A microporous membrane and method of manufacture thereof

Abstract

A first substrate 114 is wet coated with a coating composition 108, a second substrate 118 is laminated onto the wet coated first substrate, and then the laminate 106 is immersed into a coagulation ta

Description

Technical Field of Invention The present invention generally relates to microporous composite materials, such as breathable, hydrophobic microporous layer or membrane and, in particular, to the manufacture of respective laminates for a structure of fabric useful in protective garments (e.g. clothing, footwear) and other applications. Background Waterproof breathable fabrics (WBF) and materials have been around for over 40 years. In inclement weather, a user’s outerwear must be windproof and waterproof, as it is expected to provide protection against both wind and precipitation. The waterproof material is designed to fully shield a wearer from rain, snow and wind by preventing the penetration and absorption of liquid water. Typically, waterproof textiles act as a barrier between the wearer’s body and the environmental humidity. While waterproof fabrics offer excellent protection from the elements, by their very nature they are unable to effectively transport the perspiration from the inside of the clothing to the outside, potentially causing moisture buildup and making the wearer feel damp and uncomfortable. One possible solution to this problem is provided by the so-called waterproof breathable fabrics (WBFs). The technology for manufacturing waterproof breathable textiles has been continuously developing and improving since its introduction in the 1970s (Gore-Tex). Garments made of waterproof breathable textiles are typically utilized by sports and outdoor enthusiasts, as well as, professionals in any weather conditions. Here, the waterproof and breathable fabric combines two mutually contradictory distinct functions, i.e. waterproofness and breathability. The fabric is required to provide protection from the rain, snow, wind, and cold, but also maintain comfort just below the fabric layer by allowing internal water vapor to escape. Waterproof breathable fabrics (WBFs) can be categorized into three main types based on their structure. The first type is a tightly woven fabric made of long fibre cotton, which allows minimal gaps and provides breathability. The second type is a microporous layer or membrane, either laminated or coated, featuring very small gaps or holes throughout the fabric that allow water vapor to escape while preventing water from permeating from the outside. The third type is composed of nonporous structures and is developed as hydrophilic films. These films can absorb water vapor on one side and re-evaporate it from the other side, effectively preventing liquid water penetration. Other types of WBFs are usually combinations of two or more of these structures. For microporous membranes, the main principle is based on the fact that water drops cannot penetrate through the membrane, because the pores are much smaller than the waterdrop, while perspiration (vapour) can evaporate through the pores since they are much larger than the vapor molecules. Further, microporous membranes for outdoor clothing are often hydrophobic, which has the advantage of adding to the comfort feeling of the wearer, as the hydrophobicity of the base material means that the membrane does not get saturated with water, in contrast to a hydrophilic nonporous membrane. Currently, the manufacture of porous or microporous membrane systems in clothing (or other applications) is predominantly based on fluorine chemistry. For example, Per- and Polyfluorinated Alkyl Substances (PFAS) are a group of organic chemicals containing a very strong carbon-fluorine bond. Accumulation of both long chain and short chain PFAS has been observed in human and environment due to their persistency and high mobility in air and water. Exposure of human beings to such chemicals results in an increase in health problems such as decreased immune system and cancer. Some of the few well studied PFAs are already considered as moderately to highly toxic. Consequently, there is a huge demand for alternative environmentally-friendly materials (without the use of PFAS or other fluorinated materials, such as PTFE and PVDF) that have the capability to deliver the required performance without harming the environment and having potential toxicity. Common methods or processes for preparing microporous membranes include the well known non-solvent induced phase separation (i.e. NIPS, see examples in Figure 1), often used for the manufacture of filtration membranes. However, the majority of such membranes for filtration applications are still based on PFC-type materials (e.g. PVDF and PTFE) and utilise toxic solvents such as DMF (Dimethyl Formamide). In particular, the NIPS process typically involves the formation of two phases through an exchange of the solvent from the polymer solution through a non-solvent from a precipitation bath. One of the phases contains a high polymer solution and is responsible for the formation of the membrane matrix, whereas the