Apparatus and method for impregnating a fiber carrier with powder

Abstract

The present invention relates to a method for impregnating a fiber carrier (S) with a powder material (P), comprising the steps of bringing the powder material (P) into contact with the carrier (S), and passing the carrier (S) and the powder (P) between electrodes (3, 3', 4, 4') at different potentials in order to permeate the powder material (P) into the carrier (S), wherein the method further comprises an additional pretreatment step of passing an uncoated carrier (S) between electrodes (3, 3') at different potentials before bringing the powder material (P) into contact with the carrier (S). The present invention also relates to an apparatus (100) for implementing this method.

Description

Technical Field

[0001] The present invention relates to the field of impregnating a porous carrier with a powder material. The carrier is, for example, a fabric or fibrous material, a porous non-woven fabric and / or an agglomerated material.

[0002] These carriers are treated by impregnating them with powders having specific physicochemical properties, such as thermoplastic resins, thermosetting resins, flame retardants, cosmetic powders, medical powders, antibacterial powders, hemostatic agent powders, etc.

[0003] The present invention focuses particularly on enhancing the penetration of the powder into the carrier, which is particularly advantageous for enhancing the performance of the product and improving the impregnation yield when the powder is expensive, such as in cosmetics or pharmaceuticals.

Background Art

[0004] Patent Document 1 and Patent Document 2 each describe an apparatus for impregnating a fiber or a porous and non-conductive carrier with a powder. The described apparatus includes means for moving a carrier on which a powder of a solid material is deposited.

[0005] The methods of these documents are particularly intended only for non-conductive carriers, because when using a conductive material, such as carbon fiber, between electrodes supplied with alternating current, it is prevented from dispersing an electric field in the thickness of the conductive material, and there is a possibility of flashover due to the use of a strong electric field.

[0006] The carrier covered with the powder is then conveyed between electrodes connected to an alternating voltage generator, and the electrodes on each side of the carrier are connected to one of the terminals of the voltage generator.

[0007] The polarized powder will move, particularly in the direction of the center of the carrier, by the electric field between the two electrodes. The powder then impregnates the carrier.

[0008] Patent Document 3 further describes using a thermal pretreatment before applying the powder to the carrier in order to improve the penetration of the powder into the carrier.

[0009] However, thermal pretreatment is energy-intensive and can degrade heat-sensitive supports. [Prior art documents] [Patent Documents]

[0010] [Patent Document 1] International Publication No. 99 / 22920 [Patent Document 2] French Patent No. 2933327 Specification [Patent Document 3] French Patent No. 3031756 [Overview of the project] [Problems that the invention aims to solve]

[0011] Therefore, ideally, there is a need for a powder impregnation process that can improve yield without relying on thermal pretreatment. [Means for solving the problem]

[0012] To address this technical challenge, the present invention provides a method for impregnating a fiber carrier with a powder material, A step of bringing the powder material into contact with the carrier, The steps include passing the powder material through electrodes at different potentials to allow it to permeate the carrier, In a method including, We propose a method that further includes an additional pretreatment step of passing an uncoated carrier between electrodes at different potentials before bringing the powder material into contact with the carrier.

[0013] In fact, the applicant was surprised to find that samples passed between impregnation electrodes without powder material had a higher impregnation capacity. Up to 70% more powder could be impregnated into the carrier at this time.

[0014] This method may further have one or more of the following characteristics:

[0015] The carrier can pass between the electrodes in one direction before the deposition of the powder material, then come into contact with the powder material, and finally, after coming into contact with the powder material, pass between the electrodes in the opposite direction.

[0016] During the previous step, multiple cut carriers can be placed on a plate, the plate including locations of shape and size corresponding to the shape and size of the cut carriers.

[0017] The present invention relates to an apparatus for impregnating a powder material related to a fiber carrier, Means for moving the carrier, Means for bringing powder material into contact with a carrier, Electrodes connected to the terminals of a voltage generator having at least two terminals at different potentials, which generate an alternating electric field applied to the path of a moving carrier, In a device including, The means for moving the carrier also relates to an apparatus characterized in that the powder material passes between electrodes onto the carrier before passing through means for bringing the powder material into contact with the carrier.

