AU2004100440A4 - Packaging Bituminous Compositions - Google Patents

Description

09/06/2004 10:04 +613988&7B00 MORCOM PERNAT PAGE

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION INNOVATION PATENT "Packaging Bituminous Compositions" The following statement is a full description of this invention, including the best method of performing it known to me: COMS ID No: SBMI-00784176 Received by IP Australia: Time 10:11 Date 2004-06-09 09/06/2004 10:04 +61398267600 MORCOM PERIAT PAGE 06 2 PACKAGING BITUMINOUS COMPOSITIONS Field of the Invention This invention relates to the packaging of bituminous compositions. In a particular non-limiting aspect it relates to the packaging of bituninous compositions which can be supplied for road maintenance in a solid form in a package which can be readily separated from the solid bituminous composition.

Background of the Invention Because of the stress roadways are put under from passage of heavy traffic, temperature changes, soil movement and rain, cracks often appear in roadways. In order to preserve the integrity of these cracked roadways, it is common practice for road authorities to spray binding material into the cracks to seal them.

Typically, the binding material will comprise a bituminous composition such as one 2o which comprises a mix of bitumen and one or more other components which modify the properties of the bitumen.

Typically, the bituminous composition is pre-prepared at a factory at an elevated temperature at which the bituminous mix flows readily. The hot bituminous mix is poured into plastic bags and allowed to cool and iset solid. The bags of solid bituminous mix are then transported to a site where renediation work is being carried out on roadway cracks. The bituminous mix is heated to render it flowable and is sprayed directly into cracks on the roadway.

Whilst this approach is reasonably successful in most circumstances, it suffers from the disadvantage that removal of the bituminous mix from the plastic bags can be quite difficult There is even a substantial risk that the plastic may become mixed up COMS ID No: SBMI-00784176 Received by IP Australia: Time 10:11 Date 2004-06-09 09/06/2884 10:84 +61398867680 MORCOM PERNAT PAGE 07 3 with the mix and therefore cause quite substantial problems in relation to the delivery of spray through a spraying nozzle.

Thus, there is a need for an approach which avoids or reduces the likelihood of entanglement of packaging such as plastic with the bituminous mix.

Such an approach may also be associated with the development of a bituminous mix i which is suitable for use in remediating cracked roadways.

Disclosure of the Invention The invention provides in one aspect a method of packaging a bitumen containing mixture which softens and becomes tacky at temperatures above room temperature comprising, erecting an open mouthed carton having a base and walls from a generally flat surfaced carton blank, the surface of the blank forming the internal walls of the carton having an inner release layer, heating the bitumen containing mixture to a temperature at which it flows, pouring the heated bitumen containing mixtUre into the carton through the open mouth, and allowing the bitumen containing mixture to cool and set as a solid mixture in the carton, wherein the carton blank is configured so that it may be unfolded to allow the walls to be pulled directly from contact with the solid mixture and the inner release layer comprises a coating for allowing the walls to 1e readily pulled from the solid mixture.

Suitably the carton blank comprises fibre board. I1 may comprise an outer paper layer, an inner corrugated layer and an inner paper layer. A release layer may be provided overlying the inner paper layer. The release layer may comprise paper coated with wax or a silicone release agent such as solventless silicone. Suitably the COMS ID No: SBMI-00784176 Received by IP Australia: Time 10:11 Date 2004-06-09 AA Ji 3 09/06/~20084 10:04 +6139B867600 MORCOM PERNAT PAGE 08 4 release layer can withstand temperatures greater than !00C more preferably 250°C or even 300*C without becoming substantially degraded.

The carton blank may comprise a substantially sqiare base with four side wall sections joined to the base through fold lines. Each of the four side wall sections may be joined to adjacent side wall sections by corner members, the join between the adjacent side wall sections to the corner members also being through fold lines.

Thus, the perimeter of the cardboard blank may also bp square.

Diagonal fold lines may extend across each corner! member from a comer of the square base. Thus, the corner members may be folded to form triangular flaps overlying the side wall sections when the carton is erected.

