Arthropod protector screen and production method thereof

Abstract

A protector screen for use against arthropods, includes, a sheet having a core made from glass or a plastic material, which is at least partially transparent, and comprising a plurality of ventilation holes, each of said ventilation holes being designed to prevent arthropods from passing therethrough, at least a portion of each ventilation hole being closed by a lateral wall or by contiguous lateral walls forming a single piece that is open at the ends thereof, and the ventilation holes being designed such that a gaseous fluid, such as air, can pass through the screen, while optimising light transmission and optionally cooling the fluid passing through the screen.

Claims

1. A protector screen for use against arthropods comprising a sheet comprising a core made from glass or from plastic material, said sheet being at least partially transparent, and comprising two faces with a plurality of ventilation holes, each of said ventilation holes having ventilation hole openings and being configured to prevent arthropods from passing therethrough, said ventilation holes being intended to allow a gaseous fluid to pass through the protector screen, characterized in that at least one of portions of at least some of said ventilation hole openings on said faces has a straight, elongate cross section, said straight, elongate cross section comprising a longitudinal axis and a transverse axis, a dimension of each of said portions along the longitudinal axis being greater than a largest dimension of the arthropods against which the screen provides protection, a dimension of each portion along the transverse axis being less than or equal to a largest dimension of a main body of the arthropods against which the screen provides protection, the main body excluding a head and appendages of the corresponding arthropods, wherein each ventilation hole comprises a lateral wall, wherein the lateral wall is unitary for at least some of said ventilation holes, wherein a portion of at least one face of the two faces of said sheet delimiting an edge of each of these ventilation holes and/or the lateral wall comprises at least one layer configured to increase the light transmission coefficient of said sheet relative to the light transmission coefficient of a same sheet whose ventilation holes are not provided with said at least one layer.

2. The screen as claimed in claim 1, characterized in that at least a majority of the ventilation holes has a constant cross section or comprises a reduction in cross section in a direction extending between the two faces of said sheet.

3. The screen as claimed in claim 2, characterized in that each ventilation hole has a flared shape or comprises a constriction.

4. The screen as claimed in claim 1, characterized in that, at least a majority of said ventilation holes comprises a reduction in cross section in a direction extending between the two faces of said sheet configured to cool the air passing through said at least a majority of said ventilation holes.

5. The screen as claimed in claim 1, characterized in that lateral movement of a ventilation hole during elastic deformation of the sheet being x, 2 x is less than or equal to the largest dimension of the main body of these arthropods against which the screen provides protection, the main body excluding the head and the appendages of the corresponding arthropods.

6. The screen as claimed in claim 1, characterized in that the cross section of each ventilation hole has a value Ga of between 0.1 and 8 mm at a largest dimension of each ventilation hole and a value Pa of between 500 m and 1.2 mm in another dimension of each ventilation hole, the value Ga being greater than an arthropod largest dimension of the against which the screen provides protection, whereas the value Pa is less than or equal to a main body largest dimension of the arthropods against which the screen provides protection, a main body of the arthropod excluding the head and the appendages of the corresponding arthropods.

7. The screen as claimed in claim 1, characterized in that said lateral wall comprises a plurality of layers configured to increase the light transmission coefficient of said sheet.

8. The screen as claimed in claim 1, characterized in that said at least one layer is placed at a surface of said lateral wall and/or in the thickness of said sheet.

