WO2014023898A1

WO2014023898A1 - Method for metallizing a surface of a part for a motor vehicle

Info

Publication number: WO2014023898A1
Application number: PCT/FR2013/051869
Authority: WO
Inventors: Sophie Vidal
Original assignee: Compagnie Plastic Ominum
Priority date: 2012-08-06
Filing date: 2013-08-01
Publication date: 2014-02-13
Also published as: EP2880197A1; CN104718311A; CN104718311B; FR2994197A1; EP2880197B1; FR2994197B1; ES2610455T3

Abstract

The metallization according to the invention is non-electrolytic. The invention relates to a method that is carried out in a compartment (10) including at least an activating-agent sprayer (18, 20, 22) and a metal-salt sprayer (18, 20, 22), each sprayer (18, 20, 22) being immovably mounted in the compartment (10), the part (28) being handled by a manipulator robot (24), wherein the method includes the following steps: the robot (24) firstly positions the part opposite the activating-agent sprayer (18, 20, 22) and moves said part relative to said sprayer such that the entire surface is covered with the activating agent; and the robot (24) then positions the part opposite the metal-salt sprayer (18, 20, 22) and moves said part relative to said sprayer such that the entire surface is covered with the metal salts.

Description

Method for metallizing a surface of a part for a motor vehicle

The present invention relates to the metallization of parts for a motor vehicle, in particular a part comprising plastic.

There is already known a method of metallization parts by projection of a solution comprising metal salts, the method does not require the use of electric current. This type of process is particularly called electroless metallization process. It is thus distinguished from the metallization implemented using an electric current, such as electroplating chrome plating, during which electrochemical deposition of chromium is performed.

It is of particular interest to use metal salt sputtering to give a metallic appearance to a plastic part, since this avoids the use of costly and polluting plating baths.

However, the parts to be metallized by spraying metal salts must undergo a number of different processing steps. Generally, the parts are placed on a conveyor and pass from one station to another. This type of installation can be very bulky and take up a lot of space.

The invention aims in particular to overcome these disadvantages by providing a method requiring less space.

For this purpose, the subject of the invention is a method of metallizing a surface of a part for a motor vehicle, the metallization being non-electrolytic, the method being implemented in a booth comprising at least one activating product spray and a spray of metal salts, each sprayer being fixedly mounted in the cabin, the part being manipulated by a manipulator robot, the method comprising the following steps:

the robot first positions the piece next to the activating product sprayer, moves it relative to this sprayer so that the entire surface is covered with activating product, and

the robot then positions the piece opposite the metal salt sprayer and moves it relative to this sprayer so that the entire surface is covered with metal salts.

Thanks to the fact that the method is implemented in a cabin including an activating product sprayer and a metal salt sprayer, it is possible to carry out several steps in a space whose space requirement is relatively small, especially in comparison with the space required to perform these same steps when the parts move on a conveyor from a post to another for the realization of the different stages. Due to this more compact space and the use of the same robot to ensure in particular the application of activating product and the application of metal salts, reduces the investment in the implementation of the process.

In addition, each sprayer being fixedly mounted in the cabin, the piece is moved in front of each sprayer by means of the manipulator robot. The speed of movement of the part is not therefore limited as can the speed of movement of a sprayer. Indeed, when moving a sprayer, it is necessary to take into account the deformation of the projection cone during the displacement, this deformation limiting the speed of displacement. This results in a faster metallization process and it is possible in a given time interval to process more parts.

The robot can be arranged in the cabin. However, only the part positioning the part in front of the sprayers can be in the cabin, the rest of the robot being outside the cabin.

It should be noted that the part may undergo other steps than the application of activating product solutions and metal salts. In particular, the non-electrolytic metallization process generally comprises, before the spraying of activating product and metal salts, a preliminary step of depositing a varnish, also called "basecoat" or primer, thereby making it possible to metallize on any type piece, in particular on a part comprising plastic material. On the other hand, the step of spraying the activation solution may be followed by a rinsing step before the step of spraying the metal salts. In addition, the projection of metal salts is preferably followed by a step of depositing a protective varnish, also called "topcoat".

