Method of manufacturing a length of a composite sheet material

Abstract

The present invention relates to a method of manufacturing, preferably continuously, a length of a composite sheet material.

Description

[0001] Method of manufacturing a length of a composite sheet material

[0002] Technical field of the invention

[0003] The present invention relates to the production of composite sheet materials, preferably for use in the construction industry.

[0004] Background of the invention

[0005] Air entrapment in composite sheet materials during production is a significant challenge that can compromise the quality, performance, and longevity of the final product. This issue arises when air pockets or bubbles become trapped between the layers of material as they are being combined, either during the lamination process or while applying adhesives or tacky layers.

[0006] The presence of trapped air introduces several problems. One of the most immediate concerns is the reduction in mechanical integrity. Air pockets can create weak points within the composite structure, leading to delamination or separation of the layers under mechanical stress. These weak points are particularly problematic in applications where the composite material is subjected to load bearing, flexing, or environmental stresses, as the entrapped air can act as initiation sites for cracks or other forms of material failure.

[0007] Moreover, air entrapment can significantly impair the adhesive bond between layers. In the case of adhesive or tacky layers, air bubbles prevent full contact between the adhesive and the adjoining surfaces, leading to incomplete or weak bonding. This not only reduces the overall strength of the bond but can also lead to the premature failure of the adhesive, particularly under dynamic conditions such as repeated flexing, vibration, or thermal cycling.

[0008] Another issue related to air entrapment is its effect on the thermal and moisture barrier properties of the composite material. Air pockets can disrupt the uniformity of these barriers, allowing pathways for moisture, air, or other environmental factors to penetrate the composite. This can lead to corrosion of metallic layers, degradation of polymer layers, or other forms of deterioration over time. In applications where the composite material is used as a protective barrier, such as in construction, this compromise in barrier integrity can be critical.

[0009] In addition to mechanical and protective concerns, air entrapment can also negatively impact the aesthetic qualities of the composite material. Visible bubbles or irregularities on the surface can make the material unsuitable for applications where appearance is important. Even in non-visual applications, surface irregularities can affect the material’s ability to interface correctly with other components, leading to assembly issues or the need for additional processing steps to smooth out the material.

[0010] Summary of the invention

[0011] It is an object of the present invention to provide a method of manufacturing a length of a composite sheet material that solves the problem with air entrapment.

[0012] A first aspect relates to method of manufacturing, preferably continuously, a length of a composite sheet material comprising:

[0013] - providing a first sheet material lined on one side with a release liner, and where the opposite side is left as an exposed side, wherein the first sheet material primarily comprises a tacky or adhesive material;

[0014] - providing, preferably on a reel, a second sheet material of metal or polymer mesh, said mesh comprising apertures;

[0015] - perforating the first sheet material with a perforation mechanism;

[0016] - combining the first and second sheet materials, such that the exposed side of the first sheet material receives the second sheet material, to form an intermediate composite sheet material;

[0017] - applying a third layer of a polymeric material to the exposed side of the first sheet material, thereby covering the second sheet material to form a composite sheet material; and

[0018] - pressing the first, second, and third sheet materials together with a pressing mechanism, thereby forcing trapped air between the individual sheet materials through the perforations formed in the first sheet material, such that the first sheet material comes into contact with the third sheet material through the apertures of the second sheet material.

[0019] In one or more embodiments, the method further comprises the step of allowing the perforations formed in the first sheet material to self-close subsequent to, or during, the pressing step.

[0020] In one or more embodiments, the step of perforating the first sheet material with a perforation mechanism comprises placing the perforations in one or more lines that run parallel along the length of the sheet material.

[0021] In one or more embodiments, the one or more lines of perforations are designed so that strips of the release liner can be removed while the rest of the liner remains intact.

[0022] In one or more embodiments, the step of combining the first and second sheet materials comprises continuously directing and aligning, with a guide mechanism, the first and second sheet materials relative to one another.

[0023] In one or more embodiments, the pressing mechanism comprises a set of rollers.

[0024] In one or more embodiments, the tacky or adhesive material comprises PIB, BIMS, HR, EPDM, EPM, CIIR, BUR, XIIR (Cross-linked butyl), RC-Butyl (Reclaimed butyl / EP(D)M, made by degrading vulcanized butyl / EP(D)M based rubber into nonvulcanised elastomer mixtures), or mixtures thereof.

