1. Needle felt Needle felt is divided into chopped fiber needle felt and continuous strand needle felt. Chopped fiber needle felt is to chop the glas
1. Needle felt 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, and filter materials. It can also be used in the production of FRP, but the strength of the 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 with interlocking fibers. This kind of felt is mainly used for the production of glass fiber reinforced thermoplastic stampable sheet.
2. Continuous raw silk felt The glass raw filaments formed during the drawing process or the continuous raw filaments retired from the raw filament tube are laid on a continuous moving mesh belt in a figure of 8 and are bonded by a powder adhesive. The fiber in the continuous glass fiber mat is continuous, so it has a better reinforcing effect on composite materials.
3. Chopped strand mat cuts glass strands (or sometimes untwisted roving) into 50mm lengths, spreads them randomly but evenly on the mesh belt, and then applies emulsion binder or sprinkles powder binders and heats them After curing, it is bonded into chopped strand mat. Chopped strand mats are mainly used in hand lay-up, continuous board making and compression molding and SMC processes. The quality requirements for chopped strand mats are as follows: ①The area quality is uniform along the width direction; ②The chopped strands are evenly distributed in the mat surface without large holes, and the binder is evenly distributed; ③Has moderate dry mat strength; ④Excellent The resin infiltration and permeability.
4. Stitched mat 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. The other replaces continuous strand felt to a certain extent. Their common advantage is that they do not contain adhesives, avoiding pollution in the production process, and at the same time have good penetration performance and low prices.
5. Surface mat FRP products usually need to form a resin-rich layer, which is usually achieved with medium-alkali glass surface mat. 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 materials (such as checkered cloth) plays a role in surface modification. (For some FRP products with high surface requirements, polyester surface felt is basically used now)