Why is fiberglass mesh added to the back of marble?
1. Introduction to the performance of fiberglass mesh: Glass fiber (original English name: glass fiber) is a high-performance inorganic non-metallic material. It is a fiber made by melting, extruding and stretching glass. The main components are a mixture of silicates such as aluminum, calcium, magnesium and boron, and some other components can be added as needed for modification. The diameter ranges from several micrometers to tens of micrometers. There are long filaments and short filaments. It is brittle, but has extremely high tensile strength and is resistant to high temperature and corrosion. It has good sound insulation and insulation properties. It can be used to make glass cloth, etc., and is widely used in insulation, sound insulation and heat insulation materials; it can also be used as a reinforcing skeleton material, and can be combined with resin, cement and other materials to make fiberglass, reinforced plastic glass concrete and other composite materials, as well as optical fibers. Features of glass fiber mesh: Glass fiber: The advantages are good insulation, strong heat resistance, good corrosion resistance and high mechanical strength, but the disadvantages are that it is brittle and has poor wear resistance. (1) High tensile strength and small elongation (3%). (2) High elastic coefficient and good rigidity. (3) It has a large elongation within its elastic limit and high tensile strength, thus absorbing a large amount of impact energy. (4) It is an inorganic fiber, non-flammable, and has good chemical resistance. (5) It has low water absorption. (6) It has good dimensional stability and heat resistance. (7) It has good processability and can be made into products of different forms such as strands, bundles, felts, and fabrics. (8) It is inexpensive. (9) It is not easily burned and can be melted into glass-like beads at high temperatures.
2. Classification of Glass Fiber Mesh
(1) Glass fiber monofilaments are cylindrical, so their thickness can be expressed by their diameter. Generally, according to the diameter range, drawn glass fibers are divided into several types (their diameter values are in μm): Coarse fiber: its monofilament diameter is generally 30 μm; Primary fiber: its monofilament diameter is greater than 20 μm; Intermediate fiber: its monofilament diameter is 10-20 μm; High-grade fiber: (also known as textile fiber) its monofilament diameter is 3-10 μm. Glass fibers with a monofilament diameter less than 4 μm are also called ultrafine fibers. Different monofilament diameters not only affect fiber performance but also production processes, yield, and cost. Generally, 5-10µm fibers are used in textiles, while 10-14µm fibers are more suitable for untwisted rovings, nonwoven fabrics, and chopped strand mats.
(2) Classification by Glass Fiber Characteristics: This is a new type of glass fiber developed to meet specific application requirements. These fibers possess certain unique and superior properties and can be broadly classified as: 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: Based on the weight per square meter of the fiberglass mesh, it is classified into light-weight and heavy-weight fiberglass meshes. 1) Mesh area: 10mm×10mm, 8mm×8mm, 7mm×7mm, 5mm×5mm, 4mm×4mm, 3mm×3mm 2) Weight per square meter: Between 30 grams and 160 grams.
3. Mechanical Analysis of Fiberglass Mesh Reinforcement: These different types of fiberglass cloth have different mechanical properties, and the differences are significant. In actual use, the appropriate fiberglass mesh should be selected based on the condition of the cracks on the stone surface.
Selection criteria for marble fiberglass mesh: For marble with many cracks, severe damage, and low strength, a fiberglass mesh with small mesh openings and relatively thick warp and weft threads should be selected to increase the strength of the marble with cracks and severe damage. However, currently, stone processing enterprises do not select fiberglass mesh according to this principle, but instead 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 the 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.
