What are the structural layers of hand lay-up fiberglass?

Fiberglass Interlayer Structure

Hand lay-up fiberglass molding is a manual process where fiberglass fabric and resin are alternately laid on a mold, then cured to form a fiberglass product. Its interlayer structure mainly consists of four layers:

First layer: Gelcoat layer, providing good surface quality and weather resistance protection;

Second layer: Surface mat (required for products with high surface requirements), reducing surface bubbles, isolating fabric textures, and smoothing the surface. Due to its high resin content, this layer can also serve as an anti-corrosion layer;

Third layer: Putty layer, improving the adhesion of the structural fiberglass layers and reducing air bubbles beneath the product surface;

Fourth layer: Structural layer, a composite cured from resin and fiberglass, serving as the product's load-bearing structure. Additionally, depending on functional requirements, the structure can be further subdivided into functional layers such as anti-corrosion layers, anti-aging layers, and strength layers, each using fiberglass materials with different properties.

Fiberglass Reinforced Plastic (FRP) Production Process

The production process for hand lay-up FRP products is exactly the same as that for ordinary injection molded parts and compression molded parts. The equipment used in this process requires low investment, has a simple structure, and does not demanding workspace requirements. The main molding process and sequence can be summarized as follows:

Product data freezing → Mold design → Mold processing and fabrication → Mold acceptance → Mold preparation (cleaning and waxing) → Gel coat application → Putty application → Resin application and fiberglass lamination → Baking and curing → Demolding → Obtaining hand lay-up blanks → Cutting and drilling → Embedded parts → Water grinding and dewaxing → Putty application → Primer → Topcoat → Attachment packaging → Inspection → Warehousing.