IES990819A2 - Apparatus and process for manufacturing packaging pouches - Google Patents

Abstract

A pair of webs are delivered through associated web tensioners which apply a desired tension to each web. Each web is delivered through alignment means which is operable to laterally move each web as required to align side edges of the webs. When aligned the webs are overlapped and delivered to a sealing station. At the sealing station the webs are clamped between a heated die and an associated anvil plate to thermo-seal the webs together along seams which define open-mouthed pouches in the joined webs. These pouches are subsequently parted from the webs.

Description

“Apparatus and Process for Manufacturing Packaging Pouches” Introduction This invention relates to apparatus and a process for manufacturing packaging pouches, in particular packaging pouches of the type comprising a front panel bonded to a thermo-seal to a rear panel forming a pocket therebetween.

The invention is particularly concerned with the production of medical pouches, that is pouches for forming a sealed sterile environment for the packaging and storage of medical devices prior to use. it will be appreciated that in these medical applications pouches of high quality are required. In particular the sealing of the panels together is critical in maintaining the required sterile environment within the pouch during storage of the medical device.

It is an object of the present invention to provide apparatus and a process for the manufacture of such high quality medical pouches.

Statements of Invention According to the invention there is provided apparatus for manufacturing packaging pouches of the type comprising a front panel bonded by a thermo-seal to a rear panel forming a pocket therebetween, at least one of the panels being of a thermoplastics material, the apparatus including:- a ground engaging support frame, a pair of supply reel supports mounted on the support frame, each supply reel support having means for rotatably mounting a-supply reel carrying a web of either a front panel forming material or a rear panel forming material on the support frame, means for drawing a web from each supply reel and for conveying each web along a web feed path, a web tensioner associated with each web mounted on the support frame in the web feed path, each web tensioner being operable to apply a preset desired tension to a web drawn through the web tensioner, means for feeding each web incrementally along the web feed path downstream of the web tensioners, means for sensing the position of a side edge of each web, alignment means for laterally displacing each web relative to the support frame in response to the sensed web edge position for maintaining the web in a preset desired alignment as the web is delivered along the web feed path, means for overlapping the webs downstream of the alignment means, a sealing station in the web flow path for reception of an overlapped aligned pair of webs, the sealing station having a die and an associated resilient sealing mat supported on an anvil plate, the web feed path passing between the die and the mat, the die being movable on the support frame between a retracted disengaged position spaced-apart from the mat and an extended mat engaging position for clamping the webs between the die and the mat, the die having a heater operable to heat the die to a preset desirable sealing temperature.

In a preferred embodiment of the invention the resilient sealing mat at the sealing station is a silicon mat.

In another embodiment each web tensioner comprises two associated sets of rollers, namely, a fixed roller set and a movable roller set mounted spaced-apart on a carrier frame, said roller sets defining between them a tortuous path about which the web is drawn, the web being alternately wound about rollers in first one set and then the other set, the movable set of rollers being mounted between pivot arms which are pivotally mounted on the carrier for pivotal movement towards and away from the other fixed set of rollers to alter the length of said tortuous path, the pivot arms being biased away from the fixed set of rollers to apply a desired tension to the web, each of the web tensioners being mounted on a carriage which is laterally movable on the support frame in response to the sensed web edge positions to maintain web alignment.

In a further embodiment the die comprises a die plate mounted on a die holder by means of quick-release fasteners.

In another embodiment edge trimming blades are mounted downstream of the sealing station to engage and part excess material from the side edges of the joined webs, extraction conduits being mounted adjacent each edge trimming blade for reception and removal of off-cut material, each conduit terminating in a waste bin, and means for applying a vacuum to each extraction conduit and bin for drawing the off-cut material into the bin.

In a preferred embodiment a web cleaner is mounted on the support frame adjacent each supply reel support for cleaning each web as it is drawn from a supply reel.

Detailed Description of the Invention The invention will be more clearly understood by the following description of an embodiment thereof, given by way of example only, with reference to the accompanying drawing which is a schematic illustration of pouch manufacturing apparatus according to the invention.

Referring to the drawings there is illustrated 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 drawing for the sake of clarity on which the various components of the apparatus to be described later are mounted.

A pair of supply reel supports, namely an upper supply reel support 10 and a lower supply reel support 11 are mounted on the support frame for rotatably supporting supply reels 12,13 carrying webs 14,15 of a front panel forming material and a rear panel forming material respectively. In this case the front panel web 14 is of clear thermo-plastics material and the rear panel web 15 is of a paper material to which the web 14 can be joined.