[0025] In one or more embodiments, the tacky or adhesive material comprises PIB, BIMS, HR (preferably including reclaimed butyl), BUR, XIIR, CIIR, EPDM (preferably including reclaimed EPDM), EPM (preferably including reclaimed EPM), or mixtures thereof.

[0026] In one or more embodiments, the tacky or adhesive material comprises PIB or BIMS mixed with HR, EPDM, and / or EPM, or PIB mixed with BIMS. In one or more embodiments, the tacky or adhesive material comprises PIB or BIMS mixed with HR (preferably including reclaimed butyl), BUR, XIIR, CIIR, EPDM (preferably including reclaimed EPDM), and / or EPM (preferably including reclaimed EPM).

[0027] In one or more embodiments, the tacky or adhesive material comprises PIB mixed with BIMS.

[0028] In one or more embodiments, the third layer of a polymeric material comprises PIB, BIMS, or mixtures thereof.

[0029] A second aspect relates to a composite sheet material produced by the method according to the present invention.

[0030] A third aspect relates to the use of the composite sheet material according to the present invention for a roofing membrane or a protective barrier.

[0031] In the present context, the terms “mesh” is to be understood broadly, also including the term “netting”. However, meshes are typically evaluated based on their ability to allow passage of air and liquids through precisely defined and uniform openings, and are typically made by weaving, or welding wires or fibres together. Nets generally refers to a fabric-like material made by knotting a thread or cord at intersections, creating a grid that can be elastic or fixed, and evaluated more for their physical properties and ability to contain objects, with various sizes and types of openings depending on the specific use.

[0032] As used in the specification and the appended claims, the singular forms "a", "an", and "the" include plural referents unless the context clearly dictates otherwise. Ranges may be expressed herein as from "about" or "approximately" one particular value and / or to "about" or "approximately" another particular value. When such a range is expressed, another embodiment includes from the one particular value and / or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent "about", it will be understood that the particular value forms another embodiment. It should be noted that embodiments and features described in the context of one of the aspects of the present invention also apply to the other aspects of the invention.

[0033] Detailed description of the invention

[0034] The following description is to be seen as non-limiting examples of the production of composite sheet materials according to various embodiments of the present invention.

[0035] In the present context, the term “in general” when used when mentioning a feature relating to the present invention, it must be understood that the feature may be used with all embodiments of the invention, even if the mentioning is made in the detailed part of the document.

[0036] In general, the first sheet material is of tacky or adhesive material lined on one side with a release liner. The purpose of this layer is to secure initial adhesion of the composite sheet material to a surface. Preferably, the tacky or adhesive material is also capable of a more permanent adhesion to the surface on which the composite sheet material is placed.

[0037] In general, the first sheet material is lined on one side with a release liner, preventing it from sticking to itself or other surfaces during storage and handling.

[0038] In order to avoid air entrapment, the first sheet material is perforated prior to being combined with the other sheet materials, such that entrapped air between the layers can be forced out of these perforations. However, the perforations should preferably be closed afterwards to avoid weakening the produced composite sheet material. Certain adhesive or tacky compounds provided as sheet materials are designed with self-closing properties, enabling them to maintain their integrity even when perforated. These sheet materials are typically lined with a release liner, which protects the adhesive layer until it is ready to be applied. These adhesive sheet materials, such as pressure-sensitive adhesives (PSAs), are commonly used in a variety of applications, including sealing, bonding, and protective coverings. The release liner, usually made of paper or plastic, preferably wrapped in the longitudinal direction, covers the tacky adhesive surface, preventing it from sticking to unintended surfaces during storage or handling.

[0039] When the release liner is removed, the adhesive layer is exposed and ready to bond to the desired surface. Some of these adhesive materials are specifically engineered with a self-sealing / self-closing property, allowing them to close up around a perforation. This capability is particularly useful in applications where maintaining an airtight or watertight seal is essential, such as in roofing membranes.

[0040] The self-closing property is achieved through the material’s elasticity and the flow characteristics of the adhesive. When the sheet is perforated, the adhesive on either side of the puncture can flow back together, effectively sealing the hole. The elasticity of the release liner may also help to pull the adhesive into place, enhancing the self-sealing effect. The release liner plays a critical role in protecting the tacky surface until it is ready to be used, ensuring that the adhesive can perform optimally when applied. If the first sheet material is supplied on a reel, it may be lined with release liners on both sides. In this situation, one of the release liners are removed to provide an exposed side to face the second and third sheet materials.

