JPH0158762B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an inlay or cloisonné made on a rigid object, more particularly on a metal object.
It relates to a method of fixing a piece of leaf-like wood (feuille de bois) inside a. In this specification, a piece of wood refers particularly to a thin piece of wood in the shape of a leaf of a plant.

One of the major problems encountered when attempting to glue pieces of wood onto a substrate is based on the hygroscopic nature of the wood pieces, which can cause more or less dimensional changes in the wood pieces depending on the humidity of the atmosphere. , and this dimensional change can also result in rupture of the adhesive layer that adheres the wood piece to its support.

To avoid this serious disadvantage, adhesives with a high elongation coefficient are generally used for gluing wood pieces, such as, for example, neoprene-type adhesives.

However, the components of adhesives of this type exhibit a tendency to migrate to different degrees into the pores of the wood chips, resulting in partial degradation of the adhesive, as in the case of chromatographic analysis.

Furthermore, for reinforcement or purely ornamental reasons, pieces of wood may be placed in "inlays", ie holes made in the support surface. Under these conditions, when the humidity that the wood receives increases after it is inserted into the inlay,
The surface area of the wood piece also increases, leading to it protruding or distorting as it is constrained by the edges of the inlay. Such deformation is not only difficult to see, but also generally results in partial delamination of the wood piece.

Furthermore, it is known that it is extremely difficult to regularly control the thickness of even small pieces of wood. Therefore, in order to make the surface of the piece of wood exactly on the same level as the edge surface of the inlay, it is necessary to adjust the depth of the inlay to the thickness of the piece of wood. of course,
It is possible to thin the piece of wood after it has been fitted into the inlay, but this process is more difficult than the previous process. Therefore, these methods are suitable for use by craftsmen, but are difficult to use for mass production.

Of course, means for preventing dimensional changes in wood chips due to humidity fluctuations have been known. Most of these methods consist in replacing the moisture present in the fibers of the wood chips with substances that do not evaporate into the air.

That is, "Bakelite" wood chips are made by impregnating the interior of the fibers and the interstices of the fibers with an alcoholic solution of phenol/formaldehyde resin. Wood chips treated in this way are highly insensitive to changes in humidity and have improved mechanical properties.

For the same purpose, more recently methods have been proposed for coating wood chips with preferably curable synthetic resins. This is because it is easy to implement.

Although all these impregnation methods irrefutably improve the dimensional stability of the wood chips against changes in humidity, they have the disadvantage of taking away the natural appearance of the wood chips and giving them the appearance of synthetic wood chips.

The present invention seeks to solve these problems.

It is therefore an object of the present invention to provide a method for fixing a piece of foliage inside an inlay made in a rigid support, in particular a metal support, in which the piece of wood is partially impregnated from one side with a curable resin. a step of connecting a piece of wood from its side impregnated with resin to the inside of the inlay hole; and a step of making the edge of the inlay hole and the surface of the piece of wood identical by thinning the piece of wood and simultaneously processing the edge of the inlay hole. The method includes a step of surface treating the metal support, followed by a step of electrolytically plating the metal support.

This method therefore makes it possible to stabilize the wood chips against changes in humidity by impregnating them as is known, while at the same time preserving the natural appearance of the wood chips on their surface.
In fact, in the surface treatment step that follows the adhesion step,
Since only a portion of the thickness of the wood piece is affected, care is taken not to reach the resin-impregnated area from the other side of the wood piece during this process, leaving the natural wood exposed.

The method of the invention also avoids delicate adjustment operations to bring the surface of the wood piece to the same level as the edge of the inlay. This is because, during this surface treatment operation, the wood piece and the edges of the inlay are processed simultaneously.

Furthermore, since the wood chips are impregnated with a curable resin and then bonded from the impregnated side, the pores of the wood chips are blocked by the resin, and the adhesive component does not migrate differentially into these pores to change the composition of the adhesive.

Finally, the pre-cutting of the wood pieces into the shape and size of the relatively small inlays is facilitated by the impregnation with the hardened resin. This cured resin prevents the wood from cracking during the cutting operation and during storage or subsequent handling of the cut wood.

This also makes it possible to store pieces of wood that have been previously cut to the desired dimensions, greatly reducing wood waste and facilitating the continuous implementation of the method of the invention.

The applicant has used the method of the invention for pasting pieces of wood onto lighters as decorative elements.

For this, I carved a 0.5mm deep inlay hole on each side of the lighter to receive the wood piece. A piece of wood, in this case consisting of an elm knob, was then applied and impregnated with a 50% solution of epoxy resin in methyl ethyl ketone. Next, it was dried in a drying oven at 90°C for 15 minutes.
Then with various mold tools, i.e. tools with the shape of the inlay hole and the exact dimensions of each edge,
A piece of dried wood with a thickness of 1 mm was cut out.

By controlling the impregnation of the wood piece with a curable resin before cutting, it is possible to prevent the wood piece from cracking or splitting during this cutting operation.

Furthermore, the pieces of wood cut in this way are insensitive to changes in humidity and can therefore be easily stored until they are glued together.

A piece of wood was then glued into the corresponding inlay hole with its resin-impregnated side. The applicant has determined that by using the resin used for impregnation as an adhesive, the adhesion between the adhesive and the impregnated wood material is significantly improved. However, in order to obtain reliable adhesion, the product must of course also have effective adhesion to the support. The impregnating product must therefore also be selected with regard to its adhesion to the support.
Therefore, in this embodiment of the invention, since the support is brass, the applicant has excellent adhesion to this metal, achieving at the same time the partial impregnation of the wood and its adhesion. We selected an epoxide resin that is well known as a resin.

Polyurethane resins dissolved in toluene in a ratio of 2 parts by weight of polyurethane to 1 part by weight of toluene, for example, as resins suitable for impregnating the wood chips and optionally for gluing them into the inlay holes; Alternatively, a polyester resin diluted in styrene monomer in a ratio of 3 parts by weight of polyester to 1 part by weight of styrene monomer can also be used.

The examples of these resins used in carrying out the method according to the invention are, of course, non-controlling.

Next, each side of the lighter covered with a piece of wood is worked with an emery grindstone, and the edge of the inlay hole and the side of the piece of wood are simultaneously polished so that they are exactly the same surface.

Finally, the edges of the inlay and the other metal surfaces of the lighter are gilded in a known manner by immersion in an electrolytic bath.

It should be noted that such gilding was only possible by partial impregnation of the wood. This is because this treatment limited the contact of the electrolyte bath to the exposed parts of the raw wood fibers. That is, this is because the electrolyte bath is limited to woody parts that can be easily washed off.

Claims (1)

[Claims] 1. A method for fixing a leaf-like piece of wood inside an inlay made in a metal support, comprising: partially impregnating the piece of wood from one side with a curable resin; gluing the wood piece into the inlay hole from the side previously impregnated with resin, and making the wood piece thinner and simultaneously working the edges of the inlay hole so that these edges and the wood piece surface are on the same level. 1. A method comprising, at least sequentially, a surface treatment step of: and, subsequent to the surface treatment step, a step of electrolytically plating the metal support. 2. A method according to claim 1, characterized in that the composition used for gluing the wood chips comprises the curable resin used in the impregnation step. 3. A method according to claim 1 or 2, characterized in that said curable resin is selected from the group comprising epoxides, polyurethanes and polyesters. 4. A method according to any one of claims 1 to 3, comprising the step of, following the step of impregnating the wood piece, cutting the wood piece to the desired shape and dimensions.