WO1998026997A2

WO1998026997A2 - Multicompartment package and method for making the same

Info

Publication number: WO1998026997A2
Application number: PCT/EP1997/007147
Authority: WO
Inventors: Nigel Colin Theobald
Original assignee: The Boots Company Plc
Priority date: 1996-12-16
Filing date: 1997-12-12
Publication date: 1998-06-25
Also published as: AU5760998A; WO1998026997A3; GB9626050D0

Abstract

A multicompartment sachet comprises a first sheet member (1) which forms one outer face of the sachet, a second sheet member (2) which forms the other outer face of the sachet, one or more dividing sheets (3) of the same size and shape as the first and second sheet members (1, 2), said one or more dividing sheets (3) being sealed between the first and second sheet members (1, 2) around the periphery thereof to provide separate compartements (4, 5) within the sachet.

Description

PACKAGING

The present invention relates to a multicompartment pack for containing two or more incompatible ingredients and means for manufacturing such a pack.

Many products are sold in sachet form. A sachet form of packaging has many advantages. Sachets are cheap to make, provide ease of access to the contents in a single dose form whilst providing a tamper-evident and leak proof container for the product prior to use. As many products may be volatile, sachets also provide closed packaging which can be opened only once, immediately prior to use. However many formulations are unsuitable for presentation in a single sachet as they contain incompatible ingredients which have to remain separated prior to use.

Conventional twin sachets are no more than single sachets joined via a piece of web. They require the user to open each sachet separately and mix the ingredients correctly to form the resultant product. This may involve undue dexterity or skill and need instructions printed on the sachet in a suitable language. It is easy for users of such twin sachets to use the contents of only one compartment so providing an incorrect or incomplete dose. It is difficult to manufacture sachets with multiple internal compartments which dispense their contents through a single orifice.

There is a need to provide a cheap and easy method of making a simple, sealed sachet pack containing two or more separate compartments for separating incompatible ingredients which forms a product on opening the sachet without requiring skill from the user and which appears to the user as a single sachet.

The applicant has developed such a sachet and methods of manufacturing it. The present invention provides a multicompartment sachet comprising a first sheet member which forms one outer face of the sachet

a second sheet member which forms the other outer face of the sachet

one or more dividing sheets of the same size and shape as the first and second sheet members, said one or more dividing sheets being sealed between the first and second sheet members around the periphery thereof to provide separate compartments within the sachet.

The first and second sheet members may be manufactured from a laminate comprising one layer which is, for example, of a metal eg aluminium foil and a layer which is of a heat-sealable plastics material. The laminate which is used for the first and second sheet members may be the same or different. Usually the first and second sheet members will be the same. In the sachet the heat-sealable plastics material is on the inside forming the outer wall of the outermost compartments. The laminate from which the first and second sheet members are manufactured may have additional layers, eg of a plastics material or paper. Said additional layers will be on the outside of the completed sachet providing strength and/or a suitable surface to which product information and/or directions for use can be applied. During continuous manufacture and filing of the sachet the first and second sheet members may be fed into the manufacturing/filling machine as separate webs or a single web may be folded to provide the first and the second sheet members.

The dividing sheets may be manufactured from a single sheet of a plastics material or from a laminate which has a plastics material on both of its outer surfaces. The plastics material must be one that is heat sealable to the plastics material(s) of the first and second sheet members to provide the seal around the periphery. When the dividing sheet is a laminate it may comprise a central layer for example a metal foil having layers of the plastics material (which may be the same or different) on its outer faces. Preferably there is a single dividing sheet so that the number of compartments in the sachet is two.

Suitable heat sealable plastics materials include polyolefins such as polyethylene or polypropylene, nylon, polyvinylchloride or polystyrene.

The term laminate as used herein embraces multilayer sheets in which the layers are preformed and then assembled together or in which one or more layers have been coated onto a preformed substrate.

The sachet may be provided with means to ensure that the consumer can open all the compartments at the same time enabling the contents of all the compartments to be emptied out together. This means may comprise a line of weakness across the sheet members and the dividing sheets to enable the consumer to tear the sachet along the line of weakness to simultaneously open all the compartments. Alternatively a notch may be formed in the side of the sachet to provide a starting point for the tear made when the consumer opens the sachet. As an alternative to tearing, implements such as scissors may be used to open the sachet.

