AU2002313120B2

AU2002313120B2 - Refurbishing sheets of plastics

Info

Publication number: AU2002313120B2
Application number: AU2002313120A
Authority: AU
Inventors: Henri Jacques Burkhardt; Paul Harris
Original assignee: HENRI BURKHARDT
Current assignee: HENRI BURKHARDT
Priority date: 1997-08-04
Filing date: 2002-12-03
Publication date: 2005-01-27
Anticipated expiration: 2018-08-04
Also published as: AU2002313977B2

Description

St.

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION STANDARD PATENT Applicants: HENRI JACQUES BURKHARDT AND PAUL HARRIS Invention Title: REFURBISHING SHEETS OF PLASTICS The following statement is a full description of this invention, including the best method of performing it known to

US:

S-2- REFURBISHING SHEETS OF PLASTICS Technical Field This invention relates to refurbishing sheets of plastics material, and is applicable particularly, but not exclusively, to refurbishing sheets of plastics material used for product support during storage or transportation in industries such as the dairy industry.

Background Art It is already well known to support stacks of products on substantially square or rectangular plastics sheets, often called "slip sheets". Such slip sheets typically have edge dimensions in the range of 1.0 to 1.6 metres and thickness in the range of 0.5 to 0.6mm.

Typical uses are industries where wooden pallets are used, for example in the dairy industry where a heap of packets of, for example, dried milk, or of meat or the like is placed on the slip sheet, which is then lifted by a specially adapted fork-lift truck and transported to-and deposited onto similar heaps of the packets or product.

The fork-lift may draw out the slip sheet, or it may be left in situ. Other purpose-built machines may be used in production lines. The freezing, baking and other similar food industries also use plastics sheets as a hygiene barrier above a wooden pallet.

For some purposes one or more edges of the slip sheet are folded up at a permanent crease.

After use, the slip sheets are frequently discarded or sent to a plastics recycler to be ground down and used as plastics feed stock.

Such destruction of the slip sheets is wasteful and unnecessary in many cases.

Statement of the Invention In one aspect of the present invention there is provided an apparatus for refurbishing sheets of plastics \\BRIS1\tome$\LeanneM1keep\speci\P8036.doc 3/12/02 S- 3 0 material, including an input to receive the sheets successively, guide means to guide the sheets through the O apparatus, a sheet smoothing station in which each sheet is flattened or de-creased, the sheet smoothing station including at least one heated platen reciprocable onto the sheet surface, whereby to heat and press the sheet, and an Soutput from which the sheets are discharged from the apparatus.

M_ Advantageously, a stationary or movable heated

M

i 10 platen is positioned adjacent the opposite sheet surface Sand opposite the reciprocable platen.

Ci Typically the smoothing station includes one or more heated rollers to bear on the surface of the sheet as it passes.

Advantageously, cooling means is provided between the smoothing station and the discharge, to cool the sheets after smoothing.

Preferably, the apparatus includes sensor means adapted to sense a feature of each sheet such as edge dimensions, colour, thickness, weight, apertures, edge identification features and the like.

Typically the discharge includes a sorter connected to the sensor means, the sorter having positions into different ones of which sheets having the same feature can be accumulated.

In a preferred form of the invention, the apparatus further includes a cleaning station adapted to clean the sheet, the cleaning station including a pair of rotary brushes, positioned for the sheets to pass therebetween including a sheet smoothing station in which each sheets is flattened or de-creased.

More preferably, the apparatus includes the cleaning station followed by the smoothing station.

Typically the cleaning station includes a supply of cleaning liquid onto at least one sheet surface.

Advantageously, the cleaning station includes a brush movable over the sheet surface.

\\192.168.7. ll\home$\LanneH\keep\peci\P48D36 .doc 5/11/04 4 Typically at least one brush is a rotary brush which may be cylindrical.

Preferably, there is provided a pair of rotary cylindrical brushes positioned for the sheets to pass therebetween.

Typically the brushes in the pair are rotatable in opposite directions.

Advantageously, the cleaning station includes two or said pairs of rotary cylindrical brushes.

Typically those brushes on the same side of the sheet rotate in opposite directions.

Preferably, the guide means includes power drivable pairs of rollers between which the sheets are successively drawn through the apparatus.