[0018] The electrodes are arranged in a direction laterally to the direction of the carrier's advance, and can be alternately connected to opposing terminals of the AC voltage generator in the direction of the carrier's advance.

[0019] The pretreatment and impregnation electrodes can be fabricated in the form of metal strips deposited on a dielectric carrier, and the means for moving the carrier can be configured to continuously advance the carrier.

[0020] Due to the alternation of the potential along the path of the carrier, the particles of the powder material encounter a larger gradient, making it possible to stir them more effectively.

[0021] This device can include a pretreatment electrode arranged in parallel with the means for bringing the powder into contact with the carrier. The means for bringing the powder into contact with the carrier deposits the powder material on the belt of the means for moving the carrier, and the carrier comes to cover the belt and the powder material at the output of the means for bringing the powder into contact with the carrier, and then passes between the impregnation electrodes.

[0022] Alternatively, the means for moving the carrier can be configured to advance it at a continuous pitch, and the pretreatment and impregnation electrodes are fabricated in the form of continuous planar electrodes on each side of the carrier, and due to the continuous pitch, the carrier continuously passes between the pretreatment electrodes, between the means for bringing the powder into contact with the carrier, between the impregnation electrodes, and is moved. between the pretreatment electrodes, to the means for bringing the powder into contact with the carrier, between the impregnation electrodes, and is moved.

[0023] The means for bringing the powder into contact with the carrier can include a dispenser ending with an aperture that forms a mask for target-depositing the powder material according to a predetermined pattern.

[0024] The present invention will be better understood upon reading the following description, the details of which are given merely by way of example and are developed in connection with the accompanying drawings, in which the same reference numerals relate to the same elements.

Brief Description of the Drawings

[0025] [Figure 1] It is a schematic side view of the device according to the present invention. [Figure 2] It is a schematic side view of a second embodiment of the device according to the present invention. [Figure 3] It is a schematic side view of the device according to a third embodiment of the present invention operating in a roll-to-roll manner. [Figure 4] It is a schematic side view of a fourth embodiment of the present invention operating at a continuous pitch. [Figure 5] This is a schematic diagram of a fifth embodiment in which the powder is deposited beneath the carrier. [Figure 6] This is a schematic flowchart showing the main steps of the method related to the apparatus in Figure 1. [Figure 7] This table shows experimental impregnation results using the method of the present invention. [Modes for carrying out the invention]

[0026] The specific embodiments shown are given as descriptive and non-limiting examples.

[0027] Figure 1 is a schematic diagram of an apparatus 100 for impregnating a fiber or porous carrier S with a powder material P.

[0028] The carrier S is moved by a moving means 1, which is a belt conveyor. The moving means 1 advances the carrier S in a direction L that is considered to be the longitudinal direction.

[0029] The carrier S is, for example, a strip of woven or nonwoven fiber material, whether bioabsorbable or not, particularly natural, artificial, or synthetic fibers, and the powder material P can be, in particular, a functional powder with antibacterial or hemostatic properties. Thus, a functional antibacterial dressing, or hemostatic implant or "patch," is obtained that is implanted in the patient's body during surgical intervention. The antibacterial dressing can prevent infection of the patient's wound, and a hemostatic implant impregnated with coagulating hemostatic powder can prevent massive internal bleeding.

[0030] These bioabsorbable properties allow for avoiding subsequent interventions for implant removal.

[0031] Common medical active powders and hemostatic powders used are particularly expensive, do not penetrate the carrier S, and therefore the powder that is lost, even in small quantities, represents a considerable loss in terms of cost and constitutes medical waste that must be handled with particular care.

[0032] The apparatus 100 here includes a plate 10 with recesses, on which a plurality of cut carriers S, in this case substantially rectangular hemostatic implants, are arranged.

