IL103426A

IL103426A - Sealed package

Info

Publication number: IL103426A
Application number: IL10342692A
Authority: IL
Original assignee: Rhone Poulenc Agriculture
Priority date: 1991-10-16
Filing date: 1992-10-14
Publication date: 1995-12-31
Also published as: TW226321B; IL103426A0; ATE149131T1; EP0607316B1; NZ244732A; AU2783692A; EG19530A; WO1993008091A3; AP9200437A0; ZA928012B; DE69217665T2; CN1071636A; JPH07502003A; MX9205918A; CN1030831C; GB9121984D0; WO1993008091A2; AP374A; BR9206762A; DE69217665D1

Abstract

A closed package comprising one or more flexible polymeric sheets sealed to form an outer non-breachable seal, an inner breachable seal and optionally a space between the inner and outer seals. The breachable seal may be provided by a seal of lower peel strength than the non-breachable seal. The package may be made of water soluble or water dispersible material to allow the contents to be mixed with water without exposing the contents to the user. The package is particularly suitable for containing pesticidal compositions. [WO9308091A2]

Description

SEALED PACKAGE This invention relates a package particularly suitable for containing a peeticidal are often potentially harmful and are commonly produced as concentrated solution or dispersion in an organic as a gel or in solid Such chemicals typically supplied in a metal or plastics To use the chemical a quantity of the pesticide is out of the container in concentrated and then mixed with a large of water before being sprayed onto a locus to be treated or onto such concentrated materials are frequently highly toxic so great care must be taken in measuring and mixing them to avoid spillage and to avoid human or anixaal contact with the concentrated Efforts have been devoted to the design of containers to minimise the risk of accidental spillage of their contents when used also to reduce residues remaining in the containers after Plastics containers with wide necks to facilitate pouring of their contents have Blow moulded plastics containers having hollow handles have been in which the hollow isolated from the body of the container to avoid retention of material in the with present packages it is relatively easy to spill the contents during the mixing process with the resulting risk of contamination of the environment and risk of contact with humans or it is relatively rare to empty containers so that and other tend to have partly full containers left These represent a further Even when all of the contenta have been used it is difficult to dispose of the empty It is also difficult to wash adequately the containers and measuring instruments in which the concentrated pesticides arc These devices represent a further to personnel and to the It has been proposed to package agricultural chemicals in container comprising a screw fitting adapted to screw onto corresponding fitting on a spray The contents of the container should be released only when a satisfactory seal exists between the tank and the Practical difficulties exist in securing widespread such a system in view of the need for standardisation of screw sizes and the possibility of leakage if a satisfactory tight seal is not It has also been proposed to package chemicals in a water soluble container which releases the packaged chemical only after contact with Such applications have however been limited by the of known water soluble containers which are often flexible and prone to In particular when a package is dropped it is particularly prone to rupture due to mechanical or hydraulic shock if it contains a gel or fine In other fields where flexible packaging is there also a need to reduce the likelihood of rupture occurring due to mechanical The present invention seeks to overcome the disadvantages of known packages and to provide a flexible package having an improved resistance to mechanical Accordingly the present invention provides a package comprising one or more flexible polymeric sheets sealed to form an outer an inner breachable seal and optionally a space between the inner and outer When the package is subjected to mechanical shock the breachable seal may be breached dissipating the energy of the shock without damaging the outer Where the package comprises a space between the inner and outer preferably the space contains substantially none of the contents of the if the inner seal is breached the accessible to the contents may help to dissipate The breachable seal used in the package is one which may be breached when the package is subjected to mechanical shock example when dropped from a height of to The seal may be breached by peeling apart the seal or by means of a gap in the The package of the invention one or more sheets of flexible preferably thsrmoformable sealed to form a closed Preferably if more one sheet is they are of the same but they may be Preferably the package is formed by two separate sheets of material sealed to form a closed According to a particular embodiment the or every sheet comprising the package are of water soluble or water diepersible The use of such material may allow one or more of the following advantageous particularly if the contents comprise a hazardous such as a contents of package are released only after contact with water in which it is to be dissolved or minimising the possibility of accidental contact of the undiluted with the environment or with humans or contents can be provided in unit dosage suitable dilution with a predetermined amount of water removing the need for the to bo out in undiluted the package is easy to use the package can be simply placed in water prior to and the need for washing out of the residual chemical from containers to render them safe for disposal is which have been in contact with the contents remain uncontaminated which facilitates their Speci suitable water soluble or water dispersible materials polyethylene and such as hydrox polyvinyl ethers such as polymethylvinyl ether or or ethoxy pol low molecular weight low molecular weight formaldehyde ethyl polyacrylic acid and its Preferred materials are polyethylene methyl or polyvinyl moat preferably polyvinyl Generally polyvinylalcohol will be used as a partially or alcoholised or hydrolyaed polyvinyl acetate Most preferably a eg polyvinylalcohol resin is such