second phase contains only a very small proportion of the polymer and is washed out during the membrane formation process. This causes the development of the pore network within the matrix of the membrane until structure solidification sets in. Figure 2 illustrates a generally known method of coating a dispersion or compound onto a base fabric (or substrate) prior to the immersion into a water bath (coagulation, phase inversion) utilising a “blade-over-roll” coating technique. Now, when creating suitable fabrics for garments, a secondary backing fabric may be applied to the coagulated membrane, forming a 3-layer laminate, in order to increase its strength and durability and comfort from contact with a polymeric membrane. A known methods for the construction of this type of final product would be to laminate the secondary material to the membrane using an established lamination technique, such as, for example, hot melt lamination, using a reactive polyurethane (PUR) adhesive applied as a non-continuous layer to minimise the loss of breathability and product flexibility or drape. This step would be carried out as a completely separate and independent process from the production of the disclosed membrane production and is not required to be described in any more detail. However, this step requires additional adhesive material in order to securely attach or bond the fabric or textile layer (i.e. secondary fabric layer), thus, using up time, energy and resources, as well as, potentially create further waste that can pollute the environment. It is therefore an object of the invention to mitigate at least some of the drawbacks of the prior art, by providing an improved manufacturing process. In particular, it is an object of the present invention to provide a method of manufacture of a fabric for a garment comprising of at least one microporous polymer membrane layer provided between a base fabric and a secondary (backing) fabric. The microporous polymer membrane of the 3-layered fabric for a garment is a formation based on a green solvent (e.g. Cyrene), a hydrophobic non-PFC PU (e.g. ChronoSil), graphene (GNP) and a pore former (PEG) and has an improved durability and thermal conductivity (i.e. optimised removal of thermal energy from hot spots to cold spot within the microclimate next to the skin). Summary of the Invention An aspect of the invention is set out in the independent claim(s). Dependent claims describe optional features. In one first aspect of the invention, there is provided a method of manufacturing a flexible multilayered article for a waterproof garment comprising at least one layer of a microporous membrane produced from a dispersion of an organic solvent, a polymer, Graphene Nanoplatelets (GNP) and a pore forming agent, comprising the steps of: (a) coating said dispersion on a first surface of a first substrate, using a coating mechanism of a casting machine production line, forming a wet-coated first substrate; (b) laminating a second substrate onto said first surface of said wet-coated first substrate, using a lamination mechanism of said casting machine production line located downstream of said coating mechanism, forming a first laminate structure; (c) immersing said first laminate structure into a coagulation tank of said casting machine production line located downstream of said lamination mechanism, comprising a non-solvent bath adapted to induce phase inversion via immersion precipitation of said dispersion, so as to form said flexible multilayered article. The method of the present invention provides the advantage of adding a secondary fabric to a membrane during manufacture and in a single process step of a casting machine production line, thus, reducing manufacturing time, material and overall costs. In particular, the method of the present invention eliminates the need for a separate lamination step after the microporous membrane has formed in the coagulation bath. In such a separate lamination step, additional adhesives, e.g. reactive polyurethane, may need to applied in a non-continuous layer so as to minimise any loss of breathability of the previously formed microporous membrane. The method of the present invention simplifies the manufacture, as well as, eliminates any adverse effects caused by the adhesive layer of the additional backing (i.e. in order to produce a three-layer article). Advantageously, the coating mechanism is a blade-over-roll assembly configured to provide a coating of a predetermined thickness onto said first surface of said first substrate. Preferably, the lamination mechanism is a nip-roller assembly, configured to compress said second substrate onto said first surface of said wet-coated first substrate and bond said second substrate with said dispersion and said first substrate. Advantageously, the coagulation tank comprises a plurality of operably coupled rollers arranged, so as to provide for a spiral-shaped conveyor path of said first laminate structure through said coagulation tank. Such an arrangement provides for a path length through the tank sufficient to immerse and continuously move a desired length of material for a