How to choose high-quality fiberglass felt when manufacturing fiberglass reinforced plastic fishing boats?

To choose a good fiberglass substrate, you need to understand its advantages and disadvantages and whether it is suitable for use. The following are some general selection criteria

First of all, the most basic requirement for fiberglass chopped strand mat used in shipbuilding is to pass the China Classification Society (CCS) certification (mainland China) and Lloyd's Register of Shipping (Lloy's) and Det Norske Veritas (DNV) certification (foreign recognition). If you have several certifications at the same time, that is the best proof.

fiberglass mat is mainly used for manual lamination and is generally considered a good product if it meets the following conditions:

① Uniform weight per unit area.
This condition is very important, as it affects both thickness and strength. It is easier to distinguish under light, and severely uneven products can be seen with the naked eye. Thickness uniformity: uniform mass per unit area of ​​the felt does not necessarily ensure uniform thickness of the felt, which is directly related to the uniformity of the gap between the cold press rollers. Uneven thickness of the felt will lead to uneven resin content in the FRP product, and the fluffy felt will have a large resin adsorption capacity. The standard test method for uniform mass per unit area of ​​the felt is to cut 300mmx300mm felt sheets in the width direction of the felt, number them in sequence and weigh them separately, and calculate the weight deviation of each felt sample.

② The yarns are evenly distributed without excessive local accumulation.

The short-cut dispersion of the raw yarn is an important indicator in the production of raw yarn, which affects the uniformity of the mass per unit area of ​​the felt and the distribution of the raw yarn on the felt. After the raw yarn bundles on the yarn tube (cake) are short-cut, each bundle of raw yarn must be fully dispersed. If some raw yarn bundles cannot be fully dispersed, it is easy to form coarse stripes of sheet-like raw yarn bundles on the felt.

③ No yarn falling off or peeling off on the surface. Mechanical tensile strength of the felt. Low mechanical tensile strength of the felt indicates that the bonding between the original yarn bundles is not good.
④ No dirt.

⑤ After being fully dried. If it is damp, it will fall apart if it is spread out and then picked up. The moisture content of the felt is <0.2%, which is generally acceptable for normal production processes.

⑥ The resin is fully impregnated. Styrene solubility. The solubility of the felt in polyester resin should be tested, but the solubility test of the felt in polyester is quite time-consuming and difficult to quantitatively observe. Using styrene to replace polyester resin to test the solubility of the felt can also indirectly reflect the solubility of glass fiber felt in polyester. This method has been accepted worldwide and standards have been established.
⑦ The yarn does not relax after resin impregnation.
⑧ Easy to degas.