possess advantages of being adaptable to deep draw molding without significant shrinkage The material may be oriented or Water soluble materials are preferred since they provide less disposal The used will generally water cold water soluble polyvinyl alcohol is will be understood that other may be used when the package to be dissolved or dispersed in water or hot water or is not intended to be water soluble or water Where the sheets comprising the package are water soluble or water the maximum tensile strength of the material of the sheets comprising the package is preferably at least more preferably from 30 to and the elongation at is preferably 200 to more preferably from 220 to Testing for these values is generally carried out 23 and relative the package of the invention is water soluble or water preferably it should release its contents in less than about Typically the package will be placed in the spray tank of a conventional The tank will generally be partly filled with and the package the tank is provided with means to agitate the water the contents of the bag will be released more It is preferred that release it should take place in less about a for example in 30 to 40 will be understood that the time taken to release the pesticide will depend upon a number of factors apart from the nature of the including the temperature of the water and the level of The package may contain material in gel or granular When contents is in liquid or gel form it is particularly important to avoid pinholes in package through which leakage of the contents may In auch cases therefore the or each sheet may be a generally of layers of different or the same as pinholes are unlikely to coincide in two layers of When contents are in granular the sheets typically comprise a single layer of in cases where i is particularly desirable to avoid pinholes in the to prevent the escape of unpleasant a laminate material of the type described above may be The or sheet comprising package will generally be from 20 to preferably 50 to If the sheet or sheets are of water soluble or water dispersible material the thickness of them will ba kept to tha minimum needed to prevent rupture of the so that the water soluble or dispersible material is dissolved or dispersed as quickly as possible and the contents then According to a particular embodiment the package provided with an inner breachable seal or seals in the region of the package most likely to The region of the package most likely to fail will vary according to a of factors including the shape and size of the the storage and usage conditions of the package and can be determined by routine According to a particular the package may comprise an inner seal and an outer seal of higher peel strength than the inner The inner itself comprise regions of varying peel typically being of lower peel strength in the inner region of the or it may be of uniform peel The inner and outer seals may be joined to form a single continuous seal of varying peel strength or they nay be separated by a Alternatively there may be more than typically up inner seals of lower peel strength than the outer seal each of which is separated by a preferably containing substantially none of the contents of the In where more than one inner peelable seal is present then peel strengths may be the same or Where the strength of the seals does then typically the innermost breachable seal will be of lowest peel outermost breachable seal of highest peel strength and any intermediate seals will b of intermediate progressively increasing towards the outermost Mechanical shock to such a when filled with gel or granular contents may result in partial peeling of the inner seal or seals thereby absorbing the energy of the shock without damaging the outer The inner and outer seals may be heat The outer seal may be a conventional heat seal 2 to 5 mm The or each inner heat seal will typically have a thickness from 1 to 2 to Where the inner and outer seals are produced by t e same sealing platen typically each inner seal will be within 20 mm of the outer For example there may be 1 to 3 inner heat each 2 to 3mm thick with a spacing of 2 to 3 mm from the outer seal or from each Alternatively where the or each inner heat seal is produced by separate sealing platen from the outer heat then the inner and outer seals may be widely separated with the proviso that the space between them does not contain any of the contents of the For example the inner seal or seals may seal the portion of package containing the contents and the outer seal be formed around a handle portion of the Rather than using heat either or each inner seal or the outer seal may be sealed using an Conventional polymeric adhesive may be used the strength of the adhesive used may be adjusted to provide a peelable or a seal as In the case where the is water soluble or water suitable adhesives include small amounts of water or low molecular weight solutions of polyvinyl optionally mixed with polyvinyl Where the package of the comprises a peelable seal or seals and a the peelable and peelable seal or seals may constitute a double or multiple seal around the whole the In other cases the inner seals or seals may be used to reinforce the outer seal only in those regions of the package which are particularly vulnerable to by mechanical In such cases inner and outer seals way be joined to prevent the contents of the package entering the space between if Alternatively the package comprise more than one preferably of equal divided by one or more inner seals each compartment containing a portion of the contents of the When the package is subject to mechanical one or more of the inner peelable seals may be peeled apart which increases the volume of the package and allows energy of the shock to dissipated without damaging the outer According to an alternative embodiment the package of the invention stay comprise an outer seal and an inner breachable seal provided by over a of the package which contains substantially none of the contents of the package sealing the folded portion of the package with a Weak adhesive on the outer surface of the Mechanical shock to the package may be dissipated by the weak adhesive giving and allowing the package to the contents of the package may then