The term "activating product", or "activation solution", is generally understood to mean a solution capable of modifying the state of the surface of the part so as to promote the initiation of an oxidation-reduction reaction and the grip metal particles subsequently sprayed into the solution of metal salts. Thus, the activation solution can activate the surface of the part by deposition, reaction, grafting of an active product to promote the deposit resulting from the subsequent sputtering of metal salts.

The term "metal salts" generally means a solution comprising oxidizing metal cations and a reducing solution. For example, the metal cations and the reducing solution are projected by two nozzles of the same sprayer, which create two mists that meet so that a layer of metal is deposited on the surface of the room. It is understood that the activating product and the metal salts are in the form of sufficiently fluid liquids to be projected in the form of fine droplets of liquid. This provides an effective and rapid projection of the activating product and salts on the workpiece to be metallized.

The automotive vehicle part may be any part of the vehicle to which it is desired to give a metallized appearance, for example an air intake grille, a rod, an optical outline, a handle, a hubcap, a rocker , a safety band, etc. It may be made of a thermoplastic or thermosetting or composite material.

The invention may further include one or more of the following features, taken alone or in combination.

In the course of the process, at least one first type and one second type of solution are sprayed onto the part, each type of solution comprising at least one solution chosen from the group consisting of a varnish, a washing liquid, the metal salts and the activating product, the method comprising a step of recovering the first type of solution after projection into the cabin and a step of recovering the second type of solution after projection into the cabin, the cabin comprising separate means of recovery of each type of solution. Thus, the two types of solutions can be easily separated and recovered separately. As a result, the treatment of the types of solutions after recovery, for example their disposal or recycling, is facilitated because the first and second types of solutions are not mixed. Note that the first and / or the second type of solutions may each be composed of a single solution projected in the cabin or a mixture of several solutions, projected simultaneously or successively in the cabin. In this case, it is understood that a type of solution recovered by one of the recovery means may undergo subsequent treatments specific to each mixture of solutions. Moreover, a type of solution may correspond, but not necessarily, to a set of solutions of the same nature. For example, the first type of solution corresponds to one or more solutions of organic nature, while the second type corresponds to one or more solutions of aqueous nature. However, according to another way of distributing the types of solutions, the first type of solution corresponds to one or more solutions intended to be discarded directly, without treatment, whereas the second type corresponds to one or more solutions intended to undergo a treatment before to be discarded or before being recycled. However, there are many other ways of distributing the types of solutions, for example a type of solution corresponds to a particular solution to be isolated, in particular a solution for which a particular treatment is intended, and the second type corresponds to a mixture of all the other projected solutions. It is understood that "separate recovery means of each type of solution" means recovery means capable of isolating each type of solution then with respect to each other.

The first type of solution comprises an organic solution and the recovery means of this first type of solution comprise an organic product absorption floor. The floor can be arranged on a side wall, in the case of vertical projection and recovery by a vertical system, or at the bottom of the cabin. Preferably, the first type of solution is an organic solution, that is to say only consists of organic solutions. Such an absorption floor is for example used to recover organic solutions, such as varnishes, which have a viscosity greater than 0.01 Pa.s (Pascal second). These solutions are projected onto the part so that only the part of the projection cone that does not reach the part is recovered by the absorption floor. Note that it can be provided that the recovery means of the first type of solution comprise several absorption floors, for example a second floor mounted mobile relative to the first, in particular by rotation or translation. This allows to have a spare floor, when the other is soaked with solution.

- The recovery means of the second type of solution comprises a collection plate mounted movably in the cabin between a non-active position and a collection position, in which it is configured to recover the second type of solution and guide it to a pathway. 'evacuation. These recovery means are generally used to recover solutions that can flow easily and / or are projected so that they run on the part. These solutions generally have a viscosity of less than 0.01 Pa.s, preferably a viscosity close to the viscosity of water, ie approximately 0.001 Pa.s. The volume of the second type of solution to be recovered is generally larger than the volume of the first type of solution. The collection plate can be mounted mobile by rotation or by translation.

