Importance of Glass Fiber in PA66GF25 Nylon Thermal Insulation Strips

The glass fiber used in PA66GF25 nylon thermal insulation strips (PA66GF25 granules) significantly impacts the tensile performance of the strips. To achieve high tensile strength in thermal insulation strips, glass fiber plays a crucial role:

1.Quality of Glass Fiber: The glass fiber must be alkali-free and produced by large-scale enterprise. The production equipment for alkali-free glass fiber is expensive, and typically, small-sized enterprise cannot bear these costs. Only advanced equipment can produce stable and high quality glass fiber. The two most renowned glass fiber manufacturers in China are Taishan Fiberglass and Jushi Fiberglass. Our company utilizes alkali-free glass fiber produced by Taishan Fiberglass.

    
2. Diameter of Glass Fiber Filaments: The diameter of the glass fiber filaments is critical. It is generally recommended to use filaments with a diameter of less than 13μm. With a consistent content of 25%, thinner filaments result in a greater number of fibers, enhancing the toughness of the thermal insulation strip. The distribution of glass fibers within the thermal insulation strip should be irregular yet uniform. Only with a scattered arrangement of glass fibers in every direction can both transverse and longitudinal tensile strengths perform excellently.

3. Burn Test for Quality Assessment: Please cut a piece of thermal insulation strip and place it into a muffle furnace for complete combustion. The residue after burning typically consists of glass fibers. If high-quality glass fiber is used, the shape of the residue will closely resemble the original shape of the thermal insulation strip, and the color should be white. Any other color or completely deformed and collapsed residue indicates inferior quality of glass fiber.

Upon microscopic examination of the residue, it should be observed that the glass fibers maintain a scattered yet supportive structure, akin to reinforced concrete, preventing collapse while allowing for spacing and support among fibers.

In summary, high-quality glass fiber should have a fine diameter and a snow-white color, with a distribution that is uniform but irregular.

In China, some granule manufacturers attempt to reduce production costs by substituting the following materials for glass fiber, which significantly compromises the quality of the thermal insulation strips:

1. Using Medium-alkali Glass Fiber: This type of glass fiber has larger filament diameter. With the same content, a larger filament diameter results in fewer fibers, reducing the effectiveness of the bond with the nylon material. Consequently, the reinforcing effect of the glass fiber diminishes, leading to a decrease in tensile strength of the thermal insulation strips.

2. Using Glass Microspheres or Glass Powder: Glass microspheres, being rigid spheres, do not provide reinforcement, offering no help to tensile strength. Replacing alkali-free glass fiber with glass microspheres lowers costs but has no positive impact on the tensile strength of the thermal insulation strips, making this approach inadvisable.

In closing, good glass fiber improves the quality level of the product, while of poor quality lowers the level of the product. Supply of good raw materials should be all the time considered.