GB2560577A

GB2560577A - Apparatus for the production of a waterproof membrane

Info

Publication number: GB2560577A
Application number: GB1704271.4A
Authority: GB
Inventors: Rodgers Russell
Original assignee: CHESTERFELT Ltd; Chesterfelt Ltd
Current assignee: CHESTERFELT Ltd; Chesterfelt Ltd
Priority date: 2017-03-17
Filing date: 2017-03-17
Publication date: 2018-09-19
Anticipated expiration: 2037-03-17
Also published as: GB2560577B; GB201704271D0

Abstract

There is a method of producing a waterproof membrane. The method comprises the steps of providing a sheet of reinforcing material 1, applying a bituminous composition to the sheet of reinforcing material, and applying a first coating material 11 to the bituminous composition by rotating a cylinder 5. The cylinder comprising at least one groove 10 containing at the first coating material, wherein rotating the cylinder causes the first coating material to leave the at least one groove and be deposited in a pattern in the bituminous composition substantially corresponding to the at least one groove in the cylinder. Further, apparatus is described which is suitable for producing a waterproof membrane. The membrane may be suitable for use as a roofing material.

Description

(54) Title of the Invention: Apparatus for the production of a waterproof membrane Abstract Title: Grooved roller and production of waterproof membrane (57) There is a method of producing a waterproof membrane. The method comprises the steps of providing a sheet of reinforcing material 1, applying a bituminous composition to the sheet of reinforcing material, and applying a first coating material 11 to the bituminous composition by rotating a cylinder 5. The cylinder comprising at least one groove 10 containing at the first coating material, wherein rotating the cylinder causes the first coating material to leave the at least one groove and be deposited in a pattern in the bituminous composition substantially corresponding to the at least one groove in the cylinder. Further, apparatus is described which is suitable for producing a waterproof membrane. The membrane may be suitable for use as a roofing material.

FIGURE 2

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FIGURE 1

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FIGURE 2

FIGURE 3A

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FIGURE 3B

APPARATUS FOR THE PRODUCTION OF A WATERPROOF MEMBRANE

The present invention relates to apparatus for producing a waterproof membrane, a method of producing a waterproof membrane, and a waterproof membrane produced with the apparatus or in accordance with the method of the present invention. More particularly, the present invention relates to apparatus for selectively applying coating materials to a waterproof membrane, a method for applying coating materials to a roofing membrane, a cylinder for use in producing a waterproof membrane and roofing membranes made according thereto.

Waterproof membranes are typically used as roofing materials and are primarily used as roofing materials for non-residential properties. The membranes generally comprise a base sheet or reinforcing layer onto which a layer of bitumen is applied. The bitumen renders the membrane impermeable to water and the base sheet provides a medium onto which the bitumen can be applied.

Waterproof membranes are generally composed of a reinforcing layer coated on one side with a waterproofing material. Typically, the waterproofing material is a bituminous composition which is applied to the reinforcing layer. The reinforcing layer is generally a sheet of material, such as paper, polymer, such as polyester, or natural fibres. The waterproof membrane may be attached to a substrate, such as a roofing structure, to form a roof. The membrane may be attached by any suitable method or combination of methods. For example, the membrane may be attached using a pour and stick method in which a layer of heated bitumen is spread across the roofing substrate and the membrane is lain over the heated bitumen such that the membrane is attached to the roof when the bitumen cools by mechanically fixing the membrane to the substrate.

Bitumens are complex hydrocarbon products composed of very different categories of chemicals, namely asphaltenes and maltenes. The mechanical properties of bitumen are highly dependent on temperature. For example, at temperatures below about 0°C, bitumen is rigid and fragile, whereas at temperatures above the bitumen softening point, which may be around 38°C or above, the bitumen is plastic, soft, and very adhesive. As such, at low temperatures and medium temperatures (around 25°C), bitumen is not sufficiently adhesive to be attached to a surface or substrate, such as a roof, through pressure alone. Since bituminous membranes are often intended to be used as roofing, they are exposed to extremes of temperature. Due to the changes in physical properties of bitumen at different temperatures, this may result in a reduction in performance of the membrane over time and possibly failure. If the waterproof membrane fails, this will generally only be noticed when the roof starts to allow water ingress into the building and this may result in damage to the roof, the building structure itself or the contents of the building.

