AU2003244043B1 - Improvements in packaging of chemicals - Google Patents

Description

J% AUSTRALIA PATENTS ACT 1990 (AS AMENDED) COMPLETE SPECIFICATION FOR OFFICE USE Short Title: Int. Cl: Application Number: Lodged: Complete Specification-Lodged: Accepted: Lapsed: Published: Priority: Related Art: Name of Applicant: Address of Applicant: Actual Inventor: Address for Service: TO BE COMPLETED BY APPLICANT Manildra Starches Pty. Ltd.

The Crescent, Auburn NSW 2144 Jose-Maria Tomas ANDERSON-TAYLOR ASSOCIATES, Registered Patent Attorneys of 10 Harrison Avenue BONNET BAY N.S.W. 2226 Complete Specification for the invention entitled: IMPROYEMENTS IN PACKAGING OF CHEMICALS The following statement is a full description of this invention, including the best method of performing it known to me: This invention relates to materials handling. More particularly although not exclusively it discloses an improved form of chemical packaging.

There are a many chemicals used in industry which because of fume emission and/or a corrosive nature require personnel to wear protective clothing before handling them. One example is paraformaldedyde which is used in powder form in the manufacture of corrugated adhesives from raw starch. As the procedure and ingredients for making this adhesive are well known (see for example the Steinhall Process described in Chapter 8 of "THE CORRUGATED INDUSTRY" by Tony Pinnington and published by Brunton Technical Publications Ltd.) they will not be further described here. Before being combined with the colloid however the raw starch component of the adhesive requires a waterproofing ingredient to be mixed into it. This typically comprises approximately 7 parts of tannin to 1 part of paraformaldehyde powder by weight which are added to a solution of the raw starch and water in a mechanical mixer.

The procedure with the paraformadehyde packaging currently used requires personnel to unseal the powder in large bulk quantity plastic bags and then scoop or pour out the required amount for addition to the mixer. Because of the hazardous nature of paraformaldedyde and the fumes emanating from it the personnel have to wear protective clothing. Such clothing is hot and uncomfortable and moreover may not completely eliminate the risk of exposure. Also, any paraformaldehyde powder left in the -bag must either be -2tightly resealed to prevent escape of fumes or disposed of at both ecomomic and environmental cost. While it is known to package chemicals in small unit quantities to reduce waste the problem of exposure to paraformaldehyde during chemical mixing has remained a problem.

While it is also known to package detergent powders with no more than about 2% moisture content in Polyvinyl Alcohol or EVA soluble bags so that user contact is avoided such materials are not suitable for chemicals such as paraformaldehyde with moisture contents of 8% to 12%. This higher moisture content softens the material and causes the bags to lose strength.

It is therefore an object of this invention to ameliorate the aforementioned disadvantages and accordingly a novel packaging is disclosed for a chemical such as, but not limited to paraformaldehyde, said packaging having a first inner chemical retention barrier for enclosing a preselected amount of said chemical and a second fume containment barrier surrounding the inner barrier, said inner barrier being adapted to dissipate or disperse through a liquid so that after removal of the fume containment barrier said enclosed preselected amount of chemical can be added directly to said liquid without exposing the chemical to atmosphere whereby chemical contact with personnel is avoided and emission of fumes substantially reduced.

r Preferably, but not essentially, said preselected amount of chemical is a weight or volume which can be added to said liquid either singly or in multiples without significant wastage.

It is further preferred that said package is formed into a shape adapted for efficient storage or transport.

It is further preferred that said inner barrier comprise a paper material adapted to dissolve or disperse in a water based liquid mixture.

It is further preferred that the fume containment barrier comprise a plastic film which is vacuum fitted closely around said inner barrier.

The currently preferred embodiment of this invention will now be described with reference to the attached representations in which:figure 1 figure 2 figure 3 is a plan view of a package of paraformaldehyde powder in accordance with said invention, is a side elevation view of the package of figure 1i, and is a cross-sectional view of the package along the lines A-A of figure 1.