- When the collection plate is in the collection position of the second type of solution, it is inserted in front of the organic product absorption floor, so that the absorption floor is not in contact with the second type of solution . The organic product absorption floor is not in contact with the second type of solution whose volume to be recovered is important for this type of floor. Thus, the floor needs to be changed less frequently, which results in a cost saving as well as a time saving related to the step of changing the absorption floor which is avoided. In the case of a floor at the bottom of the cabin, it is understood that the collection plate is above the floor.

The second type of solution comprises the metal salts and / or the activating product and / or a washing liquid. The washing liquid is, for example, water, preferably distilled water.

- The second type of solution is an aqueous solution.

The first type of solution comprises a varnish and / or a washing liquid. The washing liquid is preferably organic in this case.

- Reusing at least a portion of the second type of recovered solution to spray on the surface of another piece for a motor vehicle. The types of solutions being recovered separately, it is conceivable to use a recovered solution and to project it again on the part or on another part for a motor vehicle. The production costs are thus reduced because a larger number of parts can be treated with the same volume of solution. This is particularly advantageous in the case where the second type of solution comprises the activating product. Indeed, generally, the entire activating product sprayed does not necessarily react with the surface of the room so that it is reusable, hence the recovery that can be implemented. Furthermore, the physical properties of the activating product, such as the viscosity or evaporation rate, remain substantially constant throughout the process, so that its recovery is facilitated, unlike a conventional paint solution, which could be more or less dry during the process.

- The cab also includes a rinse aid sprayer and the robot positions the workpiece next to the rinse aid sprayer and moves it relative to this sprayer so that the entire surface is rinsed. This spraying is particularly advantageous in the case where it is implemented between the activating product spraying step and the metal salt spraying step.

A third type of solution is projected into the cabin on the part, the method comprising a step of recovering this third type of solution after projection into the cabin, the recovery means of this third type of solution being distinct from the other means of recovery. The third type of solution optionally comprises a solution chosen from the group consisting of a varnish, a washing liquid, the metal salts and the activating product, or several of the solutions of this group. The recovery means of the third type of solution comprise a collection plate mounted movably in the cabin between a non-active position and a collection position, in which it is configured to recover the third type of solution and guide it towards a channel; 'evacuation. Thus one can isolate a third type of solution, for example metal salts, so as to recover the metal ions, relatively expensive, avoiding diluting them in other solutions such as distilled water washing. In another example, the activating product can be isolated and then sprayed again. Optionally, this collection plate is rotatable about an axis of rotation disposed on the opposite side of an axis of rotation of another collection plate for recovering another type of solution. Alternatively, the collection plate is movable by translation.

- The collection plate is made of plastic or metal.

The invention also relates to a booth for the metallization of a surface of a part for a motor vehicle according to a method as described above, characterized in that it comprises an organic product absorption floor configured to recover a first type of solution and a collection plate mounted movably in the cabin between an inactive position and a collection position, in which it is configured to recover a second type of solution and guide it to an escape route.

Optionally, when the collection plate is in the collection position of the second type of solution, it is above the organic product absorption floor, so that the absorption floor is not in contact with the floor. second type of solution.

The booth may also include one or more other collection plates superimposed on each other to recover the second type of solution, or a third or nth type of solution.

It should be noted that it is possible to envisage performing a separate recovery of several types of solutions without, however, implementing the metallization method presented above by means of a manipulator robot.

Thus, the subject of the invention is also a method for metallizing a surface of a part for a motor vehicle, the metallization being non-electrolytic, the method comprising a step of spraying an activating product and a step of spraying metal salts. , in which process is sprayed into a cabin at least a first type and a second type of solutions on the part, each type of solution comprising at least one solution selected from the group consisting of a varnish, a washing liquid, the salts Metallic and the activating product, the method comprising a step of recovering the first type of solution after projection in the cabin and a step of recovering the second type of solution after projection into the cabin, the cabin comprising separate means of recovery of each type of solution .