enter the space previously between the fold and the outer and prevent damage to the outer The outer seal and the adhesive used may be of the same type as described According to a further embodiment of the invention the package may comprise an outer seal and a gusset is in place by a breachable Mechanical shock to the package break the breachable seal thereby allowing the to unfold and afford more space into which the contents may dissipating the shock and preventing to the outer The breachable for be provided by a weak adhesive on that portion of the outer surface of the package which ia rolded inwards to form the The outer seal and the adhesive used be of the same type as described According to a third embodiment the package of the invention may comprise an outer seal and one or more inner seals having a narrow gap in or between them providing access to a space between the inner seal or seals and the outer seal which space contains substantially none of the contents of the Mechanical shock to the package may be diseipated by the entry of the contents of the package into the space between the inner and outer For example the package may compriee a single inner seal with a narrow gap in or pair of overlapping seals with narrow gaps between which gaps are in a portion of the interior of the package does not contain any of the contents of the package when in its normal upright same type of seals may be used as are a combination of and peelable seals may be used but normally the seals will be The contents of the package may be in gel or granular preferably liquid or gel Where the contents are in liquid form they may be in the form of a solution or of a dispersion an emulsion or a Similarly in gel the contents may be a single phase or a dispersion Where package comprises water soluble or water dispersible the contents will substantially seal A slightly lower jaw temperature may be used the inner portion of the sealing surface which produces a peelable a variation in sealing jaw temperature may obtained using a stepped sealing jaw having a first sealing surface closer to a heating element and at a higher temperature than a second sealing Rather than a stepped sealing jaw a contoured jaw may alternatively be used and there may be a space between the inner and outer sealing ce corresponding to a space between the a sealing jaw more than two sealing surfaces may be used to produce a package comprising more than one inner an alternative to varying peel strength by varying sealing jaw temperature as described variation may be obtained by varying sealing jaw pressure or dwell A stepped sealing jaw also be used in conjunction with a planar member of resilient A seal of variable strength may then be obtained by the variation in jaw pressure which is produced by the stepped Packages according to the invention are by way of in the accompanying drawings in Figure I illustrates a package formed by thermoforming or vacuum forming a sheet of material into a mould a peaticidal composition being contained in recess thus A second sheet of material is heat sealed to the first sheet on the flange of the mould The heat seal comprises an outer seal and an inner breachabie seal i Figure II illustrates a package having an integral handle The package contains a for example 1 to 5 of a liquid The heat seal comprises an outer seal and an inner breachable seal and may also comprise an additional breachable seal at the bottom of the The breachable seals and may have different peel The handle may have an area of III shows two heat sealing jaw arrangements which may be used to provide a variation in peel strength by varying the jaw pressure applied during the sealing Figures shows a resilient planar sealing jaw which is heated and a stepped sealing jaw having a sealing surface a portion of which is closer to the jaw and a portion further from jaw variation in jaw pressure is produced by the difference in the distance x between 14 and 16 and the distance x y between 14 and bearing in mind the jaw will resile on xt will be appreciated that than one step may be present in the jaw leading to provide more than one variation in the peel strength of the Figure shows an alternative arrangement in which the sealing surface of the jaw has a portion parallel to the heated jaw and a furthe portion which slopes away from the heated jaw providing a continuous variation in the jaw Jaw may be Figure shows that two heat sealing jaw which may be used to provide a variation in peel strength by varying the jaw temperature across the seal during the sealing Five shows a stepped heated jaw and a corresponding stepped heated sealing jaw The dietance between the corresponding sealing of jaws a constant Variation in the temperature at the steps of the sealing whioh ie due to variation in the distance of the sealing surface from a heating elemen produces a variation in peel the jaws and may be Figure shows an alternative arrangement in which two planar sealing jaws are a jaw and a heated jaw in which a variation in temperature is produced by the presence in the jaw of insulating material Due to the insulating material the portions 25 and 26 of the heated jaw are at lower temperatures than the portion 27 when in Either of the jaws and may be Figure V shows a heat sealing arrangement which may be used to provide a variation in peel strength by varying the dwell A heated jaw ie employed together with two separately removable jaws and operation the heated and jaws are separated by a constant dietance and variation in dwell time is achieved by withdrawing one of the jaws 29 and 30 while continuing to seal against the In this case a preferably jaw may be resilien Figure VI a heat sealing jaw arrangement in which variation in peel strength is produced by combination of variation in jaw pressure and is to in Fig jaw tha a portion of parallel to 31 and a which in tha jaw ra pr in tha tha jawa variation in tha of haata aw by variation in tha of of 33 a hasting of ha haat arran anant in w variation in peal is by a combination of jaw and A wit jaw having al h portion of a ia to 3 on pring and to a in h variation in tha a tha w 33 of a in with tha ra iliant If in jaw ia roaiXiant jaw 34 and ara or art tha o n a tha will ha at 5 i 3 tha ara fully insufficientOCRQuality

