IES83901Y1 - Process for manufacturing packaging pouches - Google Patents

Abstract

ABSTRACT The process includes forming a pouch assembly of a number of overlapping panels having an uneven transverse profile. This may conveniently be formed by a continuous folded web (12). A thin profile portion of the transverse profile has two overlapping main panels, at least one of which is of thermoplastics material. A thick profile portion of the transverse profile has an additional pair of overlapping panels sandwiched between the main panels. The thick profile portion is crimped by passing the web (12) between nip rollers (42). At a main welding station (50) the panels are heat welded together to form a pouch. An additional reinforcing weld is applied to the thick profile portion at a reinforcing welding station (45,60). The web (12) is delivered to a guillotine (65) which cuts away a pouch (70) from a free end of the web (12).

Description

"Process for manufacturing packaging pouches" This invention relates to apparatus and a process for manufacturing packaging pouches, and in particular packaging pouches of plastics material used in medical applications.

Sealed sterile plastics pouches are widely used in medical applications for maintaining equipment in sterile condition prior to use for example, or for collecting or delivering fluids from or to a patient. Simple pouches may comprise front and back thermoplastic panels heat welded together about side seams for example. A difficulty arises in achieving a good seal at seams on pouches where the profile of the pouch is uneven, that is additional layers of material are provided at certain parts of the seam due to a gusset fold for example. To enable such pouches to be used in medical applications it is essential to be able to provide a secure seal throughout the seam, otherwise the sterility within the pouch could be cogpromised in use with disastrous results.

The present invention is directed towards overcoming this problem.

According to the invention there is provided a process for manufacturing a pouch including: forming a pouch assembly of a number of overlapping panels having an uneven transverse profile, said uneven transverse profile comprising a thin profile portion and a thick profile portion, ‘the thin profile portion having two overlapping main panels, at least one of which is of thermoplastics material, said thick profile portion having an additional pair of overlapping panels sandwiched between portion of said main panels, crimping the thick profile portion, at a main welding station clamping the panels together between a -complementary pair of die parts and heating said die parts to a desired welding temperature for applying a thermoseal for bonding the panels together by head welding the panels together in a preselected seam configuration to form the pouch, and at a reinforcing welding station applying an additional reinforcing weld to the thick profile portion of the seam.

In one embodiment of the invention the process includes the steps: leading a thermoplastics web from a supply reel, folding the web in half about a longitudinal axis of the web to form two overlapping main panels with a common folded edge extending along one side of the web, forming a gusset along the folded edge of the web with four overlapping panels by leading the web over three overlapping guide plates, namely a top guide plate, a middle guide plate and a bottom guide plate, drawing the main panels over outer faces of the top guide plate and the bottom guide plate, the middle guide plate pushing the folded edge inwardly between the top guide plate and the bottom guide plate to form the gusset, and applying the reinforcing weld across the gusseted portion of the web.

In another embodiment the process includes the steps: leading a pair of thermoplastics webs and a filter web from supply reels, _folding the filter web in half about a longitudinal axis of the filter web, forming the pouch assembly by overlapping the webs with the folded filter web mounted between the two outer thermoplastics webs, that portion of the assembly where only the two thermoplastics webs overlap forming the thin profile portion of two panel layers and that portion of the assembly where all the webs overlap forming the thick profile portion of four panel layers, and applying the reinforcing weld across the thick profile portion of the overlapping _webs including the filter webs. in another aspect the invention provides pouches manufactured according to the process.

The invention will be more clearly understood by the following description of some embodiments thereof, given by way of example only, with reference to the accompanying drawings in which; Fig. 1 is a schematic perspective view illustrating of a pouch manufacturing apparatus and production line according to the invention; Fig. 2 is a schematic perspective view illustrating a folding section of the apparatus; -Fig. 3 is a detail perspective view of a folded web guide forming portion of the apparatus; Fig. 4 is a sectional elevational view of the folded web guide shown in Fig. 3; Fig. 5 is a perspective view of a pouch formed by the process of the invention; Figs. 6, 7 and 8 illustrate sequential steps in forming filter pouches according to another embodiment of the invention; and Fig. 9 is a perspective view of a filter pouch formed by the process of the invention. l\) ()1 Referring to the drawings, there is illustrated a pouch manufacturing apparatus according to the invention indicated generally by the reference numeral 1. The apparatus 1 has a ground engaging support frame, which has been omitted from the drawings for the sake of clarity, on which the various parts of the apparatus are mounted.

A supply reel 10 (Fig. 2) of thermoplastic material is mounted on a rotatable support spindle 11. A web 12 of the plastics material is drawn from the reel 10 and delivered through a pair of nip rollers 13 to a web tensioner 14. The web tensioner 14 has an upper set of fixed rollers 15 and a lower set of movable rollers 16 which are movable towards and away from the fixed rollers 15 to adjust the tension applied to the web 12 to maintain a required tension and to convert the web 12 from continuous feed from the reel 10 to incremental feed downstream of the tensioner 14.

Downstream of the tensioner 14 the web 12 is delivered past an edge guide 17. The edge guide 17 aligns the web 12 for delivery through a set of turning rollers 18 which turns the web 12 through 90° from a substantially horizontal orientation to a substantially vertical orientation for feeding into a folding station 19.

At the folding station 19 the web 12 is folded in half about a longitudinal axis by being drawn over a tapered folding guide 20 which narrows towards the downstream end.

