Technical Field

The present invention relates to production method of a low-density thermal insulation board which has a mineral-based core, and thermal insulation boards which are produced by this method.

Background of the Invention

Thermal insulation materials are one of the most commonly used construction elements being frequently used today.

Thermal insulation boards are materials which have thermal conductivity coefficients less than 0,065 W/m.K and thereby, they are materials used for reducing heat losses and gains in buildings. These boards used for the purpose of thermal insulation can be classified as open and closed porous. Glass wool, rock wool (mineral wools), wood wool, ceramic wool, slag wool can be cited as an example for open porous or fibrous materials whereas expanded polystyrene, extruded polystyrene, elastomeric rubber, polyethylene shell obtained from petroleum-derived materials or glass foam obtained by expanding silica sand under high temperature n be cited as an example for closed porous materials. Due to the fact that insulating materials other than mineral and ceramic wools and glass foam exhibit combustible features, the use of these materials is limited by building regulations. Thermal insulation boards usually have low density. A great majority of petroleum- derived materials and glass wool have a density lower than 30 kg/m ³ in general and they are produced in a thermal conductivity value between 0,03-0,04 W/m.K. whereas ceramic and rock wool are produced in a thermal conductivity value between 40-200 kg/m ³ and rock wool, which is often used in exterior insulation of buildings, is produced in a thermal conductivity value between 100-150 kg/m ³ due to its incombustibility feature. The said ceramic and rock wool preferably have a thermal conductivity coefficient lower than 0,045 W/m.K.

All thermal insulation boards which are open porous or fibrous such as glass wool and rock wool are obtained by melting silica sand or basalt in furnaces preferably at high temperatures at first and then turning them into fiber form by cooling and laying them onto a continuous belt following these. Due to both high installation costs and high operating costs of melting furnaces operated at high temperatures, the glass and rock wools having the said incombustibility feature are more expensive than petroleum-derived thermal insulation materials.

Materials are classified according to their combustibility in regulations on the protection of buildings from fire and materials to be used in locations are determined according to building types and purpose of use. It was stipulated for the materials in non-combustible (Al) class to be used on facades and roofs of high- rise buildings, especially buildings higher than 28.5 meters, in the“Regulation on the Protection of Buildings from Fire” published in the Official Gazette dated September 9, 2009 and numbered 27344 and then the amendments published in the Official Gazette dated July 9, 2015.

Non-combustibility of insulation boards is determined by methods described in EN ISO 1716 and materials are classified according to their gross calorific potential (PCS Potentiel Calorifique Superieur) values. All kinds of mineral wool, rock wool, ceramic wool and glass foams are A1 class insulation materials known. All of these materials are obtained by very high energy consumption and they are high cost materials. In addition, all mineral wools, rock wools and ceramic wools are affected by moisture and water. All rock-based wools based on stone or ceramic, particularly mineral wools, significantly lose their thermal insulation features after getting humid or contacting water or they are fold or piled up by not being able to maintain their integrity at the application sites.

Use of expanded perlite is widely known for insulation material production in the state of the art. Among these products, the product trademarked as“Fesco” and manufactured by Johns Manville company of the United States origin can be stated as the most successful commercial product wherein perlite is mainly used. Fesco, which is essentially a roof insulation board, has been produced since the early 1960’s. Fesco is produced using Fourdrinier technique fundamentally by mixing perlite and scrap paper fiber. The United States patent document no. US3042578, an application in the state of the art, discloses using perlite and scrap paper together. The main recipe of the Fesco product, which has been ongoing to date, is created by addition of starch into mixture of paper fiber and perlite in the United States patent document no. US4126512.

The United States patent document no. US4011183, an application in the state of the art, discloses obtaining a board having a density of 200 kg/m ³ by spraying methylene chloride and diphenylmethane diisocyanate to 75% perlite and 25% scrap paper fiber by weight. In spite of that, the board obtained in this patent document and Fesco board are by no means an A1 class non-combustible insulation material.

In the United States patent document no. US4072533, a non-cementitious low- density building material is obtained via binding of sodium silicate by using dense perlite and polyester fiber. The board disclosed in the said document both includes a very expensive recipe and it is also produced at high cost by coating technique.

The United States patent document no. US4297311 discloses a series of recipes with a density higher than kg/m ³ by breaking the grains upon crushing the expanded perlite under press while the expanded perlite is being hardened by urea formaldehyde (UF). The said products are bare products to the degree that they will be partially open to dusting or crumbling. Also, non-combustible material is not targeted in the invention disclosed in this document as well.

The United States patent document no. US4313997 discloses a perlite-based board obtained by binding polyacrylic (Styrene Butadiene (SB)) or latex. Latex is used for giving flexibility to the board.

The United States patent document no. US4451294 discloses a perlite-based non combustible board which is obtained by hardening sodium silicate and perlite, and gets support from use of borax for non-combustibility.