[0033] As the carrier S advances along its longitudinal direction L, it passes through three stations in sequence: the fiber pretreatment station 101, the powder contact station 103, and the impregnation station 105.

[0034] The fiber pretreatment station 101 includes open electrodes 3, 3', which are connected to a voltage generator G, which carries an alternating potential to the electrodes.

[0035] Means 5 for bringing the powder material P into contact with the carrier S are positioned above the carrier S, immediately behind the open electrodes 3, 3', and in accordance with the direction L of the carrier S's advance.

[0036] The contact means 5 deposits the powder material P onto the upper surface of the carrier S, in particular, in a substantially uniform and continuous distribution along its surface. According to one modification, the powder material P can be applied by following a specific geometric pattern on the surface of the carrier.

[0037] The pre-treatment electrodes 3 and 3' are alternately connected to the terminals of the generator G, in particular, the AC electrostatic generator.

[0038] Although only the connection between the generator G and the electrode 3 positioned above the carrier S is shown, the electrode 3' positioned below is also connected to the terminal on the opposite side of the generator G from the electrode 3 positioned above.

[0039] Generator G is, for example, an AC voltage generator with a frequency on the order of 100 Hz and a nominal voltage of several thousand volts, typically on the order of 20 kV to 50 kV.

[0040] Electrodes 3 and 3' thus generate a variable electric field that is applied to the path of the moving carrier S, with different values ​​and directions along the path of the carrier S.

[0041] As the fibers of the carrier S pass between electrodes 3 and 3' for a predetermined time, they become charged throughout the entire thickness of the carrier, pushing each other away. As a result, the fibers separate from each other, and charge is transferred to the fibers, causing the carrier S to expand substantially. The ratio of empty space to openings within the volume of the carrier S increases.

[0042] In particular, the length occupied by electrodes 3, 3' of the pre-processing station 101 is large enough for the carrier S to remain between electrodes 3, 3' for at least 2 seconds, and especially between 5 and 30 seconds, at the expected rate of advancement.

[0043] At the output of the fiber pretreatment station 101, the carrier S arrives at station 103 for bringing the powder into contact with the carrier.

[0044] The station 103 for bringing the powder into contact with the carrier includes, in particular, means 5 for depositing the powder material P only on the carrier S, specifically, by means of a mask for collecting adjacently deposited powder material.

[0045] The particles of the powder material P are particularly fine enough to be inserted between fibers or into the pores of the carrier S.

[0046] Once the powder material P is deposited, the carrier S arrives at the impregnation station 105.

[0047] The impregnation station 105 includes a second set of electrodes 4, 4' connected to a second voltage generator G'. These electrodes 4, 4' are also alternately connected to the terminals of the second generator G'.

[0048] According to one particular embodiment, a single generator G can supply power to two sets of electrodes 3, 3', 4, and 4'.

[0049] Electrodes 3, 3', 4, and 4' can be fabricated, for example, in the form of strips of conductive material arranged transversely to the direction L of movement of the support S on plates 30 and 40 of dielectric material. In this case, the electrodes are those described in Patent Document 2. Other forms of electrodes 3, 3', 4, and 4' are of course possible (see Figure 4).

[0050] Electrodes 3 and 3' are configured in particular to avoid any destruction and thus not induce large-scale ionization of the support S. Only electron displacement from the support S is induced, without the supply of electrons from electrodes 3 and 3' to the support S or vice versa.

[0051] In particular, strips of conductive material can be alternately connected to different terminals of generators G and G' according to the direction of advancement of the carrier S. Generators G and G' can be DC voltages in this case. The electric field is then uniform in time but variable in space. The variable electric field for impregnation is then generated by the advancement of the carrier S.

[0052] Electrodes 3, 3', 4, and 4' can be partially connected to the neutral potential (earth), or to the terminals opposite to generators G and G', or more generally, to phase-shifted terminals.

[0053] When the powder material P placed on the carrier S passes through the space below the second set of electrodes 4, 4', the charged particles of the powder material P are agitated by the generated power and penetrate the carrier S.