predetermined time, while minimising the otherwise required dimensions of the tank and / or required volume of the coagulation fluid. Advantageously, the casting machine production line is configured to move said first laminate structure at a speed between 0.1 and 1.0 meters per minute. Preferably, the casting machine production line is configured to move said first laminate structure at a conveyor speed between 0.3 and 0.7 meters per minute. Even more preferably, the casting machine production line is configured to move said first laminate structure at a conveyor speed of 0.5 meters per minute. Advantageously, the casting machine production line is configured to immerse said first laminate structure within said non-solvent bath for a predetermined time of at least 30 minutes. Advantageously, the at least one polymer is provided in the amount of 13wt% to 17wt% with respect to said at least one organic solvent, said Graphene Nanoplatelets (GNP) are provided in the amount of 0.1 wt% to 0.5wt% with respect to said at least one polymer, and said at least one pore forming agent is provided in the amount of 10wt% to 20wt% with respect to said at least one polymer. Preferably, the at least one organic (non-toxic and biodegradable) solvent is Dimethyl Sulfoxide (DMSO), said at least one polymer is a polyurethane-based polymer, in the amount of 17wt% with respect to said DMSO solvent, said GNP is in an amount of 0.5wt% with respect to said polyurethane-based polymer, and said at least one pore forming agent is Polyethylene Glycol 300 in an amount of 10wt% with respect to said DMSO solvent. Even more preferably, polyurethane-based polymer comprises [Poly[4,4'-methylenebis(phenylisocyanate)-alt-1,4-butanediol / di (propyleneglycol) / polycaprolactone]. Advantageously, the at least one organic (non-toxic and biodegradable) solvent is Dihydrolevoglucosenone (Cyrene™), said at least one polymer is a polyurethane-based polymer in the amount of 13wt% with respect to said Dihydrolevoglucosenone (Cyrene™) solvent, said GNP is in an amount of 0.5wt% with respect to said polyurethane-based polymer, and said at least one pore forming agent is Polyethylene Glycol 300 in an amount of 10wt% with respect to said Dihydrolevoglucosenone (Cyrene™) solvent. Advantageously, the at least one organic (non-toxic and biodegradable) solvent is Dihydrolevoglucosenone (Cyrene™), said at least one polymer is a polyurethane-based polymer in the amount of 15wt% with respect to said Dihydrolevoglucosenone (Cyrene™) solvent, said GNP is in an amount of 0.1wt% with respect to said polyurethane-based polymer, and said at least one pore forming agent is Polyethylene Glycol 300 in an amount of 20wt% with respect to said Dihydrolevoglucosenone (Cyrene™) solvent. Preferably, said polyurethane-based polymer comprises a polycarbonate-based polyurethane (Chronosil®). Even more preferably, GNP has a platelet thickness in the region of 1 nm to 15 nm (nanometer), and a platelet mean diameter in the region of 2 pm to 25 pm (micrometer). Advantageously, the non-solvent bath is a water bath. In one second aspect of the invention, there is provided a flexible multilayered article for a waterproof garment formed by a method according to the first aspect of the invention. Preferably, the flexible multilayered article comprises a three-layer textile material. In one third aspect of the invention, there is provided a casting machine production line comprising a coating mechanism, a lamination mechanism and a coagulation tank arranged in sequence of the direction of movement of the casting machine production line. Advantageously, the coating mechanism comprises at least one blade-over-roll assembly. Advantageously, the lamination mechanism comprises a nip-roller assembly, comprising at least one cooperating pair of nip-rolls. Advantageously, the coagulation tank comprises a plurality rollers operably coupled within the coagulation tank and arranged, so as to provide for a spiral-shaped conveyor path of an article passing through said coagulation tank. Brief Description of the Drawings An exemplary embodiment of the invention is explained in more detail hereinbelow with reference to the figures: Figure 1 (a) and (b) shows two different schematic illustrations of the known NIPS method; Figure 2 shows (a) a simplified schematic illustration of a coating technique using a blade-over-roll mechanism, where the knife or blade is suspended above a roller, and (b) an illustration of a typical coating application; Figure 3 shows a simplified schematic illustration of a casting machine production line including, sequentially arranged, a coating station, a lamination station and an immersion station, and Figure 4 illustrates (a) to (d) the assembly and installation process of the production line, and (e) an example embodiment of the assembled casting machine production line of the present invention. Detailed Description Unless otherwise stated, the following definitions / characterisations for the formation of the microporous membrane utilising the method of manufacture of the present invention shall apply in this specification: Polymer: The term "polymer" is