In the world of building insulation materials, centrifugal glass wool felt has become a standard for both industrial and residential construction due to its lightweight, high thermal insulation, and low energy consumption. Essentially, it's a man-made inorganic fiber, formed by melting natural minerals at high temperatures and centrifugally blowing them into fibers, which are then bonded and cured with thermosetting resins. We'll begin by examining its raw material composition to uncover its core formula.
The composition of centrifugal glass wool felt can be divided into three main systems:
The cornerstone of glass fiber, formed from the melting of natural minerals:
| Ore Type | Chemical Composition | Core Function | Typical Percentage (Total Ore) |
| Quartz sand | SiO₂ | Forming a glass network skeleton, determining chemical stability and high temperature resistance | 55%-65% |
| Limestone | CaCO₃ | Adjust melting temperature to improve mechanical strength and weather resistance | 12%-18% |
| Dolomite | CaMg(CO₃)₂ | Provides MgO to enhance flexural and water erosion resistance | 8%-12% |
The three are precisely matched in ratios (such as SiO₂:CaO: MgO≈6:2:1) to balance the difficulty and performance of fiber melting.
Lowering the Melting Temperature and Optimizing Performance:
Soda Ash (Na₂CO₃): Acts as a flux, reacting with SiO₂ to form sodium silicate, lowering the melting temperature from 1700°C to 1360°C (3%-5%);
Borax (Na₂B₄O₇·10H₂O): Provides B₂O₃, improving fiber flexibility (increasing flexural strength by 20%+, 2%-4%);
Salad (Na₂SO₄): Clarifying agent, eliminating melt bubbles and ensuring fiber uniformity (0.5%-1%).
Curing the loose fibers into felt:
Main binder: Bio-based formaldehyde-free resin (environmentally friendly water-based epoxy resin), heat-pressed to form a three-dimensional network structure (3%-8% of the finished product weight);
Functional Additives:
Hydrophobic (e.g., silicone emulsion): Reduces water absorption to ≤ 0.5% (standard ≤ 1%);
Curing agent (e.g., hexamine): Accelerates resin crosslinking;
Anti-aging agent (hindered amine): Extends service life to 15-20 years.
Unlike traditional asbestos, centrifugal glass wool felt is certified non-carcinogenic. Its advantages include:
Non-toxic process: The ore is melted at 1360°C to completely decompose harmful substances;
Environmentally friendly bonding: Low free formaldehyde formula (≤ 0.05 mg/m³, exceeding the national standard GB 18580-2017);
Fire safety: Meets Class A fire protection standards and shrinks in the event of fire without releasing toxic gases.
Recommended key parameters for different scenarios:
| Application Scenarios | Recommended Density (kg/m³) | Recommended Thickness (mm) | Core Requirements |
| Exterior wall insulation | 48-64 | 50-100 | Low thermal conductivity (≤0.038W/m·K) |
| Steel structure roof | 16-24 | 50-150 | High compressive strength (≥4kPa) |
| Pipe insulation | 64-110 | 50-100 | Low cost, cuttable |
| Acoustic noise reduction | 32-120 | 40-100 | High sound absorption coefficient (≥0.8) |
Beware of products that pass themselves off as mineral wool:
| Specifications | Centrifugal glass wool | Ordinary mineral wool |
| Fiber diameter | 3-5μm (fine and soft) | 8-10μm (rough and prickly) |
| Thermal conductivity | ≤0.038W/m·K | ≥0.05W/m·K |
| Temperature resistance | ≤400℃ long-term use | Used at ≤250℃, easy to pulverize, with many slag balls |
| Environmental protection | Asbestos-free + low formaldehyde | Contains formaldehyde, impurities, recycled cotton, salt and other organic matter |
1. Cutting: Use a dedicated wallpaper knife to avoid fiber breakage;
2. Splicing: Leave a 5-10mm expansion joint to prevent cracking due to thermal expansion and contraction;
3. Moisture-Proofing: Apply aluminum foil to the surface in humid environments to prevent moisture absorption and increased heat conduction.
The development of centrifugal glass wool felt combines the scientific wisdom of silicate chemistry and material forming technology. When selecting, pay attention to the scientific nature of the ingredients, parameter matching, and brand reliability to maximize the effectiveness of this "invisible insulation jacket."
If you have purchase needs for high-quality insulation products or want to learn more about the products, please contact our EcoFox insulation team.
TIANJIN GREEN BUILDING TECH CO., LTD. is a leading manufacturer of environmentally friendly heat insulation materials, specializing in high-cost performance glass wool and stone wool insulation solutions for the building, industrial, and maritime sectors. Our products... [ Read More >>]
