January 11, 2022

What Are the Types of Manufacturing Processes for FRP

Fiberglass is manufactured in a variety of different ways, depending on the product you are making. 

Fiberglass reinforced plastic is not a new invention. In fact, FRP has been made for over 110 years. Today, you can find FRP being used in a wide variety of industries. The oil industry uses FRP grating for offshore wellhead platforms, and water parks use it for stairs, railings, slides, and even decks.

In fact, FRP is the most versatile and strongest material available for all degrees of structural use. How did something so revolutionary come about? To answer this question, we must talk about chemistry so that you can understand the composition of FRP.

The composition of FRP

Plastic resins are used as binding agents to hold the glass fibers to the structural layers of FRP. These resins can also contain many different properties, such as fire and corrosion resistant qualities. FRP is manufactured in a 3-layer lay-up process and these FRPs, called laminates, are made up of the following components

Structural layers

The foundation that gives the composite its strength and structural integrity, as well as its temperature resistance.

Chemical barrier layer

This layer gives FRP its signature chemical resistance, giving it the highest durability against corrosive agents.

Surface protection layer

Depending on the purpose for which the product is manufactured, this layer gives it resistance to the environment. It also adds an additional layer of temperature resistance.

The most outstanding features of this unique composite material are its strength, durability and ability to adapt to any environment.

FRP/GRP Pipe Fittings

FRP/GRP Pipe Fittings

How FRP is made

Most products are manufactured using three different methods, depending on the end use. We use the pultrusion method, the open mold method and the hand gluing method. Each process has its own unique application. FRP products manufactured using the pultrusion process are the most desirable. Due to the nature of the pultrusion process, this method has several advantages over other methods, such as increased strength, improved corrosion resistance and better impact resistance.

Pultrusion Technology

Pultrusion is a technique for creating a continuous structural shape without distorting the cross section. The process involves pulling the three previously mentioned laminates through a heated die to form them to specification. We will cover this method more extensively as most of our products are manufactured using this process.

Pultrusion processes are used in a wide range of different applications in many industries. This is because they can replicate the strong properties of traditional materials while correcting their weak properties. For example, pultruded fiberglass grating can replicate the strength of steel grating, but unlike steel, it is corrosion resistant.


Hand Lay-up

Hand lay-up is an open molding process - the oldest molding process used to manufacture FRP products. It does not require any technical skills or sophisticated machinery. It is ideal for small, labor-intensive quantities of large products such as ships, tanks, vehicle hulls and oil pipelines.

The mold contains the desired structural shape, so careful steps must be taken. For example, if the end product is to be glossy or textured, the surface finish of the mold needs to reflect this specification. If the outer surface of the product needs to be smooth, a master die is used to create the product.

Unlike pultrusion, a release agent is required because the resin is tacky and is poured into the mold.

Upgrade your structure

No matter what industry you are in, our products can benefit your company in many ways. We've helped water parks, municipalities, chemical plants and many other companies with long-lasting fiberglass. They rely on us to provide safe, strong, durable FRP products that will last through the toughest conditions. 

Contact WEITONG today to see how our products can fit your project.