Since waterproof membranes are intended for use as roofing, the membranes will be exposed to the weather and need to be protected. The roofing membranes may be exposed to extremes of temperature as well as precipitation and direct sunlight. Since the bitumen used as the waterproofing material in waterproof roofing membranes is generally black, it absorbs heat readily and can reach temperatures which are considerably higher than the surrounding air temperature. This can result in the bitumen becoming more fluid. The bitumen may therefore have a tendency to move and may result in weakened portions of the roofing membrane. The weakened portions may fail prematurely and cause the membrane to leak. The bitumen may also be degraded by exposure to UV light. In addition, if the bitumen is softened by an increase in temperature, any materials or detritus which falls on the bitumen in its softened state may be caught by the bitumen and retained on the surface of the membrane when the bitumen cools. Again, this can result in premature failure of the membrane. In addition, the detritus may retain other detritus and this can lead to a build-up of unwanted materials on the roof structure. Detritus can include leaves.

One way of protecting the bituminous layer is to cover it with a suitable coating. The coating may comprise sand, mineral (which is crushed or powdered slate) or similar. This coating serves to protect the membrane from overheating in direct sunlight and also provides a non-stick layer so that any materials falling on the membrane are not inadvertently stuck to the membrane. It also provides UV protection for the bitumen.

In addition, the provision of a coating on the bituminous layer also allows the roofing membrane to be rolled up without the membrane adhering to itself.

Despite the benefits of coating the bituminous layer with a coating material, there remain some shortcomings. Since the coating of known waterproof roofing membranes provides for a homogenous layer of the coating material, i.e. the entire surface is covered with a substantially uniform coating material^ this does not offer any differentiation of properties across the surface of the membrane. As such, in cases where different properties are required across the surface of a roofing membrane, existing membranes are unable to offer this. Similarly, known apparatus and methods do not allow for the provision of different coating materials in discrete areas of the surface of the membrane. In addition, known apparatus for applying the coating material to the bitumen layer is unable to selectively and repeatably apply the coating material to the bitumen layer. Instead, the coating material is simply applied homogenously across the entire surface of the membrane and it is not possible to selectively apply the coating material in a particular distribution or pattern.

Modification of the surface of bituminous membranes is known. US2199660 discloses a method of making roofing material which differs from previously known waterproof membranes in which a base sheet of roofing felt is saturated with a waterproofing compound and coated with a layer of high melting point asphalt and has an upper layer of granular mineral material, such as crushed slate, embedded or partly submerged in the asphalt coating. US2199660 discloses that previously known membranes could be superficially provided with grooves extending down or longitudinally along the roof. The grooves are suggested to have the advantage of preventing leakage by resisting the travel of rain transversely of the roof under the action of wind and to prevent cracks through the asphalt coating of the roofing, preventing blisters in the roofing, or limiting them to small areas. However, it was found that the relatively soft ridges were flattened when the membranes were rolled up, which reduced their purpose and were so sharp that cracks in the membrane developed. To address these problems, US2199660 discloses embossing the roofing material when the coating is still relatively soft to cause the coating and surfacing material to flow upwardly adjacent the sides of the grooves instead of laterally, thereby giving the ridges between the grooves a concave, instead of convex, contour.

Similarly, EP253952O discloses a method of making a bituminous membrane wherein a web of a reinforcing material is provided, a layer of hot bituminous liquid adhesive is applied to one side of the reinforcing material and a roller is applied against the adhesive bituminous layer to form a pattern of grooves in the surface of the membrane. The bituminous adhesive is cooled to below the Ring and Ball softening temperature while applying the roller to the membrane and a slip agent such as water is applied between the membrane and roller, and air is blown onto the adhesive layer to remove the slip agent before a plastic film is applied. However, in order to retain the grooves in the surface of the material, the membrane is cooled and it is therefore more difficult to apply a protective coating of granular mineral material. Further, the membrane is configured such that the grooves are formed in the face of the material which is applied to the substrate and is not exposed to the weather. As such, this may result in air being trapped between the substrate and the membrane when the membrane is applied. This would result in a weaker bond between the substrate and the membrane and may result in premature failure.

