Technology of injecting piolyurethane foam in composite panel

Abstract

Technology of injecting composite panels (4.4) with polyurethane foam is wherein the injecting of the space between the two facing boards (1.1) is carried out so that the insulating bi-component polyurethane foam (1.2) is injected under pressure in the space between these facing boards, wherein the facing boards are the gypsum fibreboards whose dimensions are such that their height most frequently corresponds to the height of one level of the building in which said panel will be installed and their length is determined as required. The composite panel supporting structure, the frame as well as the internal vertical and transversal reinforcements, are made of thin-walled steel C-sections (2.1) to which plastic spacers (3.1) are installed, to which facing gypsum fibreboards are fixed, thus ensuring smooth passage of the polyurethane foam between the facing boards and the supporting structure of thin-walled steel C-sections. The composite panel is filled placed horizontally in the press (4.1), which acts with its pressure on the external facing gypsum fibreboards thus preventing their deformation during the foam polymerisation process. After the injecting with bi-component polyurethane foam under pressure, the injecting interconnects the whole composite panel into a compact whole of improved mechanical properties.

Description

[0001] PATENT APPLICATION

[0002] Title of the invention:

[0003] Technology of injecting polyurethane foam in composite panel

[0004] 1. Technical field

[0005] The present invention designated as Technology of injecting polyurethane foam in composite panel is covered by the technical fields marked as B29C 44 / 00 and B29C 45 / 00 of the International Patent Classification.

[0006] 2. Technical problem

[0007] The technical problem of injecting the whole space inside the panel between the facing boards within polyurethane foam is the need to fill-up all parts of the composite panel with polyurethane foam, because the space between facing boards is occupied by densely arranged steel C sections wherein the panel shall be laid horizontally in the press whereby necessary volume is achieved and maintained during the foam polymerisation process which in that process develops sufficient pressure of approx. 0.20 MPa, whereby the bi-component polyurethane foam is injected into the panel via a high pressure pump through specially designed and positioned nozzles, positioned laterally on the panel, whereby positive effects are achieved through satisfactory injecting of polyurethane foam.

[0008] The problem associated with polyurethane foam injection is how to evenly and completely fillup the space between facing boards, through “obstructions” in terms of the steel structure composed of thin-walled steel C-sections in the panel core.

[0009] 3. State of the art

[0010] The structures composed of cold formed steel (CFS) or light steel frames (LSF) are widely applied in construction of various purpose buildings worldwide.

[0011] Light steel frames (LSF) have been developed as a fast and relatively simple construction system because most of the components are prefabricated. Steel structure components are traditionally manufactured in factory and assembled on the construction site into structural elements such as roofs, ceilings and walls. On the construction site, the steel structure is then coated with facing boards and the space in between is filled with insulating materials. Thus, most of the construction processes are carried out on the construction site. In order to speed-up the construction works and to transfer a part of the construction process into factories thus increasing the building accuracy and speed and reducing the need for labour, modular construction has been introduced. Elements of modular constructions include the wall, ceiling and roof. Such elements are made in factory and then transported to and mounted on the construction site.

[0012] The facing boards are selected based on fireproofing, soundproofing, moisture resistance and durability requirements.

[0013] Different materials are used for injecting, such as glass-, rock- and mineral wool, light concrete, lightweight gypsum with polystyrene granules, polyurethane foam and many other materials contributing to improved thermal and acoustic properties and preferably to mechanical resistance of the whole panel.

[0014] With the growth of lightweight structure industry, insulation materials have become very important. The first use of insulation materials in lightweight structures dates back to the end of 19thcentury when limestone rock wool was produced. The rock wool was a very popular insulation material for lightweight structures. Later on, the rock wool was replaced with asbestos which was promoted as the best alternative. Though available, insulation was not deemed to be necessary until 1920s when the public became more aware of the importance of thermal insulation. The increasing popularity and use of lightweight construction materials and gradual introduction of air-conditioning contributed to increased need for thermal insulation.