In accordance with a further aspect of the present invention, there is provided a method of producing multicompartment sachets on a continuous production line comprising the steps of:

(a) folding an outer web about a longitudinal axis in a V-shape;

(b) inserting one or more dividing webs in between the arms of the V with one longitudinal edge contacting the fold line of the folded outer web;

(c) guiding the outer and dividing webs to a forming station whilst maintaining their relative positions; (d) joining the dividing web and the two arms of the folded outer web along the foldline of the outer web and along two spaced lines transverse to the direction of movement to define a plurality of fluid retaining pockets, the pockets being open along a side of the webs parallel to the direction of movement;

(e) moving the webs so that they pass horizontally through a filling station with the unsealed side of the pockets facing upwards;

(f) filling each pocket through the open side with a fluid product from a filling means at the filling station;

(g) sealing the top of all the pockets to produce a closed sachet comprising a plurality of internal compartments containing said fluid products ; and

(h) separating the filled sachets from the web.

In accordance with a further aspect of the present invention there is provided a method of producing multicompartment sachets on a continuous production line which comprises the steps of

(a) positioning a first outer web, a second outer web and one or more dividing webs such that the sides of the webs which are parallel to the direction of movement are aligned;

(b) guiding the webs to a forming station whilst maintaining their relative positions;

(c) joining the outer webs and the dividing webs along the said sides of the webs and across the webs transverse to the direction of travel to define a plurality of fluid retaining pockets, the pockets being open along a side transverse to the direction of travel of the webs;

(d) moving the webs so that they pass vertically through a filling station with the unsealed side of the pockets facing upwards;

(e) filling each pocket through the open side with a fluid from a filling means at the filling station;

(f) sealing the top of all the pockets to produce a sachet comprising a plurality of internal compartments containing said fluid products; and

(g) separating the filled sachets from the webs.

The sachets of the present invention have various advantages. A sachet with two or more compartments permits presentation of products comprising two or more incompatible ingredients which can be separated until use. Thus the shelf life and/or quality of products may be extended. Products can be formed in situ just before use, so formulations which would not normally be stable or acceptable as a commercial product can be stored as separate components in the sachet. The sachets are particularly useful for carrying products where mixing of different ingredients produces a benefit to the consumer. The sachets are also useful for products where two ingredients are compatible when mixed for a short time but which would react if mixed over a significant period of time. The compositions in each compartment may be any suitable fluid e.g. powders and/or liquids. If the compartments comprise a powder and a measured volume of liquid the sachet may provide a drink where water supplies are limited or contaminated or may provide a product for rehydration therapy

Examples of products to be contained in the multicompartment sachets of the present invention include: two part adhesives for example epoxy or cyanoacrylate adhesives where two components are stored in separate compartments in the sachet and are mixed immediately prior to use;

hair dyes where two components are stored in separate compartments in the sachet and are mixed immediately prior to use to generate the desired colour;

effervescent compositions in which the effervence is produced by mixing the components of an effervescent couple (eg an acid and a carbon dioxide source such as a carbonate or bicarbonate salt) in which the components of the effervescent couple are stored in separate compartments in the sachet and mixed with a solvent, for example water immediately prior to use;

pharmaceutical compositions in which the components would be incompatible if stored together but which have a satisfactory shelf life if the components are stored in separate compartments in the sachet and are mixed immediately prior to use.

Examples of suitable pharmaceutical compositions are:

antibiotic formulations in which the powdered antibiotic is stored in one compartment of the sachet and a liquid carrier is stored in a second compartment. The antibiotic and liquid carrier are mixed immediately prior to use;

vitamin formulations in which the vitamins are stored in one compartment of the sachet and other components of the formulation which may cause degradation of the vitamins are stored in another compartment, for example ibuprofen and vitamin C; controlled release formulations in which a drug component for immediate release is contained in one compartment and a second drug component, which may be the same as or different from the first drug component, in sustained release form is contained in a second compartment, for example an immediate release analgesic and a sustained release analgesic;

flavoured formulations in which some or all of the flavouring components are contained in one compartment and the other components of the formulation which may cause degradation of the flavouring components are contained in a second compartment;

combination formulations in which a first drug is contained in one compartment and a second drug, which may be incompatible with the first if they are stored together, is contained in a second compartment, for example ibuprofen and/or flurbiprofen and other actives such as codeine or pseudoephedrine;

skin care formulations in which active medicaments are contained in a suitable form in one compartment and carrier or diluent components are contained in a second compartment. The active medicament and carrier or diluent are mixed prior to use.

