GB2323653A

GB2323653A - Python

Info

Publication number: GB2323653A
Application number: GB9720362A
Authority: GB
Inventors: Colin Brown
Original assignee: Individual
Current assignee: Individual
Priority date: 1997-09-26
Filing date: 1997-09-26
Publication date: 1998-09-30
Anticipated expiration: 2017-09-26
Also published as: WO1999016699A2; GB9720362D0; GB2323653B; WO1999016699A3; AU9088898A

Abstract

The python, comprising a bundle of tubes 12 in a foam sleeve 13, is characterised by a protective coating 15 applied to the outer surface of the foam sleeve in liquid form and cured. The coating may be a dispertion, a water-based emulsion, or polyurethane and may comprise a pigment or fire retardant. Application is by brushing, spraying or dipping with two or three coats. Curing is by infra-red or ultra-violet radiation, or by convected heat. If the python is wound, an anti-blocking agent, e.g. talcum powder, silicone release agent or poyethylene sleeve, is used to prevent sticking.

Description

PYTHON This invention relates to "pythons", that is to say bundles of tubes for delivery e.g. beverages from a cellar to a bar, encased in an insulating foam sheath.

Conventionally, the sheath itself is wrapped in a protective layer of tape, as it is of a crumbly texture and can easily be damaged e.g. by abrasion. The tape is applied by wrapping it helically around the sheath.

The tape itself, however, is prone to "grinning", i.e. parting at its overlaps when the python negotiates a sharp bend and tape winding tension has to be carefully controlled to reduce the likelihood of grinning while at the same time not putting the tape under such a high tension that it compresses the foam sheath unduly, reducing its insulating efficiency.

The present invention provides python not subject to this problem, yet which can be produced at no greater cost, even, possibly, at less cost, than conventional, tape-wrapped python.

The invention comprises a "python" comprising a bundle oftubes in a foam sleeve, characterised by a protective coating applied to the outer surface of the foam sleeve in liquid form and cured.

The coating may be applied as a dispersion and may for example comprise a polyurethane - a highly elastic coating is desirable which will not be prone to cracking and which accommodates flexure of the python. The coating may be a water based emulsion.

The coating may comprise a pigment, and may comprise a fire retardant.

The coating may be applied by spraying, dipping or brushing and at least two coats, preferably three, may be applied to build up the coating to a thickness of 100200 microns.

The wet coating may be cured by infra-red or ultra-violet radiation, or by convected heat.

As the python may be wound up on a reel, it may be desirable to apply an anti-blocking agent after curing, so that the adjacent turns do not stick together. The blocking agent may comprise talcum powder, a silicone release agent or a polyethylene sleeve.

Embodiments of python according to the invention will now be described, together with methods for their manufacture, with reference to the accompanying drawings, in which: Figure 1 is a view of a python with parts cut away to reveal the structure; and Figure 2 is a block diagram showing methods for making the python illustrated in Figure 1.

Figure 1 illustrates python comprising a bundle 11 of tubes 12 in a foam sleeve 13. The tubes 12 comprise beverage delivery tubes 12a and coolant tubes 12b, the bundle 11 being wrapped in a cling film 14, essentially containing the bundle 11 for application of the foam sleeve 13.

Conventionally, the foam sleeve 13, after application to the bundle 11, would be wrapped in a plastic tape, applied helically by a wrapping machine.

Python of this general type is described, together with methods for making the same, in EP 0 328 233 B and EP 0 560 464 B.

Instead, however, ofthe conventional helically wrapped protective tape, the foam sleeve 13 is, according to the invention coated with a protective coating 15 applied to its outer surface in liquid form and cured.

The coating is applied e.g. as a dispersion of polyurethane in a water base, and may also comprise a pigment, e.g. for colour-coding - python, while essentially capable of being made with any desired numbers and diameters of tubes 12 in the bundle 11, is often supplied in a range of standard formats, which could be readily identified by colour coding, and it becomes much easier to do this, with the invention, by stocking a range of pigments for incorporation into the coating rather than by stocking a range of coloured tape.

The coating may also comprise a fire retardant and any other beneficial additive as may be desired.

Figure 2 illustrates, in block form, methods for making a python as illustrated in Figure 1.

Box 21 indicates the python production process up to the application of the foam sleeve 13 to the tube bundle 11. This is essentially a discontinuous process in which python of any desired length, say 200 m or 300 m, is produced by feeding the tube bundle through a number of lengths of sheath held expanded by differential air pressure inside-to-outside.

Python passes from this production stage, box 21, to a coating stage, box 22, in which the water based polyurethane suspension is applied, by spraying, dipping as by running the python through a bath - or brushing, and in which two or three coats may be applied to build up a desired thickness, usually 100 to 200 microns.

The wet python passes then to a curing stage, box 23 where it is cured by infra-red or ultra-violet radiation, or by air convection as will be appropriate for the coating polymer.

The cured polymer may be tacky, still, and box 24 indicates a stage in which an anti-blocking agent such as talcum powder or a water based silicone release agent or even a polyethylene sleeve is applied prior to the python being wound up in a drum at winding step 25.

Claims

1. A "python" comprising a bundle of tubes in a foam sleeve, characterised by a protective coating applied to the outer surface of the foam sleeve in liquid form and cured.

2. A python according to claim 1, in which the coating is applied as a dispersion.

3. A python according to claim 1 or claim 2, in which the coating comprises a polyurethane.

4. A python according to any one of claims 1 to 3, in which the coating is water based.

5. A python according to any one of claims 1 to 4, in which the coating comprises a pigment.

6. A python according to any one of claims 1 to 5, in which the coating comprises a fire retardant.

7. A python according to any one of claims 1 to 6, in which the coating is applied by spraying.

A A python according to any one of claims 1 to 6, in which the coating is by by by dipping.

9. A python according to any one of claims 1 to 7, in which the coating is applied by brushing.

10. A python according to any one of claims 1 to 9, in which at least two coats of the coating are applied.

11. A python according to any one of claims 1 to 10, in which the coating is cured by infra-red radiation.

12. A python according to any one of claims 1 to 10, in which the coating is cured by ultra-violet radiation.

13. A python according to any one of claims 1 to 12, in which the coating is cured by convected heat.

14. A python according to any one of claims 1 to 13, in which the coating is 100-200 microns thick.

15. A python according to any one of claims 1 to 14, in which an anti-blocking agent is added after curing.

16. A python according to claim 15, in which the anti-blocking agent comprises talcum powder.

17. A python according to claim 15, in which the anti-blocking agent comprises a silicone release agent.

18. A python according to claim 15, in which the anti-blocking agent comprises a polyethylene sleeve.

Amendments to the claims have been filed as follows 1. A python comprising a bundle oftubes in a foam sleeve, characterised by a protective coating applied to the outer surface of the foam sleeve in liquid form and cured.

8. A python according to any one of claims 1 to 6, in which the coating is applied by dipping.