9. The screen as claimed in claim 1, characterized in that said at least one layer is a layer of colored fillers.

10. A method of using a protector screen against arthropods the method comprising: insulating a space from mosquitoes, in particular tiger mosquitoes, with the protector screen while allowing ventilation of the space, said space being intended to be occupied by humans, animals or food, wherein the protector screen includes: a sheet comprising a core made from glass or from plastic material, said sheet being at least partially transparent, and comprising two faces with a plurality of ventilation holes, each of said ventilation holes having ventilation hole openings and being configured to prevent arthropods from passing therethrough, said ventilation holes being intended to allow a gaseous fluid to pass through the protector screen, characterized in that at least one of portions of at least some of said ventilation hole openings on said faces has a straight, elongate cross section, said straight, elongate cross section comprising a longitudinal axis and a transverse axis, a dimension of each of said portions along the longitudinal axis being greater than a largest dimension of the arthropods against which the screen provides protection, a dimension of each portion along the transverse axis being less than or equal to a largest dimension of a main body of the arthropods against which the screen provides protection, the main body excluding a head and appendages of the corresponding arthropods, wherein each ventilation hole comprises a lateral wall that is unitary, for at least some of said ventilation holes, a portion of at least one face of the two faces of said sheet delimiting an edge of each of these ventilation holes and/or the lateral wall comprises at least one layer configured to increase the light transmission coefficient of said sheet relative to the light transmission coefficient of a same sheet whose ventilation holes are not provided with said at least one layer.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Other advantages, aims and special features of the present disclosure will be understood upon reading the following description, which is provided for explanatory purposes and is in no way limiting, in view of the appended drawings, in which:

(2) FIG. 1 is a partial perspective view of a protector screen for use against arthropods according to a first aspect of the present disclosure, one edge of this screen being pressed against a wall delimiting an opening in a construction;

(3) FIG. 2 is a partial enlarged top view of a protector screen for use against arthropods according to a second aspect of the present disclosure;

(4) FIG. 3 is a schematic representation of ventilation holes of a protector screen according to a third aspect, these ventilation holes having an elliptical section;

(5) FIG. 4 is a partial enlarged view of a protector screen showing an oblong ventilation hole with its transverse and longitudinal axes;

(6) FIG. 5 is a partial enlarged view of a protector screen showing a ventilation hole in front of which a tiger mosquito is placed;

DETAILED DESCRIPTION

(7) It should first be noted that the figures are not to scale.

(8) FIG. 1 shows, schematically, a protector screen 10 for use against arthropods, in particular insects and spiders, according to a first aspect of the present disclosure.

(9) This screen 10, which in this case forms a glazing element, comprises a plate 11 of plastic material, in this instance poly(methyl methacrylate)PMMA, obtained by casting. It has a thickness of two (2) mm.

(10) This plate 11 is perforated with oblong ventilation holes 12, these ventilation holes 12 being aligned in two directions (x, y) in the plane of the plate and spaced apart from each other at regular intervals. Naturally, the ventilation holes 12 could alternatively have been arranged in staggered rows.

(11) The opening ratio of this plate 11 is twenty-five (25) %, these ventilation holes 12 having been made by pure water jet cutting.

(12) The section of each of these oblong holes, which are identical, has a value Ga of the order of 3 mm in its largest dimension, i.e. in a direction substantially transverse to the plate, and a value Pa of the order of 800 m in its other dimension, i.e. substantially in the height direction of same.

(13) Each ventilation hole 12 of this plate 11 has been treated using a composition comprising 95% by volume of acetone and 5% colored fillers, in this instance carbon black pigments, in order to form a layer of colored fillers that helps increase the light transmission of the screen 10.

(14) This plate 11 advantageously has a light transmission coefficient greater than 80%.

(15) FIG. 2 shows, schematically, a protector screen 20 for use against arthropods according to a second aspect of the present disclosure.

(16) The protector screen 20 is in this instance formed from a sheet 21 of polycarbonate having a thickness of 250 m such that the latter is flexible and can be rolled up/unrolled like a blind in order to open or close an opening.

(17) This sheet 21 is perforated with oblong ventilation holes 22, the opening ratio of this sheet being 2.5%.

(18) These ventilation holes 22 have advantageously been formed by laser cutting the sheet 21, and more specifically by means of a CO.sub.2 laser cutting machine with a power of 100 W and at a cutting speed of 0.6 m/min. The size of the laser beam spot on the surface of the sheet is approximately 70 m.

(19) Each ventilation hole 22 of this sheet has then been treated using a composition comprising a solvent, in this instance Pyridine and colored fillers, in this instance carbon black pigments, in order to form a layer 23 improving the light transmission of this sheet.