[0054] Electrodes 4 and 4', in particular, stir the particles of the powder material P through the electric field they generate, because the particles become polarized and then collide with each other and repel one another. This stirring causes the particles to penetrate between the fibers of the carrier S and adhere to them, thus enabling the powder material P to permanently penetrate the carrier S.

[0055] At this time, by passing through the pre-processing station 101, a larger amount of powder material P can enter the carrier S, the concentration gradient becomes lower, and thus the distribution of the powder material within its volume becomes better.

[0056] Figure 2 shows an alternative embodiment of the device 100.

[0057] In this embodiment, the means 1 for moving the carrier S can transport the carrier S in two opposite directions: forward and backward motion.

[0058] The apparatus 100 includes only one set of electrodes 3, 3' which perform both pretreatment and the infiltration of powder material P into the carrier S.

[0059] At this point, the carrier S, positioned on plate 10, passes between electrodes 3 and 3' for the first time, and the carrier S is moved forward by the moving mechanism. The carrier S is maintained between electrodes 3 and 3' for a predetermined time, particularly longer than 2 seconds, typically between 5 and 30 seconds.

[0060] At the output of electrodes 3 and 3', after pretreatment of the fibers, the deposition of the powder material P is carried out by means of bringing the powder into contact with the carrier S.

[0061] When the entire support S is covered with the powder material P, the support S has reached its end position, and the moving means 1 reverses the displacement of the plate 10 at this time. Due to the displacement of the support S in the return direction, they move again under electrodes 3, 3', and this time the powder material P is deposited on their surface.

[0062] During this second pass under electrodes 3 and 3', the particles of the powder material P are moved and penetrate the carrier S. The generator G can be configured differently, in particular, during the movement of the plate 10 of the carrier S back relative to the first forward pass.

[0063] This embodiment is particularly suitable for small laboratories where space is limited and continuous production of the product is also limited. In fact, there is only one pair of electrodes 3, 3' and only one generator G with limited capacity. The same electrodes 3, 3' are used for pretreatment and then impregnation into the carrier S. However, the back-and-forth movement means that only one plate 10 of carrier S can be processed at a time.

[0064] Figure 3 shows a side view of an alternative embodiment of the apparatus 100.

[0065] In this embodiment, the carrier S is in the form of a continuous strip, starting from a starting roll R1 and ending as a processed roll R2 after processing.

[0066] The apparatus in Figure 3 is essentially identical to that in Figure 1, with the only differences being the shape of the carrier S and the absence of the plate 10. Additional moving means can be provided specifically for feeding and winding the carrier S on the rolls R1 and R2.

[0067] Figure 4 shows a fourth embodiment of the device 100, which operates at a continuous pitch.

[0068] The apparatus 100 in Figure 4 has two sets of electrodes 3, 3', 4, and 4', through which a cut-out carrier S placed on a plate 10 passes. Between the two sets of electrodes 3, 3', 4, and 4', a means for bringing the powder into contact with the carrier S is arranged. The contact means 5 here includes a dispenser in which the powder material P is suspended, which ends in an opening that forms a mask for target deposition of the powder material P in a predetermined pattern, specifically on the cut-out carrier S rather than on the plate 10.

[0069] A mask can also be used to spread powder material P onto a carrier S according to a specific pattern. Multiple spreaders equipped with specific masks can be used sequentially on the carrier S between two sets of electrodes to deposit multiple different powder materials P according to a specific pattern (e.g., drawing, gradient of powder material P, different functional parts on the same carrier S).

[0070] Electrodes 3, 3', 4, and 4' are here fabricated in the form of continuous metal plates insulated by a dielectric material covering the carrier S and plate 10 during processing.

[0071] The means 1 for moving the carrier S operates in a continuous pitch, during which the carrier S advances by a predetermined length, with a pause between each pitch. The length of displacement in each pitch is greater than the length of the carrier S and the plate 10, and the pause between each pitch is, for example, several seconds to tens of seconds, in order to allow processing of the carrier S after each pitch.