In both cases, the variation in thickness of the bituminous layer in order to produce the grooves necessarily results in areas of the membrane which are weaker relative to other areas. In addition, in cases where the membrane is affixed to a roof using nails or similar, there is a tendency for the nails to be put in the thinnest and therefore weakest areas of the membrane. This may result in premature failure of the membrane. There is also no means for controlling how the coating material is applied to the surface of the membrane.

The present invention has been made in consideration of the known problems and limitations with existing waterproof membranes as well as methods and apparatus for the production of waterproof membranes.

According to a first aspect of the present invention, there is provided a method of producing a waterproof membrane, comprising the steps of providing a sheet of reinforcing material, applying a bituminous composition to the sheet of reinforcing material, and applying a first coating material to the bituminous composition by rotating a cylinder comprising at least one groove containing the first coating material, wherein rotating the cylinder causes the first coating material to leave the at least one groove and be deposited in a pattern in the bituminous composition substantially corresponding to the at least one groove in the cylinder.

The ability to selectively apply a first coating material to the bituminous layer allows for precise control of which part or parts of the surface of the waterproof membrane are coated with the first coating material. Since the cylinder does not imprint a pattern into the bituminous layer itself, but rather deposits the first coating material onto the surface of the bitumen, this means that there are no weakened portions of the membrane which may be prone to failure, as is the case with prior art membranes comprising grooves in the bituminous layer. In addition, the method according to the first aspect of the present invention provides for the production of a waterproof membrane which is able to be rolled up without the risk of the 'peaks' of the bituminous material becoming flattened. Initial attempts to provide a method for selectively applying a coating material to a bituminous membrane comprised a tray with holes placed in it at specific patterns to provide an array. The tray was moved back and forth as the bitumen coated membrane travelled underneath. However, the resulting pattern and distribution of the coating material was inconsistent and this method was ultimately unsuccessful.

The method of the first aspect of the present invention allows for the first coating material to be deposited in any required pattern or configuration. As such, for example, the first coating material may be applied in a single line extending across the width of the membrane. Roofing membranes are generally elongate with a length that exceeds the width. The method of the first aspect of the present invention allows for a line of the first coating material to be deposited on the membrane substantially perpendicular to the length of the membrane. Alternatively, the first coating material can be applied to the membrane in a line substantially parallel to the length of the membrane, or at any angle relative to the length of the membrane. The first coating material may be deposited in a grid. As such, the method of the present invention allows a first coating material to be applied to particular portions of the bituminous layer, whilst leaving other portions substantially free of the first coating composition.

The method according to the first aspect of the present application may additionally comprise the step of applying a second coating material to the bituminous composition. Preferably, the second coating material is different to the first coating composition. The second coating material is preferably applied after the first coating material. The second coating material may be applied by any suitable means. For example, the second coating material may be applied under pressure to the waterproof membrane or the waterproof membrane may pass under a stream of the second coating material. The second coating material may be applied by a cylinder in a similar way to the first coating material.

Since the first coating material will have been at least partially embedded in the bituminous material, the second coating material is prevented from adhering to the bituminous material in the areas where the first coating material has been applied. As such, the second coating material is only able to stick to the bituminous material in the areas which are substantially free of the first coating material. The second coating material is therefore able to fall away from the membrane.

Any coating material which has not bonded to the bituminous material may be removed by any suitable method. For example, the loose coating material may be removed under the force of gravity or by application of a stream of air or by vibration of the membrane. Any recovered coating material may be collected for re-use. Any coating material which has been applied to the membrane, but has not bonded to the bituminous layer may be referred to as excess coating material. Excess coating material is loose and may be removed readily.

The method according to the first aspect of the present invention allows for a first coating material to be applied to a bituminous membrane in a highly controlled manner and avoids embossing a pattern in the surface of the membrane. The method also allows select areas of the bituminous layer to remain uncoated, if required. By using a cylinder comprising at least one groove, it is possible to deposit a coating material on a bituminous membrane quickly, so that complex patterns of the coating material can be formed on the bituminous membrane without having to reduce the speed at which the membrane may be produced. Preferably, the bituminous composition is liquid or semi-liquid when the coating material or materials are applied.

In addition, due to the accuracy of the method in depositing the coating material or materials, it is possible to selectively apply a first coating material to a specific area or areas of the bituminous material, and apply a different second coating material to another area or areas of the bituminous material. This allows the production of a waterproof membrane which has different surface properties. The difference in surface properties will depend on the nature of the coating materials.

