiving the product (L) to the outside, while leaving an opening (O) for access to said receiving volume free, independently

of said channel; - filling 5) said volume with a desired quantity of product via said opening, and - closing said opening by welding (Z7) said sheets.