The full name of GRG in Chinese is pre-cast glass fiber reinforced plastic molding (GlassFibre Renforcd Gypsum). It is made of high-quality natural modified gypsum as the base material, adding gypsum-specific reinforced glass fiber and trace modification additives. A new type of pre-cast decorative material. The randomness of its shape makes it the first choice for architects who require personalization, and its unique material composition is strong enough to resist breakage, deformation and cracking caused by the external environment. Tianjin First Decoration reminds that this material can be made into various flat panels, various functional products and various artistic shapes. It is currently the most popular updated product in the international building material decoration industry.
In foreign countries, especially in the economically developed European and American architectural decoration circles, the production and application of GRG materials has a history of more than 30 years. The world-famous Sydney Opera House, Dubai's seven-star Burj Al Arab and other top buildings all use GRG materials extensively in their interior decoration. In China's architectural decoration industry, GRG products are increasingly used, and architectural shapes are becoming more and more colorful. With the rapid development of China's economy and urban construction, the GRG industry has developed rapidly, and the application scope of the material has also been widely expanded.
GRG products are tailor-made for different projects. Designers can realize their design concepts through GRG products. GRG materials perfectly combine architecture and art, providing talented designers with realistic wings to realize their bold, avant-garde, and even crazy design dreams. Due to the waterproof performance and good acoustic performance of GRG material, it is especially suitable for places with frequent cleaning and sound transmission, such as schools, hospitals, shopping malls, theaters and other places. As a building interior decoration material, GRG materials are widely used by designers and architects on suspended ceilings, partition walls, signboards, panels, columns, vaults, domes, cornices and wall panels.
1. GRG material characteristics
1. Strong plasticity and rich shapes: GRG products are pre-cast gypsum products laminated on the mold through a special process. It can meet the randomness of shape and mechanism. The product can be customized with single-curved surface, double-curved surface, three-dimensional covering, various geometric shapes, hollow patterns, relief patterns and other artistic shapes, which can fully meet the designer's individual requirements. It not only has high hardness but also has good flexibility. It can be made into various sizes, shapes and designs. It is easy to use and can be used in complex ceiling and wall decorations. Architects can use GRG products to achieve the required design effects on the interior surfaces of buildings.
2. Rich selection of toppings. The surface of GRG material is delicate and smooth. The whiteness can reach more than 90%, and it can bond well with various coatings and various surface materials (wood veneer, fabrics) to form different styles of decorative effects.
3. High strength and impact resistance. Experiments show that the fracture load of GRG products is greater than 1200N, which is 10 times higher than the national standard JC/T799-1988 (1996) decorative gypsum board fracture load of 118N.
Bending strength: 10-20MPa ASTMD790-2003 test method.
Tensile strength: 10-15MPa ASTMD790-2003 test method.
Impact strength: 30-35KJ/m2 ASTMD790-2003 test method.
4. Stable quality. GRG material does not deform or crack, and the main material gypsum has a low thermal expansion coefficient. The dry and wet shrinkage rate is less than 0.01%. When stored at 120 degrees for 72 hours, the variability is only 0.07%. The product is not affected by environmental changes in cold, heat, dryness, or humidity, and its performance is stable and does not deform. The product never deforms and has a very small expansion coefficient. The unique cloth fiber processing technology also makes the product crack-free and has a long service life.
5. High density and light weight. The standard product thickness is 3.2 to 8.8mm (can be thickened for special requirements), and the weight per square meter is only 4.9 to 9.8kg. If there are acoustic requirements, the back of the product can be thickened by grouting as required (the acoustic effect is best when the thickness is 40mm) . While meeting the needs of large-plate ceiling division, it can also reduce the weight of the main building and the load of components. Thickness and weight can be varied to meet acoustic requirements. The grouting density can reach a minimum of 650kg/cubic meter.
6. Fire prevention and flame retardancy.
GRG material is a Class A fireproof material. When a fire occurs, in addition to being flame retardant, it can also release moisture equivalent to 15% to 20% of its own weight, which can significantly reduce the temperature of the fire surface and reduce fire losses.
7. Strong moisture resistance. GRG material is an inorganic material that is anti-mildew, anti-moth and anti-static. The test results prove that the water absorption rate of the product is only 0.3%, so GRG products can be used in humid environments without causing mildew or yellowing.
8. Good acoustic effect. GRG material has good sound wave reflection properties. The test shows that the 4mm thick GRG material has a transmission loss of 500Hz23db and 100Hz27db; the air-dry specific gravity is 1.75, which meets professional acoustic reflection requirements. After good shape design, a good sound-absorbing structure can be formed to achieve the functions of sound insulation and sound absorption.
9. Green and environmentally friendly. GRG materials have no odor and do not contain any chemical resins or radioactive harmful substances. The radionuclide limit complies with the standards for Class A decorative materials stipulated in GB6566-2001. Made of 100% natural inorganic minerals, the far-infrared emissivity is about 0.88. And it can be recycled and used, which is a green and environmentally friendly material.
10. Short processing cycle. The demoulding time of GRG products only takes 30 to 120 minutes, and the drying time only takes 4 to 8 hours, so the construction cycle can be greatly shortened.
11. Convenient construction and low loss. GRG products can be precisely segmented according to the designer's specifications. All products are prefabricated in the factory and do not require on-site secondary processing. The installation adopts embedded parts. It has good on-site processing performance, fast and flexible installation, and can be seamlessly assembled in large areas to form a complete shape. Especially for details such as openings, arcs, corners, etc., no errors can be ensured.
2. GRG raw materials
Using high-density Alpha gypsum powder, special glass fiber, environmentally friendly additives, water, and release agent.
1. High-density Alpha gypsum powder (surface layer, grouting and caulking): At present, domestic raw material procurement is divided into imported gypsum powder and domestic gypsum powder. The advantage of imported gypsum powder is that the product properties are stable and the quality of the finished product is reliable. It has good controllability, better strength and flexibility, and smoother surface; disadvantages are high cost and long delivery cycle. Domestic gypsum powder has a short supply cycle and low cost, but the product has relatively many impurities, large particles, poor stability, poor operability, and unstable GRG finished product quality.
2. There are two main types of glass fiber materials, alkali-free glass fiber cloth and alkali-free broken glass fiber. GRG products using alkali-free glass fiber cloth have high strength and will continue to crack under strong impact. The required strength can be achieved with a thickness of 6mm, and the product is light in weight. GRG products using alkali-free broken glass fiber have low strength, and the product will break brittlely under strong impact. GRG product thickness must reach 8-10mm, and the product must be heavy.
3. Additives: At present, the modified additives used by different domestic manufacturers are different. Most of them are confidential and patented formulas. The formulas originate from the United Kingdom and Japan. Some manufacturers use self-developed additive formulas. It can effectively improve the physical properties of products.
4. Surface treatment materials: According to different requirements of the surface layer, it can be completed in the factory or on site.
3. GRG production process
GRG is a pre-cast gypsum product that is laminated or sprayed on the mold. The accurate forming of GRG depends on the accurate production of molds. It can be said that the production of high-quality molds is a necessary condition for the quality of GRG products. The production of mold products must be highly consistent with the designer's plan. Only the final production and installation can combine the designer's ideas. The design intent is revealed.
The main materials used in the production of molds are wood, industrial wax, silicone, fiberglass, GRG, foam, etc. Various molds have different uses and scopes of application.
With the continuous changes in modern design concepts, more and more designs use three-dimensional multi-surface and arbitrary surface modeling. In this context, traditional woodworking molding technology is being replaced by advanced CNC numerical control molding machine tool molding technology.
CNC CNC engraving machine tools have great advantages. They can carry out CNC engraving of complex shapes, and can produce any 2D or 3D shapes; the production process is fully automatic, and the quality of mold products is stable; the machine production has high precision, high reliability, and guaranteed products It is consistent with the architect's electronic mold; the mold product has strong consistency and is not affected by the technical quality of skilled workers; the production efficiency is high and the production capacity is stable, which can effectively guarantee the construction period; however, the one-time investment in using CNC numerical control molding machine tool equipment and site is large; The production cost is high; the system is complex and the maintenance cost is high; it requires high-end modeling and related software application personnel, and the labor cost is high. The production cost of molds produced by traditional woodworking moldmaking technology is low, and the molds can be reused through mold repair and other methods, which can significantly reduce product costs. The disadvantage of the traditional woodworking molding process for producing molds is that it cannot produce complex shapes and can produce 2D shapes; the quality of mold products is affected by the technical quality of skilled workers, and the quality is unstable and has poor consistency; the precision of mold products is low, and it is impossible to guarantee products and architects' electronic molds consistent; production efficiency is low, and production capacity is affected by product complexity. The production of GRG products is completed by laminating or spraying processes depending on the selected fiberglass materials.
4. GRG installation method:
GRG products are all factory-formed and manufactured, with pre-embedded installation components. They are easy to install and joints are processed on-site, so there is basically no construction loss.