GB2098126A - Production of marble granulate blocks - Google Patents

Abstract

A mixture of marble grit, marble powder and the minimum essential quantity of polymerizable synthetic resin is loaded into a mould box which is transported into a vacuum chamber in which a ram equipped with vibrators applies combined pressure and vibration under vacuum to the mixture, to compact the mixture, for producing blocks which can be cut into slabs or smaller blocks, as required.

Description

SPECIFICATION Production of marble granulate blocks The present invention relates to a method for the production of blocks of marble granulate and marble powder having the strictly necessary quantity of synthetic resin needed to bind the inert materials, and intended to be cut into slabs or smaller blocks for use in building.

In Italian Patent No. 82.5401A/75 filed by the same applicant on 5.9.1975 and a first Addition No.

85.5641A/77 filed on 22.4.1977, (U.K. Patent No.

1592959) there is disclosed a method using combined vibration and pressure in an airless environment to form slabs of grit bound with resin.

The same method is now applied to blocks of marble granulate designed to be cut into slabs or smaller blocks for building purposes.

According to the present invention a method, for the production of blocks of marble granulate, comprises the steps of: (i) loading a mould box, by means of a dispenser, with a mixture of marble grit, marble powder, and a quantity of polymerizable synthetic resin (ii) applying force to the material in the mould box to compact it therein, under conditions of vibration and of reduced pressure, (iii) allowing or causing the synthetic resin to polymerize.

Preferably the quantity of the synthetic resin, relative to the quantity of the remainder of the mixture, is such that the resin is the minimum amount necessary to coat the surface of the granules and keep them closely bound together.

The resin may be a cold-polymerizable resin, or a heat-polymerizable resin, and in the latter case heat is applied to the compacted contents of the mould box to polymerize the resin content thereof. The mould box, with the compacted mixture therein, may be transported to an oven where heat is applied for polymerization.

An apparatus suitable for use in carrying out the method of the present invention is hereinafter particularly described with reference to the accompanying drawing, wherein the single figure is a side elevation of the apparatus.

In the drawing there is shown a mould box 1 into which is loaded, by means of a dispenser 2, a quantity of a mixture 3 comprising marble grit, marble powder and the minimum quantity of synthetic resin strictly necessary to coat the individual granules of marble but without filling the gaps between the granules.

The mould box 1 mounted on a transport platform 4 moves forward in the direction of the arrow on rollers 5 until it is within the machine proper in which there is a vacuum chamber 6 equipped with a suction tube 7 through which air can be sucked out by means of pumps (not illustrated). The chamber 6 has entry and exit sealable closures which can be pivoted by fluid jacks. Inside the vacuum chamber 6 there is a ram 8 which is moved downwards by pneumatic jacks 9, in the direction of the arrow, to compress the granular mass contained in the mould box 1.

A set of mechanical vibrators 10, arranged on the ram 8, provides vibratory action during exertion of pressure on the granular mass inside the vacuum chamber 6.

During this operation, the platform 4 supported on rollers 11 moves downwards, under the pneumatic control of jacks 12, so as to rest the bottom of mould box 4 on fixed supports 13 while the ram 8 applies pressure and vibration.

The volume of the granular mass is considerably reduced as can be seen in mould box 1 after it has left the vacuum chamber 6 and has moved forward on the rollers Sin the direction of the arrow.

If the synthetic resins used in the mixture are the type which can be cold-polymerized, the blocks of marble so obtained can simply be stored without further processing.

Polymerization of the resins hardens the block, which can subsequently be used, after cutting, in the form of slabs or smaller blocks, as required.

If the resins used are hot-polymerizable, it is necessary to take the blocks to suitable ovens, not illustrated in the drawing, to obtain a similar result.

The invention provides blocks obtained by the method here described and which, because they can be cut from time to time to the most convenient dimensions, lend themselves better to practical uses such as making baseboardsforwall claddings, floor tiles of various sizes and designs or the like, than the slabs of uniform thickness obtained by the process described in the previous patents cited above.

1. A method, for the production of blocks of marble granulate, comprising the steps of: (i) loading a mould box, by means of a dispenser, with a mixture of marble grit, marble powder, and a quantity of polymerizable synthetic resin (ii) applying force to the material in the mould box to compact it therein, under conditions of vibration and of reduced pressure, (iii) allowing or causing the synthetic resin to polymerize.

2. The method, as claimed in claim 1, wherein the quantity of the synthetic resin, relative to the quantity of the remainder of the mixture, is such that the resin is the minimum amount necessary to coat the surface of the granules and keep them closely bound together.

3. The method, as claimed in either of claims 1 and 2, wherein the resin is a cold-polymerizable resin.

4. The method, as claimed in either of claims 1 and 2, wherein the resin is a heat-polymerizable resin, and wherein heat is applied to the compacted contents of the mould box to polymerize the resin content thereof.