[0041] Similarly, tacky compounds / materials, such as rubbers, also have self-closing properties, especially if composed of relatively low molecular weight polymers. Among the many possible combinations, blends involving Polyisobutylene (PIB), Brominated Isobutylene-lsoprene Rubber (BIMS), Isobutylene-lsoprene Rubber (HR), Ethylene Propylene Diene Monomer (EPDM), and Ethylene Propylene Rubber (EPM) are particularly noteworthy.

[0042] A preferred material for the first sheet material is one or more non-vulcanised elastomeric polymers, preferably selected from: Brominated Isobutylene paraMethyl- Styrene (BIMS), Isobutylene-lsoprene Rubber (HR), Chlorinated Isobutylene- lsoprene Rubber (CH R), Brominated Isobutylene-lsoprene Rubber (BUR), Precrosslinked Isobutylene-lsoprene Rubber (XIIR), Co-polymers of Ethylene Propylene Rubber (EPM), Ter-polymers of Ethylene Propylene Diene Monomer Rubber (EPDM), mixtures thereof, and reclaimed rubber based on the rubbers or mixtures of rubbers described above.

[0043] A preferred material for the first sheet material is PIB, BIMS, HR, CIIR, BUR, XIIR, EPDM, EPM, and mixtures thereof.

[0044] A more preferred material for the first sheet material is PIB or BIMS mixed with HR (preferably including reclaimed butyl), BUR, XIIR, CIIR, EPDM (preferably including reclaimed EPDM), and / or EPM (preferably including reclaimed EPM).

[0045] The blend of PIB and HR, both being derivatives of isobutylene, creates a material that is highly impermeable to gases and liquids while maintaining excellent flexibility and tackiness. PIB contributes to the material’s self-sealing properties, making it ideal for roofing membranes that need to remain watertight even when punctured. HR enhances this blend by adding resilience and durability, ensuring that the material can withstand mechanical stress and environmental exposure without losing its sealing capabilities.

[0046] Combining BIMS with HR results in a material that balances chemical and thermal resistance with excellent sealing properties. BIMS, being a brominated version of butyl rubber, introduces enhanced adhesion and stability at higher temperatures, making it particularly suitable for environments where the material may be exposed to heat or chemicals. When blended with HR, the resulting material retains flexibility and impermeability, making it well-suited for applications in protective barriers where both durability and resistance to harsh conditions are required.

[0047] A blend of PIB and BIMS leverages the strengths of both materials to create a highly tacky and durable adhesive compound. PIB’s natural stickiness and elasticity make it an excellent base for self-sealing applications, while BIMS enhances the overall durability and chemical resistance. This combination is particularly effective in roofing membranes that need to maintain their integrity over time, even under challenging environmental conditions, by providing both immediate adhesion and long-term stability. The combination of PIB with EPDM results in a material that is not only flexible and impermeable but also highly resistant to weathering. EPDM is renowned for its ability to withstand UV radiation, ozone, and extreme temperatures, making it an ideal partner to PIB in creating a roofing membrane or protective barrier that can endure prolonged exposure to outdoor elements. The blend ensures that the material remains effective over time, providing reliable sealing and protection against environmental factors.

[0048] Similarly, blending PIB with EPM, which is chemically similar to EPDM but without the diene component, produces a material that offers good weather resistance and flexibility. EPM adds stability and elasticity, which, combined with PIB’s tackiness and impermeability, creates a versatile material suitable for both roofing and protective applications. This blend is particularly advantageous in situations where long-term exposure to varying weather conditions is expected, as it maintains its sealing properties while resisting environmental degradation.

[0049] When BIMS is combined with EPDM, the result is a material that excels in chemical and thermal resistance while also being highly durable in outdoor conditions. BIMS contributes to the material's adhesive strength and resistance to chemicals, making it particularly useful in applications where exposure to harsh substances is a concern. EPDM, with its excellent resistance to UV radiation and ozone, ensures that the material remains functional and resilient in outdoor environments, making this blend ideal for protective barriers and roofing membranes that must perform reliably in harsh conditions.

