Introduction to the maximum strength of glass rod in arrangement

Isotropic distribution: Its fiber distribution is non-directional and randomly distributed in three-dimensional space. Bulk molding compound products belong to this category. Its fibers are short and the fiber content of glass rod is low, generally not exceeding 30% (mass fraction), or even only 10%.

Plane isotropic distribution: Its fibers are randomly distributed in the X and Y planes, showing isotropy; in the Z direction, they are layered. Laminated products of chopped fiber mat and continuous fiber mat belong to this category. Its fiber content is not high, and glass rod is generally 25%~35% (mass fraction), and the maximum can only reach 50% (mass fraction).
Plane bidirectional vertical distribution: Plane bidirectional vertical distribution is also called plane orthogonal distribution. Its fibers are distributed in the X and Y wind directions: Z direction is layered distribution. For example, plain glass cloth, twill glass cloth, herringbone glass cloth layered composite products or untwisted coarse plaid laminated products. The Fiber Glass content in glass rod is relatively high, generally 40%~65% (mass fraction)
Unidirectional distribution: The fibers in composite materials are all distributed in unidirectional parallel. Such as rods, bars, tubes and other products produced by pultrusion, as well as parallel wire sheets or unidirectional cloth laminated products. This kind of product has dense fiber filling and high content, generally 60%~90% (mass fraction). The glass rod has the greatest strength in the direction of fiber arrangement. In theory, the fibers can be filled in hexagonal shapes.
At the same Fiber Glass content, the tensile strength and elastic modulus of polyester Fiber Glass reinforced plastics obtained by unidirectional distribution, bidirectional distribution and random distribution decrease in turn. In actual design, glass rod, for example, uses different winding angle changes in winding products to obtain strength in each direction according to the use conditions and performance requirements of the product: in laminated products, coarse checkered cloth and short-cut fiber mat are alternately stacked to improve the interlayer bonding force and prevent distribution: glass rod or increase the unidirectional fiber arrangement in the direction of maximum force to ensure unidirectional strength, etc.
Due to the low heat resistance of the resin, the strength of the composite material will decrease with the increase of the ambient temperature of use. The heat resistance of the glass rod resin matrix generally determines the heat resistance of the composite material.