What is Fiberglass Pultrusion?
Is your building in a wet area and prone to rust and deterioration?
Are you processing food, serving food, or needing to sanitize doors?
Do you need easy care and maintenance in a beautiful, smooth finished door and frame with a long life expectancy?
If you are asking any of these questions, your answer is FIBERGLASS.
Now… how do you choose what type of FIBERGLASS door and frame?
Let me explain…
There are many different commercial fiberglass door and frame manufacturing methods, but the one that is proving to be one of the best – if not the best – is the Pultruded Fiberglass Door and Frame.
Many are familiar with fiberglass pultrusion manufacturing process from its history in producing pultruded products such as FRP door frames. Today, we use this high fiber-to-resin ratio approach in the production of the toughest fiberglass doors on the market.
What is the Fiberglass Pultrusion Process?
Pultrusion is a process where raw materials (in this case glass fiber reinforcements and resins) are drawn into a profile die by a mechanical pulling force. These fibers are injected with resins while under tension where they are combined and cured.
This technology is used to create an entirely pultruded door panel. A high-density, closed cell polyurethane foam core accompanies the woven rovings, woven knits, veil and resins into the die. This core reduces the weight of the door without diminishing its strength and delivers outstanding thermal performance.
Multiple layers of glass fiber reinforcing fabrics envelop both sides of the core panel as it moves through the process: a woven layer for impact resistance, two layers of random continuous filament for flexural strength, and a thin veil top layer to provide a smooth surface finish. Glass reinforcements wrap around the panel edges from both sides to improve the door’s structural properties. This combination of reinforcing fabrics is necessary to consider, as it is this high fiber-to-resin ratio that gives the fiberglass door such impressive strength.
An FDA- and USDA-compliant resin fully saturates the glass fiber fabrics before the door enters the profile die. Here, the die compresses reinforcements around the core panel. The resin fully cures around the core as the panel passes through the heated portion of the die. This process produces a hermetically sealed, incredibly durable door panel free of voids. The FRP has as much as a 65% glass content and provides excellent impact resistance and screw holding strength.
Performance Beyond Avoiding Rust and Rot of Metal and Wood Doors
While fiberglass doors have gained favor in both the commercial and residential markets, it is important to point out key opportunities for improved performance that a fiberglass pultruded door delivers. The benefits go far beyond the avoidance of rust, rot, and the replacement cost of using wood and steel doors.
Constructed with Materials that Last
There is no door built to last like a fiberglass door. Fiberglass boasts impressive strength to weight ratio. Lighter weight allows the hardware attached to have a longer life. All fiberglass doors, so long as they are sealed, are impervious to moisture, chemicals, seawater and salt solutions. A fiberglass pultruded door delivers extraordinary performance.
No molds – No Gel Coat
The pultrusion process works without the use of a mold and therefore does not require the use of a gel coat. A fiberglass pultruded door is prime coated and finished with a two-part urethane finish that delivers superior UV protection. This 5 mil thickness finish is resistant to corrosive airborne agents and is not susceptible to chalking, discoloration, or leaching. The color maintains a high gloss appearance and flexibility for many years, even in full sun exposure and corrosive environments. This aliphatic polyurethane coating allows for easy surface damage repair. Pultruded doors with this finish are FDA and USDA compliant.
Hermetically Sealed – Really
A manufacturer can feed various core materials into the die. There is a bias toward the use of a closed cell polyurethane foam core to enhance its structural performance. This process allows doors, in constant contact with water or high humidity, to avoid constant expansion and contraction. Continual expansion and contraction quickly deteriorates a metal or wood door and damages the physical properties of a fiberglass door. Since pultruded doors are hermetically sealed, they avoid this damaging expansion and contraction.
Above and Beyond
Finally, pultruded fiberglass doors can use alternate cores adding scalable protection performance. You can order these doors manufactured with fire or ballistic cores adding safety performance to entry ways where needed. You even can order oversized doors pultruded in very long lengths without any seams!
Click below to read the original article by Special-Lite VP of Sales and Marketing, Roger Stempky, as published in DHI’s November 2016 Doors + Hardware Magazine: