A MULTILAYER COMPOSITE FLAME BARRIER AND ITS PRODUCTION METHOD

Technical Field

The invention relates to a multilayer composite flame barrier developed for the purpose of providing high flame resistance and thermal insulation.

The invention relates to a composite flame barrier with sandwich form which is developed with the aim of being used primarily in the defense industry, comprising in respective order; a first silicone blend layer which provides flame resistance, a carbon impregnated aerogel layer which provides lightness and thermal insulation and a second silicone blend layer which provides thermal insulation, mechanical strength and unification and to its production method.

Present State of Art

Today, materials with homogeneous structure in which aerogel and silicone are used in combination exist. These materials are only used as thermal insulating materials in architectural structures.

These materials which are used in the current art and which include aerogel and silicone do not have any resistance against flame. There is a need for light and durable materials providing flame resistance and thermal insulation to be used mainly in the defense industry.

Applications below with regards to the subject are found in the literature.

In the application with number TR 2016 / 12230 and titled “A heat and flame resistant plate production method”, method for production of a heat and flame resistant plate which is impact and open flame resistant in environments with a temperature up to 1000 ^Q C and with risk of fire; which does not have leakage or dripping, which does not produce halogen and toxic gases, which acts as a barrier against fire and flame is mentioned. In the production method of the invention, the product with high resistance to the produced temperature, heat and flame is vulcanized by creating a mixture by using silicone polymer and additives. The final product obtained here is flame resistant; however, the lightness of the product is not mentioned.

In the application with number CN109809776 and titled “A Non - flammable Light Panel with Thermal Insulation Properties and Its Production Technique”; a panel comprising Portland cement, fly ash, micro silica, rubber powder, polystyrene, a modified flame retardant, toluene sulphonic acid, polyethylene glycol, water, modified silicone resin and cellulose. It mentions that the endurance and non - flammability and thermal insulation performance of this light panel is high and therefore mentions its implementations in the construction sector; nonetheless; it does not provide any information regarding its usage in other sectors.

Therefore, due to the shortcomings described above and due to the lack of existing solutions on the subject, a development in the relevant technical area is required.

Brief Description of the Invention

The present invention relates to a multilayer composite flame barrier and its production method that meet the requirements mentioned above, while eliminating all disadvantages and providing some additional advantages.

An aim of the invention is to develop a composite flame barrier which manifests high resistance against flame by the virtue of the first silicone blend layer it comprises.

Another aim of the invention is to develop a composite flame barrier which manifests high thermal insulation and mechanical strength by the virtue of the second silicone blend layer it comprises.

Another aim of the invention is to develop a composite flame barrier wherein thermal insulation is enhances while the weight is decreased by the virtue of the carbon impregnated aerogel layer it comprises.

In order to accomplish the purposes mentioned above, the invention encompasses a multilayer composite flame barrier with sandwich form comprising a carbon impregnated aerogel layer between a first silicone blend layer and a second silicone blend layer and its production method.

The structural and characteristic features and all advantages of the invention will be understood more clearly through the detailed explanation written with the following figures and references to these figures, and therefore assessment should be made by considering these figures and detailed explanation.

Brief Description of Drawings

Figure 1 shows a lateral sectional view of the flame barrier of the invention.

Figure 2 shows a perspective view of the flame barrier of the invention. Drawings do not necessarily have to be scaled, and details that are not necessary to understand the current invention may have been omitted. Furthermore, elements that are at least largely identical, or at least have largely identical functions, are denoted by the same number.

Reference Notes

1 Flame Barrier

2 First Silicone Blend Layer

3 Carbon Impregnated Aerogel Layer

4 Second Silicone Blend Layer

Detailed Description of the Invention

In the herein detailed description, a multilayer composite flame barrier (1) of the invention and its production method are described only for a better understanding of the subject matter, without posing any limitations.

The invention fundamentally is a multilayer composite flame barrier (1) comprising a first silicone blend layer (2) which provides flame resistance, a second silicone blend layer (4) which provides thermal insulation, mechanical strength and unification , and a carbon impregnated aerogel layer (3) which provides lightness and thermal insulation to the flame barrier (1) by being connected between the said first silicone blend layer (2) and the second silicone blend layer (4).

The invention, of which the lateral sectional view is shown in Figure 1 , is composed of three main layers in the composite material class. On the outer surface, the flame resistant first silicone mixture layer (2) which is directly exposed to the flame is located, a carbon impregnated aerogel layer (3) with high flame resistance and thermal insulation is located under that and a second silicone mixture layer (4), which enables the structure to remain monolithic, is located in the inner surface.

The flame barrier (1), which is developed within the scope of the invention, comprises a first silicone mixture layer (2) with weight - wise ratio of 30 - 40 %, a carbon impregnated aerogel layer (3) with weight - wise ratio of 20 - 40 % and a second silicone mixture layer (4) with weight - wise ratio of 30 - 40 %. The preferred and usable weight - wise percentages of the layers composing the invention are shown in Table 1 .

Table 1 . Percentage by weight of the layers forming the flame barrier (1 )

The first silicone mixture layer (2), which is directly exposed to the flame, comprises flame resistant solid silicone within the weight - wise range of 65 - 80 %, calcium carbonate within the weight - wise range of 5 - 7 %, huntite within the weight - wise range of 5 - 7 %, aluminum hydroxide within the weight - wise range of 5 - 7 %, catalyzer within the weight - wise range of 2 - 4 % and pigment powder coat preferably within the weight - wise range of 1 - 2 %. The preferred and usable weight - wise amounts of the components composing this layer (2) are shown in Table 2. The active catalyzer material which decreases the activation energy threshold here can be selected as Trigonax in a preferred structuring of the subject of the invention.