[0015] Mineral wool (MW) is frequently used when improved fire resistance of the entire system of a building is required and is the most frequently used insulation material for LSF structures with a wide range of application of this material. It turned out that high temperatures have no impact on mineral wool insulation in building industry. In addition to high fire resistance, a significant advantage is the soundproofing property of this material. The wool acts as an absorbent due to material flexibility and porosity of the material. The greatest problem with this material arises when the wool is used at places exposed to risk of condensation and moisture. When water penetrates the system, MW absorbs moisture increasing the thermal conductivity of the material and reducing its insulating properties. This consequently requires additional membranes and precautions. Cellulose fibres for thermal and acoustic insulation are produced in factories from recycled paper, wood fibres and certain chemical composites in order to improve their resistance to pests, fire and rotting. Although it is possible to manufacture boards and mats, they are more frequently sold as bulk material blown into the wall hollows. Due to its elasticity and porosity, this material is excellent for sound absorption in floating floors. Water and moisture have negative impact on thermal properties of materials.

[0016] EPS and XPS in LSF systems are polyurethane materials of a similar structure and properties. They are both classified as highly flammable closed cell foams without significant acoustic properties. A significant difference between EPS and XPS materials is that EPS has a greater moisture absorbing capacity as compared to XPS.

[0017] When considering the use of sandwich panels for LSF systems, PUR and PIR had a significant impact on the use of sandwich concept because they are generally cheaper, strong, easily glued on macroscopic level and provide high thermal insulation. Therefore, these two types of insulation materials experienced a significant growth in building industry and LSF construction systems. In general, PUR foams feature higher thermal resistance (R- value) as compared to other commercially available insulating products and hence PUR results in thinner structural elements with lower height and improved space utilisation, maximum efficiency and reduced operating expenses. Over the last decades, PUR has been particularly used for obtaining composites of low density, high resilience and ductility, high impact resistance, efficient acoustic insulation and excellent mechanical properties.

[0018] 4. Essence of the invention

[0019] The essence of the present invention consists of injecting the space between two facing boards (Pos. 1.1) with insulating foam, in this particular case the bi-component polyurethane foam (Pos. 1.2).

[0020] The gypsum fibreboard facing boards (Pos. 1.1) used for panel manufacture are made in required size, to shat their height most frequently corresponds to the height of one level of the building in which the panel will be installed. The facing board thickness is typically determined by the manufacturer of the gypsum fibreboards.

[0021] One of possible embodiments of the composite panel supporting structure is shown in Fig. 2. The frame, as well as the internal, vertical and transversal reinforcements are made of thinwalled steel C-sections (Pos. 2.1). The composite panel components are shown in Fig. 3, consisting of a supporting structure made of thin-walled steel C-sections (Pos. 2.1), to which plastic spacers (Pos. 3.1) are installed, to which gypsum fibreboards (Pos. 1.1) are fixed, connected with the supporting structure with the bi-component polyurethane foam injecting (Pos. 1.2).

[0022] The panel prepared for injecting is placed into a frame the dimensions whereof correspond to external dimensions of the panel supporting structure. The frame thickness corresponds to the total thickness of the panel including the thickness of the facing gypsum fibreboards. On one side of the frame openings are provided for pressure injection of liquid bi-component polyurethane foam, while on the other side of the frame openings are provided for air exhaust from the panel during its injecting with polyurethane foam thus preventing the creation of “air pockets” inside the panels and incomplete injecting of the whole panel volume with polyurethane foam.

[0023] During the injecting of composite panel with bi-component polyurethane foam (Pos. 1.2) it is extremely important to prevent deformation of the two facing gypsum fibreboards (Pos. 1.1), that may occur during the process of foam polymerisation which in that process develops the pressure 0.20 MPa, which is achieved by placing the frame with the composite panel horizontally in the press, whereby any deformation of the facing gypsum fibreboards is prevented.

