What is the mesh on the back of the marble?
Marble is currently used extensively in the stone industry, especially in interior decoration, where it almost dominates half of the market. This is because, aside from the issue of repairing cracks in marble, its hardness is much lower than that of granite. Furthermore, marble boasts a wider variety of textures and colors, offering a more intense and richer feel, leading to its broader application in interior stone decoration. However, marble formation is influenced by geological factors, geographical conditions, and its internal structure, resulting in numerous cracks. Some marble varieties (such as Golden Spider, Spanish Beige, Old Beige, and Saarana Beige) have even more cracks. Without pre-processing reinforcement, marble cannot be processed at all. Even after processing, long-distance transportation and handling during construction can cause breakage and damage. Besides adhesives, a common but essential material in marble reinforcement is fiber mesh. Don't underestimate this material; it is indispensable in marble reinforcement and plays an indelible role! The combined action of fiber mesh and adhesive enhances the strength of marble cracks, preventing breakage. In the event of a breakage, the tensile strength of the fibers prevents the marble from falling and breaking further. The fiber mesh also improves the quality of marble crack repair adhesive, ensuring the safety of the product during long-distance transportation and handling during construction. In short, fiber mesh is a crucial and indispensable material in marble repair adhesive.
1. Introduction to Fiberglass Mesh Performance: Fiberglass (original English name: glass fiber) is a high-performance inorganic non-metallic material. It is a fiber produced by melting, extruding, and stretching glass. Its main components are a mixture of silicates such as aluminum, calcium, magnesium, and boron, with other components added as needed for modification. Its diameter ranges from several micrometers to tens of micrometers. It exists in both long and short filament forms. It is brittle but has extremely high tensile strength and is resistant to high temperatures and corrosion. It has good sound insulation and electrical insulation properties. It can be used to make glass cloth, widely used in insulation, sound insulation, and heat insulation materials; it can also be used as a reinforcing skeleton material, combined with resins and cement to make fiberglass, reinforced plastic glass-reinforced concrete, and other composite materials, as well as optical fibers. Characteristics of fiberglass mesh: Fiberglass has the advantages of good insulation, strong heat resistance, good corrosion resistance, and high mechanical strength, but its disadvantages are brittleness and poor wear resistance. (1) High tensile strength and small elongation (3%). (2) High elastic coefficient and good rigidity. (3) Large elongation within the elastic limit and high tensile strength, so it absorbs a lot of impact energy. (4) It is an inorganic fiber, non-flammable, and has good chemical resistance. (5) Low water absorption. (6) Good dimensional stability and heat resistance. (7) Good processability and can be made into different forms such as strands, bundles, felts, and woven fabrics. (8) Inexpensive. (9) Not easy to burn and can be melted into glass-like beads at high temperatures.
2. Classification of fiberglass mesh (1) Fiberglass monofilaments are cylindrical, so their thickness can be expressed by diameter. Glass fibers are typically classified into several types based on their diameter range (measured in µm): Coarse fibers: generally 30µm in diameter; Primary fibers: diameter greater than 20µm in diameter; Intermediate fibers: 10-20µm in diameter; High-grade fibers (also known as textile fibers): 3-10µm in diameter. Glass fibers with a diameter less than 4µm are also called microfibers. Different filament diameters not only affect fiber properties but also influence production processes, yield, and cost. Generally, fibers with a diameter of 5-10µm are used for textile products, while fibers with a diameter of 10-14µm are more suitable for untwisted rovings, nonwoven fabrics, and chopped strand mats.
(2) Classification by Glass Fiber Properties: This is a new type of glass fiber developed to meet special application requirements. The fiber itself possesses certain special and superior properties. It can be roughly divided into: high-strength glass fiber; high-modulus glass fiber; high-temperature resistant glass fiber; alkali-resistant glass fiber; acid-resistant glass fiber; ordinary glass fiber (referring to alkali-free and medium-alkali glass fiber); optical fiber; low dielectric constant glass fiber; conductive fiber, etc.
(3) Classification by Glass Raw Material Composition: Alkali-free fiber (commonly known as E-glass): R2O content is less than 0.8%, and it is an aluminoborosilicate component. It has excellent chemical stability, electrical insulation properties, and strength. High-alkali fiber: Glass component with R2O content equal to or greater than 15%.
(4) Classification by Mesh Size and Weight: Classified according to the weight per square meter of the glass fiber mesh. Lightweight fiber mesh, heavyweight fiber mesh. 1) Mesh area: 10mm×10mm, 8mm×8mm, 7mm×7mm, 5mm×5mm, 4mm×4mm, 3mm×3mm
2) Weight per square meter: Between 30g and 160g
3. Mechanical Analysis of Fiberglass Mesh Reinforcement: Different types of fiberglass cloth have different mechanical properties, and these differences can be significant. In practical application, the appropriate fiberglass mesh should be selected based on the condition of the cracks on the stone surface.
Selection criteria for marble fiberglass mesh: Marble with many cracks, severe damage, and low strength should be selected with fiberglass mesh that has small mesh openings and relatively thick warp and weft threads to increase the strength of marble with cracks and severe damage. However, currently, stone processing companies do not follow this principle when selecting fiberglass mesh; instead, they use the same type of fiberglass mesh regardless of the degree of cracks or damage on the stone surface. This is an incorrect practice.
4. Fiberglass Mesh Reinforcement Operation: The operation process for reinforcing stone with fiberglass mesh is as follows: Cleaning the slab surface → Drying the slab surface (kiln drying) → Mesh selection → Laying the mesh → Cutting the mesh → Mixing the adhesive → Applying the adhesive → Curing the adhesive → (If necessary) Turning the slab over. In this process, the drying of the slab surface, the selection and laying of the mesh are the most important. If the slab surface is not dried properly, or if there is moisture or high moisture content, it will severely affect the adhesive strength, thus affecting the adhesion between the mesh and the slab, and preventing the mesh from achieving its reinforcing effect. The mesh selection should be based on the condition of the cracks on the stone surface; suitable materials and applications are essential for the effective reinforcement of fiberglass mesh. The mesh should be laid flat and without bulges.
5. Application Scope of Fiberglass Mesh: Fiberglass mesh is mainly used for reinforcing the back of marble slabs; reinforcing the back of mosaic and inlaid products; reinforcing the back of exterior wall stone; and reinforcing waterproof adhesive-backed stone.
6. Quality of Fiberglass Mesh Reinforcement (1) The surface of the fiberglass mesh is flat; (2) The adhesive completely covers the fiberglass mesh, and the adhesive on the surface of the fiberglass mesh is uniform, without accumulation or adhesive scars; (3) The fiberglass mesh is cut flat; (4) The fiberglass mesh is firmly bonded to the stone, with strong adhesion. Reinforcing cracked marble with fiberglass mesh can greatly improve the strength of the marble, reduce the breakage rate of the stone, and thus improve the utilization rate of the marble. At the same time, it can also reduce breakage and damage during the production, processing, handling, transportation, and construction of marble, ensuring the integrity and good condition of the marble.