WOOD-BASED COMPOSITE WITH FORMALDEHYDE-FREE, BIOBASIC, AND PHASE-CHANGE MATERIAL FOR THERMAL ENERGY STORAGE IN BUILDINGS.

Abstract

The invention relates to a wood-based composite panel developed for use in the technical fields of building materials, wood-based composite materials, and energy-storage building elements. This panel combines phase-change materials, wood fiber, and a lignin-based bio-based binder within an integrated composite structure. It is formaldehyde-free, possesses energy-storage properties, mechanical integrity, and dimensional stability, and is suitable for use in non-load-bearing building components where mechanical loads are limited. It can be applied as interior partition wall panels, ceiling cladding elements, suspended ceiling systems, interior wall coverings, decorative wall panels, interior thermal insulation layers in building envelopes, sandwich panel cores, prefabricated lightweight panel systems, and interior cladding panels. The invention also relates to the production method of this composite panel.

Description

FORMALDEHYDE FOR THERMAL ENERGY STORAGE IN BUILDINGS WOOD THAT DOES NOT CONTAIN BIOBASIZED AND PHASE CHANGE MATERIAL. ESSENTIAL COMPOSITE TECHNICAL FIELD The invention relates to building materials, wood-based composite materials, and energy storage. Phase-changing structural elements developed for use in technical fields. The material is an integrated composite structure of wood fiber and lignin-based bio-based binder. It is assembled inside, is formaldehyde-free, and has energy storage properties. Having mechanical integrity and dimensional stability, and subject to limited mechanical loads. Suitable for use in non-load-bearing building components and interior partition walls. panels, ceiling cladding elements, suspended ceiling systems, interior wall coverings, decorative wall panels, internal thermal insulation layers found in the building envelope, sandwich panels panel cores, prefabricated lightweight panel systems and interior cladding panels wood-based composite panels that can be applied in this way, and the composite panels in question It is related to the production method. PREVIOUS TECHNIQUE Increasing energy efficiency and improving indoor thermal comfort. the development of building materials with energy storage properties for this purpose Various studies are being conducted. Within this scope, phase change materials, which possess... Due to their latent heat storage capacity, they are integrated into building elements. and to reduce fluctuations in indoor temperature It is used. In current technology, the integration of phase change materials into building materials, Phase-changing materials include inorganic porous materials such as perlite, diatomite, graphite, and attapulgite. by impregnating the carriers and stabilizing them, and the resulting structure is made of cement mortar, concrete, This is achieved by adding it to building materials such as plaster or drywall. This approach limits the leakage of phase-change material to a certain extent. interface mismatch between carrier and matrix, matrix integrity This leads to weakening and a decrease in mechanical properties. In current technology, phase change materials can be made from solid wood, fiberboard, or particleboard. There are also applications where it is integrated into panel systems. 1 In a significant number of applications, phase-changing materials are solid wood or timber. It is directly impregnated into the porous structure of the fibers, and the resulting structure is bound. a composite plate with mechanical integrity and continuity using the system It is not being converted. In structures based on the impregnation of solid wood with phase-change materials, the phase... because the modifying material is mostly concentrated in regions close to the surface Homogeneous distribution across the cross-section cannot be achieved, and phase changes occur during long-term use. A leak of the altered material may occur. This leakage... additional surface coating or a second encapsulation process to prevent this This may need to be implemented, and as a result, the production process becomes more complex. Production costs are increasing. In wood fiber-based phase change material systems, the binder not being used or the binder being used is a material that undergoes phase change with wood. inability to achieve sufficient compatibility between them results in reduced internal bond strength. And problems arise in terms of dimensional stability. Phase shifting Properties such as swelling, bending and internal bonding strength are improved with the addition of materials. This negative impact limits the mechanical performance of the resulting structure and This particularly reduces their areas of use in the construction sector. In the current technology, synthetic materials are used to ensure mechanical integrity. There are also applications where binders are used. However, the aforementioned Continued use of formaldehyde-based resins in applications poses environmental risks. in terms of sustainability and especially air quality in indoor applications This constitutes a disadvantage. In the literature, formaldehyde-free and bio-based solutions are discussed. There are also wood-based composite systems created using binders. together, phase shifting systems provide the energy storage function in these systems. No materials are available. In contrast, wood contains phase-changing material. In these robust systems, a binder that provides mechanical integrity is not used, or Synthetic resins are used to ensure mechanical performance. Another technical problem encountered in existing structures is phase shifting. Leakage or phase degradation of the material from the composite matrix as a result of prolonged thermal cycling. The change function is negatively affected. This situation... This can lead to a decrease in the energy storage performance of the composite. 2 THE PURPOSE OF THE INVENTION The aim of the invention is to create a phase-change material with energy storage properties. while enabling its use within a wood-based structure, the structure in question a mechanically integrated system with a formaldehyde-free bio-based binder system It enables the formation of composite panels. Another aim of the invention is to make the phase-change material available only in wood or timber. A material that undergoes a phase change unlike the structures in which its fibers are impregnated, such as wood fiber. and a lignin-based binder are brought together in an integrated composite structure. It ensures that it is brought about. Another objective of the invention is to integrate phase-change material into the composite. By enabling its distribution, the energy storage function of the phase-changing material This enables its use within composite panels. Another objective of the invention is to utilize a lignin-based bio-based binder. the bonding of wood fibers to each other, thus in non-load-bearing building components. a plate structure with suitable mechanical integrity and dimensional stability It enables its acquisition. Another aim of the invention is to replace formaldehyde and petroleum-based resins with lignin-based resins. A formaldehyde-free wood-based product achieved through the use of a bio-based binder. It enables the production of energy storage composites. Another objective of the invention is to prevent the leakage of phase-change material from the composite structure. By limiting it, it ensures the preservation of the energy storage function. DETAILED DESCRIPTION OF THE INVENTION The wood-based composite with energy storage properties developed within the scope of the invention, It contains wood fiber, phase-change material, and a lignin-based bio-based binder. In the composite, wood fibers form the wood-based structure, a phase-change material. It provides energy storage function and a modified lignin-based binder. A mechanically intact board containing a phase-change material with wood fiber