Needle felt is divided into chopped fiber needle felt and continuous strand needle felt. Chopped fiber needle felt is to chop the glass fiber roving into 50mm, and randomly place it on the substrate placed on the conveyor belt in advance, and then use a barbed needle for needle punching. The needle pierces the chopped fiber into the substrate In the middle, and the crochet hook brings up some fibers to form a three-dimensional structure. The substrate used can be a thin fabric of glass fiber or other fibers. This needled felt has a fluffy feel. Its main uses include heat insulation and sound insulation materials, heat lining materials, filter materials, and can also be used in the production of FRP, but the strength of FRP is low and the scope of use is limited. Another type of continuous strand needle felt is a felt in which continuous glass strands are randomly thrown onto a continuous mesh belt with a filament throwing device, and then needled through a needle plate to form a three-dimensional structure in which fibers are interconnected. This kind of felt is mainly used for the production of glass fiber reinforced thermoplastic stampable sheet.
Chopped glass fibers from 50mm to 60cm in length can be stitched into chopped fibers or long fiber mats with a stitchbonding machine. The former can replace traditional binder-bonded chopped mats in several applications, while the latter can be used in certain applications. To a certain extent instead of continuous raw silk felt. Their common advantage is that they do not contain adhesives, avoiding the pollution of the production process, and at the same time have good permeability and low price.
FRP products usually need to form a resin-rich layer, which is usually achieved by using medium-alkali glass surface mats. Because this kind of felt is made of medium-alkali glass c, it gives FRP chemical resistance, especially acid resistance. At the same time, because the felt is thin and the diameter of the glass fiber is small, it can also absorb more resin to form a resin-rich layer, which covers The texture of glass fiber reinforced material (such as checkered cloth) plays a role in surface modification.
1. The area quality is uniform along the width direction;
2. The chopped strands are evenly distributed in the felt surface, no large holes are formed, and the binder is evenly distributed;
3. It has moderate dry felt strength;
4. Excellent resin infiltration and permeability.