[0050] A blend of BIMS with EPM offers a similar balance of properties, with the added benefit of EPM’s stability and elasticity. This combination results in a material that is both chemically resistant and flexible, capable of maintaining its integrity under mechanical stress and environmental exposure. The blend is particularly well-suited for applications in protective barriers, where the ability to resist chemicals and withstand outdoor conditions without losing flexibility is critical. The molecular weight of each polymer in these blends is critical in achieving the right balance of tackiness, adhesion, and mechanical properties. For blends like PIB with HR or BIMS, lower molecular weights of PIB can enhance tackiness, while medium to higher molecular weights of HR or BIMS provide elasticity and durability. In combinations involving EPDM or EPM, the molecular weight is crucial for maintaining flexibility and weather resistance, with adjustments made to the PIB component to ensure adequate adhesion. By carefully selecting and balancing the molecular weights of these polymers, materials can be engineered to meet the specific demands of applications, such as roofing membranes and protective barriers, where both adhesion and durability are essential.

[0051] Polyisobutylene (PIB), for instance, is widely recognized for its inherent tackiness, which is directly influenced by its molecular weight. Low molecular weight PIB tends to be more tacky and sticky, making it highly effective as an adhesive component in self-sealing applications. This tackiness is due to the fact that lower molecular weight polymers have shorter chains, which allows them to flow more easily and interact with surfaces at the molecular level, enhancing adhesion. In blends where PIB is a key component, such as PIB with HR or PIB with BIMS, selecting a PIB with an appropriately low to medium molecular weight is essential for achieving the desired level of tackiness. However, if the molecular weight is too low, the material may become too soft or fluid, potentially compromising its structural integrity and long-term performance.

[0052] Isobutylene-lsoprene Rubber (HR), or butyl rubber, also exhibits properties that vary with molecular weight. Higher molecular weight HR tends to be more elastic and durable, which is beneficial for applications requiring long-term flexibility and resistance to environmental factors. However, to maintain adequate tackiness and adhesion when blended with PIB or BIMS, a balance must be struck. Typically, a medium molecular weight I IR is chosen to ensure that the material retains sufficient elasticity without sacrificing the adhesive properties conferred by PIB or BIMS. In the case of HR’s blend with BIMS, the molecular weight of HR can influence how well the rubber interacts with the brominated segments of BIMS, affecting both the blend’s adhesion and its resistance to thermal degradation. Brominated Isobutylene-lsoprene Rubber (BIMS), due to its bromination, has a different set of molecular interactions compared to PI B or HR. The molecular weight of BIMS affects its cross-linking density, which in turn influences the adhesive properties and thermal stability of the blend. Higher molecular weight BIMS provides greater thermal stability and chemical resistance, which is important in applications where the material will be exposed to heat or aggressive chemicals, such as in roofing membranes. However, if the molecular weight is too high, it may reduce the tackiness of the blend, making it less effective as a self-sealing material. Therefore, when blending BIMS with PIB or HR, a medium molecular weight is often preferred to balance adhesion with durability.

[0053] Ethylene Propylene Diene Monomer (EPDM) and Ethylene Propylene Rubber (EPM) are known for their excellent weather resistance, which is largely unaffected by variations in molecular weight. However, molecular weight still plays a role in determining the mechanical properties of these materials. Higher molecular weight EPDM or EPM provides greater tensile strength and elasticity, which is beneficial for maintaining the structural integrity of roofing membranes and protective barriers. In blends where EPDM or EPM is combined with PIB, a lower molecular weight for PIB might be chosen to enhance tackiness, while the EPDM or EPM remains at a higher molecular weight to ensure durability and flexibility. This combination allows the blend to be both adhesive and resilient, providing long-lasting performance in outdoor environments.

[0054] In general, the second sheet material is a metal and / or polymer mesh. When selecting a mesh material to reinforce composite membranes used in construction, particularly for applications like roofing, waterproofing, and flexible barriers, the choice between metal and polymer meshes may be important. These meshes are intended to provide reinforcement, shapeability, and the ability to accommodate deformations out of the plane of the composite sheet material. The mesh can be produced from either metal or polymer, and can be fabricated through methods such as knitting, weaving, or punching.

