| JP2002265638 | CELLULOSE ACYLATE FILM |
| JP2011167917 | MEMBER FOR FORMING OPTICAL FILM AND DEVICE FOR FORMING THE SAME |
| JP2001079864 | APPARATUS FOR PRODUCING RESIN FILM |
Golinelli, Alcide (N°5/A Via Circonvallazione, Camposanto, I-41031, IT)
| 1. | 1). A process for realizing an elastic natural rubber film, comprising following stages: forming a first thin layer (13) of elastic natural rubber latex on an upwardsfacing side of a first upper branch (11) of a first support belt (10) which is kept in motion along a predetermined pathway, and which is stretched between rollers on which it is partially wound and to which it adheres; at least a partial vulcanization of the first thin layer (13) of latex; forming and depositing a second thin layer (23) of latex on the first thin layer (13) of latex; vulcanization. 2). A plant for realizing an elastic natural rubber film, comprising: a first support belt (10) which is kept in motion along a predetermined pathway and stretched between rollers on which it is partially wound and to which it adheres; the first support belt (10) identifying an upper first branch (11) of the pathway in which a side of the first support belt (10) is facing in an upwards direction; a first supply bath (12), operating on the first support belt (10), which first supply bath (12) is supplied with elastic natural rubber latex (2) and which is predisposed to deposit a first thin layer of latex (13) on the upwardsfacing side of the first support belt (10); a first continuous tunnel kiln (14) which is crossed by at least a part of the upper branch (11) of the first support belt (10), and which at least partially vulcanizes the first layer (13) of latex; a second support belt (20) which is kept in motion along a predetermined pathway, is stretched between rollers on which it is partially wound and adheres, and identifies a second upper branch (21) presenting a side thereof facing in an upwards direction, the second upper branch (21) of the second support belt (20) being located immediately downstream of the first upper branch (11) and constituting a sort of prolongation thereof, for receiving on the upwardsfacing side thereof the first thin layer of latex (13); a second supply bath (22), operating on the second support belt (20), which second supply bath (22) is supplied with elastic natural rubber latex (2) and which is predisposed to deposit a second thin layer (23) of latex on the first thin layer (13) of latex already present on the upwardsfacing side of the second support belt (20); a second tunnel kiln (24) which is crossed by a part of the second upper branch (21) and which completes the vulcanizing process. 3). The plant of claim 2, wherein in an initial part of the first upper branch (11) the first belt (10) is partially wound on a first heated drum (15); the first supply bath (12) exhibits a slitted discharge mouth arranged parallel to an axis of the first heated drum (15) against an external surface of which the first belt (10) winds and to which it adheres ; the mouth of the first supply bath (12) presses against the upwardsfacing surface of the first belt (10). 4). The plant of claim 3, wherein the first heated drum (15) is kept at a temperature which favours vulcanization of the first layer of latex (13) and has a diameter which is not less than 0.5 metres. 5). The plant of claim 4, wherein in an initial part of the second upper branch (21) the second belt (20) is partially wound on a second heated drum (25); the second supply bath (22) exhibits a slitted discharge mouth arranged parallel to an axis of the second heated drum (25) against an external surface of which the second belt (20) winds and to which it adheres; the mouth of the second supply bath (22) pressing against the upwardsfacing surface of the first belt (20). 6). The plant of claim 5, wherein the second heated drum (25) is kept at a temperature which favours vulcanization of the second layer of latex (23) onto the first layer of latex (13) and has a diameter which is not less than 0.5 metres. |
Technical Field The invention relates to a process and plant for realizing an elastic natural rubber Him.
Specifically, though not exclusively, the invention is usefully applied after being stably and intimately coupled to elasticated textile materials to form a special liquid-proof elastic material which is used for manufacturing clothing and protective clothing which require the following characteristics: hygiene; considerable elasticity in order to adhere to a human body and no transpiration of liquids.
Background Art The problem the present invention proposes to solve is that of providing a thin film of elastic natural rubber which is not porous, and which has no major defects of other like type which would render it poorly liquid-proof.