known in the field. The term refers to a material of repeating structural units ("monomers"), particularly to synthetic polymers (synthetic monomers). The term thus includes homo-polymers, co-polymers and blends thereof. Polymers may be cross-linked. Pore size: The "pore size" of a material as described herein is the middle size of the pore size distribution throughout the membranes. A particularly suitable method in the context of this invention is the optical analysis of the membranes' surface thereby providing information on pore mouth size. Cyrene™: The synthesis of Cyrene is based on a two-step process using renewable cellulose waste. Water is the main biproduct of the synthesis process and the final product has very low toxicity, well below the hazard thresholds defined by the Globally Harmonized System of Classification and Labelling of Chemicals (GHS). Similarly, there is no GHS symbol known for DMSO. The described method and obtained membrane is believed to be the first example for preparing a PU-based waterproof breathable microporous membrane that exploits the benefits of hydrophobic graphene (i.e. graphene nanoplatelets (GNP), not to be confused with Graphene Oxide (GO)), and a pore forming agent (i.e. polyethylene glycol, PEG300) as a textile coating. (i) Microporous Membrane fabrication based on non-PFA substances: In this particular detailed example, the manufacturing method of the present invention is used to produce a microporous polymer membrane (e.g. pore size of 5nm to 10pm) from a dispersion that comprises at least one organic (non-toxic and biodegradable) solvent; at least one polymer in the amount of 13wt% or 17wt% with respect to the at least one organic solvent; Graphene Nanoplatelets (GNP) in an amount of 0.1wt% to 0.5wt% with respect to the at least one polymer, and at least one pore forming agent in an amount of 10wt% to 20wt% with respect to the at least one polymer. One manufacturing method for the microporous membrane itself may include the steps of coating a substrate with the dispersion, then inducing a phase inversion (phase separation) by immersion precipitation in a non-solvent coagulation bath at a predetermined coagulation bath temperature (CBT) and, optionally, removing the obtained microporous polymer membrane from the substrate. To summarise, for this example of the manufacturing method, a polyurethane (PU) based solution containing GNP particles (Graphene Nanoplatelets) was prepared in a desired solvent (DMSO or Cyrene). Pore forming agent (e.g. PEG300) was used to help improve the porosity and breathability of the final microporous membrane. After optimisation of the membrane formulation by testing various loadings, the following formulations were chosen for the optimally performing membrane (dispersion used with the manufacturing method of the present invention) in terms of breathability, porosity, mechanical performance, as well as, thermal properties: PU-based with DMSO 17 wt.% PU [(Poly[4,4'-methylenebis(phenyl isocyanate)-alt-1,4-butanediol / di(propylene glycol) / polycaprolactone], Sigma Aldrich), 0.5 wt.% GNP-M5 (XGSciences, USA) with respect to the polymer content, 10 wt.% PEG300 with respect to the polymer content and the rest being DMSO as the main solvent. ChronoSil based with Cyrene 13 wt.% ChronoSil polycarbonate-based PU (thermoplastic silicone polycarbonate elastomer with 5% Silica, AdvanSource Biomaterials, USA), 0.5 wt.% GNP-M5 (XGSciences) with respect to the polymer content, 10 wt.% PEG300 with respect to the polymer content and the rest being Cyrene as the main solvent. (ii) Manufacturing method of a three-layered fabric formation for a garment: When creating a three-layered fabric formation with a centre layer of a microporous membrane, using the manufacturing method of the present invention, a dispersion or compound (wet state) as the one described in section (i) is first prepared to be used with a casting machine production line configured to perform the improved method of manufacturing a flexible multilayered article for a waterproof garment. In particular, and as shown in Figure 3, the casting machine production line 100 comprises a conveyor-type arrangement including sequential stations to perform the steps in a specific order. The stations to perform the method of manufacture include a coating station 102, a lamination station 104, located directly downstream of the coating station 102 and an immersion station 106 for a coagulation bath, located directly downstream of the lamination station 104. Further stations, prior to I upstream of the coating station 102 and / or subsequent I downstream of the immersion station 106, may be added to the casting machine production line 100, in order to process or handle the basic material (s) (substrates, dispersion) and / or the laminated article 200 in addition to the manufacturing method of the present invention. The dispersion or coating compound 108 is prepared in accordance with the components and relative ratios described in section (i) and provided at the coating station 102. In this particular example, the coating station includes a blade-over-roll arrangement