It is understood that the characteristics developed previously or in the following relating to the process or the cabin can also be applied to the implementation of this method.

The invention will be better understood on reading the description which follows, given solely by way of example and with reference to the drawings in which:

- Figure 1 is a schematic perspective view of a metallization cabin of a part for a motor vehicle;

- Figure 2 is a schematic sectional view of a metallization booth comprising an absorption floor and a collecting plate mounted in the cab.

FIG. 1 shows a metallization booth 10 comprising a floor 12, side walls 14 and an upper wall 16. In this example, the cabin 10 comprises three sprayers 18, 20, 22, fixedly mounted in the cabin 10.

The cabin also comprises a manipulator robot 24 arranged, in this example, in the cabin 10. This robot 24 carries a support 26, or gripper, on which are fixed three parts 28 for a motor vehicle, to be metallized. The parts 28 are for example an air intake grille, a rod, an optical outline, a hubcap, a rocker, a protective strip.

In Figure 2, there is shown a sectional view of the cabin 10 to show in more detail the floor 12 of the cabin 10. For reasons of clarity, the robot 24 has not been shown. The elements common to the two figures are identified by the same numerical references.

Thus, the floor 12 comprises an organic product absorption floor 30 and a collection plate 32 mounted movably about an axis of rotation 34. This collection plate 32 can take, in the cabin 10, an inactive position in which it extends in a substantially vertical plane, and a collection position in which it is configured to recover a solution and guide it to a discharge path 36, the plate then extending for example in a substantially horizontal plane as shown in FIG. 2, being slightly inclined so as to guide the liquids towards the track 36.

In the collection position, the plate 32 is above the floor absorption 30; in the inactive position, the plate 32 is positioned vertically so that the products sprayed on the part 28 can be absorbed by the absorption floor 30.

We will now describe the operation of the cabin 10.

The robot 24 takes the support 26 on a display. This display can be positioned in the cabin 10, or out of the cabin 10 facing an opening of the cabin 10.

The robot 24 will present a first piece 28 in front of the first sprayer 18. In this example, the first sprayer 18 sprays a first solution, here composing a first type of solution as presented above, comprising an organic varnish having a viscosity of about 0.15 Pa.s. During the varnish spraying step, the plate 32 is in the inactive position and the absorption floor 30 is not covered by the plate 32. Thus, the spray varnish and which is not deposited on the first piece 28 is absorbed by the absorber floor 30.

Once the varnish layer has been deposited on the part 28, the layer is heat-treated for crosslinking or drying.

Then, the robot 24 will present the first piece 28 in front of the second sprayer 20. The second sprayer 20 projects a second solution, here comprising activating product, for example an aqueous solution having a viscosity close to the viscosity of water. In this example, the second solution is part of a second type of solution. During this second projection step, the plate 32 is in the collection position, so that the activating product which is not deposited and which has run on the first part 28 is directed towards the evacuation route 36.

It will therefore be understood that the recovery means of the first type of solution, comprising the floor 30, are distinct from the recovery means of the second type of solution, comprising the collection plate 32. It is therefore possible to treat the residual solutions separately, for example a separate treatment as waste and / or solution to be recycled.

It is conceivable, after recovery of the second type of solution, to use it again and to project it on a second part 28.

The first piece 28 is then presented in front of the third sprayer 22 which projects a third solution, here comprising the metal salts. In this example, the metal salts are also in the form of an aqueous solution and are considered as part of the second type of solution, so that when they are projected, the plate 32 is also in the collection position. The metal salts may be directed by the plate 32 towards the same escape route 36. It may be envisaged that the cabin 10 comprise means, such as valves, for separating the recovered solutions on the plate 32. In this case, the cabin comprises three distinct ways of recovering the first, second and third solutions.

It is understood that the number of sprayers mounted in the cabin 10 may vary depending on the process steps performed in the cabin. Thus, it is conceivable to have an additional sprayer that rinses the first part 28 between the spraying step of the activating product and the step of spraying the metal salts.

The booth 10 may also comprise an additional sprayer for depositing on the metallized part 28 a basecoat before metallization and / or a protective varnish of the metallization layer.