A complementary pair of draw rollers 20,21 mounted on the support frame are operable to pull both webs 14,15 from their associated supply reels 12,13, at the same time overlapping the webs 14,15 prior to delivery of the overlapped webs to a sealing station 22, described later. A second set of draw rollers is mounted downstream of the sealing station 22 and is drivably linked to the first draw rollers.

Each web 14,15 as it is drawn off its associated reel 12,13 is delivered through a web cleaner 26,27 which essentially comprises a pair of rollers between which the web 14,15 is passed, the rollers having a tacky surface to pick up any dirt and loose material from the surface of the web 14,15.

Downstream of each web cleaner 26,27 the web 14,15 passes through a web tensioner 30,31. Each web tensioner comprises two associated sets of rollers, namely an upper fixed roller set having a number of spaced-apart in-line rollers 32 and a complementary lower movable roller set comprising a number of rollers 33 mounted between a pair of spaced-apart pivot arms 34 on the support frame. As shown in the drawing the web 14,15 is alternately wound about upper rollers 32 and lower rollers 33 to define a tortuous path about which the web 14,15 is drawn. The movable rollers 33 are mounted on the pivot arms 34 which are pivotally mounted on a carrier on the support frame for pivotal movement towards and away from the fixed rollers 32 to alter the length of the tortuous path. The draw rollers 20,21 are operable to incrementally feed the webs 14,15 to the sealing station 22. When the draw rollers 20,21 are engaged they pullihe webs 14,15 from the tensioners 30,31, the arms 34 pivoting upwardly to release the webs 14,15 on demand to the draw rollers 20,21. When the draw rollers 20,21 are stopped in between feeding steps each pair of arms 34 drops downwardly moving the rollers 33 away from the fixed rollers 32 to store up the web prior to the next delivery step. In this way the webs 14,15 can be fed continuously from the supply reels 12,13 for a smooth delivery of the webs 14,15 from the supply reels 12,13 and through the tensioners 30,31. It will be noted that the arms 34 carrying the movable rollers 33 may be biased away from the fixed rollers 32 by any suitable means to apply a desired tension to the webs 14,15.

Each of the web tensioners 30,31 is mounted on a carnage which is laterally movable on the support frame for independent sideways movement of the webs.

A web edge sensor 40 is provided for each web 14,15. Each web sensor 40 is connected to a controller for the web tensioner carriage for adjustment of the carriage position in response to the sensed web edge positions for maintaining the web edge positions in a preset desired alignment as the webs 14,15 are delivered through the apparatus. This way the webs 14,15 are maintained accurately in alignment and are delivered through the draw rollers 20,21 in accurate overlapping alignment. The webs are aligned relative to the sealing station 22 to ensure accurate sealing of the webs.

The overlapped aligned pair of webs are delivered to the sealing station 22. The sealing station 22 has a die 45 and associated anvil plate 46 on an upper surface of which is located a silicone mat 47. The webs are delivered between the die 45 and the mat 47. The die 45 is vertically movable on the support frame by means of rams 48 between a raised disengaged position spaced-apart from the mat 47 and a lowered extended mat engaging position for clamping the webs between the die 45 and the mat 47. The die 45 incorporates heating elements to heat the die to a preset desirable sealing temperature for sealing the webs together to provide open ended pockets forming pouches in the overlapped webs. When the die 45 is raised into the retracted position the webs are again fed on one step and the next pouch configuration is formed in the webs.

The silicone mat is typically about 6 mm thick and has a hardness in the range 55-75 shore A. The mat has a smooth surface and is preferably compression moulded to ensure uniform density.

Downstream of the sealing station 22 the sealed webs are delivered past vertical edge trimming blades 50 which engage and part excess material 52 from the side edges of the joined webs. Such excess material 52 is delivered into extraction conduits 54 mounted adjacent each trimming blade 50 for reception and removal of off-cut material. Each conduit 54 terminates in a waste bin having associated means for applying a vacuum to the bin and the extraction conduit 54 for drawing the off-cut material into the bin.

It will be noted that the blades 50 are not fixed, but can move vertically so that the whole of the blades are used and evenly worn down when cutting the web material.

The webs with the formed pouches are then delivered through a guillotine which cuts the joined webs transversely to separate each pouch from a leading end of the joined webs. The pouches are delivered by a take-off conveyor 62 for packaging. Alternatively, the pouches can be wound up on a roll and later separated.

The invention is not limited to the embodiments hereinbefore described but may be varied in both construction and detail.