-4- The package as shown may comprise a generally rectangular block shaped quantity of paraformaldehyde powder 1 which with this embodiment is 3 kg in weight. The shape of the block is determined by the inner barrier 2 which encloses and holds the powder. With this embodiment the barrier may comprise a No. 12 SOS brown food bag A2313 having dimensions 334 x 178 x 112 mm as available from P I O'Kelly Pty. Ltd. of Dandenong Victoria. The weight of the paper used in such bags preferably does not exceed 52 gsm. A second moisture and gas impermeable outer barrier formed by a plastic film 3 is closely fitted over the inner barrier to seal in fumes emanating from the paraformaldehyde during storage and to reinforce the strength and shape of the inner paper barrier.

The profile of the enclosed block is shown in part by broken lines 3A in figures 1 and 2. Preferably the plastic film is vacuum fitted and heat sealed so as to substantially eliminate any air pockets between it and the inner paper barrier where fumes could collect. It also provides a readily noticable means of detecting a package which has been pierced or broken as the plastic film would then relax and detach from the inner barrier on admission of air pressure. With this embodiment the plastic outer barrier is preferably formed from natural co-extruded nylon material and sold as polybag 300 x 450 x 70 um by Ruscon Plastics Pty. Ltd. of Dandenong Victoria.

Preferably an excess of plastic film over that required to enclose the block may be left at each end to form ears 4.

These provide a convenient means for lifting and handling the package.

When handling the paraformaldehyde powder for example as required in the manufacture of corrugated adhesives the outer plastic barrier 3 is first cut away while the inner chemical retaining barrier 2 is left intact. The enclosed block of powder is then placed directly into the mixing machine without any exposure of fumes to the air or any chemical contact with operating personnel. By virtue of the solubility of the paper the paraformaldehyde is quickly released into the mixture and the remnants of the paper have also be found to dissipate through the mixture without any undesirable effects. Preferably a filtering device is associated with the mixer to remove any remnants which do not disperse sufficiently.

It will thus be appreciated that this invention at least in the form of the example described provides a novel and improved form of chemical packaging. In addition to providing long term sealed storage of a chemical it also allows said chemical to be handled and mixed in compact unit quantities without exposure to operating personnel. Clearly however the example disclosed is only the currently preferred form of the invention and a wide variety of modifications may be made which would be apparent to a person skilled in the art. For example the size, shape and configuration of the package may be changed according to mixing, storage or other 0 CA requirements. Also, while the inner soluable barrier is currently composed of paper and the outer fume cantainment barrier of plastic other materials may be used according to the chemicals involved.

Claims (7)

1. 2. The packaging as claimed in claim 1 wherein said plastic film is double heat sealed.
2. 3. The packaging as claimed in claim 1 wherein said inner barrier is formed from a paper adapted to dissipate or disperse in said liquid.
3. 4. The packaging as claimed in claim 3 wherein said inner barrier is formed by a paper which does not exceed 52 gsm. The packaging as claimed in claim 1 wherein said packaging is formed into a generally rectangular block-like shape.
4. 6. The packaging as claimed in claim 1 wherein an excess of plastic film over that required to enclose the inner barrier is left at each end thereof to form ears for handling said preselected amount of said chemical.
5. 7. The packaging as claimed in claim 3 wherein the inner barrier is adapted to dissipate or disperse in a water based liquid.
6. 8. A packaging for a chemical, said packaging being substantially as described herein with reference to figures 1 to 3.
7. 9. A method of adding a preselected amount of chemical to a liquid, said method including the steps of:- procuring said preselected amount of chemical in a packaging having a first inner chemical retention barrier for enclosing said amount of chemical and a second fume containment barrier of plastic film closely vacuum fitted around the inner barrier and sealed so as to substantially eliminate air pockets between said fume containment barrier and said inner chemical retention barrier, the inner barrier being adapted to dissipate or disperse through the liquid, removing the fume containment barrier, placing said amount of chemical directly into the liquid with the inner chemical retention barrier intact, and operating a liquid mixing means in a manner which causes said inner chemical retention barrier to dissipate or disperse through the liquid thereby releasing said amount of chemical. Dated this 2/ day of October, 2003. Manildra Starches Pty. Ltd. By Our Patent Attorney MICHAEL ANDERSON-TAYLOR