Suitably, the bitumen containing mixture may be prepared by heating a mixture of rubber, bitumen and butadiene block co-polymer and mixing the components when i the mixture is in a liquid state. Typically, the temperature of mixing will be in excess of 160(2.

The proportions of the various components in the bitmen mix are suitably present in the following proportions by weight:- Rubber 5% to Bitumen 10% to Styrene Butadiene Block Co-polymer 5% to 00% The invention also covers packages containing bitumen mixture when prepared according to the method of the invention described hereinbefore.

A preferred aspect of the invention will now be described with reference to the accompanying drawings.

COMS ID No: SBMI-00784176 Received by IP Australia: Time 10:11 Date 2004-06-09 09/06/2004 10:04 +61398867600 HORCOM PERNAT PAGE 09 Brief Description of the Drawings Figure I shows a plan view of a carton blank for use in association with the method of the invention; Figure 2 shows the carton blank of Figure 1 partially folded; Figure 3 shows an isometric view of the carton blank of Figures 1 and 2 erected and filled with a bitumen mix; Figure 4 shows a corner section of the carton blank of Figure 3; and Figure 5 shows a fragmentary enlarged view of the layers comprising the carton blank of the preceding Figures.

Detailed Description of the Preferred Embodimen The various elements identified in the drawings are listed in the following integer list.

Integer List I Carton blank 3 Fold line 4 Fold line Fold line 7 Base 9 Side wall 11 Triangular flap 13 Staple Bitumen 17 Outer layer 18 Corrugated layer 19 Inner layer 20 Inner surface layer COMS ID No: SBMI-00784176 Received by IP Australia: Time 10:11 Date 2004-06-09 09/06/2004 10:04 +61398867600 MORCOM PERNAT PAGE 6 Referring to Figures 1 and 5, there is shown a carton blank generally designated I which comprises a square flat sheet of heat resistant corrugated cardboard.

The corrugated cardboard comprises an outer layer 1 of paper sheet. This is bonded by a conventional glue to the corrugated layer 18 which comprises corrugated paper and is in turn bonded to an inner layer 19 of paper sheet.

The inner layer 19 includes an inner surface layer 20 laminated thereto. The inner surface layer comprises paper coated with a release material. The release material may comprise wax or solventless silicone. By solventless silicone, we mean that the silicone resin preferably contains less than 15% more preferably less than 7% of resin for the solvent.

The blank I includes a number of fold lines generally 'designated 3, 4 and 5. The fold lines may be formed as creases in the cardboard to allbw easy folding. The fold lines define a square base 7, and square side walls 9. 'The fold lines also define the triangular flaps 11 which are formed when the squae corner sections of the blank defined by the fold line 5 are folded about fold lines 3. This is more clearly illustrated in Figures 2 and 3 where it can be seen that folding of the blank along the various fold lines results in the formation of a square, base 7, the side wall 9 and the triangular flaps 11.

The triangular flaps are stapled to the side walls using staples 13 as is shown in Figures 3 and 4.

In this way, the box can be easily erected as an open-faced cubic box into which a molten bitumen mix 15 may be poured.

In a typical production operation, recycled rubber obtained by comminuting car or truck tyres, a compatible polymer such as styrene-btftadiene block co-polymer and bitumen are mixed in a large tank with heating to a temperature in excess of 160C.

The proportions of the components comprise 5% to 60% by weight of recycled COMS ID No: SBMI-00784176 Received by IP Australia: Time 10:11 Date 2004-06-09 09/06/2004 10:04 +'613989167688MR0 ERA0AE 1 MORCOM PERNAT PAGE I I 7 rubber, 5% to 60% by weight polymer and 10% to' 80% by weight bitumen. The proportions of the various components in the mix ina be varied to vary the properties of the final product in accordance with the conditions under which the product must be used. For instance a product used on roads in cold climates should be formulated so as to not become brittle at low temperatures wherq~as a hot climate product should be formulated so as to resist melting or softening at higher temperatures.