[0055] Metal meshes, such as those made from stainless steel or aluminium, are particularly well-suited for construction membranes where durability and mechanical strength are paramount. Stainless steel mesh, known for its corrosion resistance and high tensile strength, can be woven, knitted, or punched to create a structure that offers both reinforcement and some flexibility. This makes it ideal for applications exposed to harsh environmental conditions, such as roofing membranes that must withstand moisture, UV radiation, and mechanical stress. Aluminium mesh, while lighter and more flexible than stainless steel, also provides excellent corrosion resistance. Aluminium meshes can also be woven or knitted, much like stainless steel meshes. However, woven and knitted aluminium meshes are less common than expanded or punched aluminium meshes due to the metal’s specific properties, such as its softness and lower tensile strength compared to stainless steel. Its expanded form, created by stretching a solid sheet into a mesh, balances strength and flexibility, allowing it to be shaped and adapted to complex surfaces without adding significant weight. Such metal meshes are particularly advantageous in situations where the membrane needs to maintain structural integrity under load or where the composite material must conform to irregular surfaces.

[0056] On the other hand, polymer meshes offer distinct advantages in applications where flexibility, weight reduction, and resistance to chemicals and moisture are critical. Polyester (PET) mesh is a common choice for construction membranes due to its lightweight nature, flexibility, and resistance to environmental factors. Woven or knitted polyester mesh can easily deform out of plane, making it suitable for roofing membranes that need to adapt to the movement of the underlying structure while providing reinforcement. Polypropylene mesh, another popular option, is known for its chemical resistance and cost-effectiveness. This mesh is often used in environments where the membrane is exposed to chemicals or moisture, such as in waterproofing systems. Its flexibility and tensile strength make it a strong candidate for use in membranes that require both reinforcement and the ability to accommodate thermal expansion and contraction. Nylon (polyamide) mesh, with its high toughness and abrasion resistance, is also used in construction applications where durability and flexibility are important. Nylon mesh is particularly effective in reinforcing membranes that need to withstand mechanical wear and tear, such as those used in industrial settings or high-traffic areas. The choice between metal and polymer meshes for reinforcing construction membranes depends on the specific requirements of the application. Stainless steel and aluminium meshes are best suited for scenarios demanding high strength and environmental resilience, while polyester, polypropylene, and nylon meshes are preferred for applications where flexibility, lightweight, and chemical resistance are more critical.

[0057] When the composite sheet material is designed to mimic the malleability of lead for roof flashings, particularly in areas like the junctions below windows, certain mesh materials are preferred. The goal is to achieve a material that is highly shapeable, can conform to complex surfaces, and maintains its form after being manipulated, much like lead. Given these requirements, the preferred mesh type would need to combine flexibility, durability, and sufficient reinforcement to provide structural integrity without compromising the material's ability to be easily moulded.

[0058] Aluminium mesh, such as expanded aluminium mesh, is a preferred choice for this application. Expanded aluminium mesh may e.g., be created by cutting and stretching a solid sheet of aluminium, forming a mesh with diamond-shaped openings. Woven aluminium mesh is another viable option. Woven mesh is produced by interlacing aluminium wires, creating a grid-like structure that is both flexible and durable. This type of mesh can easily follow the contours of a roof and maintain its shape after being bent or folded. Woven aluminium mesh offers a slightly softer and more pliable structure compared to expanded mesh, which could further enhance the lead-like malleability of the composite sheet used for roof flashings.

[0059] As a polymer option, woven polyester mesh is preferred. Polyester mesh is known for its flexibility, strength, and resistance to environmental degradation. Woven polyester mesh can provide the necessary reinforcement while still allowing the composite sheet to be highly malleable. This type of mesh can deform out of plane, enabling the composite to conform to complex shapes and surfaces, similar to how lead would in roof flashings. Polyester mesh is also lightweight and resistant to UV radiation and moisture, making it suitable for outdoor roofing applications. While it may not provide the same level of structural rigidity as metal meshes, it offers excellent flexibility and durability, making it a suitable reinforcement material for a composite sheet designed to mimic lead in roof flashings.

[0060] In general, prior to combining the first and second sheet materials, the first sheet material is perforated with a perforation mechanism. In a production facility, the processing of the first sheet material is, if supplied on a reel, first unwound from the reel in preparation for the perforation process. A release liner serves as a protective layer, preventing the adhesive surface of the first sheet material from sticking to unwanted surfaces or itself before application. If two release liners are present, one on both sides, one of the release liners may be removed at this stage.