The United States patent document no. US5256222 discloses a production method comprising transactions of turning expanded perlite and sodium silicate into a mortar form; laying this mortar between two cardboards on a moving belt as in the methods being used in the production of plasterboard and setting on the belt; and then firing it upon cutting. The product obtained by this method comprises combustible paper and a lightweight drywall board which can substitute plasterboard is received as target product.

In the United States patent document no. US6355098, the product is hardened by perlite, sodium or potassium silicate and a production method aiming to dry the product by using microwave energy before the wet product containing intense water is dried in furnaces, is disclosed. Although it is mentioned in the descriptions about the prior art mentioned above briefly and the referred patent documents that boards having low density are obtained through organic or inorganic binders by using intensely expanded perlite, none of these descriptions mentions use of a thermal insulation board providing A1 class incombustibility.

In addition, the Turkish patent document no. TR2019/06279, which pertains to the same applicant, discloses production method of a low-density thermal insulation board which has mineral-based core and surfaces of which are coated with a gauze or net-like coating material, and thermal insulation boards which are produced by this method.

Summary of the Invention

An objective of the present invention is to realize a method for producing a lightweight and economical thermal insulation board on a belt continuously without using a moulding technique, and thermal insulation boards produced by this method such as insulated roof board.

Another objective of the present invention is to realize a method for producing a mineral-based thermal insulation board which is A1 class, non-combustible and less affected by moisture and water, and thermal insulation boards produced by this method.

Another objective of the present invention is to realize a method for producing a thermal insulation board which is A1 class, non-combustible and preferably has a thermal conductivity coefficient less than 0,065 W/m.K by using intense perlite instead of insulation boards having intense energy consumption obtained by melting rocks such as glass or stone or ceramic wool at high temperatures, and thermal insulation boards produced by this method. Another objective of the present invention is to realize a method for producing a thermal insulation board on which it is possible to walk and which is A1 class, non combustible and preferably has a thermal conductivity coefficient less than 0,065 W/m.K, and thermal insulation boards produced by this method.

Detailed Description of the Invention

“Production Method of a Thermal Insulation Board and a Thermal Insulation Board Produced by this Method” realized to fulfil the objectives of the present invention is shown in the figure attached, in which:

Figure 1 is a schematic view of the production line wherein the inventive thermal insulation board is produced.

The components illustrated in the figures are individually numbered, where the numbers refer to the following:

1. Thermal insulation board

2. Wet blend

3. Compressed wet blend

4. Wet blend slab

5. Dry blend slab

A. Production line

B. Belt conveyor

C. Blender

D. Front press belt

E. Press

F. Heat treatment station G. Cutting station

The inventive method for enabling to produce a low-density thermal insulation board (1) which has a mineral-based core comprises steps of:

feeding a mineral-based wet blend (2), which is prepared by mixing perlite and at least one type of binder in a blender (C), onto a belt conveyor (B) having a configuration suitable for carrying the wet blend (2);

obtaining a compressed wet blend (3) by compressing the wet blend (2), which is carried on the belt conveyor (B), by means of a front press belt (D); obtaining a wet blend slab (4) by compressing the compressed wet blend (3) exiting the front press belt (D) until it reaches a desired thickness and hardness upon being subjected to a pressing transaction by means of a press

(E).

The inventive method also comprises step of obtaining a dry blend slab (5) by subjecting the wet blend slab (4) exiting from the press (E) to a heat treatment in a heat treatment station (F). In a preferred embodiment of the invention, a heat treatment is carried out in the heat treatment station (F) by means of a drying oven. In an exemplary embodiment of the invention, the said drying oven can be consecutively close-rolled or a wire tape.

The inventive method also comprises step of obtaining thermal insulation boards (1) which are taken into a desired size by cutting the dry blend slab (5) exiting the heat treatment station (F) by means of suitable cutters in a cutting station (G). In a preferred embodiment of the invention, the dry blend slab (5) is cut in the cutting station (G) both from its edges and lengthwise. Thereby, it is enabled to increase the production speed. The thermal insulation board (1) exiting the heat treatment station (F) becomes ready for shipment. In a one embodiment of the invention, the inventive method also comprises step of feeding at least one strengthening material having incombustible feature from at least one coil (not shown in the figures) positioned between the blender (C) and the front press belt (D), to the wet blend (2) fed from the blender (C) onto the moving belt conveyor (B). In the final thermal insulation board (1) obtained by this embodiment, the strengthening material remains inside the wet blend (2) layer hardened. Thereby, it is enabled to increase the strength of the final thermal insulation board (1) obtained.

In a preferred embodiment of the invention, a certain degree of compressed wet blend (3) is obtained by compressing the wet blend (2) on the moving belt conveyor (B) by means of the front press belt (D) which an opening reducing in the direction of progress of the conveyor belt (B).