(20) This sheet 21 has also received an anti-UV surface treatment.

(21) FIG. 3 is a schematic representation of ventilation holes 30 of a protector screen according to a third aspect, these ventilation holes 30 having an elliptical section.

(22) This protector screen comprises a sheet 31 having a thickness of the order of 300 m.

(23) The edges of this sheet 31 are not perforated, thus allowing the uprights of the frame to obtain a better mechanical grip on the sheet, thus increasing its mechanical resistance, for example to impacts.

(24) The sheet 31, which is transparent, is made from a polycarbonate such as the polycarbonate Makrolon.

(25) The substantially elliptical ventilation holes 30 of dimensions 1 mm by 4 mm have been obtained by pure water jet cutting.

(26) The holes have been arranged in staggered rows and nested in order to obtain a void density of the order of 0.25 in the useful zone of the protector screen.

(27) The inside of each ventilation hole has received a layer of paint sprayed by means of a can of spray paint comprising a composition of carbon pigments/solvent, so as to obtain a very thin uniform coating thickness of the order of a few microns.

(28) In order to demonstrate the technical advantage contributed by the protector screens of the disclosure, measurements of the light irradiance through a mosquito of the prior art, the protector screens described in FIGS. 1 and 2, before making the ventilation holes, then after making these ventilation holes but before treating them to improve the light transmission coefficient of the corresponding screen, then after applying such a treatment to each ventilation hole, are shown in table I.

(29) These measurements are taken at an ambient temperature of approximately 20 C., using a tungsten light source with a reflector having a power of 45 W, a light meter such as an ISO-TECH ILM-1 luxmeter and a lens for focusing the luminous flux passing through the object interposed between the source and the light meter on the sensor of the latter.

(30) TABLE-US-00001 TABLE I Results of the optical measurements Measured light Constituent material of the object intensity value under study in kLux No object interposed between the light 8.16 source and the detector - For reference Mosquito net with perpendicular 4.82 crossing, textile threads Screen of FIG. 1, not perforated 7.38 Screen of FIG. 1, perforated with 6.90 untreated oblong holes Screen of FIG. 1, perforated with 7.25 treated oblong holes Screen of FIG. 2 not perforated 7.32 Screen of FIG. 2, perforated with 7.19 untreated oblong holes Screen of FIG. 2, perforated with 7.29 treated oblong holes

(31) These measurements clearly show that: the light irradiance through the protector screens of the disclosure is considerably higher than that measured through the mosquito nets of the prior art, and by treating the ventilation holes and/or the peripheral zone of each ventilation hole in order to form at least one layer increasing the light transmission coefficient, superior light irradiance is obtained compared to the same products without treatment.

(32) Tensile tests have also been carried out on protector screen samples with and without ventilation holes by means of an MTS Autotrac machine. The test conditions de were as follows: dumbbell specimen 160 mm total length, 80 mm useful length, 10 mm useful width, and tensile speed of the order of 50 mm/min.

(33) The following measurements were obtained: tests on specimens without holes: 1162 N breaking strength for a sheet of polycarbonate (PC) 2 mm thick without holes, and tests on specimens with holes: 1025 N breaking strength for a sheet of polycarbonate (PC) 2 mm thick with oval holes and 1027N breaking strength for this same sheet but with oblong holes.

(34) These measurements demonstrate that the ventilation holes made in the sheets have little effect on the tensile performances of same.

(35) Similarly, Charpy impact tests according to standard ISO 179, carried out with a Wolpert Werke Gmbh nPW5K-E machine, moving object 7.5 Joules, a specimen 80 mm long and 10 mm wide, showed that the presence of ventilation holes has no significant influence on the mechanical strength of the sheets.

(36) Additional tests were carried out to demonstrate the advantageous effects obtained by a protector screen according to the disclosure in terms of cooling an air flow passing therethrough.

(37) Wind tunnel tests were therefore carried out by positioning various protector screens in turn in the middle of a sealed tunnel 110 cm long with an approximately square section having 7.5 cm sides. This tunnel was placed in a closed and thermoregulated enclosure measuring sixty (60) m.sup.3.