structure. It enables the transformation into its current state. Within the scope of the invention, a phase-change material is applied to wood fiber, and then wood fibers containing phase-changing material are bonded using a lignin-based binder They are combined. Thus, the phase-changing material is not only solid wood or fiber. Unlike binder-free systems in which it is impregnated into the structure, the phase-changing material, 3 an integrated composite structure containing both wood fiber and binder is being created. Methyl palmitate as a phase-change material in the application of the invention. It is used. Wood fibers in weights determined at the beginning of the production process and Molten methyl palmitate is brought together in a mixing vessel. (The rest of the sentence is a jumbled mix of Turkish words and phrases, likely a typo or a garbled translation error.) The subject of the mixture is the homogeneous addition of phase-changing material with wood fiber. Sufficient ethanol is added for distribution. Wood fiber with added ethanol. and the phase-changing material mixture is stirred for one hour using a mechanical mixer. They are mixed. Through this mixing process, the wood fibers and the molten phase-change mixture are combined. The distribution of the material within the mixture is ensured. The result obtained from mixing is... The resulting sol-gel mixture is used to remove trapped air within the structure and to separate the phases. 50 °C to ensure the modifying material penetrates into the fiber structure. It is kept in a vacuum oven at a certain temperature for one hour. The vacuum process... Then, in order to remove the ethanol from the mixture, the material is heated to 90 °C. It is heated to a temperature. Thus, dried wood fiber containing phase-changing material. samples are being obtained. Within the scope of the invention, the wood fiber and phase-change material structure in question Bio-based lignin adhesive modified for conversion into composite sheets. It is used. Equal amounts of dried wood fiber and phase-change material samples are used. It is bound using modified bio-based lignin. Lignin-based Technical lignin with increased alkali solubility in adhesive preparation It is used. Technical lignin is used in distilled water at a concentration of 10 percent by weight. It is dispersed. The resulting mixture is continuously stirred at a temperature of 60 °C. And this process is carried out in a way that ensures the complete dissolution of lignin. After the lignin dissolves, the temperature of the mixture is gradually increased to 95 °C. The speed is increased and the mixing rate is raised to 1000 rpm. This process As a result, a homogeneous lignin solution is obtained. The homogeneous lignin solution... after extraction, in order to promote the cross-linking of lignin into the mixture Citric acid is added at a rate of 5 percent by weight. After the addition of citric acid... Sodium hypophosphite was added to the mixture as a catalyst at a concentration of 2% by weight. The mixing process is continued until the start of gelation, and Thus, it will be used in the bonding of phase-change material structures with wood fiber. A modified lignin-based bio-based adhesive is obtained. 4 Samples of pre-prepared wood fiber and phase-change material were obtained. The surface is coated homogeneously with a modified lignin-based adhesive. Coating After this process, excess water is removed and sufficient separation of the fibers is ensured. To achieve this, the fibers are opened using a mixer. Wood fiber and phase-change material coated with lignin-based adhesive. The mixture is then shaped in a hot press. The hot pressing process... The process is carried out at a temperature of 100 °C and the pressing pressure is gradually increased to 30 kg / cm². Its value is increased. The composite material is placed in a hot press for one hour. They are pressed and the process results in composite panels with dimensions of 15 × 15 × 2 cm. is being done. The result of hot pressing is wood fiber, phase-change material, and modified lignin. The essential binder is integrated within the same composite plate structure. Lignin a fundamental binder that enables the bonding of wood fibers, thus facilitating phase-change in the material. the wood-based structure containing it gains mechanical integrity in the form of panels This provides a solution consisting only of phase-changing material impregnated fibers. Unlike other structures, a continuous composite panel is being created. The amount of phase-change material that can be used in the composites produced To determine this, composite samples were subjected to leakage tests. Leakage test During this process, the samples were placed on a heater at 50 °C for 30 minutes. is positioned. The phase formed in the composite samples after the heating process. The leakage of altering material was visually inspected and also examined in the samples. The mass loss that occurred was evaluated. The mass loss was less than 1%. It has been determined as an acceptable leakage limit. The leakage criterion in question... In the evaluation conducted accordingly, the optimum phase within the final composite structure was determined. It was determined that the amount of material that changes the phase is 50 percent by weight. Thus, the phase composites by harnessing the energy storage function of the modifying material The containment of the leak inside was achieved through collaboration. Within the scope of the invention, the energy storage function of the composite, composite structure This is provided by the phase-change material integrated into it. Phase The modifying material is present within the composite along with the wood fiber structure, and the word The subject matter is mechanically modified using a lignin-based bio-based binder. It is integrated. In the first stage of production, the melted phase-change material is wood. fibers are mixed with ethanol and undergo phase change as a result of mechanical stirring. The material is distributed within the fibers. Then, a vacuum is applied. The trapped air is removed during the process, and the fiber structure of the phase-changing material is altered. It is ensured that it penetrates into it. By removing ethanol through heating. Then, wood fibers containing phase-changed material are obtained. Separately. In the prepared lignin-based binder, technical lignin is dispersed in distilled water. And by heating and mixing, a homogeneous lignin solution is obtained. Citric acid and lignin-based adhesive modified by the addition of sodium hypophosphite, previously It is applied to the prepared wood fiber and phase-change material structure. Lignin Fibers coated with a base adhesive are subjected to a hot pressing process at 100 °C. under pressure that is gradually increased to 30 kg / cm² with temperature for one hour It is pressed. At the end of the pressing process, wood fiber, phase-change material and lignin are obtained. Mechanically integrated wood with an integrally incorporated essential binder. composite panel is obtained. The resulting structure contains phase-changing material for energy storage. While providing its function, the lignin-based binder holds the wood fibers together and This structure enables the creation of a composite plate structure. thanks to energy storage without the use of synthetic resins containing formaldehyde. A wood-based composite panel with these properties is obtained. The resulting composite plate is a non-load-bearing material suitable for applications where mechanical loads are limited. a wood-based structural element with energy storage properties for building applications It can be used as a composite panel for interior partition walls. in panels, ceiling cladding elements, suspended ceiling systems, interior walls and in decorative wall panels, interior thermal insulation layers, sandwich panels in cores, prefabricated lightweight panel systems and interior cladding panels It is applicable. 6