For example, in this way, depending on the relative orientation and shape of the areas of the first coating material and the second coating material, it may be possible to control the travel of water across the membrane. For example, rain falling on the membrane may be able to pass across one of the first and second coating materials more easily than the other. As such, the rain will preferentially pass across one area of the membrane when compared to the other area. Thus, the flow of water may be controlled such that it is at least partially directed away from areas of the roof which may be susceptible to leakage, such as joints between membranes. Similarly, the positioning of the two different materials may be used to increase the rate at which water runs off the membrane or may be used to resist water passing across the surface of the membrane towards joints during windy weather. The membrane may be attached to the roof by mechanical fixings. These are generally metallic and are susceptible to corrosion. Thus, diverting water away from the areas of the membrane punctured by mechanical fixings, such as_nails or similar, results in a reduced rate of corrosion. Further, different coating materials may offer differing amounts of UV protection and the method according to the first aspect of the present invention allows for a coating material which offers higher UV resistance to be applied in certain areas where required. In addition, it is possible to build up a pattern of materials on the surface which reproduces the appearance of a tiled roof.

The configuration of the areas covered by the first coating material and those covered by the second material can be readily altered by changing the cylinder or cylinders used. The cylinder may have any suitable cross section, including triangular, square, pentagonal, circular, and so on.

In an embodiment of the first aspect of the present invention, a third coating material is applied to the membrane. The third coating material may be provided by a cylinder in a similar way as the first and/or second coating materials. The third coating material may be applied after the first coating material, but before the second coating material, or it may be applied after the second coating material. In this way, it is possible to provide a more complex pattern of coating materials on the membrane.

For example, the first cylinder may apply the first coating material in regularly spaced lines. The second or third cylinder may be configured to apply the second or third coating material in lines parallel to those applied by the first roller. The second or third coating material may abut the first coating material or may be spaced apart from the first coating material. The second or third coating material may therefore be spaced between each line of the first and third or second materials, or may separate one edge of the second or third material from one edge of the first material, the first and third or second materials abutting at one edge.

It is contemplated that further cylinders may be employed. Fourth, fifth or further materials may also be applied to the membrane.

Preferably, the cylinder is rotated at a speed which substantially matches the linear speed of the reinforcing material.

A doctor blade may be provided to remove any coating material from the cylinder which is not contained within the at least one groove of the cylinder.

The method may comprise heating, cooling, and rolling steps as are known in the art.

The bituminous material used in any of the aspects of the present invention may be any suitable bitumen composition. The bituminous material may be bitumen or a modified bitumen. The modified bitumen may comprise bitumen, synthetic rubber, and crumb rubber. The crumb rubber may be ground crumb rubber and may be recycled from tyres or any other polymer type used to modify bitumen, including blowing bitumen to oxidise it.

According to a second aspect of the present invention, there is provided an apparatus for producing a waterproof membrane, comprising a cylinder having at least one groove for containing a first coating material; means for rotating the cylinder; and means for advancing a reinforcing material comprising a bituminous composition.

Preferably, the cylinder rotates in or adjacent a reservoir of coating material.

The cylinder is preferably rotated at a speed which substantially matches the linear speed of the reinforcing material.

Preferably, a doctor blade is positioned adjacent the cylinder such that only the first coating material which is contained within the at least one groove of the cylinder is able to pass. As the cylinder rotates, the at least one groove of the cylinder passes through and picks up the first coating material. The doctor blade is positioned such that substantially all of the first coating material which is not within the at least one groove is pushed or scraped off the cylinder. In this way, only the material contained within the at least one groove of the cylinder is able to pass the doctor blade. As the cylinder continues to rotate, the material contained within the at least one groove is able to fall out of the groove and onto the bituminous material on the reinforcing material. Where there are multiple cylinders, each cylinder may be provided with a doctor blade.

The cylinder may comprise a plurality of grooves. The grooves may be of any suitable size and shape. The groove or grooves may be linear or curved. The grove or grooves may form a grid-like pattern. The groove or grooves may be symmetrically disposed around the circumference of the cylinder. The groove or grooves may be interconnected or may be distinct from one another. The groove or grooves may be of a uniform depth or may be of different depths. The depth of the groove will determine the amount of the coating material deposited over a particular area, with a deeper groove holding a greater amount of material and thereby forming a thicker layer of the material when applied to the membrane. Preferably, the at least one groove is formed in the outer surface of the cylinder. The cylinder may also comprise projections from the surface which form receiving means for receipt of the coating materials.