configured to coat a first substrate 114 (or base substrate) with the dispersion 108 at a predetermined thickness. The thickness of the coating 108 may be controlled by the gap between the knife or blade 110 and a corresponding back-up roller 112. In this particular example embodiment, the coating gap is 0.08 mm, however, any other suitable coating gap may be used. For that, the blade 110 and / or back-up roller 112 may be adjustable to increase / decrease the gap between them. Further, it is understood by the person skilled in the art, that any other coating technique may be used to provide a layer of dispersion 108 on the top surface of the first or base substrate 114, without diverting form the scope of the present invention. The lamination station 104 is provided immediately following the coating station 102 and includes, for example, a nip roller assembly utilising two opposingly arranged first and second nip-roll 116a,b. The second or backing substrate 118 may be fed to the lamination station 104 via the first nip-roll 116a, but, any other suitable arrangement may used. For example, the second or backing substrate 118 may be fed to the lamination station 104 via the second nip-roll 116b, or two separate backing substrates (not shown) my be fed via a respective nip-roll 116a,b, so as to laminate the first substrate 114 on both surfaces (though this would requires a second coating on the lower surface of the first substrate 114). Since the dispersion or coating compound 108 is still in a “wet” state, there is no need for any additional adhesive during the lamination process. Following the lamination station 104, the wet-laminated article is immersed in the coagulation bath (e.g. water, non-solvent) of the immersion station 106, for a predetermined time (e.g. 30 min) to cause polymer precipitation and membrane formation in the dispersion layer 108. In this particular example, the temperature of the coating is kept below 80°C (Degrees Celsius), so as to not affect the coating properties. During manufacture, the casting machine production line 100 may move the flexible articles (substrates, laminated article) at a speed of ca. 0.5 meters / minute, wherein the laminated article is immersed in the coagulation bath for a period of at least 30 minutes. In order to provide for a 30 minute immersion while moving through the coagulation bath, the tank 120 may be sufficiently large (i.e. long) to allow for the article to be submerged for the desired time (e.g. 30min) at 0.5 m / min. Alternatively, the tank 120 may be dimensioned so as to allow for conveyor rollers 122 to be arranged in such a way that a specific conveyor path can be ran through the tank 120 so as to maximise the immersed path length through the tank 120. For example, conveyor rollers 122 may be arranged so as to provide for a spiral-shaped conveyor path for the laminated article 200, as shown in Figure 3. Here, the roller contact with the surface of the laminate article 200 changes from the bottom surface to the top surface (opposing surface) half way through the spiral-shaped conveyor path. It is understood by the person skilled in the art, that the actual shape of the conveyor path through the coagulation path is not a determining factor of the manufacturing method of the present invention, as long as the wet-laminated article is immersed in the coagulation bath for the required time (i.e. the time necessary to effect membrane formation). Further, the conveyor rollers 122 may be arranged in any other way to provide a predetermined path (shape) at a predetermined length through the tank 120. The advantage of the spiral-shaped conveyor path configuration is that it provides a very compact immersion station 106 configured to provide a suitable path length through the coagulation bath (i.e. water) allowing for the required predetermined time for immersion at a suitable conveyor speed. A further advantage of the compact tank and roller configuration is a uniform dispersion of the coagulation fluid (e.g. water) through the laminated article 200 or product, ensuring a uniform and consistent coagulation throughout the desired product and thus, resulting in an improved quality of the formed microporous membrane layer. In the particular example embodiment, the conveyor rollers 122 may include stainless steel bearings, though, in order to avoid potential problems (e.g. corrosion, oxidation, rust of metal bearings), other bearing types and materials, such as, bearings made from polymer and / or ceramic or any other suitable compound, may be used instead. In addition, when manufacturing at an industrial scale any suitable configuration of the tank 120 and the conveyor rollers 122 may be used in the casting machine production line 100 of the present invention. It will be appreciated by persons skilled in the art that the above embodiment(s) have been described by way of example only and not in any limitative sense, and that various alterations and modifications are possible without departing from the scope of the invention as defined by the appended claims. Various modifications to the detailed designs as described above are possible.