(38) A variable speed blower with the possibility of heating the blown air, reference number KH2113 (manufactured by Kompernass GmbH, 44867 Bochum, Germany) was placed at the entrance to this tunnel.

(39) The temperature of the air was measured at different locations in the tunnel with temperature sensors, in particular digital precision thermometers.

(40) This tunnel was long enough to have a stabilized flow, and the measurements were taken when the temperature had stabilized.

(41) These tests were carried out with the following protector screens:

(42) *Commercial Mesh Mosquito Net

(43) weave coated with polyvinyl chloride (PVC) and 0.26 mm thick, density of holes (t) 38,000 t/m.sup.2.
*Screen M1 PMMA sheet 2 mm thick, density of holes (t) 5,000 t/m.sup.2, straight (taper-free) shape of the longitudinal section of the ventilation holes, i.e. in a direction extending between the two faces of the sheet, with inlet and outlet diameter of 1.0 mm.
*Screen M2 polycarbonate (PC) sheet 2 mm thick, density of holes (t) 5,000 t/m.sup.2, diabolo shape (referred to hereinafter as D shape) of the longitudinal section of the ventilation holes, with inlet and outlet diameter of 1.0 mm, with a constriction having a minimum dimension of 0.6 mm approximately at the center of the thickness of the sheet.
*Screen M3 polycarbonate (PC) sheet 2 mm thick, density of holes (t) 5,000 t/m.sup.2, cone-shaped (referred to hereinafter as C shape) longitudinal section of each ventilation hole, with inlet diameter of 1.5 mm and outlet diameter of 0.5 mm.

(44) The air flow rate is arbitrarily denoted Di, where i=1 to 3, the air flow rate increasing as the index i increases.

(45) TABLE-US-00002 Air flow Inlet Outlet Delta T rate temperature temperature ( C.) Reference test D1 22.5 22.5 0 without screen Commercial mesh D1 22.5 22.5 0 mosquito net D2 30.2 30.2 0 D3 75 75 0 M1 (straight hole) D1 27 27.2 0.2 D2 23.7 23.3 0.4 D3 46.1 42.1 4 D3 73 67 6 M2 (D shape) D1 15.7 15.4 0.3 D1 22.2 21.9 0.3 D2 24.4 23.7 0.7 D2 39.1 37.1 2 D3 37.4 31.5 6.9 D3 93 77 16 M3 (C shape) D1 15.5 15.1 0.4 D1 22 21.6 0.4 D2 24 22.7 1.3 D2 37.5 34.4 0.4 D3 45.9 36.4 9.5 D3 83 69 14

(46) In conclusion, these thermal tests help demonstrate that: Commercial mesh mosquito nets have no thermal effect, regardless of the ventilation and/or temperature conditions. The protector screens of the disclosure, regardless of whether the version is M1, M2 or M3, cool the air passing through them. The higher the air flow rate, the more significant the cooling of the air The higher the temperature measured downstream of the tunnel, i.e. after the protector screen, the greater the temperature change. The presence in each ventilation hole of a significant constriction, i.e. a constriction with a small section, helps increase the temperature difference measured upstream and downstream of the protector screen.

(47) These tests also helped demonstrate that a longitudinal section, i.e. between the two faces of a sheet, in the form of a diabolo helps not only optimize the cooling of the air passing through the screen but also affords the user greater visual comfort, since the footprint of the hole, or its surface area projected on a face, is smaller than a hole with a frustoconical shape, for example.

(48) Additional tests were also carried out in order to study the variation in light transmission through various objects.

(49) The operating conditions were as follows: light source sending a uniform beam onto a lens, which made the luminous flux converge on a fluxmeter in order to measure the quantity of light transmitted. The object to be studied was introduced at the outlet of the light source.

