GB2332688A

GB2332688A - A process for the manufacture of buffed ceramic pavements and coatings

Info

Publication number: GB2332688A
Application number: GB9828235A
Authority: GB
Inventors: Montolio Oscar Carnicer
Original assignee: EMIGRES SL
Current assignee: EMIGRES SL
Priority date: 1997-12-22
Filing date: 1998-12-22
Publication date: 1999-06-30
Also published as: PT102171B; PT102171A; ES2146154B1; GR980100207A; IT1315463B1; DE19860664A1; CN1220982A; FR2772747A3; FR2772747A1; JP2000203925A; GB9828235D0; BR9805593A; ES2146154A1; IL127695A0; ITTO980265A1

Abstract

Process for the manufacture of buffed ceramic pavements and coatings which consist of a section of covering material suitable for buffing, supported by a section of basic material such as a combination of natural and mineral clays. These sections are dry pressed, dried and decorated before firing and buffing by an abrasive method.

Description

2332688 EMIGRES,S.L. Ref: 97-02661 PROCESS FOR THE MANUFACTURE OF BUFFED

CERAMIC PAVEMENTS AND COATINGS -g-

DESCRIPTION

OBJECT OF THE INVENTION The present invention patent application has as an object a process for the manufacture of buffed ceramic pavements and coatings having remarkable advantages and innovations with respect to the present prior art processes used with the same or like purpose.

More particularly, in the presente invention, a process for the manufacture of a buffed ceramic pavement or coating has been designed, remarkably outshining all the other processes being presently used for achieving this kind of products because it has much better technical and effective features.

BACKGROUND OF THE INVENTION

Presently and referring to the state of the art, it should be mentioned that an earthenware manufacturing process usually named as a quick single-firing is already known, in said process dried and pressed parts are glazed and decorated while unfired, prior to the firing, this fir ing being performed at the so-called rollerfitted ovens, wherein the material to be fired runs over said rollers at the same time while being fired, so the firing cycles are very short, in this kind of ovens, a consistent earthenware pavement is however obtained by liquid-glazing in a layer arranged on a support made up by pressing. The surface thickness suitable for buffing is the least to be usually achieved as a liquid.

A porcelanic pavement manufacturing process requiring a chemical conversion and diverse physical ones, 1 in a way such as a porcelanic pavement overall suitable for buffing can be obtained is also known.

DESCRIPTION OF THE INVENTION

The process for the manufacture of buffed ceramic pavements and coatings, object of the present invention, consists of the manufacturing of a solid part having two clearly differentiated sections, one of the them there makes up the support of the other section being suitable for buffing, both parts dryly obtained by pressing in a double load hydraulic press.

Said process basically comprises a plurality of steps consisting in an accommodation of the raw materials, by pressing, drying, decorating, firing and buffing.

Acgommodation of the raw M5-;ktprials The part section pertaining to the support consists of a combination of natural clays, at the manufacturer's option, while white body or red earthenware can however be obtained.

These clays are characterized for their low carbonate, soluble salts and organic material content and generally are prepared by a wet process, the composition being ground with Alsing type drum mills, whereby a controlled granulometry and a composition slip is obtained therein.

The slip obtained in the former process is converted into a granular powder suitable to be pressed by using a sprayer which leaves the product in optimum wetting and granulometric conditions for a good pressing.

Regarding the part section to be buffed, it comprises a selection and a combination of natural raw materials, such as clays, kaolins, feldespars, etc.

These raw materials are stored at a granary while a metering system is charged with the implementation of the 5 mixture in the recommended percentage for every one.

The milling of the raw materials is usually performed with Alsing type cylindrical mills. In this step, the alumina balls filling the mill operate as a milling element and are causing a particle size reduction, until the desired granulometric distribution is obtained. Additives and water addition improve the operation performance by facilitating subsequent processing of the high-density and low-viscosity slip-called product obtained. This step is known as a wet-process milling.

The slip is stained with the addition of ceramic pigments in suitable quantities, thereafter while being homogenized, is discharged by pumps to the nozzles which comminute it into the inside of a chamber (sprayer), and drops are being formed which by contacting the countercurrent- inserted hot air undergo a flash-drying, which is turning them into more or less spherical granules (atomized).

The atomized material is stored at resting silos which facilitate homogenization of its moisture.