A gusset fold 22 is formed along one edge of the folded web 12. The gusset fold 22 is formed by feeding the web 12 through an associated set of guide plates 25. The guide plates 25 comprise three overlapping guide plates, namely a top guide plate 26, a middle guide plate 27 and a bottom guide plate 28. The main folded panels 31, 32 of the web 12 are drawn over outer faces 33, 34 of the top guide plate 26 and bottom guide plate 28, the middle guide plate 27 pushing the folded edge 38 inwardly between the top guide plate 26 and bottom guide plate 28 to form the gusset told 22.

Downstream of the guide plates 25 a gusset edge 29 of the web 12 passes beneath a creasing plate 30 which creases the folded gusset edge 29 of the web 12 to form a creased gusset. y 4 U'l kA/ C7‘ The gusseted web 12 then passes through nip rollers 35 and a second tensioner 36 of similar construction to the first tensioner 14.

A pair of edge guides 40, 41 mounted on each side of a pair of nip rollers 42 align and feed the gusseted web 12 between the nip rollers 42. The nip rollers 42 have a stepped configuration to accommodate the extra two layers of web film along the gusset edge 29. At this stage there are four layers of web film at the gusset edge 29 and only two layers across the remainder of the web 12.

Downstream of the nip rollers 42 the web 12 is delivered to a first reinforcing welding station 45 at which a first reinforcing weld 46 is formed at the gusset edge 29, extending across the folded gusset edge 29.

The partially welded gusseted web 12 is then delivered to a main welding station 50.

At the main welding station 50 the web 12 is clamped between die parts 52 which are heated for forming main transverse side seam welds in the web 12 defining the pouches.

Downstream of the main weld station 50 the web 12 of pouches may be delivered to a second reinforcing weld station 60 at which a second reinforcing weld is provided at the gusset edge 29 of the web 12.

The web 12 is then delivered to a guillotine 65 which cuts away a gusseted pouch 70 from a free end of the web 12. A number of the gusseted pouches 70 are stacked and sent for packaging.

Fig. 5 shows the pouch 70 having a pair of overlapping main panels 71, 72 with the gusset fold 22 at an inner end 73 of the pouch 70. Welded side seams 74, 75 extend between the inner end 73 and a free outer end 74 of the pouch 70 which is open to receive an article before a thermoseal is applied along the outer end 74 also to seal the pouch 70. it will be noted that the reinforcing welds 46 are coincident with the norma|"side seam welds 74, 75 and extend across the inner gusseted portion of the pouch 70.

Referring now to Figs. 6 to 9 the manufacturing process for forming a filter pouch 80 using the apparatus of the invention will be described. A pair of thermoplastics webs 81, 82 and an intermediate filter web 83 are led from supply reels. The filter web 83 is folded in half about a longitudinal axis of the filter web as shown in Fig. 6. A pouch assembly is formed by overlapping the webs 81, 82, 83 with the folded filter web 83 mounted between the two outer thermoplastics webs 81, 82. At the first reinforcing welding station 45 (Fig. 1) in this case a reinforcing weld 86 is formed across the thick profile portion of the overlapping webs where the two outer thermoplastics webs 81, 82 and the intermediate folded filter web 83 overlap. Then at the main welding station 50 a transverse side seam weld 87 is applied across the webs 81, 82, 83 at the reinforcing weld 86 and longitudinal side seams 88 are applied down each side of the overlapping thermoplastics webs 81, 82. Longitudinal welds 90 also secure free ends 91, 92 of the folded filter web 83 to the upper plastics web 81 and lower plastics web 82 respectively.

When the pouch 80 is cut away from the web by the guillotine 65 it has an open end 89 opposite the end with the transverse seal 87.

The invention is not limited to the embodiments hereinbefore described which may be varied in both construction and detail within the scope of the appended claims.

Claims (1)

1. A process for manufacturing a pouch including: forming a pouch assembly of a number of overlapping panels having an uneven transverse profile, said uneven transverse profile comprising a thin profile portion and a thick profile portion, the thin profile portion having two overlapping main panels, at least one of which is of thermoplastics material, said thick profile portion having an additional pair of overlapping panels sandwiched between portion of said main panels, crimping the thick profile portion, at a main welding station clamping the panels together between a complementary pair of die parts and heating said die parts to a desired welding temperature for applying a thermoseal for bonding the panels together by heat welding the panels together in a preselected seam configuration to form the pouch, and at a reinforcing welding station applying an additional reinforcing weld to the thick profile portion of the seam. A process as claimed in claim 1 which includes the steps: leading a thermoplastics web from a supply reel, folding the web in half about a longitudinal axis of the web to form two overlapping main panels with a common folded edge extending along one side of the web, forming a gusset along the folded edge of the web with four overlapping panels by leading the web over three overlapping guide plates, namely a top guide plate, a middle guide plate and a bottom guide plate, drawing the main panels over outer faces of the top guide plate and the bottom guide plate, the middle guide plate pushing the folded edge inwardly between the top guide plate and the bottom guide plate to form the gusset, and applying the reinforcing weld across the gusseted portion of the web. A process as claimed in claim 1, including the steps: leading a pair of thermoplastics webs and a filter web from supply reels, folding the filter web in half about a longitudinal axis of the filter web, forming the pouch assembly by overlapping the webs with the folded filter web mounted between the two outer thermoplastics webs, that portion of the assembly where only the two thermoplastics webs overlap forming the thin profile portion of two panel layers and that portion of the assembly where all the webs overlap forming the thick profile portion of four panel layers, and applying the reinforcing weld across the thick profile portion of the overlapping webs including the filter webs. A process for manufacturing a pouch substantially as hereinbefore described with reference to the accompanying drawings. A pouch whenever manufactured by the process as claimed in any preceding claim.