FR2471957A1 - Cloisonne enamelling process - using no partitions and only one firing step - Google Patents

Abstract

Method of enamelling in a furnace which produces a cloissone enamelled effect by fusion without using partitioning materials is described in which pieces of vitrifiable material are employed in conjunction with powdered enamel. The various components agglomerate during the fusion and after cooling present a monolithic structure. The vitrifiable material pieces can be applied onto a metallic support and may be transparent, translucent, opaque, coloured or clear. No partitions are used. The cloissone effect can be achieved in a single firing process thus reducing considerably the energy expenditure and processing time.

Description

 The present enameling process makes it possible to make clear separations between various parts or color of enamels without using material partitions.

In the usual enamelling processes, the clear separation between the various colors or parts of enamel is obtained by the use of material separations, for example in metal, called partitions, which have given this way of enameling the name of the cloisonne. This work is meticulous and long, it may require several passages in the oven of the piece to be glazed.

 Other methods consist in assembling various transparent or translucent elements of small thickness and small dimensions by means of an adhesive on a support, or by means of a binder; the intervals between the elements that can be filled with the binder, this operation being carried out most often cold.

Other methods also consist in depositing liquid enamels on areas delimited on the support forming the desired design, the partitions delimiting the areas may remain or disappear after firing, the desired effect being the clear delimitation and the non-interpenetration of the areas enamels of different colors.

 The present process makes it possible to avoid the use of any partition as well as successive cooking. It does not in fact require any partitioning equipment and only requires a single passage in the oven, which considerably reduces working time and energy consumption; in addition it allows a wide variety of decorations and colors.

 This process uses vitrifiable materials in flattened pieces of small thickness and defined shapes, geometric or not, of different sizes, adapted to the decor to be produced: square, circle, rectangle, triangle, hexagon, or other ... Pieces of material vitrifiable can also be of any shape in the case where the desired decoration must be any.

 These pieces of vitrifiable material are placed according to the decoration to be produced, on a layer of powder enamel previously spread on the support or on the metal to be enameled. The color of this layer of powder enamel can be chosen according to the shade, the transparency or the opacity of the partitions which it is desired to obtain.

The pieces of vitrifiable material can be transparent translucent or opaque, single-colored or multi-colored, or themselves include decorations, in order to allow a wide variety
Cloisonne enameling process without the use of partitions.

of designs and colors.

When baking, the partitions are formed in two stages:
firstly the layer of powdered enamel melts, the weight of the pieces of vitrifiable material then drives out the molten enamel towards the periphery of these pieces; the molten enamel collects in the spaces between the pieces.

 -in a second step, the pieces of vitrifiable matter in turn melt, spread out and tend to meet by tightening between them the molten enamel which then reduces to a partition separating the different molten masses.

 The optimum cooking time is obtained when all of the powder enamel and the pieces of vitrifiable material are completely in the molten state and the surface of the whole becomes smooth. Enamelling could be stopped earlier, but in this case, the location of the pieces of vitrifiable material would be marked by a rounded prominence.

After melting and cooling, all of the enamel is in the form of a monolithic block.

The accompanying drawings illustrate, by way of example, the production of partitions during baking in the oven:
FIG. 1 shows in profile the installation of the enamels before cooking. The metal plate or support (1) is covered by the spread powder enamel (2) on which the pieces of vitrifiable materials (3) are arranged.

 FIG. 2 shows in plan an example of arrangement of the pieces of vitrifiable materials of various colors on a support covered with powdered enamel spread before baking.

 FIG. 3 shows the first stage of cooking when the powdered enamel melts and where the weight of the pieces of vitrifiable matter drives the molten enamel into the spaces between the pieces before the latter are fused.

 FIG. 4 shows the same plate when it comes out of the oven after a maximum cooking time, the surface of the whole is smooth, the powdered enamel on melting has concentrated at the intersections of the pieces of vitrifiable materials which on melting spread out and tried to join.

FIG. 5 shows in plan the artistic effect obtained by using at the start pieces of flattenable vitrifiable materials, of defined geometry, the concentration of the enamel powder after fu
Cloisonne enameling process without the use of partitions.

sion at the intersections of the pieces, gives a very visible partition which perfectly delimits the colors. Depending on the number, the thickness of the pieces of vitrifiable material and the quantity of powder enamel used, the partitions may be more or less wide or more or less marked.

 FIG. 6 shows in profile a plate, such as that prepared in FIG. 1, on leaving the oven after a cooking time less than the optimum time; the surface has rounded prominences at the location of the pieces of vitrifiable matter that are incompletely melted. This can be used to create an additional artistic effect to the drawing.

 FIG. 7 shows in plan the effect obtained with pieces of vitrifiable materials of any shape.

 The present method allows the economical production of a very wide variety of decorations on a flat or moderately curved or curved surface.

 The present process also allows the production of self-supporting enamels (FIG. 8) when the support which has been used for cooking is abandoned after cooling. In this case, a monolithic enamel plate is obtained which can be used for decoration by transparency or set on a frame.

Claims (8)

Cloisonne enameling process without the use of partitions. REVNDTCATI ONS 1-Oven enamelling process allowing to obtain by fusion and without the use of material partitions an effect of partitioned enamel, characterized by the fact that it uses pieces of vitrifiable materials in conjunction with powder enamels.  2-A method according to claim 1, characterized in that the different components agglomerate during the melting and occur after cooling in monolithic structure. 3-A method according to claim 1, characterized in that the pieces of vitrifiable materials used are flat shapes of variable thicknesses and defined or arbitrary shapes. 4-A method according to claim 1 and claim 3, characterized in that the batch materials or powder enamels used can be transparent, translucent, or opaque, of various colors, or themselves include decor elements.  5-A method according to claim 1, characterized in that it can be applied to enameling on a metal support or for ltobtaining self-supported enamels after removal of the support. 6-A method according to claim 1, characterized in that a single cooking is sufficient to obtain the partitioning effect.  7-A method according to claim 6, characterized in that the surface obtained can be embossed in the case where the cooking is stopped before total fusion in order to create an artistic or functional effect. 8-A method according to claim 6, characterized in that the cooking is carried out by charging in an oven at constant temperature.