[0061] Once unwound, the sheet material and its release liner are fed into a perforation unit. This unit / machine is equipped with tools designed to create perforations through both the sheet material and the release liner. If two release liners are present, one on both sides, one of the release liners may be removed at this stage. The release liner may be peeled away by passing the sheet material through a separation mechanism. This mechanism is designed to grip the release liner and pull it away smoothly without distorting or stretching the underlying first sheet material and release liner.

[0062] The perforations may be strategically placed in lines that run parallel along the length of the sheet material. The precision in this process ensures that the perforations are consistent and aligned, making it possible to easily remove sections of the release liner without affecting the integrity of the sheet material.

[0063] The lines of perforations may be designed so that (relatively narrow) strips of the release liner can be removed while the rest of the liner remains intact. This feature is particularly advantageous in applications where the composite sheet material needs to be adhered to a surface incrementally, rather than all at once. For example, in scenarios where a large surface area needs to be covered, an operator can peel away a narrow section of the release liner, exposing only a portion of the adhesive or tacky material. This allows for the precise positioning and adherence of the sheet material onto the surface, followed by the gradual removal of the remaining liner and adhesion of the rest of the sheet material.

[0064] This method of processing and perforating the sheet material provides greater control and flexibility during application, reducing the likelihood of errors, such as misalignment or air bubbles that can occur when attempting to adhere large sections at once. Additionally, the ability to remove the release liner in smaller sections makes the material easier to handle, particularly in situations where the application surface is complex or irregular. The overall process ensures that the sheet material can be efficiently and effectively applied in a controlled manner, optimizing both the quality and ease of the application.

[0065] The tool used for performing the perforations in the first sheet material and release liner could be designed as a roller with knives or blades extending from its surface. This roller, often referred to as a perforation roller or perforation drum, is a common and effective tool for creating consistent and precise perforations in materials processed on a reel.

[0066] The roller could be equipped with knives that are strategically positioned in a specific pattern. For example, these knives could be arranged in a series of concentric rings around the circumference of the roller. Each ring of knives would correspond to a line of perforations to be made along the length of the sheet material. The spacing between these rings would determine the distance between the lines of perforations on the material.

[0067] The knives themselves may in general be designed to extend just enough to penetrate both the sheet material and the release liner, thereby avoiding causing excessive damage or completely severing the material. This allows for the creation of perforations in the release liner that are easy to tear along but still keep the first sheet material intact during handling and processing.

[0068] By adjusting the distance between the rings of knives on the roller, manufacturers can control the width of the strips that can be peeled away from the release liner. For instance, if the application requires narrow strips of liner to be removed, the rings would be placed closer together. Conversely, if wider strips are needed, the rings would be spaced further apart.

[0069] This design allows for great flexibility in the production process. Depending on the application requirements, the roller can be customized with different patterns of knives, such as straight lines, zigzag patterns, or even more complex shapes, to achieve the desired perforation pattern. The use of a roller also ensures that the perforations are made continuously and consistently as the sheet material is fed through the machine, making the process highly efficient for large-scale production.

[0070] The third sheet layer of a polymeric material is then added to the exposed side of the first sheet material, thereby covering the second sheet material to form a composite sheet material. It is in this step that air entrapment is normally most prominent due to the mesh leaving space for air in its apertures, i.e., the open space or gap between the strands or wires of the mesh. However, due to the formation of temporary (self-closable) perforations in the first sheet material, air can escape therethrough. The perforations self-close due to the selection of material type, as discussed above.

[0071] Once the first, second, and third sheet material are prepared, they may be guided through a series of rollers that help align them properly. This alignment is important to ensure that the layers / sheet materials are perfectly stacked without any wrinkles or misalignments, which could compromise the integrity of the final composite sheet material. The rollers may apply slight tension to each layer, which helps to maintain a consistent feed rate and prevents slack that could lead to errors in the layering process.

[0072] In general, positioned at various points along the production line, guide rollers may be adapted to help direct the sheet materials along the correct path. The rollers are preferably aligned to ensure that the sheets follow a straight and consistent path toward the combining area.

[0073] In general, edge guides may also be utilized in the guiding and aligning operation.

[0074] These are adjustable mechanisms that maintain the lateral alignment of the sheets. Edge guides ensures that the sheet materials do not drift to one side as they move along the production line. They help in keeping all layers / sheet materials aligned at their edges.