Claims

CLAIMS :

1. A closed package comprising one or more flexible water dispersible or water soluble polymeric sheets sealed to form an outer non-breachable seal and one or more inner breachable seal and optionally a space between the inner and outer seals.

2. A package according to claim 1 which comprises a space between the inner and outer seals containing substantially none of the contents of the package .

3. A closed package according to claim 2 wherein said inner seals are breachable by means of a narrow gap in or between them providing, access to said space between the inner and outer seals containing substantially none of the contents of the package and effective to dissipate mechanical shock applied to the package by entry of the contents into the space.

4. A closed package according to claim 1 which comprises a gusset which is tacked in place by a breachable seal.

5. A package according to any one of the preceding claims which comprises more than one , breachable seal .

6. A package according to any one of the preceding claims in which the breachable seals is of lower peel strength than the non-breachable seal.

7. A package according to claim 6 comprising more than one inner breachable seal of lower peel strength than the outer non-breachable seal, and a space between the inner and outer seals and between each inner seal. 103426/2, - 22 -

8. A package according to claim 1, divided into more than one compartment, each containing a portion of the contents of the package, by the or each inner seal.

9. A package according to claim 2 which comprises an outer non-breachable seal and an inner breachable seal provided by a folded portion of the package containing substantially none of the contents of the package, which folded portion is adhered to an outer surface of the package by a weak adhesive.

10. A package according to any one of the preceding claims which comprises a breachable seal in the region of the package most likely to fail. ;

11. A package according to any one of the preceding claims in which the or each flexible polymeric sheet is water soluble or dispersible and comprises polyethylene oxide, methyl cellulose or a polyvinyl alcohol.

12. A package according to claim 11 in which the water soluble or water dispersible material comprises a cold water soluble polyvinyl alcohol which is 40 to 99% hydrolysed or alcoholised polyvinyl acetate.

13. A package according to claim 11 or 12 in which the contents are released in less than 10 minutes after contact with water.

14. A package according to claim 13 in which the contents are released in less than 1 minute.

15. A package according to any one of the preceding claims which contains a composition in liquid or gel form.

16. A package according to any one of the preceding claims which contains from 5ml to 10 litres in liquid or gel form. - 23

17. A package according to any one of the preceding claims which contains a pesticidal composition.

18. A package according to claim 17 in which the composition comprises a hydroxybenzonitrile herbicide .

19. A package according to claim 18, in which the hydroxybenzo-nitrile herbicide comprises a mixture of ioxynil and bromoxynyl esters.

20. A package according to any one of the preceding claims in which the or each sheet has a thickness from 20 to 500/im.