Sachets produced by the method of the present invention are opened by a single operation (e.g. tearing or cutting across one end of the sachet) to open both compartments at the same time. Thus when the sachet is opened the contents of each compartment can be dispensed together and mixed to form the desired product as each compartment is opened at the same time and mixing occurs as the compartments are emptied through the single orifice. Thus mixing is out of the control of the user which prevents the possibility of incorrect mixing or dosing. The end-user of the sachet will be unaware of the mixing of the contents of all the compartments on opening and will treat the sachet as if it were a conventional single chambered sachet. The method of making these sachets has the advantage of using readily available conventional tools on a packaging production line which are modified simply and inexpensively to reduce the extra cost of manufacturing the new sachets. Sachets produced by the method described above use less material that would be required for conventional double or twin sachets which are joined side by side through a connecting web without a common inner wall.

Specific non-limiting embodiments of the invention will now be described as follows with reference to the drawings in which:-

Figure 1 is a cross-sectional view of one embodiment of a two compartment sachet according to the present invention.

Figure 2 is an enlarged cross-sectional view of a part of Figure 1.

Figure 3 is a plan view from above of a continuous production line used in one embodiment of a method according to the invention.

Figure 4 is plan view from above of a continuous production line used in a second embodiment of a method according to the invention.

Figure 5 is the same plan view of the line shown in Figure 4 at a different point in the cycle of sachet production.

Figure 6 is a schematic side view of apparatus for manufacturing two compartment sachets of the present invention.

The sachet shown in Figures 1 and 2 comprises a first sheet member 1 , a second sheet member 2 and a dividing sheet 3. The sheet members 1, 2 and the dividing sheet 3 are sealed together around their periphery to provide two separate compartments 4, 5 to contain fluid products (not shown). The first sheet member 1 is a laminate comprising an outer layer 6 which may be a metal foil for example of aluminium and a heat sealable plastics layer 7, for example a polyolefin such as polyethylene. The second sheet member 2 is a laminate comprising an outer layer 8 which may be a metal foil and a heat sealable plastics layer 9. The outer layers 6, 8 and the plastics layers 7, 9 in the first and second sheet member may be the same or different. The dividing sheet is a laminate of a central layer, for example a metal foil 10 having layers of heat sealable plastics layers 11 , 12 on each face thereof. The plastics layers 11 , 12 may be same or different and may be the same or different from the plastics layers 7, 9. The plastics layers 7 and 11 must be heat sealable to one another to form a fluid tight seal and must be compatible with the fluid product contained in compartment 4. Similarly the plastics layers 9 and 12 must be heat sealable to one another and compatible with the fluid product contained in compartment 5. The first and second sheet members may have additional layers (not shown) to provide strength to the sachets or a suitable surface to which product information and/or directions for use can be applied.

With reference to Figure 3, in a process to manufacture the sachets of the present invention, the sachet is formed by using two webs of material, one web (101) forming the first and second sheet members which are the outer walls of the sachet and the other web (103) forming the dividing sheet.

Both webs are fed continuously from reels (not shown). The outer web (101) is made from a laminate of a heat sealable plastics material, for example a polyolefin, coated on one side with an outer layer which may be a plastics material or a metal foil. The outer web is folded to make a V in transverse cross section, the heat sealable plastics material being on the inner side of the V. The outer web forms the outer walls of the sachet. On the production line the inside of the V is accessed from the top side only. The web (103) which is a central layer, for example, a metal foil coated with a heat sealable plastics material such as a polyolefin on both sides is fed between the folded outer web (101 ) with one longitudinal edge of the web 103 in contact with the fold in the outer web to divide the V into two sections. Two friction rollers (105) guide the inner web (103) into a central position. The two webs (101 ,103) are fed horizontally into a forming station (107) into which are inserted several vacuum ports (108) which are adjusted to suit the shape required for the sachet. The vacuum ports (108) are connected through flexible tubes to a vacuum pump (not shown) which controls the lateral movement of the outer web (101) in the forming box. The inner web (103) is held in a central position within the forming box by the frictional rollers (105). In the forming box filler funnels (111) can enter the open side of the web from the top side. Either side of the forming box (107) and along the main axis of the production line are side jaws (109) which close and seal the webs (101 , 103) together to define pocket(s) (112) in the webs (101 ,103) which will become a sachet.

At the forming station (107) two filling tubes (111) are positioned so then each can move above one of the two pockets (112) defined by those parts of the outer web (101) and the inner web (103) between the two sets of side sealing jaws (109). Each pocket (112) is filled with a different fluid ingredient from a respective filling tube (111) which are moved into the pocket whilst that part of the outer web (101) within the forming station (107) is held apart laterally by reduced pressure through the vacuum tubes (108).

After filling the pockets (112), the filling tubes (111 ) are retracted and the web is moved forward to advance the filled pockets (112) to the next station (113) where they are heat sealed along the open top edge. At the same time the vacuum at the forming station (107) is released and the jaws (109) are opened and returned to their initial position adjacent the forming station (107) for the next cycle.