After homogenization of product by mixing, it is poured whilst still hot into the box which has been described with reference to Figures 1 to 5 and allowed to cool.

Typically 22 liftres is added to each box.

After cooling for 24 hours, the boxes filled with product may be stacked. Generally speaking, the proportions of components in the bitumpn-based mix will typically give a product which becomes soft in the range of 35QC to 40 0 C and becomes tacky at about 800C.

As can be seen clearly in Figure 4, the cooled bitumpin 15 comes in contact with the side wall 9 faced with the inner surface layer 20 having a release coating. Thus, it is an easy matter to grab hold of the triangular flaps I1, and pull them outwardly from the sides of the box and away from the staples. It is then possible to pull the side walls 9 away from the solidified bitumen mix 15 as the inner surface layer 20 by virtue of the fact that it is coated with a release compound which does not bond with the bitumen mix. The bitumen mix can then be place~d directly into a heating vessel free of contamination by the carton in which it was supplied and heated to a temperature at which it may be sprayed.

Whilst the above description includes the preferred e :ibodiments of the invention, it is to be understood that many variations, alterations,i, modifications and/or additions may be introduced into the constructions and arrangements of parts previously described without departing from the essential featutes or the spirit or amnbit of the invention.

COMS ID No: SBMI-00784176 Received by IP Australia: Time 10:11 Date (Y-M-tl) 2004-06-09 09/G/2004 10:04 +61398867600 MORCOM PERNAT PAGE 12 It will be also understood that where the word "comprise", and variations such as "comprises" and "'comprising", are used in this specification, unless the context requires otherwise such use is intended to imply the inclusion of a stated feature or features but is not to be taken as excluding the presence of other feature or features.

Si The reference to any prior art in this specification is not, and should not be taken as, an acknowledgment or any form of suggestion that such prior art forms part of the common general knowledge in Australia.

COMS ID No: SBMI-00784176 Received by IP Australia: Time 10:11 Date 2004-06-09

Claims (4)

1. A method of packaging a bitumen containing mixture which softens and becomes tacky at temperatures above room temperature comprising, erecting an open mouthed carton having a base and walls from a generally flat surfaced carton blank, the surface of the blank fonning the internal walls of the carton having an inner release layer, heating the bitumen containing mixture to a temperature at which it flows, pouring the heated bitumen containing mixture into the carton through the open mouth, and allowing the bitumen containing mixture to cool and set as a solid mixture in the carton, wherein the carton blank is configured so that~it may be unfolded to allow the walls to be pulled directly from contact with the soli4 mixture and the inner release layer comprises a coating for allowing the walls to be readily pulled from the solid mixture.

2, A method according to claim 1 wherein the carton blank comprises, a substantially square base, four side wall sections joined to the base through fold lines, a corner member between each adjacent pair of side walls sections and joined to the adjacent side wall sections through fold lines, and a diagonal fold line extending across each corner member from a corner of the square base, wherein the corner members fold to formi triangular flaps overlying the side wall section when the canton is erected.

3. A method according to claim I or claim 2 wherein the bitumen containing mixture comprises, to 60% by weight of rubber I to 80% by weight of bitumen COMS ID No: SBMI-00784176 Received by IP Australia: Time (1-tm) 10:11 DatE 2004-06-09 09/06/2004 10:04 +61398867600 MORCOM PERNAT PAGE 14 to 60% by weight of a styrene butadiene block copolymer, and the inner release layer comprises paper coated with solventless silicone.

4. A method according to any one of the preceding claims substantially as hereinbefore described with reference to the accompanying example Package containing a bitumen containing mixture when constructed by the method according to any one of claims I to 4 substantially as hereinbefore described. Dated this 9th day of June 2004 Road Maintenance Pty Ltd by their patent attorneys Morcom Pernat COMS ID No: SBMI-00784176 Received by IP Australia: Time 10:11 Date 2004-06-09