In a further aspect of the invention, there is provided a method of refurbishing sheets of plastics material, including the steps of passing the sheets successively through an apparatus as described above, smoothing the sheets in the apparatus and discharging the sheets from the apparatus.

Brief Description of the Drawings One embodiment of the invention is described by way of example only, with reference to the accompanying drawings in which: Figure 1 is a diagrammatic side elevation of washing apparatus forming part of apparatus for refurbishing sheets of plastics material, according to the invention; and Figure 2 is a diagrammatic side elevation of pressing apparatus forming part of apparatus for refurbishing sheets of plastics material, according to the invention.

Detailed Description of the Preferred Embodiments In the drawings, apparatus for refurbishing sheets of plastics material, such as slip sheets, includes \\BRIS1\homeS\LeanneH\keep\speCi\P48036 .doc 3/12/02 SC 5 a frame 10 and unshown internal structure.

The frame 10 carries a pair of input rollers 11, 12, which pick up a sheet of plastics material moving in the direction of arrow 13. These are followed by an upper transverse row or rows of water jets 14, and a lower transverse row or rows of water jets 15. In the embodiment shown, two upper rows of water jets and two lower rows of water jets are shown.

The jets 14 and 15 are followed by a further pair of drive rollers 16, 17 which may be linked to drive rollers 11 and 12 respectively, for example, by belts 18 and 19 so that motors 20 and 21 can drive rollers 11 and 16, and 12 and 17, respectively. Other drive arrangements are, of course, possible.

Scrubbing brushes 30, 31, 32 and 33 are provided, which again may be driven in pairs by motors 34 and The brushes 30, 31, 32 or 33 are desirably contra-rotating with respect to the input rollers, 11, 12, 16, 17 so that the drive rollers push the sheets against the movement of the brushes. The speeds of rotation of the rollers and brushes may be chosen to induce tension in the sheets, to pull creases out of the sheets and to aid removal of foreign matter.

A further pair of rows of water jets 40 and 41 may be provided at the exit from the brushes 31, 32, 33 and 34 to remove loosened material from the sheets. Water falling from the jets 14, 15, 40, 41, the brushes 30, 31, 32 and 33 and the rollers 11, 12, 16 and 17 is collected in a hopper 50 and passes along pipes 51 and 52 from the hopper 50 which forms also a reservoir to the jets 14, and 41. The water may contain detergents or solvents and alternative cleaning fluids may be used instead of water. A pump 53 is provided to provide water to the jets 14, 15, 40 and 41.

The brushes 30, 31, 32 and 33 are cylindrical and may be rotated in pairs as above described or individually so that the bristles thereon travel in the same direction \\BRISI\hmeS\LeanneH\keepi\spci\P4 8 03 6 doc 3/12/02 .1 6 as the sheet moves past the brushes, or in the opposite direction, as required. After the rinsing water has been applied to the sheet an air knife driven by motors 60 or 61 may be used to remove most of the water.

The sheets then pass in the preferred form to a conveyor 70 which delivers the sheets to a pressing station 71 which provide a infeed conveyor 72 driven by motor 73 through gearbox 74. In the preferred form conveyor 72 traves faster than conveyor 70. For example, conveyor 70 may move at 6 metres per minute or conveyor 72 at 13 metres per minute.

The pressing station provides a fixed platen and a reciprocating platen 76.

The platen 76 is reciprocated up and down by a suitable ram, eccentric, crank or other mechanism. This allows the whole or successive adjacent areas of the sheet to pas beneath the platen 76 and over the platen Thereby, the sheet is compressed between the platen 76 and platen 75, to flatten, smooth and de-crease the sheet.

That process can be aided or enabled by heating the sheet.

For this purpose the platen 75, the platen 76, or both are heated to soften the plastics material of the sheet. A sensor 77 is provided to sense when the sheets is in position and cause the platen 76 to move.

On emerging from between the pressing station 71, the sheet may be cooled, for example by passing between a pair of water cooled rollers (not shown) one or both of which may be driven.

The cooled and stabilised sheet is discharged from the apparatus onto a collecting rack pallet or the like.

Instead of using the platen 75, or platen 76 the sheets can be heated by passing between pairs of heated rollers.

