GRP Products

How do you make a product out of GRP?

Depending on the final products’ desired shapes, qualities, and applications, different GRP production methods are used.

To form from GRP

For instance, an Evergrip GRP Industrial Moulded Mesh Walkway Grating Panel undergoes a lengthy hand procedure and is cured in an open mold. These sheets can be as large as 4 meters wide by 1 and a half meters high, and their thickness can vary from 12 millimeters to 60 millimeters. Here, the skeleton of the final panel is formed by weaving glass fiber strands back and forth over the length and width of a steel mold with a cellular structure using a comb-like instrument.

The desired grade and color of catalyzed resin is poured into the hot mold, where it will cure and harden. After that, a layer of Aluminum Oxide grit is glued onto the top of the GRP gratings.

Pultrusion of glass-reinforced plastic

Pultrusion is an automated machine method used to create structurally shaped parts like GRP Handrail profiles. Pictures of a machine process diagram, a factory architecture (provided by Fiberline Composites a/s), and typical product portions created using this method are provided below.

Mold for Fiberglass Reinforced Plastic (GRP)

The Hand Lay-up method is typically employed in low-volume production and custom-made GRP items since it necessitates minimal tooling. The quality of the finished laminate is directly proportional to the operatives’ level of manual expertise.

The glass fiber reinforcement may be a woven or chopped-strand mat, and it may also include a coremat for additional stiffness. Materials are prepared by cutting them to size or shape, then laying them into (or onto) the surface of an open mold that has been waxed (the release agent).  The glass or core laminate is then ‘wet’ out with resin using a roller or brush. This is then put into a warm, dry room with enough ventilation and left to cure for at least a few hours, preferably overnight. The component can then be taken apart, trimmed, painted, and polished as needed.

Applying a layer of gelcoat to the mold before inserting the reinforcement can help improve the surface finish. The side of the final object that is in contact with the mold is the top or displayed surface. 

Due to the semi-automated nature of the Spray Lay-up method, a unique set of manual skills is required.  It makes use of more costly machinery and frequently offers a computer-controlled resin/catalyst dosing system.  To apply the laminate to the mold in one motion, a pressurized spray pistol fitted with a glass fiber ‘chopper’ head unit is used.  Fiber is unwound from a bobbin and quickly chopped into rovings before being deposited into the resin stream used to fill the mold.  Common uses include plumbing fixtures, storage containers, and boat bottoms. Here’s a look at the steps involved:

Molding with Glass-Reinforced Plastic Using a Resin Transfer Process

During resin transfer molding, a resin mixture is injected into a mold at high pressure. GRP molding allows for the mass manufacturing of high-quality, consistently small-sized parts.

A heated polymer is poured into a mold’s open cavity, and the top is sealed with a plug so that the material may reach every surface.  This method is commonly employed in the transportation and automotive industries and can make use of epoxy resin systems in the fabrication of parts. This is how the system works, according to a well-known American manufacturer

Injection Molding Using Glass-Reinforced Plastic

An innovative, highly automated technique for producing huge, precision-made components that must have both high strength and stiffness and low weight.  Here, a polyurethane matrix with long glass fibers is robotically applied into a mold, where it is squeezed, cured, and hardened into the required shape via the GRP molding technique.

Pultrusion of Glass-Reinforced Plastic

Pultrusion is another highly automated industrial process for making GRP composite profiles in long, uninterrupted lengths.  Such structural forms, including channels and beam sections, are commonly used in load-bearing applications.  This method produces profiles with repeatable cross-sectional dimensions, enabling the engineering design of structures with known mechanical properties.  This method, which was invented in the United States, has been used for over fifty years, and the technology used guarantees consistent high quality across multiple iterations.

Multiple bobbins feed a mass of densely packed, continuous glass fiber rovings. Process gear subsequently pulls the reinforcements, fiberglass matting, and “surface veil” through the resin bath. The final section shape is formed and cured as it is fed through a high-pressure, high-temperature mold.  When a certain length is reached, the completed pieces are automatically trimmed.

The final GRP products are lightweight yet extremely durable, require no upkeep, and can be used in numerous places where metals and wood were previously employed.  They don’t need regular upkeep, last a long time, and won’t break the bank because of their smooth surface and resistance to corrosion.

Applications of Fiberglass

There are an almost infinite number of uses for GRP products. With proper testing and innovative thinking, GRP materials can be used in a wide variety of industries. 

• Building: Static and Movable Work Platforms
• Light fixture
• Winding stairway
• Crossings
• Roof flashing and skylights
• Downspouts
• Glazing Technique
• use of cooling towers
• Glasshouses for growing plants

• Panels for construction
• “Rebar” means reinforcing rods.
• The Use of Signs
• Signs