Fiberglass Fabrication
Fiberglass fabrication is the process of combining thin glass fibers with different resins to produce a strong, light weight product. Since the introduction of fiberglass, it has been used as a reinforcing agent for plastics as well as insulation in buildings and appliances. Fiberglass is used in fabrication applications that demand light-weight material with high-strength and scratch-resistant qualities.
The History of Fiberglass Fabrication
The earliest form of fiberglass wasn’t truly fiberglass as it is currently understood. While in modern industry fiberglass usually refers to fiberglass reinforced plastics, when originally created the term referred to mass produced glass wool.
Games Slayter invented the process for mass production of glass fiber in 1932, which he used to produce glass wool he called ‘fiberglas’ by trapping gas in glass fibers.
Modern plastic fiberglass composite came several years later in 1936, when du Pont used a combination of fiberglass and resin to create a product with the gas of glass wool replaced with plastic. This greatly reduced the insulation properties of fiberglass, but added significant structural strength such that the material might be used in construction.
By 1942, peroxide curing and polyester resins similar to those used in fiberglass fabrication today were being used in the production of fiberglass. The development of plastics over the last century has accordingly led to significant improvements in basic fiberglass, and the expansion to countless special varieties and configurations.
In modern parlance, fiberglass usually refers to the newer form of glass fiber composite made using plastics and glass fibers, but also encompasses various glass fiber composites such as low-density glass wool used in insulation.
Fiberglass Fabrication Process
Fiberglass fabricating begins with one of three molding processes before continuing on the certain steps consistent across methods. These initial molding processes are open molding, closed molding, and centrifugal molding.
Open Molding
A one-piece structure or mold is used. A layer of gel coat is applied and cured, then fiberglass and resin layered in and allowed to cure. Notably released more emissions than alternative molding techniques.
Closed Molding
Uses a two-part structure in a more complex process than open molding. After the application of gel coat to the mold, glass fibers are added to one part of the mold as laminated sheets or small chopped pieces of glass fiber. The part is cured in a sealed vacuum and specially catalyzed resin is injected into the mold.
Centrifugal Molding
A process used specifically in the production of cylindrical fiberglass products, such as pipes and fiberglass tanks. In this process, a rotating cylindrical mold has gel coat applied to the sides, then resins saturated with fibers are layered into the mold via sprayer until the cylinder reaches the desired thickness.
Demolding
All three molding processes come together. There are several potential approaches to demolding, offering different degrees of stress, speed, and convenience. These options include mechanical demolding, demolding by hand, and demolding via compressed air.
Trimming
After a fiberglass structure has been removed from its mold, it is then trimmed or cut using any number of specialty tools and systems. Depending on the end product and the fabricator’s toolset, this may be a highly automated process using modeling software and high end mechanical automation, or a manual crafting process using hand-tools and simpler fiberglass cutting machines.
Other Processes
Some fiberglass products will require additional coatings and treatments after the trimming process to produce the final desired specifications. However, most forms of fiberglass can be fabricated with specific colors, resistances, and applications in mind, minimizing the need for post-processing relative to other fabricated materials.