For the manufacturing of the granite type models, a mixing of differently coloured atomized items is performed at the desired ratios.

Pressina The part forming method used is the drying pressing one, using hydraulic presses with double slide allowing to make a distinction between the two sections comprising the part in a way such that the atomized powder undergoes a mechanical compression at the press's metal mould, when the higher pressures are applied.

The facebrick reliefs of the nonsmooth models are achieved in this step.

Dr,Mi na Subsequently the parts are inserted into dryers 10 wherein most of the moisture retained therein is lost.

Decoratina The application of soluble salts penetrating into the part is required by the decorated models and also the surface decorating techniques for achieving the desired 15 aesthetic effects.

Firin The material to be fired is directly conveyed on a roller plane inside the oven and is running on areas undergoing different temperatures which conform with the quick 20 firing cycle.

The energetic provision is made by the introduction into the burners of the gas/air combustion products, the burners being arranged along the oven above and below of the roller plane.

The raw materials used and their accommodation to the firing conditions and to a high temperature during an extended time are causing a viscositycontrolled vitreous-step highly formation.

1 The atomic portion caused by the detachment of the vitreous step covers the existing pores between the particles, drastically reducing porosity and consequently originating a large part shrinking.

Buffin The buffed material shall pass through a step consisting in the brightening of the part surface with abrasive mechanical methods, such as the diamond-fitted rolls performing the first part etching, which originate a rough abrasion while the grinding wheels arranged in rotating and independent heads abrate the parts when they are moved under the rotating heads while a suitable grinding wheel sequence of diverse grain thickness gives a remarkable gloss to the buffing.

To complete the following description, as explained herein and with the purpose to help in the better understanding of its features, the present description is accompanied by a set of drawings which figures illustratively and non-exhaustively show the most substantial details of. an embodiment of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 shows a cross-section partial view of a buffed pavement part obtained with the process of the present invention.

Figure 2 shows a block diagram of the present invention's process. Figure 3 shows diagrammatically the processing step. Figure 4 shows a detail of the previous figure 3.

DESCRIPTION OF THR PREFERRED AMBODINENT

In view of the discussed figures and according to the adopted numbering, a preferred embodiment, although non exhaustive of the present invention can there be seen, this embodiment consisting of a process for manufacturing buffed ceramic pavements and coatings, which parts consist of a suitable section 1 for buffing, arranged on another section 2 making up the support of the former one.

Said process follows a plurality of steps which basically consist of an accommodation of the raw materials 3 which in the supporting section 2 consist of a combination of natural and mineral clays, at the manufacturer's option, while in the section 1 to be buffed, consist of clays, kaolins, feldespars and other natural raw materials; a dry pressing 4 by means of double load press allowing to make a distinction between the two sections 1,2 of the part, by facilitating its obtention, as diagrammatically illustrated in figure 3 and detailed in fig-ure 4, wherein the mould 9 having the part and the plate 10 executing a pressure thereon is shown; a drying 5 of the parts at the driers facilitating the detachment of the moisture retained thereon; a decor 6 by means of soluble salts penetrating into the part surfaces; a firing 7 in a roller-fitted oven; and a buffing 8 by abrasive methods.

- S_

Claims

C L A I M S

1. - PROCESS FOR THE MANUFACTURE OF BUFFED CERAMIC PAVEMENTS AND COATINGS characterized in that the buffed ceramic pavement or coating is made up with parts consisting of a section I suitable for buffing, arranged on another section 2 making up the supporting means of the former one, having been envisaged in this process, a plurality of steps which basically consist of an accommodation of the raw materials 3 which at the supporting section 2, consist in a variable combination of natural and mineral clays, while at the section I to be buffed, consist of clays, kaolins, feldespars and other raw materials suitable to be buffed after firing; a dry pressing 4 by means of a double load press suitable to make a distinction between two sections 1,2 of the part, by facilitating its obtention; a drying 5 of the parts at the driers suitable to facilitate the detachment of the moisture retained therein; a decor 6 by means of soluble salts penetrating into the part surfaces; a firing 7 in a roller fitted oven; a buffing 8 by means of abrasive methods.

2. A process for the manufacture of buffed ceramic pavements and coatings, substantially as described herein with reference to the accompanying drawings.