The sachets may be provided with opening means at a further station (not shown) so both compartments must be opened simultaneously. For example the sachet can have a pre-stressed line of weakness across both compartments at one side or a notch adjacent one side of the sachet. In this embodiment the production line may be circular and each station may be arranged around a turret. Alternatively the various station components (e.g. jaws (109) and filling funnels (11) may be moved linearly by reciprocal mounts so the production line may be arranged in a straight line.

A second process to manufacture the sachets of the present invention will now be described with reference to Figures 4 and 5 in which features similar to those in Figure 3 carry the same reference numerals and are not described again in detail.

The inner web (103) and outer web (101) are initially arranged as described for Figure 2 The base of the outer web (101 ) opposite the open end of the V passes over a heater (104) which heat seals the inner web (103) to the inside of the fold of the V-shaped outer web (101). A divider (105) (down-stream of the heater 104) which is movable along the longitudinal axis of the production line guides the inner web (103) and outer webs (101) towards the forming/filling station (107) and keeps the webs apart at the top of the V.

In Figure 4 the divider (105) has been moved forward towards a forming/filling station (107) in the direction of travel of the web. The divider (105) advances with the webs (101 , 103) horizontally and shapes the pockets (112) at the forming/ filling station (107). The divider (105) guides the outer web (101) around the outside of filler tubes (111) and the guides the central inner web (103) between the tubes (111). As the divider (105) is retracted to the position shown in Figure 5 the two filler tubes (111) descend to a filling position inside the pockets (112).

The webs (101 ,103) are heated by laterally movable side heaters (109) to seal them together across the height. This seals the rear end of the pockets (112) and the beginning of the following pockets. Each of the pockets (112) is then filled with fluid material. The filler tubes (111) are then withdrawn and the web advances to a sealing station so that the tops of the pockets (112) can be sealed by heater (115).

At a further station (not shown) a line of weakness may be added to the end of the sachet to facilitate opening. Then the completed sachet is cut from the end of the web. The cycle is repeated to produce the next sachet.

In the apparatus illustrated in Figure 6 a first outer web 201 passes over rollers 202, 203 which position the web 201 in a vertical plane. Similarly a second outer web 204 passes over rollers 205, 206 which position the web 204 in a vertical plane adjacent the web 201. A dividing web 207 is positioned between the first and second outer webs 201 , 204. The webs 201 , 204 and 207 are the same width. Means (not shown) simultaneously advance the three webs stepwise by the distance X as shown in Figure 6. When the webs are in the position shown in Figure 6 they are joined by a seal 208. The sides of the webs 201 , 204, 207 are then sealed together along their side edges 209, 210 to form two pockets between the seal 208 and the seals formed along the side edges 209, 210. A filling tube 211 has its lower open end located in the upper open end of the pocket formed between the first outer web 201 and the dividing web 207. In a similar way a filling tube 212 (represented by dotted lines in Figure 6) has its lower open end located in the open end of the pocket formed between the second outer web 204 and the dividing web 207. The pockets are then each filled with a predetermined amount of a fluid material through the filling tubes 211 , 212 respectively. The webs 201 , 204, 207 are then moved on by the distance X and the seal 208 is made to enclose the fluid materials in the two compartments of the sachet which at this point is still attached to the webs. Cutting means (not shown) at 213 in Figure 6 then separate the lower most filled sachet from the webs. The stepwise advance of the webs is then repeated as each successive sachet is formed, filled, sealed and separated from the webs.

Claims

1. A multicompartment sachet comprising

a first sheet member which forms one outer face of the sachet

a second sheet member which forms the other outer face of the sachet

2. A method of producing the multicompartment sachets of claim 1 on a continuous production line comprising the steps of:

(a) folding an outer web about a longitudinal axis in a V-shape;

(c) guiding the outer and dividing webs to a forming station whilst maintaining their relative positions;

(d) joining the dividing web and the two arms of the folded outer web along the foldline of the outer web and along two spaced lines transverse to the direction of movement to define a plurality of fluid retaining pockets, the pockets being open along a side of the webs parallel to the direction of movement;

(e) moving the webs so that they pass horizontally through a filling station with the unsealed side of the pockets facing upwards; (f) filling each pocket through the open side with a fluid product from a filling means at the filling station;

(h) separating the filled sachets from the web.

3. A method of producing the multicompartment sachets of claim 1 on a continuous production line comprises the steps of

(e) filling each pocket through the open side with a fluid from a filling means at the filling station; (f) sealing the top of all the pockets to produce a sachet comprising a plurality of internal compartments containing said fluid products; and

(g) separating the filled sachets from the webs.