Composite FRP Container

FRP storage tanks have excellent physical properties, with higher strength than steel, cast iron and molecular compound plastics. However, their thermal conductivity is only 0.5 that of steel, making them a viable alternative to steel. FRP products have great flexibility in design, and their wall structure performs exceptionally well. The operating temperature of the products ranges from -50 to 200℃, and the normal pressure resistance is below 6.4MPa. They have the advantages of pressure resistance, corrosion resistance, anti-aging, and a long service life. 

I. Determination of the Thickness of FRP Storage Tank Molds

Due to the complexity of various forces acting on FRP storage tank molds, it is difficult to conduct quantitative analysis. Currently, there are no guiding materials for determining the thickness of FRP molds. Generally, the thickness of the mold is determined based on experience, which is approximately 2 to 3 times the thickness of the FRP product.

In addition, an empirical method can also be used to determine the thickness of the mold based on its surface area. The empirical data is as follows: for a mold surface area less than 1 square meter, the thickness of the FRP mold is approximately 5mm; for a mold surface area of 2 to 10 square meters, the thickness of the FRP mold is approximately 7 to 8mm; for a mold surface area greater than 10 square meters, the thickness of the FRP mold is approximately 10mm. 

II. Determine the Demolding Method for FRP Storage Tanks

It must be pointed out that the mold structure is closely related to the demolding method. Generally, a mold structure design that is relatively easy to demold should be chosen. Due to the wide variety and diverse shapes of FRP products, the factor of convenient demolding must be fully considered when designing molds.

When the product wall has no demolding taper (usually the demolding taper should not be less than 5 degrees), or has a large vertical surface, or has an inverted taper, or has concave and convex parts that affect demolding, a split mold structure must be adopted. For example, for products with a vertical and deep wall, the mold is usually designed as a combined mold.

However, if the demolding method is the pneumatic method, an integral mold can be made without affecting the demolding effect. When determining the mold thickness and demolding method for FRP storage tanks, there are certain grounds, aiming to achieve better usage effects.

FRP storage tanks are classified into vertical and horizontal mechanical agitation FRP storage tanks, FRP transport tanks, FRP reaction tanks, various chemical facilities, horizontal FRP tanks, vertical storage tanks, transport tanks, vessels, and large series vessels. Depending on the medium used (storage or transportation), epoxy furan natural resin, modified or polyester natural resin, and phenolic natural resin are selected as binders. They are composed of a corrosion-resistant inner lining layer with high natural resin content, a seepage prevention layer, a fiber-reinforced layer, and a surface finish layer.

FRP products have excellent physical properties, with higher specific strength than steel, cast iron, and molecular compound plastics. Their thermal conductivity is only 0.5 that of steel, making them excellent thermal and electrical insulators. FRP products have great flexibility, and their wall structure performance is particularly good. The operating temperature of the product is between -50 and 200°C, and the pressure resistance is generally below 6.4 MPa. They have the advantages of pressure resistance, corrosion resistance, anti-aging, and long service life. Moreover, they are lightweight, high-strength, anti-seepage, heat-insulating, insulating, non-toxic, and have a smooth surface.

Mechanical agitation FRP vessels can adjust the physical and chemical properties of the product by using different resin systems or suitable reinforcing materials to meet the requirements of different media and operating conditions. Different pressures can be set by adjusting the thickness of the structural layer, the angle of agitation, and the wall thickness. This is a significant unique feature of fiber-reinforced composite materials.