[0075] Tension control systems may also be utilized in the guiding and aligning operation. These systems may be configured to continuously monitor and adjust the tension of each sheet as it moves through the line. Proper tension is vital to prevent issues like wrinkles, stretching, or snapping of the sheet material, especially when dealing with delicate or elastic materials.

[0076] In general, once the first, second, and third sheet material are aligned, they are brought together and may be passed through a set of compression rollers or a pressing mechanism prior to being combined with the third sheet material. The second sheet material may be compressed with the first sheet material prior to compressing all three sheet materials together. Alternatively, although less preferred, the second sheet material may be compressed with the third sheet material prior to compressing all three sheet materials together.

[0077] Hence, once aligned, the sheet materials are fed into the pressing section of the production line, where they are combined into a single composite sheet material. The pressing can involve several methods depending on the sheet materials.

[0078] Rollers may be utilized in the pressing operation. The aligned sheets are then passed through a set of rollers. These rollers apply pressure to the layers, bonding them together. These rollers are designed to apply significant pressure, which is essential for bonding the layers into a cohesive single composite sheet material. The pressure applied by the rollers may be adjusted depending on the thickness and material properties of the sheets being combined. In some cases, heat may also be applied during this pressing stage, particularly if the materials involved are thermoplastic.

[0079] Alternatively, the sheet materials might be fed into a laminating press. The press may apply both heat and pressure, ensuring a strong bond between the layers. After passing, e.g., through the pressing rollers, the now-unified composite sheet material may undergo further processes such as trimming to remove any excess material or edges that are not properly aligned. Finally, the single, consolidated composite sheet material is either wound onto a new reel or cut into specific lengths, depending on the end-use requirements.

[0080] Returning to the third sheet material, the polymeric material is preferably flexible and can stretch and deform significantly. The polymeric material’s primary component may comprise both vulcanisable and un-vulcanisable polymers. Fillers and other functional components may be present in the third sheet material composition.

[0081] When creating a composite sheet material for roofing applications, where the first sheet is designed to provide adhesion to the roofing surface, the second sheet material being designed as discussed above, and the third sheet is intended to offer mechanical strength and weather resistance, it is possible to use the same polymer, such as polyisobutylene (PIB) or brominated Isobutylene-co-p-methylstyrene (BIMS), but with different molecular weights to achieve the desired properties for each layer.

[0082] For the first sheet material, which is meant to adhere to the roofing substrate, a relatively lower molecular weight version of PIB or BIMS can be employed. The lower molecular weight polymers exhibit lower viscosity, allowing them to flow more easily and penetrate surface irregularities, which enhances their ability to form strong adhesive bonds with the roofing surface. This characteristic makes the lower molecular weight version ideal for applications where robust adhesion is essential.

[0083] For the third sheet material, which is responsible for providing the composite with mechanical strength and weather resistance, a higher molecular weight version of the same polymer, such as PIB or BIMS, would be more suitable. Higher molecular weight polymers are known for their improved mechanical properties, including greater tensile strength, toughness, and resistance to environmental factors, such as UV radiation, moisture, and temperature fluctuations. These properties make the higher molecular weight version effective in protecting the roofing structure from weather-related damage and ensuring the long-term durability of the composite sheet material.

[0084] Furthermore, the combination of PIB or BIMS with other elastomers like butyl rubber (HR), ethylene propylene diene monomer (EPDM), or ethylene propylene monomer (EPM) can enhance the third material’s overall performance. For example, mixing PIB with BIMS can leverage the excellent impermeability and adhesion properties of PIB with the enhanced thermal stability and bonding capabilities of BIMS.

[0085] Alternatively, blending BIMS with HR or EPDM could result in a third sheet material that exhibits superior elasticity, flexibility, and resistance to environmental degradation.

[0086] Using the same polymer with different molecular weights for both sheet materials, and / or mixing the polymer with compatible elastomers, offers significant advantages. The chemical compatibility between the sheet materials ensures strong interlayer adhesion, while the cohesive material properties contribute to the overall integrity and performance of the composite sheet material. Additionally, this approach simplifies the manufacturing process by reducing the need to handle multiple different polymers, which can also help in maintaining consistent quality and potentially reducing costs.