[0072] A plate 10 supporting the cut-out carrier S comes, for example, from a stock of plates 10 and comes between the pre-treatment electrodes 3 according to a first displacement pitch. During the pause time after this first displacement pitch, the generator G makes the electrodes 3, 3' variable potential in order to generate a variable electric field in the space between the plates 10 and the carrier S located in the electrodes 3, 3'.

[0073] The plate 10 on which the carrier S is located is then moved under the sprayer forming the contact means 5 by the next displacement pitch. During the pause after this second pitch, the powder material P is sprayed onto the carrier S.

[0074] During the second displacement pitch, the second plate 10 on which the carrier S is located is moved between the pretreatment electrodes 3 and 3'.

[0075] During the third displacement pitch, the plate 10 on which the support S with the deposited powder material P is located is moved between the second set of electrodes 4, 4'. During the pause time after this third pitch, the second generator G' brings the second set of electrodes 4, 4' to an alternating potential in order to allow the powder material P to penetrate the support S.

[0076] During the third displacement pitch, the second plate 10 is moved from the pretreatment electrodes 3, 3' to the means for contacting the powder material P, and the third plate 10 is moved between the pretreatment electrodes 3, 3'.

[0077] During the fourth displacement pitch, the processed plate 10 is discharged toward the output, the second and third plates 10 move to the next station, and the fourth plate 10 is inserted between the pre-treatment electrodes 3, 3'.

[0078] In the embodiments shown in Figures 1 to 3, the electric field between the same set of electrodes 3, 3', 4, and 4' is variable in the direction L of the advance of the carrier S, in addition to the variability related to the AC characteristics of the voltage at the terminals of the generator G. As the carrier S advances between electrodes 3, 3', 4, and 4', it thus experiences a dual change in the electric field, becoming stronger when the carrier is positioned below the electrode strip and weaker when the carrier is positioned between the strips of two electrodes, i.e., resulting in a spatially non-uniform electric field.

[0079] In contrast, in the embodiment shown in Figure 4, only a pair of electrodes 3, 3', 4, and 4' are present on each side of the carrier S of the plate 10, and the electric field is consequently less spatially variable. However, the carrier S remains fixed under electrodes 3, 3', 4, and 4', whose generators G and G' are under AC voltage, for a predetermined time interval, which can be extended until sufficient pretreatment and / or penetration of the powder material P is achieved.

[0080] Figure 5 is a schematic side view of the device 100 that implements the present invention.

[0081] Here too, the carrier S is a continuous strip moving from the starting roll R1 to the ending roll R2.

[0082] In the embodiment shown in Figure 5, the powder material P is applied to a rotating belt 11 which is moved by a moving means 1, and a pre-treated carrier S then comes above the powder material P deposited on the belt 11.

[0083] For this purpose, the pre-treatment station 101 is arranged parallel to the powder contact station 103. In particular, in the illustrated embodiment, the pre-treatment station 101 is arranged above the powder contact station 103.

[0084] The carrier S passes between the pre-treatment electrodes 3 and enters the pre-treatment station 101. Parallel to this, below, at the powder contact station 103, the powder P is deposited on the belt 11. The belt 11 may include, in particular, irregularities, grooves, and concave patterns to contain the powder P and control its distribution on the carrier S after impregnation.

[0085] The carrier S is then applied above the powder P on the belt 11 for contact with the powder at the output of the pre-treatment station 101 103. The carrier S is driven by the belt 11 toward the impregnation station 105, with the powder P always sandwiched between the carrier S and the belt 11.

[0086] In the impregnation station 105, the belt 11, the carrier S, and the powder P sandwiched between them pass between the impregnation electrodes 4 and 4'. Between the impregnation electrodes 4 and 4', the powder particles P are moved by the alternating electric field, which then moves toward the inside of the carrier S.

[0087] At the output of the impregnation station 105, the carrier S impregnated with powder P is directed toward the roll R2 and wound onto it.