(50) TABLE-US-00003 Light intensity Object studied transmitted (Lux) Reference measurement - no object inserted 972 +/ 1 (100%) Commercial mesh mosquito net 554 +/ 4 (57%) PC, 2 mm, not perforated 860 +/ 2 (88%) PC, 2 mm, holes untreated, density 5,000 t/m2, 835 +/ 2 (86%) D shape PC, 2 mm, holes treated, grey blue on both sides, 850 +/ 2 (87%) density 5,000 t/m2, D shape PC, 2 mm, holes treated, grey blue on both sides, 762 +/ 3 (78%) density 10,000 t/m2, D shape PC, 2 mm, holes treated, cyan blue on both sides, 846 +/ 3 (87%) density 5,000 t/m2, D shape PC, 2 mm, holes treated, cyan blue on one side, 807 +/ 1 (83%) density 5,000 t/m2, C shape PC, 2 mm, holes treated, cyan blue on one side, 782 +/ 2 (80%) density 7,000 t/m2, C shape PC, 2 mm, holes treated, black on both sides, 853 +/ 2 (88%) density 5,000 t/m2, D shape PC, 2 mm, holes treated, black on one side, 845 +/ 2 (87%) density 5,000 t/m2, D shape PC, 1 mm, not perforated 860 +/ 2 (91%) PC, 1 mm, holes treated, grey blue, 856 +/ 2 (88%) density 5,000 t/m2, D shape PC, 250 m, not perforated 934 +/ 1 (96%) PC, 250 m, holes untreated 855 +/ 3 (88%) PC, 250 m, holes treated, black with process 865 +/ 2 (89%) 1 on one side, density 5,000 t/m2, C shape PC, 250 m, holes treated, black with process 875 +/ 2 (90%) 2 on one side, density 5,000 t/m2, C shape Note: * process 1 = laser foaming, process 2 = chemical process. When not specified, process 2 was implemented. C shape = conical shape of the longitudinal section of the ventilation holes, i.e. in a direction extending between the two faces of the sheet D shape = diabolo shape of the longitudinal section of the ventilation hole.

(51) These measurements give rise to the following points: a) the light irradiance through the commercial mosquito net is far lower than all the screens forming the subject matter of the disclosure, regardless of the shape of the tested ventilation holes, the treatment process used, the density of holes or indeed the color of the layers formed in these ventilation holes in order to improve the light transmission coefficient of the corresponding sheet, b) higher light irradiance is obtained with the formation in each ventilation hole of one or more layers in order to improve the light transmission coefficient of the corresponding sheet than when the ventilation holes of this sheet remain untreated, c)a range of treatment colors appears optimal (dark colors and, in particular, grey blue) in order to ensure optimal light transmission (a high %), d)a hole profile (in the thickness) with the centered diabolo shape optimizes the aesthetic aspect by reducing the impact of the treatment on vision regardless of the viewing angle, and maximizing light transmission. Indeed, the projected surface area of the hole for a given passage diameter is minimized, regardless of the viewing angle.

(52) FIG. 4 is a partial enlarged view of a protector screen 40 showing a single oblong ventilation hole 41. This protector screen 40 comprises a unitary sheet comprising a first face 42 and a second face (not shown). This sheet comprises a plurality of ventilation holes 41 extending and opening on the two faces 42 of this sheet in order to allow air to pass therethrough.

(53) Only the free end of a ventilation hole 41 opening on the first face 42 of this sheet and therefore contained in this face is shown, for the sake of simplicity.

(54) The part, or free end, of the ventilation hole opening on the maximizing first face 42 therefore has a first dimension along an axis 43 transverse to this hole and a second dimension along an axis 44 longitudinal to this hole.

(55) Advantageously, the dimension of this ventilation hole 41 along its longitudinal axis 44 is greater than the largest dimension of the arthropods against which the screen provides protection, whereas its dimension along the transverse axis 43 is less than or equal to the largest dimension of the main body of the arthropods against which the screen provides protection, this main body excluding the head and the appendages of the corresponding arthropods.

(56) This allows a higher air flow rate through the protector screen 40 while guaranteeing its role as a mechanical barrier against the corresponding arthropods.

(57) FIG. 5 is an example of the implementation of the screen of FIG. 4 for forming a mechanical barrier against tiger mosquitoes.