[0087] If the composite sheet material needs to be rolled onto a reel, the process needs to ensure proper alignment to maintaining the quality and integrity of the material. This alignment is achieved through a combination of specialized mechanisms designed to monitor and adjust the position and tension of the sheet material as it is wound.

[0088] Web guiding systems play a central role in this process. The term “web” in this context refers to any continuous roll of material that is being processed or wound. These systems use sensors to continuously monitor the position of the composite sheet material, particularly its edges, and make real-time adjustments to ensure that the material remains aligned as it is wound onto the reel. Edge sensors detect any drift of the material, and the system responds by adjusting the path of the material or the position of the reel to correct the alignment. Tension control is another important component in maintaining alignment during the winding process. By keeping the tension in the composite sheet material consistent, tension control systems prevent issues like stretching or slack, which could lead to misalignment. Load cells measure the tension in the material, and this data is used to adjust the speed or braking force of the reel, ensuring that the material winds evenly. Dancer rolls, which adjust the path length of the material, also help maintain smooth and consistent winding.

[0089] Nip rollers are used to apply pressure to the composite sheet material as it is fed onto the reel, ensuring that the material is wound tightly and evenly. These rollers can be adjusted to accommodate different thicknesses and properties of the composite sheet material, helping to keep the material aligned throughout the process.

[0090] Servo-driven winding systems enhance this process by providing precise control over the winding speed and reel rotation. These systems ensure that the winding process is synchronized with the feed rate of the composite sheet, which is crucial for maintaining alignment, particularly in high-speed production environments.

[0091] Additionally, tension-sensitive reels can automatically adjust their speed or torque based on the tension in the sheet material, further aiding in maintaining alignment by preventing the material from becoming too loose or too tight as it is wound.

[0092] Advanced winding systems may also include automatic alignment correction mechanisms that detect slight misalignments and make necessary adjustments to the position of the reel or the material path, ensuring perfect alignment throughout the winding process.

Claims

Claims1 . A method of manufacturing, preferably continuously, a length of a composite sheet material comprising:- providing a first sheet material lined on one side with a release liner, and where the opposite side is left as an exposed side, wherein the first sheet material primarily comprises a tacky or adhesive material;- providing, preferably on a reel, a second sheet material of metal or polymer mesh, said mesh comprising apertures;- perforating the first sheet material with a perforation mechanism;- combining the first and second sheet materials, such that the exposed side of the first sheet material receives the second sheet material, to form an intermediate composite sheet material;- applying a third layer of a polymeric material to the exposed side of the first sheet material, thereby covering the second sheet material to form a composite sheet material; and- pressing the first, second, and third sheet materials together with a pressing mechanism, thereby forcing trapped air between the individual sheet materials through the perforations formed in the first sheet material, such that the first sheet material comes into contact with the third sheet material through the apertures of the second sheet material.

2. The method according to claim 1 , further comprising the step of allowing the perforations formed in the first sheet material to self-close subsequent to, or during, the pressing step.

3. The method according to any one of the claims 1-2, wherein the step of perforating the first sheet material with a perforation mechanism comprises placing the perforations in one or more lines that run parallel along the length of the sheet material.

4. The method according to claim 3, wherein the one or more lines of perforations are designed so that strips of the release liner can be removed while the rest of the liner remains intact.

5. The method according to any one of the claims 1-4, wherein the step of combining the first and second sheet materials comprises continuously directing and aligning, with a guide mechanism, the first and second sheet materials relative to one another.

6. The method according to any one of the claims 1-5, wherein the pressing mechanism comprises a set of rollers.

7. The method according to any one of the claims 1-6, wherein the tacky or adhesive material comprises PIB or BIMS mixed with HR (preferably including reclaimed butyl), BUR, XIIR, CIIR, EPDM (preferably including reclaimed EPDM), and / or EPM (preferably including reclaimed EPM).

8. The method according to any one of the claims 1-6, wherein the tacky or adhesive material comprises PIB or BIMS mixed with HR, EPDM, and / or EPM, or PIB mixed with BIMS.

9. The method according to any one of the claims 1-8, wherein the third layer of a polymeric material comprises PIB, BIMS, or mixtures thereof.

10. A composite sheet material produced by the method according to any one of the claims 1-9.11 . Use of the composite sheet material according to claim 10 for a roofing membrane or a protective barrier.