Claims

1. A method of manufacturing a flexible multilayered article for a waterproof garment comprising at least one layer of a microporous membrane produced from a dispersion of an organic solvent, a polymer, Graphene Nanoplatelets (GNP) and a pore forming agent, comprising the steps of:(a) coating said dispersion on a first surface of a first substrate, using a coating mechanism of a casting machine production line, forming a wet-coated first substrate;(b) laminating a second substrate onto said first surface of said wet-coated first substrate, using a lamination mechanism of said casting machine production line located downstream of said coating mechanism, forming a first laminate structure;(c) immersing said first laminate structure into a coagulation tank of said casting machine production line located downstream of said lamination mechanism, comprising a non-solvent bath adapted to induce phase inversion via immersion precipitation of said dispersion, so as to form said flexible multilayered article.

2. A method according to claim 1, wherein said coating mechanism is a blade-over-roll assembly configured to provide a coating of a predetermined thickness onto said first surface of said first substrate.

3. A method according to any one of the preceding claims, wherein said lamination mechanism is a nip-roller assembly, configured to compress said second substrate onto said first surface of said wet-coated first substrate and bond said second substrate with said dispersion and said first substrate.

4. A method according to any one of the preceding claims, wherein said coagulation tank comprises a plurality of operably coupled rollers arranged, so as to provide for a spiral-shaped conveyor path of said first laminate structure through said coagulation tank.

5. A method according to any one of the preceding claims, wherein said casting machine production line is configured to move said first laminate structure at a speed between 0.1 and 1.0 meters per minute.

6. A method according to claim 5, wherein said casting machine production line is configured to move said first laminate structure at a conveyor speed between 0.3 and 0.7 meters per minute.

7. A method according to claim 6, wherein said casting machine production line is configured to move said first laminate structure at a conveyor speed of 0.5 meters per minute.

8. A method according to any one of the preceding claims, wherein said casting machine production line is configured to immerse said first laminate structure within said non-solvent bath for a predetermined time of at least 30 minutes.

9. A method according to any one of the preceding claims, wherein said at least one polymer is provided in the amount of 13wt% to 17wt% with respect to said at least one organic solvent, said Graphene Nanoplatelets (GNP) are provided in the amount of 0.1 wt% to 0.5wt% with respect to said at least one polymer, and said at least one pore forming agent is provided in the amount of 10wt% to 20wt% with respect to said at least one polymer.

10. A method according to claim 9, wherein said at least one organic (non-toxic and biodegradable) solvent is Dimethyl Sulfoxide (DMSO), said at least one polymer is a polyurethane-based polymer, in the amount of 17wt% with respect to said DMSO solvent, said GNP is in an amount of 0.5wt% with respect to said polyurethane-based polymer, and said at least one pore forming agent is Polyethylene Glycol 300 in an amount of 10wt% with respect to said DMSO solvent.

11. A method according to claim 10, wherein said polyurethane-based polymer comprises [Poly[4,4'-methylenebis(phenylisocyanate)-alt-1,4-butanediol / di (propyleneglycol) / polycaprolactone].

12. A method according to claim 9, wherein said at least one organic (non-toxic and biodegradable) solvent is Dihydrolevoglucosenone (Cyrene™), said at least one polymer is a polyurethane-based polymer in the amount of 13wt% with respect to said Dihydrolevoglucosenone (Cyrene™) solvent, said GNP is in an amount of 0.5wt% with respect to said polyurethane-based polymer, and said at least one pore forming agent is Polyethylene Glycol 300 in an amount of 10wt% with respect to said Dihydrolevoglucosenone (Cyrene™) solvent.

13. A method according to claim 9, wherein said at least one organic (non-toxic and biodegradable) solvent is Dihydrolevoglucosenone (Cyrene™), said at least one polymer is a polyurethane-based polymer in the amount of 15wt% with respect to said Dihydrolevoglucosenone (Cyrene™) solvent, said GNP is in an amount of 0.1 wt% with respect to said polyurethane-based polymer, and said at least one pore forming agent is Polyethylene Glycol 300 in an amount of 20wt% with respect to said Dihydrolevoglucosenone (Cyrene™) solvent.

14. A method according to any one of claims 12 and 13, wherein said polyurethane-based polymer comprises a polycarbonate-based polyurethane (Chronosil®).

15. A method according to any one of the preceding claims, wherein said GNP has a platelet thickness in the region of 1 nm to 15 nm (nanometer), and a platelet mean diameter in the region of 2 pm to 25 pm (micrometer).

16. A method according to any one of the preceding claims, wherein said non-solvent bath is a water bath.

17. A flexible multilayered article for a waterproof garment formed by a method according to any one of claims 1 to 16.

18. A flexible multilayered article according to claim 17, comprising a three-layer textile material.

19. A casting machine production line comprising a coating mechanism, a lamination mechanism and a coagulation tank arranged in sequence of the direction of movement of the casting machine production line.

20. A casting machine production line according to claim 19, wherein said coating mechanism comprises at least one blade-over-roll assembly.

21. A casting machine production line according to any one of claims 19 and 20, wherein said lamination mechanism comprises a nip-roller assembly, comprising at least one cooperating pair of nip-rolls.

22. A casting machine production line according to any one of claims 19 and 21, wherein said coagulation tank comprises a plurality rollers operably coupled within the coagulation tank and arranged, so as to provide for a spiral-shaped conveyor path of an article passing through said coagulation tank.

Images