[0088] Figure 6 is a flowchart showing the main steps of the impregnation method 200 implemented in the aforementioned apparatus 100.

[0089] The first step 201 is to pre-treat the carrier S before bringing the powder material P into contact with the carrier S. This step is performed by electrodes 3, 3', through which the carrier S passes before contacting the powder material P.

[0090] The second step 203 is to bring the powder material P into contact with the carrier S that has been previously passed between the pre-treatment electrodes 3, 3'. This step 203 is performed by the contact means 5.

[0091] The third step 205 is a second pass between electrodes, which are either the same 3, 3' or an additional dedicated set 4, 4' as in the first step 201 in the return direction, allowing the powder material P to penetrate the carrier S.

[0092] The impregnation method 200 and the associated impregnation apparatus 100 make it possible to enhance the penetration of the powder material P into the carrier S, which means that less powder material P is lost during impregnation. This aspect is particularly important in the case of expensive or environmentally polluting powder materials P.

[0093] Figure 7 illustrates the advantages provided by the impregnation method 200 according to the present invention.

[0094] Figure 7 is a table showing experimentally obtained results, where three different nonwoven fabric carriers S correspond to the data in the three rows of the table.

[0095] The three carriers S are listed in the "Reference" column in descending order. Cotton, type used in cosmetics, spunlace nonwoven fabric, Nonwoven needled polyester, and Airlaid cellulose fiber paper, a type used in tablecloths and sanitary products, airlaid nonwoven fabric, That is the case.

[0096] In the experiment, the support S is cut into a 5cm x 10cm rectangle and inserted into a plate 10 whose surface is covered with a honeycomb grid. The mass M0 of the support S before impregnation is given in grams (g) in the first data column of the table in Figure 7.

[0097] When applied, powder P is raked into the honeycomb grid on which the cut-off carrier S is deposited. The powder P used is a green clay called "cosgreen(trademark) superfine" manufactured by Argile du Velay, with particle sizes ranging from 0 μm to 100 μm.

[0098] Electrodes 3, 3', 4, and 4' are under a potential of 40kV AC at a frequency of 100Hz. The carrier S is maintained between the electrodes for 15 seconds.

[0099] The second column of the table shows the mass M1 of the powder impregnated into the carrier S, which was directly coated with powder and then passed between electrodes 4 and 4', without any pretreatment by passing it between electrodes without powder.

[0100] The third column of the table shows the mass M2 of powder P impregnated into the carrier S, after pretreatment by passing the powder P between electrodes 3 and 3' before deposition.

[0101] The mass M1 or M2 of powder P is estimated, in particular, by weighing the impregnated carrier S and subtracting the mass M0 of the carrier S before impregnation.

[0102] The fourth column of the table shows the mass difference ΔM of the powder P impregnated into the carrier S between the cases with and without treatment, by passing the device through electrodes 3, 3', 4, and 4' in an empty state. The fifth column shows the percentage of additional powder P impregnated into the carrier S as a result of the pretreatment.

[0103] In the case of cotton, the mass of impregnated powder P was 0.719 grams without pretreatment and 0.955 grams with pretreatment, which is an additional 0.236 grams, and therefore an increase of 33%.

[0104] In the case of polyester, the mass of powder P impregnated without pretreatment was 0.666 grams without pretreatment and 0.958 grams with pretreatment, which is an additional 0.292 grams, and therefore an increase of 44%.

[0105] In the case of a carrier S having cellulose fibers deposited by air, the mass of the impregnated powder P without pretreatment is 0.123 grams without pretreatment and 0.209 grams with pretreatment, which is an additional 0.086 grams, and therefore an increase of 70%.

[0106] The applicant has further conducted additional tests in which a polyester thermosetting resin powder with an average diameter of 41 μm is impregnated into a polyester carrier S, both with and without the pretreatment described in detail above. The resulting product can then be used in the context of a thermoformable composite material.