Claims

1. It is a wood-based composite panel, the characteristic of which is; - wood fiber, - as a phase-change material that has penetrated into the wood fiber in question, The composite structure contains 50% methyl palmitate by weight, and - modified bio-based, by weight, that binds the wood fibers in question. Containing 5% citric acid and 2% sodium hypophosphite by weight. It is characterized by containing lignin-based binders.

2. This is the production method of wood-based composite panels, and its characteristics are determined as follows: Wood fiber weighing approximately 1 / 2 kg and molten methyl palmitate are mixed together in a mixing bowl. the introduction of wood fiber and methyl palmitate into the mixture in a homogeneous manner adding enough ethanol to the mixture to allow for its dispersion, Mixing with a mechanical stirrer for 1 hour, the resulting sol-gel removal of trapped air from the mixture and the fibrous structure of methyl palmitate To allow it to penetrate, it is placed in a vacuum oven at 50°C for 1 hour. The mixture is left to stand at 90°C to remove the ethanol. Obtaining dried wood fibers containing methyl palmitate by heating to a certain temperature, alkali-solipidated technical lignin at 10% by weight in distilled water. dispersing the lignin in a ratio, then boiling the resulting lignin mixture at 60°C. Continuous stirring until completely dissolved, gradually increasing the temperature. Raising the temperature to 95°C and increasing the mixing speed to 1000 rpm, To the resulting homogeneous lignin solution, 5% by weight of citric acid was added and then add 2% by weight of sodium hypophosphite, and mix. modified bio-based by continuing the process until the start of gelation Obtaining a lignin-based binder from dried wood fiber and methyl palmitate. equal amounts of the aforementioned modified lignin-based binder in the samples homogeneous coating, removal of excess water and fibers opening using a mixer, the resulting mixture is heated to 100°C under pressure in a hot press where the value is gradually increased to 30 kg / cm² in 1 hour It is characterized by the fact that it involves steps of pressing for a certain period of time. 7