The cylinder is an essential element required for the method and apparatus according to the first and second aspects of the present invention. Therefore, in accordance with a third aspect of the present invention, there is provided a cylinder for the production of a waterproof membrane, wherein the cylinder comprises at least one groove for receipt of a coating material.

Preferably, the at least one groove is formed as a cut out from the surface of the cylinder. As such, the at least one groove may be formed by machining or milling out material from the surface of a cylinder. The cylinder may have a substantially circular cross-section.

According to a fourth aspect of the present invention, there is provided a waterproof membrane made in accordance with the method of the first aspect of the present invention, the apparatus of the second aspect of the present invention, or the roller of the third aspect of the present invention.

The waterproof membrane is preferably a roofing membrane. Preferably, the membrane comprises a reinforcing layer, a bituminous layer, and a coating material on the bituminous layer, wherein the coating material covers less than the entire surface of the bituminous layer. Preferably, the coating material is arranged in a pre-selected pattern. Preferably, the coating material is arranged in a line, lines, or a grid. The coating material may be arranged in any suitable pattern.

Preferably, the membrane comprises a second coating material. The second coating material may be different to the first coating material. The first and second coating materials may be provided in separate areas of the bituminous layer. In this way, the first and second coating materials may define different areas on the surface of the membrane. The first and second coating materials may be arranged to reproduce a tile pattern on the membrane.

The membrane may comprise three, four, five, or more different materials.

The coating materials may be selected from any suitable materials. The coating material may be selected from sand, mineral, plastic, stone, or any other suitable material. The coating material may comprise a mixture of different materials. Where one of the coating materials is a mixture of materials, the other coating material may comprise one of the materials comprising the first coating material, but the overall composition of the two coating materials will be different. For example, the first coating material may comprise a mixture of sand and mineral, and the second coating material may comprise sand or mineral. It is also contemplated that the first and second coating materials may both comprise the same materials, but in different ratios. The key is that the two materials are not the same. The waterproof membrane of the present invention may comprise a reinforcing layer, a bituminous layer, and a coating layer, the coating layer comprising at least two different coating materials, wherein the coating materials are provided in separate areas of the surface of the membrane.

Any combination of the first, second, third, and fourth aspects of the present invention is contemplated. As such, any features of the invention disclosed in respect of one aspect of the present invention may be used to clarify, limit, or define any other aspect of the present invention.

The invention of the first, second, third, and fourth aspects of the present invention will now be further described with reference to the following non-limiting figures in which:

Figure 1 is a schematic representation of the apparatus according to the second aspect of the present invention;

Figure 2 is an enlarged schematic representation of the apparatus according to the second aspect of the present invention showing the cylinder; and

Figure 3a and 3b are 2-D representations of the configuration of the grooves of an exemplary cylinder.

Figure 1 illustrates a schematic representation of the apparatus according to the second aspect of the present invention. The carrier or reinforcing layer 1, which may be in the form of a film or fabric, is carried on a roll and it unrolled and passed to a first saturator 2. The saturator 2 may or may not saturate the reinforcing layer 1 in liquid or semi-liquid bitumen. The reinforcing layer 1 is then optionally passed through one or a series of rollers and a dancing roller 3 and then passed to a saturator/coating applicator 4 where the reinforcing layer may or not be saturated and the coating bitumen is applied. The one or series of rollers may be calendar rollers which provide the membrane with the desired thickness. The bitumen coated reinforcing layer is then passed to the cylinder 5 which comprises at least one groove containing a first coating material. As the bitumen coated reinforcing layer passes by or under the cylinder 5, the cylinder 5 rotates at a speed which is substantially the same as the linear speed of the coated reinforcing layer 1. The cylinder 5 rotates in a reservoir of the first coating material, such as sand or mineral. As the cylinder rotates, the coating material in the reservoir is able to fill the groove or grooves in the cylinder 5. A doctor blade in close proximity to the surface of the cylinder 5 ensures that any coating material which is not contained in the groove or grooves is removed from the surface of the cylinder 5. The doctor blade also ensures that an excess material from the groove or grooves is removed.