The apparatus can be accept and process sheets of different thickness and dimensions. Furthermore, different users may require different shapes, or may use \\BRIS1\home$\LeanneH~keep\speci\P48036.doc 3/12/02 A. L* 7 identification holes or edge indentations or the like to identify their preferred sheet.

Sheets which are successively different can be identified by, for example, infra-red edge, shape or aperture sensors. Signals from the sensors can be used to divert sheets having the same features, including thickness or weight, to the same collector in a sorter.

Sheets of a different feature are directed to a different collector, as required. The signals can be used to adjust brush, roller or plate position to accommodate the different sheet thicknesses.

\\BRIS1NhomeS\LealneHHkeeP\SPeCi\RI8O06 doc 3/12/02

Claims

2-2 including at least one heated platen reciprocable onto the Ssheet surface, whereby to heat and press the sheet, and an output from which the sheets are discharged from the apparatus. Ci 2. Apparatus as claimed in claim 1, wherein a stationary or movable heated platen may be positioned adjacent the opposite sheet surface and opposite the reciprocable platen.
3. Apparatus as claimed in either of claims 1 and 2, wherein the smoothing station may include one or more heated rollers to bear on the surface of the sheet as it passes.
4. Apparatus as claimed in any one of the preceding claims, wherein cooling means is provided between the smoothing station and the discharge, to cool the sheets after smoothing. Apparatus as claimed in any one of the preceding claims, wherein the apparatus includes sensor means adapted to sense a feature of each sheet such as edge dimensions, colour, thickness, weight, apertures, edge identification features and the like.
6. Apparatus as claimed in any one of the preceding claims, wherein the discharge includes a sorter connected to the sensor means, the sorter having positions into different ones of which sheets having the same feature can be accumulated.
7. Apparatus as claimed in any one of the preceding claims further including a cleaning station adapted to clean the sheet, the cleaning station including a pair of rotary brushes, positioned for the sheets to pass \\192.168.7 .1\l\home$\LeanneH\kee\.Bpeei\P4036. doc 5/11/04 9 0 c therebetween including a sheet smoothing station in which each sheets is flattened or de-creased. 0 z 8. Apparatus as claimed in claim 7, wherein the apparatus includes the cleaning station followed by the smoothing station.
9. Apparatus as claimed in either of claims 7 and 8, owherein the cleaning station includes a supply of cleaning liquid onto at least one sheet surface.
10. Apparatus as claimed in any one of claims 7 to 9, wherein the cleaning station includes a brush movable over othe sheet surface. C 11. Apparatus as claimed in claim 10, wherein at least one brush is a rotary brush which may be cylindrical.
12. Apparatus as claimed in any one of claims 7 to wherein there is provided a pair of rotary cylindrical brushes positioned for the sheets to pass therebetween.
13. Apparatus as claimed in claim 12, wherein the brushes in the pair are rotatable in opposite directions.
14. Apparatus as claimed in claim 10, wherein the cleaning station includes two of said pairs of rotary cylindrical brushes. Apparatus as claimed in claim 12, wherein those brushes on the same side of the sheet rotate in opposite directions.
16. Apparatus as claimed in any one of the preceding claims, wherein the guide means includes power drivable pairs of rollers between which the sheets are successively drawn through the apparatus.
17. Apparatus substantially as herein described with reference to and as illustrated in the drawings.
18. A method of refurbishing sheets of plastics material, including the steps of passing the sheets successively through an apparatus according to any one of claims 1 to 17 smoothing the sheets in the apparatus and discharging the sheets from the apparatus.
19. A method of refurbishing sheets of plastics \\192 .168.7ll\home$\Le4anH\kcp\mpeCi\P4036 .doc 5/11/04 10 material as claimed in claim 18 further including the step of passing the sheets successively through the apparatus of any one of claims 7 to 17 to clean the sheets in the apparatus.
20. A method of refurbishing sheets of plastics material as claimed in claim 18 substantially as herein described with reference to and as illustrated in the drawings. 0 Dated this 9 th day of November 2004 HENRI JACQUES BURKHARDT and PAUL HARRIS By their Patent Attorneys GRIFFITH HACK H:\LeanneH\keep\speci\P48036.doc 9/11/04