[0107] The amount of powder P impregnated without pretreatment was 0.603 grams, while with pretreatment it was 0.975 grams. Therefore, approximately 62% more powder was impregnated into the carrier S with pretreatment.

[0108] Therefore, there is a significant and quantifiable technical effect in that better impregnation of the carrier S is possible and the loss of powder P is reduced. [Explanation of symbols]

[0109] 100 devices 1. Means of transportation 10 plates 101 Fiber pre-treatment station, fiber release station 103 Powder Contact Station 105 Impregnation Station 3, 3' electrode 4, 4' electrode 5 Contact means 30, 40 Dielectric material plates 11 belts G, G' voltage generator L Direction of forward movement P powder material R1 Starting Role R2 Processed Roll S fiber carrier

Claims

1. A method for impregnating a fiber carrier (S) with a powder material (P), The steps include bringing the powder material (P) and the carrier (S) into contact, The steps include passing the powder material (P) through electrodes (3, 3', 4, 4') at different potentials to permeate the carrier (S), In a method including, The method further comprises an additional pretreatment step of passing the carrier (S), which is not coated with the powder material (P), between electrodes (3, 3') at different potentials for a predetermined time, before bringing the powder material (P) into contact with the carrier (S).

2. The method according to claim 1, characterized in that the carrier (S) passes between the electrodes (3, 3') in one direction before the deposition of the powder material (P), then comes into contact with the powder material (P), and finally, after coming into contact with the powder material (P), passes between the electrodes (3, 3') in the opposite direction.

3. The method according to claim 1 or 2, characterized in that, during the previous step, a plurality of cut carriers (S) are arranged on a plate (10), and the plate (10) includes locations of a shape and size corresponding to the shape and size of the cut carriers (S).

4. An apparatus for impregnating a fiber carrier (S) with a powder material (P), Means (1) for moving the carrier (S), Means (5) for bringing the powder material (P) into contact with the carrier (S), Electrodes (3, 3', 4, 4') connected to the terminals of a voltage generator (G, G') which includes at least two terminals at different potentials, generating an electric field applied to the path of the moving carrier (S), In a device equipped with, The apparatus is characterized in that the means (1) for moving the carrier (S) passes the carrier (S) between the electrodes before it passes through the means (5) for contacting the powder material (P).

5. The impregnation apparatus according to claim 4, characterized in that the electrodes (3, 3', 4, 4') are arranged laterally with respect to the direction (L) of the advance of the carrier (S), and are alternately connected to the terminals of the voltage generator (G, G') with respect to the direction of the advance of the carrier.

6. The apparatus according to claim 4 or 5, characterized in that the pretreatment and impregnation electrodes (3, 3', 4, 4') are manufactured in the form of metal strips deposited on dielectric carriers (30, 40), and the means (1) for moving the carrier (S) is configured to continuously advance the carrier (S).

7. The apparatus according to any one of claims 4 to 6, comprising pre-treatment electrodes (3, 3') arranged parallel to the means (5) for bringing the powder into contact with the carrier, wherein the means (5) for bringing the powder into contact with the carrier deposits powder material (P) on a belt (11) of the means (1) for moving the carrier (S), and the carrier (S) is covered by the output of the pre-treatment electrode (3) by the belt (11) and the powder material (P), and then passes between the impregnation electrodes (4, 4').

8. The means (1) for moving the carrier (S) is configured to advance the carrier (S) at a continuous pitch, and the pretreatment and impregnation electrodes (3, 3', 4, 4') are manufactured one for each surface of the carrier (S) in the form of a continuous planar electrode, and the carrier (S) is moved continuously by the continuous pitch. Between the pretreatment electrodes (3, 3'), The means (5) for bringing the powder into contact with the carrier, Between the impregnated electrodes (4, 4'), The apparatus according to claim 4 or 5, characterized by being transferred.

9. The apparatus according to claim 8, wherein the means (5) for bringing the powder into contact with the carrier includes a dispenser ending at an opening that forms a mask for target deposition of the powder material (P) according to a predetermined pattern.

Images