As the cylinder 5 rotates past the doctor blade, the coating material contained in the groove or grooves is able to fall out of the groove or grooves and onto the surface of the bitumen-coated reinforcing layer 1. Thus, the coating material is deposited on the surface of the bitumen-coated reinforcing layer in a pattern which is complementary to the pattern of grooves in the cylinder 5. The pattern of the grooves of the cylinder 5 therefore forms a repeating pattern on the surface of the bitumen-coated reinforcing layer as the cylinder 5 rotates and the bitumen-coated reinforcing layer moves through the apparatus.

The bitumen-coated reinforcing layer 1, now partially coated with coating material, then passes to a second cylinder 6. The second cylinder may be similar to the first cylinder 5 and comprise at least one groove or may have a surface which does not comprise any surface grooves. The second cylinder applies the second coating material, which is different to the first coating material. The second cylinder may be a pair of cylinders which regulates the flow of the second coating material. The second coating material may also be applied using a conveyor belt or a vibrating apparatus. Since the first coating material has adhered to the bitumen layer, the second coating material is only able to attach to the areas of the bitumen which have not been covered by the first coating material.

The reinforcing layer 1 is then optionally passed to a first cooling roller 7 to at least partially cool the bitumen. As the reinforcing layer 1 moves around the cooling roller, any excess first and second coating materials fall off and may be collected for re-use.

The reinforcing layer 1 may optionally be passed under a third cylinder, which applies a coating material to the opposite face of the reinforcing layer 1. The reinforcing layer 1 is then optionally passed to a second cooling roller 9 to further cool the bitumen. Following this, the reinforcing layer may be passed for further processing as is known in the art, which may include reeling to the desired length, cutting and packaging.

Figure 2 depicts a schematic of the cylinder which comprises at least one groove. The cylinder 5 comprises at least one groove 10 into which coating material 11 is able to flow. The coating material 11 is retained in a reservoir or hopper 12. A doctor blade 13 is provided in close proximity to the outer surface of the cylinder 5. The doctor blade 13 may be integral with a wall of the reservoir or hopper 12 or may be separate. The cylinder is rotated by any suitable means, such as an electric motor (not shown). As the cylinder 5 rotates, the coating material 11 in the reservoir 12 fills the groove 10. As the groove 10 passes the doctor blade 13, any excess coating material 11 is removed. As the cylinder 5 continues to rotate, the groove 10 ultimately passes a point where the coating material 11 contained within the groove 10 begins to fall out. The coated reinforcing membrane passes under the cylinder 5 such that as the coating material falls out, it lands on the reinforcing membrane 1 in a pattern which corresponds to that of the grooves of the cylinder 5. The cylinder 5 continues to rotate and passes back through the reservoir 12 of coating material 11 to begin the process again.

Figures 3a and 3b depict 2-D representations of exemplary arrangements of grooves of a cylinder 5 according to the present invention. It will be appreciated that the grooves as depicted in Figures 3a and 3b are representative of the configuration of the grooves on the surface of the cylinder and may not show all of the grooves.

In Figure 3a, the grooves are arranged in a series of grooves 14 which pass substantially along the length of the cylinder 5 and a series of grooves 15 which pass at least partially around the circumference of the cylinder 5. The grooves 15 which pass at least partially around the circumference of the cylinder 5 do not completely pass around the circumference of the cylinder 5 and are staggered so as to form rows of substantially rectangular areas 16 around the surface of the cylinder 5.

Similarly, in Figure 3b, the grooves are not perpendicular to or parallel with the length of the cylinder 5, but are instead angled. As such, grooves 17 and 18 form rows of substantially diamond-shaped areas 19 around the surface of the cylinder 5. It will be appreciated that the grooves may be of any shape depending on the pattern in which the coating material or materials are to be applied.

The method and apparatus of the present invention provides numerous advantages over known method and apparatus for producing waterproof membranes. The method and apparatus of the present invention allows waterproof membranes to be formed with a particular distribution of coating material on the surface of the membrane, and allows the controlled and repeatable application of more than one coating material. The method and apparatus of the present invention does not weaken the membrane unlike methods and apparatus of the prior art, and allows waterproof membranes to be manufactured quickly and efficiently. The apparatus and method of the present invention allow the efficient manufacture of waterproof membranes.