In a preferred embodiment of the invention, the belt used in the conveyor belt (B) is made of a belt material of PVC-based endless type.

In a preferred embodiment of the invention, the belt used in the front press belt (D) is made of a belt material of PVC-based endless type.

In one embodiment of the invention, the press (E) used for obtaining the wet blend slab (4) is a reciprocating press.

In one embodiment of the invention, the press (E) used for obtaining the wet blend slab (4) is a sheet belt press.

In one embodiment of the invention, the press (E) used for obtaining the wet blend slab (4) can be a hot press. Thereby, it is ensured to shorten the hardening time of the binder. In a preferred embodiment of the invention, the wet blend (2) fed from the blender (C) onto the moving conveyor belt (B) comprises at least organic binders in perlite and liquid and/or solid state. In a preferred embodiment of the invention, perlite is included within the wet blend (2) between 50% to 95%, preferably 60% to 80%. the organic binders are selected from the group comprising polyvinyl alcohol, polyvinyl acetate, urea formaldehyde, phenol formaldehyde, melamine formaldehyde, styrene butadiene in such a way that the PCS value of the final thermal insulation board is 2 MJ/kg maximum. Type of binder, maximum binder amount and PCS values of these binders are provided as an example in the following Table 1.

Table 1. PCS values of exemplary binders after full combustion

Organic binders of various types like vegetable-based organic binders such as latices, methyl celluloses, carboxy methyl celluloses, starches; organic binders of synthetic monomer type such as acrylonitriles, cyanoacrilites, all acrylic monomers and resorcinol; organic binders of synthetic polymer type such as epoxy resins, ethylene, vinyl acetate, polyamides, polyester-based resins, polyethylene binders, polypropylenes, polysulfides, polyurethanes, polyvinylpyrrolidone, silicone resins, modified silyl polymers and styrene acrylic copolymers -including but not limited to the organic binder types shown in the Table 1 entirely by way of example- can be used in the invention by way of illustration without being limiting to realize the invention.

Apart from the components explicitly mentioned above, the wet blend (2) can also comprise silicon and its derivatives for changing water repellency or water absorption feature and even other additional materials in line with the requirement of colouring.

In a preferred embodiment of the invention, a gauze or net made of glass fiber that is taken into a fabric form by means of a woven or non-woven, spunbond or spunlace technique is used as the strengthening element.

In one embodiment of the invention, one or more-layered glass fiber net is used as the strengthening element. Particularly in an embodiment wherein the final thermal insulation board (1) is a roof insulation board on which it is possible to walk, the strengthening element can comprise multiple-layered glass fiber nets, preferably two and thereby fracture strength of the final thermal insulation board (1) in bending is increased. In an alternative embodiment of the invention, carbon fiber net and materials showing similar feature can also be used instead of glass fiber net in order to increase fracture strength in bending.

In one embodiment of the invention, the thermal insulation board (1) obtained by the above-mentioned method is an A1 class non-combustible insulation board. In one example, the said A1 class non-combustible insulation board is obtained from a wet blend (2) comprising 200 units of expanded perlite, 45 units of 30% active polyvinyl alcohol binder, 0,2 units of silicon and 65 units of water by weight. In this example, the A1 class non-combustible insulation board having 5 cm thickness obtained after a 50-minutes of drying which does not preferably exceed 190°C in the heat treatment station (F) following a pressing transaction of 4 kg/cm ² in the press (E) has a density of 118 kg/m ³ and a PCS value of 1,88 MJ/kg. Thermal conductivity coefficient of the A1 class non-combustible insulation board obtained in this way has a 0,042 W/m.K value.

In another embodiment of the invention, the thermal insulation board (1) obtained by the above-mentioned method is an A1 class non-combustible insulated roof board. In one example, the said A1 class insulated roof board is obtained from a wet blend (2) comprising 200 units of expanded perlite, 45 units of 30% active polyvinyl alcohol binder, 0,65 units of silicone and 65 units of water by weight. In this example, the A1 class insulated roof board having 6 cm thickness obtained after a 60-minutes of drying which does not preferably exceed 175°C in the heat treatment station (F) following a pressing transaction of 9,5 kg/cm ² in the press (E) has a density of 235 kg/m ³ and a PCS value of 1,9 MJ/kg. Thermal conductivity coefficient of the A1 class insulation board obtained in this way has a 0,065 W/m.K value.

It is possible by means of the inventive method to produce thermal insulation boards (1) such as an A1 class non-combustible insulation board or an A1 class non combustible insulated roof board without the need for using high-cost coating technique which is frequently used in the prior art, by shaping the expanded perlite by means of a front press belt (D) and particularly at least one press (E) on a moving belt conveyor (B) via organic binders continuously in an economic way.

It is possible to develop various embodiments of the inventive production method of a thermal insulation board (1) and a thermal insulation board (1) produced by this method; the invention cannot be limited to examples disclosed herein and it is essentially according to claims.