Traditional processes, used for elastic synthetic materials, applied to natural elastic rubbers, do not provide satisfactory results.
The main aim of the present invention is to obviate the limitations and drawbacks in the prior art.
A further advantage of the invention is that known apparatus can be used for its manufacture, including machines already individually used in making synthetic material films.
These aims and more besides are all attained by the invention as it is
characterised in the claims that follow.
Disclosure of Invention Further characteristics and advantages of the present invention will better emerge from the detailed description that follows, of a preferred but non- exclusive embodiment of the invention, illustrated purely by way of example in the appended figure of the drawing, in which: figure 1 is a schematic front view in vertical elevation.
With reference to the figure of the drawings, the process for realizing an elastic natural rubber film according to the invention comprises the following stages: forming a first thin layer 13 of elastic natural rubber latex on an upwards-facing side of a first upper branch 11 of a first support belt 10 which is kept in motion along a predetermined pathway, and which is stretched between rollers on which it is partially wound and to which it adheres; at least a partial vulcanization of the first thin layer 13 of latex; forming and depositing a second thin layer 23 of latex on the first thin layer 13 of latex; vulcanization.
The process is actuated using a plant comprising: a first support belt 10 which is kept in motion along a predetermined pathway and stretched between rollers on which it is partially wound and to which it adheres; the first support belt 10 identifying an upper first branch 11 of the pathway in which a side of the first support belt 10 is facing in an upwards direction; a first supply bath 12, operating on the first support belt 10, which first supply bath 12 is supplied with elastic natural rubber latex 2 and which is predisposed to deposit a first thin layer of latex 13 on the upwards-facing side of the first support belt 10; a first continuous tunnel kiln 14 which is crossed by at least a part of the upper branch 11 of the first support belt 10, and which at least partially vulcanizes the first layer 13 of
latex.
The plant further comprises a second support belt 20 which is kept in motion along a predetermined pathway, is stretched between rollers on which it is partially wound and adheres, and identifies a second upper branch 21 presenting a side thereof facing in an upwards direction, the second upper branch 21 of the second support belt 20 being located immediately downstream of the first upper branch 11 and constituting a sort of prolongation thereof, for receiving on the upwards-facing side thereof the first thin layer of latex 13; a second supply bath 22, operating on the second support belt 20, which second supply bath 22 is supplied with elastic natural rubber latex 2 and which is predisposed to deposit a second thin layer 23 of latex on the first thin layer 13 of latex already present on the upwards-facing side of the second support belt 20; a second tunnel kiln 24 which is crossed by a part of the second upper branch 21 and which completes the vulcanizing process.
In the initial part of the first upper branch 11 the first belt 10 is partially wound on a heated drum 15. The first supply bath 12 exhibits a slitted discharge mouth arranged parallel to an axis of the first heated drum 15 against an external surface of which the first belt 10 winds and to which it adheres; the mouth of the first supply bath 12 presses against the upwards-facing surface of the first belt 10.
The first heated drum 15 is kept at a temperature of preferably about 180°C, sufficient to vulcanize the first layer of latex 13.
The first drum 15 has a diameter of considerable proportions, in any case no smaller than 0.5 metres.
At the initial part of the second upper branch 21 the second belt 20, similarly to the first belt 10, is partially wound around a second heated drum 25.
The second supply bath 22, similarly to the first supply bath 12, exhibits a slitted discharge mouth which is arranged parallel to an axis of the second heated drum
25 against an external surface of which the second belt 20 winds and to which it adheres; the mouth of the second supply bath 22 presses against the upwards- facing surface of the second belt 20.
The second heated drum 25 is kept at a temperature suitable for vulcanizing the second layer of latex 23 onto the first layer of latex 13, and has a diameter of not less than 0.5 metres.
The first kiln 14 and the second kiln 24 are predisposed and dimensioned so as to enable realization and completion of the vulcanization of the latex film.
The final result is a single non-porous thin film of elastic natural rubber with no break in continuity and no holes; the film can be rolled onto a reel 30, ready for use in coupling with elasticated textile strips.
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