Table 2. Percentage by weight of the components forming the first silicone blend layer (2)

The first silicone mixture layer (2), which provides resistance against flame, can maintain its structure without any disintegration or deformation, even though it contacts with the flame obtained by LPG gas, which is at 1000 Ό temp erature and has a length of 25 cm, for 1 hour in a distance of 10 cm. In an example of the invention, which has a size of 350 ^* 250 mm and a weight of 1.118 gr, the inner temperature of a panel which is obtained by spreading 2 mm of the first silicone mixture layer (2), 4 mm of the carbon impregnated aerogel layer (3) and 2 mm of the second silicone mixture layer (4) located on the inner surface and which is exposed to a flame with 990 Ό temperature for an hour only reached to 53 ºC degrees of temperature. In the end of the test, no disintegration or puncture is seen on the plate. Smoke evolution, which has been dense after the third minute, decreased to plausible levels afterwards. External and internal temperature variances regarding this test are given in Table 3.

Table 3. Internal temperature variance table regarding the panel of the invention exposed to flame at approximately 990°temperature

The layer located under the first silicone blend layer (2) is the carbon impregnated aerogel (3) layer. This layer is composed by impregnating carbon into the aerogel structure with high thermal insulation. This layer enhances the resistance of the invention against flame as well as its thermal insulation. This aerogel - based layer has a porous structure and constitutes 60 % of main structure in volume. Although this layer occupies 60 % of space in volume, it constitutes only 20 % of the main structure weight - wise. Therefore; this layer not only contributes to the properties of flame resistance and thermal insulation, but it also contributes to the lightness of the flame barrier (1) in terms of weight.

A second silicone mixture layer (4) with high thermal insulation is located on the inner surface. This layer ensures that the structure remains in monolithic form and increases the mechanical strength. This layer which provides a unification property comprises solid silicone with insulator properties within the weight - wise range of 70 - 80 %, quartz within the weight - wise range of 10 - 20 %, huntite within the weight - wise range of 5 - 10 %, aluminum hydroxide within the weight - wise range of 3 - 10 %, catalyzer within the weight - wise range of 1 - 2 % and pigment powder coat preferably within the weight - wise range of 1 - 2 %. The preferred and usable weight - wise percentages of this layer are shown in Table 4. Here, the catalyzer can be selected as Trigonax or Perkadox in a preferred structuring of the subject of the invention.

Table 4. Percentage by weight of the components forming the second silicone blend layer The production method of the multilayer composite flame barrier (1 ) of the invention fundamentally comprises the procedure steps of; a. mixing the raw materials comprised by the first silicone blend layer (2) in determined amounts, b. mixing the raw materials comprised by the second silicone blend layer (4) in determined amounts, c. cutting the carbon impregnated aerogel in the determined sizes, puncturing air channels on it and obtaining the carbon impregnated aerogel layer (3) by pressing into the determined form, d. spreading and pressing the pre - prepared silicone mixtures into a mould in a manner that the carbon impregnated aerogel layer (3) is located between them.

In order to obtain the first silicone mixture layer (2) and the second silicone blend layer (4) in the flame barrier (1) developed within the scope of the invention; pure solid silicones in base state are processed for a while between two rollers operating in parallel to each other with the aim of providing elasticity. Afterwards, the processing is continued until it dissolves homogeneously within the silicone structure by compensating the additives, which are given in Table 2 for the first silicone mixture layer (2) and in Table 4 for the second silicone mixture layer (4), into the silicones by hand lay - up technique with the ratios given in the Tables.

The carbon impregnated aerogel layer (3) in roll form is cut in desired size by limit cutting mould. After this, air channels with 2 mm diameter are punctured onto this surface with intervals of 3 cm in the x and y coordinates. This puncturing process is implemented by an adamantine drill. The carbon impregnated aerogel layer (3) is a material composed of 98 % air and it results in expansion in the structure by dilatation due to heat during covering with the silicone layers (2.4). In order to prevent this; the said air channels are formed mechanically on the carbon impregnated aerogel layer (3). By this way; it is ensured that the structure can be covered in monolithic form and with desired measures. These air channels hold great significance in terms of integrating the structures into each other. If these air channels are not punctured or are punctured incorrectly or faultily, problems in the final structure such as expansion, layers not being adhered to each other and deformations can occur due to the air compressed within the press. After forming air channels with puncturing process, the carbon impregnated aerogel layer (3) is formed in the desired manner by being pressed in the vertical axis.

Layers (2,3,4) obtained separately are pressed in groups in layers in a mould with temperature of 135° - 145 °C (preferably 140 “C at most). First, the first silicone mixture layer (2) is spread into the heated mould and afterwards the carbon impregnated aerogel layer (3) is located on top of it. After this, pressure is applied manually. As the last step, the second silicone mixture layer (4) is spread onto this structure and the mould is closed and pressed. The final structure is obtained by curing the silicone layers (2.4) under pressure and heat for 15 minutes. The curing period for the silicone layers (2.4) must be long and the temperature must be low. By this way; the silicone layers (2.4) can penetrate into the air channels punctured on the carbon impregnated aerogel layer (3) within this time period. This results in obtaining a monolithic structure which has a higher mechanical endurance. In a preferred structuring of the flame barrier (1 ) developed within the scope of the invention, the thickness of the first silicone mixture layer (2) which is put into the mould is selected as 2 mm.