Fiberglass | What is it and How is it made?
Fiberglass is one of the most widely used synthetic materials in modern times, it finds its way into all manner of things from automobiles to construction and even surgical uses as well. It’s been around for quite some time, but many people are unsure of exactly what it is, and how it’s made.
It sure doesn’t look like glass, does it? And, well, “fiber” could mean any number of things these days. With more people recommending fiberglass grating for drainage and industrial purposes in recent years, maybe it’s time we take a look at what fiberglass is, how it’s made and used, and what’s involved in taking care of it. Maybe with a little more understanding of the technology, we can fully appreciate it for the miracle it is.
At its core, fiberglass is an epoxy resin composed of bonding material and micro-fibers of silicate glass. In its raw form, upon initial mixture, it has a viscous form similar to other epoxy compounds. It is often mixed with acetone or ether as well to increase the speed at which it coalesces and hardens in industrial practices. Once dried, depending on the process involved, it has a slightly plastic-like rigidity and a unique texture resembling a hardened putty or recycled plastic compound.
So, how exactly is this odd substance shaped into so many interesting things, and how do they get it to be smooth and shiny in some cases? Well, it’s surprisingly simple, but there are a few different processes used.
Remember, fiberglass is a viscous liquid in its initial state, and as such, it’s molded into various forms. One of the older methods for shaping fiberglass is to use vacuum or pressure molds not unlike the die casting process for some metals. The fiberglass, in its liquefied state, is pressed or injected into a mold. After this it is either chemically hardened with catalysts and acetone, or it is baked very briefly in a furnace between 330-420 degrees Fahrenheit.
This process creates a more rigid form of fiberglass that can be smooth to the touch and rather resistant to weather conditions that other processes cannot. However, with this process, it can be slightly brittle, meaning that it cannot exceed the posted stress levels by much. Fiberglass grating can be made this way, and this process is ideal for grating that will be used in drainage systems, but not really for industrial systems.
A similar process involves pressing it into sheets that are chemically hardened. These are then mounted onto rigging called a “jig”, where either robotic arrays or skilled workers cut it into various shapes. This process creates slightly less rigid, slightly less smooth fiberglass, which can be used to make grating that withstands a bit more stress. It’s somewhat costlier to manufacture due to the length of time to harden, and the effort that goes into cutting and shaping this form of fiberglass, but for industrial and construction purposes, it tends to be the most precise and durable, especially for grating and sheet work.
A third process is used, often for the creation of pool shells and some parts of vehicle bodies – seldom for grating. This involves manual or robotic spraying of epoxy fiberglass onto a shaping mold in a series of coats not unlike paint or plastic epoxy. This produces the well-known “bubbly” form of fiberglass which isn’t very rigid but very durable against water and stress. It’s less aesthetically appealing, and is therefore seldom used for things that will be directly visible in a structure. It is usually heat-hardened, but can be chemically hardened as well.
An extra stage in this process may be employed where a single side of the finished component is polished or sanded by either machines or skilled workers, to remove the uneven “bubble” appearance of one side of the shell. Automobile plants employ this heavily in modern times. Combining this with press mold techniques can also produce a rigid, transparent glass similar to Plexiglas, though this process is not yet heavily used as the product is costly and not quite as strong or scratch resistant as Plexiglas.
When it comes to maintaining fiberglass, be it grating or otherwise, it’s important to know how your fiberglass was cured. Different curing and hardening processes make it more or less resistant to thermal variation and sun exposure. Some forms of fiberglass become brittle and decay with over-exposure to UV, so it is important to be sure that the material is rated for high UV exposure in overly sunny places where this may be an issue. Fiberglass intended for draining is intended to be exposed for long periods of time to moisture, so it is important to make sure this material isn’t used in locations where long periods of absolute zero moisture may occur.
Fiberglass may develop cracks or weak spots, but these can sometimes be repaired with standard epoxy putty. Do not, however, attempt to use epoxy putty to repair grating, as any segment being weakened compromises the entire structure and it should then be replaced.