5. The method claimed in claim 4 comprising the further step of transporting the mould box, with the compacted mixture therein, to an oven and there applying said heat for polymerization.

6. The method, for the production of blocks of marble granulate, substantially as described herein

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (7)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Production of marble granulate blocks The present invention relates to a method for the production of blocks of marble granulate and marble powder having the strictly necessary quantity of synthetic resin needed to bind the inert materials, and intended to be cut into slabs or smaller blocks for use in building. In Italian Patent No. 82.5401A/75 filed by the same applicant on 5.9.1975 and a first Addition No. 85.5641A/77 filed on 22.4.1977, (U.K. Patent No. 1592959) there is disclosed a method using combined vibration and pressure in an airless environment to form slabs of grit bound with resin. The same method is now applied to blocks of marble granulate designed to be cut into slabs or smaller blocks for building purposes. According to the present invention a method, for the production of blocks of marble granulate, comprises the steps of: (i) loading a mould box, by means of a dispenser, with a mixture of marble grit, marble powder, and a quantity of polymerizable synthetic resin (ii) applying force to the material in the mould box to compact it therein, under conditions of vibration and of reduced pressure, (iii) allowing or causing the synthetic resin to polymerize. Preferably the quantity of the synthetic resin, relative to the quantity of the remainder of the mixture, is such that the resin is the minimum amount necessary to coat the surface of the granules and keep them closely bound together. The resin may be a cold-polymerizable resin, or a heat-polymerizable resin, and in the latter case heat is applied to the compacted contents of the mould box to polymerize the resin content thereof. The mould box, with the compacted mixture therein, may be transported to an oven where heat is applied for polymerization. An apparatus suitable for use in carrying out the method of the present invention is hereinafter particularly described with reference to the accompanying drawing, wherein the single figure is a side elevation of the apparatus. In the drawing there is shown a mould box 1 into which is loaded, by means of a dispenser 2, a quantity of a mixture 3 comprising marble grit, marble powder and the minimum quantity of synthetic resin strictly necessary to coat the individual granules of marble but without filling the gaps between the granules. The mould box 1 mounted on a transport platform 4 moves forward in the direction of the arrow on rollers 5 until it is within the machine proper in which there is a vacuum chamber 6 equipped with a suction tube 7 through which air can be sucked out by means of pumps (not illustrated). The chamber 6 has entry and exit sealable closures which can be pivoted by fluid jacks. Inside the vacuum chamber 6 there is a ram 8 which is moved downwards by pneumatic jacks 9, in the direction of the arrow, to compress the granular mass contained in the mould box 1. A set of mechanical vibrators 10, arranged on the ram 8, provides vibratory action during exertion of pressure on the granular mass inside the vacuum chamber 6. During this operation, the platform 4 supported on rollers 11 moves downwards, under the pneumatic control of jacks 12, so as to rest the bottom of mould box 4 on fixed supports 13 while the ram 8 applies pressure and vibration. The volume of the granular mass is considerably reduced as can be seen in mould box 1 after it has left the vacuum chamber 6 and has moved forward on the rollers Sin the direction of the arrow. If the synthetic resins used in the mixture are the type which can be cold-polymerized, the blocks of marble so obtained can simply be stored without further processing. Polymerization of the resins hardens the block, which can subsequently be used, after cutting, in the form of slabs or smaller blocks, as required. If the resins used are hot-polymerizable, it is necessary to take the blocks to suitable ovens, not illustrated in the drawing, to obtain a similar result. The invention provides blocks obtained by the method here described and which, because they can be cut from time to time to the most convenient dimensions, lend themselves better to practical uses such as making baseboardsforwall claddings, floor tiles of various sizes and designs or the like, than the slabs of uniform thickness obtained by the process described in the previous patents cited above. CLAIMS

1. A method, for the production of blocks of marble granulate, comprising the steps of: (i) loading a mould box, by means of a dispenser, with a mixture of marble grit, marble powder, and a quantity of polymerizable synthetic resin (ii) applying force to the material in the mould box to compact it therein, under conditions of vibration and of reduced pressure, (iii) allowing or causing the synthetic resin to polymerize.

2. The method, as claimed in claim 1, wherein the quantity of the synthetic resin, relative to the quantity of the remainder of the mixture, is such that the resin is the minimum amount necessary to coat the surface of the granules and keep them closely bound together.

3. The method, as claimed in either of claims 1 and 2, wherein the resin is a cold-polymerizable resin.

4. The method, as claimed in either of claims 1 and 2, wherein the resin is a heat-polymerizable resin, and wherein heat is applied to the compacted contents of the mould box to polymerize the resin content thereof.

5. The method claimed in claim 4 comprising the further step of transporting the mould box, with the compacted mixture therein, to an oven and there applying said heat for polymerization.

6. The method, for the production of blocks of marble granulate, substantially as described herein with reference to the accompanying drawing.

7. Blocks of marble granulate produced by the method claimed in any one of claims 1 to 6.