[0024] 5. Brief description of the drawings

[0025] Fig. 1 : Illustration of a panel with injecting

[0026] Pos. 1.1 Facing gypsum fibreboard;

[0027] Pos. 1.2 Panel injecting of bi-component polyurethane foam;

[0028] Fig. 2: Illustration of the composite panel supporting structure

[0029] Pos. 2.1 Thin-walled steel C-section;

[0030] Fig. 3: Illustration of the final composite panel structure

[0031] Pos. 3.1 Spacer

[0032] Fig. 4: Illustration of industrial plant for injecting of composite panels with polyurethane foam

[0033] Pos. 4.1 . Press

[0034] Pos. 4.2. Tank with polyurethane foam and injecting pump;

[0035] Pos. 4.3. Hose with injecting nozzles;

[0036] Pos. 4.4. Composite panel prepared for injecting;

[0037] Pos. 4.5. Trolley - at the entrance of composite panel to the press;

[0038] Pos. 4.6. Trolley - at the exit of composite panel from the press.

[0039] 6. Description of at least one mode of carrying out the invention

[0040] The present invention is designed for application in manufacture of composite panels to be used as structural elements in building construction with pre-fabricated elements.

[0041] All components of the technical solution according to this invention are achieved with usual building industry technological procedures, including mechanical engineering, involved in metal processing, are well known and present a reliable practice worldwide, in addition to conventional requirements regarding the processing accuracy and use of generally known available materials.

[0042] 7. Approach to the industrial or other applications of the invention

[0043] The present invention is primarily designed for application in industrial production of buildings where composite panels would be manufactured under factory conditions ensuring the achievement of:

[0044] - Improved product quality;

[0045] - Possibility of manufacturing process control;

[0046] - Optimal use of human resources;

[0047] - Working process optimisation;

[0048] - Reduced on-site installation time;

[0049] - Optimisation of transport to the site

Claims

PATENT CLAIMS1 . Technology of injecting composite panels with polyurethane foam characterised in that filing of the space between two facing boards (1.1) is carried out by pressure injection of bicomponent polyurethane foam (1 .2) into the space between such facing boards.

2. Technology of injecting composite panels with polyurethane foam characterised in that the facing gypsum fibreboards (1.1) used for the panel manufacture are made in a required size so that their height most frequently corresponds to the height of one level of the building in which the panel will be installed.3 Technology of injecting composite panels with polyurethane foam characterised in that the composite panel supporting structure, the frame, as well as the internal, vertical and transversal reinforcements are made of thin-walled steel C-sections (2.1).4 Technology of injecting composite panels with polyurethane foam characterised in that the components of the composite panel (3), including the supporting structure, comprise thinwalled steel C-sections (2.1), to which plastic spacers (3.1) are installed, to which gypsum fibreboards (1.1) are fixed.5 Technology of injecting composite panels with polyurethane foam characterised in that the components of the composite panel (3), after the pressure injecting with bi-component polyurethane foam (1.2), are interconnected into a compact whole.6 Technology of injecting composite panels with polyurethane foam characterised in that the panel prepared for injecting is placed into a frame whose dimensions correspond to external dimensions of the panel supporting structure.7 Technology of injecting composite panels with polyurethane foam characterised in that the frame thickness corresponds to the total thickness of the panel, including the thickness of facing gypsum fibreboards.8 Technology of injecting composite panels with polyurethane foam characterised in that on one side of the frame openings are provided for pressure injection of the polyurethane foam while, on the other side of the frame, openings are provided for air exhaust from the panel during the injecting with polyurethane foam.9 Technology of injecting composite panels with polyurethane foam characterised in that during the injecting of the composite panel with polyurethane foam (1.2), the frame holing the composite panel is horizontally placed in the press which acts with its pressure on the external facing gypsum fibreboards (1.1) preventing their deformation during the foam polymerisation process.

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