As an alternative to this method, it is also possible to treat several parts 28 simultaneously. Thus, one could project the activation product on a first part 28 and simultaneously projecting the metallization salts on a second part 28 which would have already been treated by spraying activation product or rinsing liquid.

The solution recovered on the collection plate 32 would then be a mixture of activation product and metal salts, making up the second type of solution.

Advantageously, the recovery floor 30 is provided to recover a solution or a mixture of organic solutions, such as varnish, and the collection plate is provided to recover a solution or a mixture of aqueous solutions, such as washing, or metal salts or the activating product when these solutions are aqueous.

It is understood that the invention is not limited to the embodiments described in the figures and that the features developed in the preamble description can be combined with each other. In particular, the recovery means have mainly been described as horizontally disposed means, however it is possible to envisage a recovery of liquids on a vertical wall of the cabin, especially in the case of horizontal spraying products. In particular, it is possible to envisage an absorption floor disposed on a vertical wall, and for other products that are not very viscous to flow into a gutter leading to the bottom of the cabin.

Claims

1. Method for metallizing a surface of a motor vehicle part (28), the metallization being non-electrolytic, the method being implemented in a booth (10) comprising at least one product sprayer (18, 20, 22) an activator and a sprayer (18, 20, 22) of metal salts, each sprayer (18, 20, 22) being fixedly mounted in the cabin (10), the workpiece (28) being manipulated by a manipulator robot (24), the process comprising the following steps:

the robot (24) first positions the workpiece facing the activating product sprayer (18, 20, 22), moves it relative to the sprayer so that the entire surface is coated with activating product, and

the robot (24) then positions the coin opposite the sprayer (18, 20, 22) of metal salts and moves it relative to the sprayer so that the entire surface is covered with metal salts.

2. Method according to the preceding claim, wherein is projected into the cabin (10) during the process, at least a first type and a second type of solutions on the part, each type of solution comprising at least one solution selected from the group consisting of a varnish, a washing liquid, the metal salts and the activating product, the process comprising a step of recovering the first type of solution after projection in the cabin (10) and a step of recovering the second type of solution after projection in the cabin (10), the cabin (10) comprising separate means for recovering each type of solution.

3. Method according to the preceding claim, wherein the first type of solution comprises an organic solution and the recovery means of this first type of solution comprise an organic product absorption floor (30).

4. The method of claim 2 or 3, wherein the means for recovering the second type of solution comprises a collection plate (32) mounted movably in the cabin (10) between an inactive position and a collection position, in which is configured to retrieve the second type of solution and guide it to an escape route (36).

5. Method according to claims 3 and 4, wherein, when the collection plate (32) is in the collection position of the second type of solution, it is inserted in front of the organic product absorption floor (30), so that the absorption floor (30) is not in contact with the second type of solution.

The process according to any one of claims 2 to 5, wherein the second type of solution comprises the metal salts and / or the activating product and / or a washing liquid.

7. The method of any one of claims 2 to 6, wherein the first type of solution comprises a varnish and / or a washing liquid.

8. A method according to any one of claims 2 to 7, wherein is projected in the cabin (10) a third type of solution on the part, the method comprising a step of recovering this third type of solution after projection into the cabin (10), the recovery means of this third type of solution being distinct from the other recovery means.

9. Cabin (10) for the metallization of a surface of a part (28) for a motor vehicle according to a method according to any one of claims 1 to 8, characterized in that it comprises:

a manipulator robot,

an activating product sprayer,

a spray of metal salts, each sprayer being fixedly mounted in the cabin,

an organic product absorption floor (30) configured to recover a first type of solution, and

a collection plate (32) movably mounted in the cabin (10) between an inactive position and a collection position, in which it is configured to retrieve a second type of solution and guide it to an escape route (36); ).

10. Cabin (10) according to the preceding claim, wherein the collection plate (30), when in the collecting position of the second type of solution, is above the organic product absorption floor (30). ), so that the absorption floor (30) is not in contact with the second type of solution.