Claims

1. A method of producing a waterproof membrane, comprising the steps of providing a sheet of reinforcing material, applying a bituminous composition to the sheet of reinforcing material, and applying a first coating material to the bituminous composition by rotating a cylinder comprising at least one groove containing the first coating material, wherein rotating the cylinder causes the first coating material to leave the at least one groove and be deposited in a pattern in the bituminous composition substantially corresponding to the at least one groove in the cylinder.

2. A method according to Claim 1, wherein the first coating material is deposited in a line substantially perpendicular to the length of the membrane.

3. A method according to Claim 1, wherein the first coating material is deposited in a line substantially parallel to the length of the membrane.

4. A method according to Claim 1, wherein the first coating material is deposited in a grid.

5. A method according to any preceding claim, wherein a second coating material is applied to the bituminous composition.

6. A method according to Claim 5, wherein the second coating material is different to the first coating material.

7. A method according to any receding claim, wherein the second coating material is applied after the first coating material.

8. A method according to any preceding claim, wherein the second coating material is applied by a cylinder comprising at least one groove containing the second coating material.

9. A method according to any of Claims 5 to 8, comprising the step of removing excess first and/or second coating material.

10. A method according to Claim 9, wherein the excess coating material is removed by the force of gravity, application of a stream of air, and/or by vibration of the membrane.

11. A method according to Claim 10, wherein the excess coating material is recovered.

12. A method according to any of Claims 5 to 11, wherein a third coating material is applied to the bituminous composition.

13. A method according to any preceding claim, wherein the cylinder is rotated at a speed which substantially matches the linear speed of the reinforcing material.

14. A method according to any preceding claim, wherein the cylinder rotates in a reservoir of coating material.

15. A method according to any preceding claim, wherein a doctor blade removes any coating material from the cylinder which is not contained within the at least one groove of the cylinder.

16. An apparatus for producing a waterproof membrane, comprising a cylinder having at least one groove for containing a first coating material; means for rotating the cylinder; and means for advancing a reinforcing material comprising a bituminous composition.

17. An apparatus according to Claim 16, wherein the cylinder is located in or adjacent a reservoir of coating material.

18. An apparatus according to any of Claims 16 or 17, wherein a doctor blade is positioned adjacent the cylinder.

19. An apparatus according to any of Claims 16 to 18, wherein the cylinder comprises a plurality of grooves.

20. A cylinder for the production of a waterproof membrane, wherein the cylinder comprises at least one groove for receipt of a coating material.

21. A cylinder according to Claim 20, wherein the cylinder has a substantially circular cross-section.

22. A cylinder according to any of Claims 20 or 21, wherein the cylinder has a substantially symmetric cross-section.

23. A cylinder according to any of Claims 20 to 22, wherein the cylinder comprises a plurality of grooves.

24. A cylinder according to Claim 23, wherein the plurality of grooves form a net.

25. A waterproof membrane made in accordance with the method of any of Claims 1 to 15, the apparatus according to any of Claims 16 to 19, or the cylinder according to any of Claims 20 to 24.

26. A waterproof membrane according to Claim 25, wherein the waterproof membrane is a roofing membrane.

27. A waterproof membrane according to Claim 25 or 26, wherein the membrane comprises a reinforcing layer, a bituminous layer, and a coating material on the bituminous layer, wherein the coating material covers less than the entire surface of the bituminous layer.

28. A waterproof membrane according to any of Claims 25 to 27, wherein the coating material is arranged in a pre-selected pattern.

29. A waterproof membrane according to Claim 28, wherein the coating material is arranged in a line, a plurality of lines, or a grid.

30. A waterproof membrane according to any of Claims 25 to 29, wherein the membrane comprises a second coating material.

31. A waterproof membrane according to Claim 30, wherein the second coating material is different to the first coating material.

32. A waterproof membrane according to Claim 31, wherein the first and second coating materials are provided in separate areas of the bituminous layer.

33. A waterproof membrane according to any of Claims 30 to 32, wherein the first and second coating materials are arranged in a tile pattern.

34. A waterproof membrane according to any of Claims 25 to 33, wherein the coating material is selected from sand, mineral, plastic, stone, or any other suitable material.

Intellectual

Property

Office

Mr Rhys J. Williams

18 September 2017