Fiberglass Reinforced Polymer (FRP)
Fiberglass Reinforced Polymer (FRP) is a material in which two or more distinct, structurally complementary materials, glass fiber and a corrosion resistant vinylester resin, combine to produce an extremely durable and structurally sound product. Fiberglass is capable of being molded into complex shapes at reasonable cost, whereas fabricating out of metal can be difficult. This is apparent in the Axijet High Plume Dilution Nozzle which involves a venturi configuration inside the bifurcated nozzle.
The Advantages of Fiberglass Construction
Corrosion can be a big problem in the HVAC industry, particularly in waste- water treatment plants, fume-scrubber systems, acid fume hood laboratory exhaust and galvanizing and etching processes, to name but a few. Although HAVC equipment can be made of coated metals, stainless steel or ‘exotic’ metals such as Monel and Hastelloy, fiberglass is an economical alternative as well providing superior resistance to the majority of corrosive elements.
Other than its primary function of providing outstanding corrosion resistant properties, fiberglass can also offer the following advantages:
- If properly installed and maintained, the life expectancy of FRP material can range from anywhere from 25 years to 50 years.
- Very high strength-to weight ratio. Pound-per-pound basis, FRP is stronger than steel.
- Extremely durable to impact or scratches, the surface will not corrode.
- Weighs up to 30% less compared to equipment made out of steel and metal alloys.
- Price advantage over stainless steel, Phenolic coated steel and Monel (can be as much as 50% savings in original cost, over long term).
- Less maintenance – no repainting required due to corrosion and rusting.
- ASTM B-117 Salt Spray Testing: 8,000 hours+ after testing, and no corrosion is expected even after 25 years (200,000+ hours).
Standard FRP Fan & Blower Construction Features
- Fiberglass is constructed using Ashland Derakane 510-A corrosion resistant vinylester resins.
- Class I flame spread rate of 25 or less for all housing & wheels, per ASTM E 84 Flame Spread Testing.
- All parts in the airstream are coated in FRP, surfaces are protected with a minimum 8-10 mil thickness of chemical, ultraviolet and flame resistant resins, that conforms to ASTM D4167-97 Standard Specification for Fiber-Reinforced Plastics Fans and Blowers.
Powder Coating Systems – for Laboratory Exhaust Applications
There are applications where the severity of the corrosive exhaust is not an issue. Factors such as rate of corrosion, concentration of fumes, exhaust temperature, the amount of moisture, a variety of available colors and of course initial costs can sometimes make a Polyester or an Epoxy Powder coating on metal or aluminum HVAC equipment an attractive alternative to all fiberglass.
Why Powder Coating?
Powder coating is the application of paint in the form of a finely ground powder. The powder adheres by means of electrical attraction. After application, the coated part is heated to melt the powder then cooled so the melted powder forms a solid film. Powder coatings are the best choice for most applications and is a preferred method over the traditional Liquid Coating, which requires multiple coats to bring the mil thickness up to specification requirements. Powder coating has the following advantages:
- Excellent corrosion and chemical resistance
- Superior finish because of its uniform coverage and thickness
- Less tendency to trap airborne dirt, making for a smoother surface
- Compared to liquid coating – no drips, no pockets and no steaks
- Powder coating has little processing impact on the environment
- Better adhesion, especially on edges, crevices and surfaces difficult to reach
- Powder coating requires less time to completely cure, which means quicker shipping times
- Better hardness finish
M.K. Plastics Plastifer™ high performing two-part electrostatically applied, baked, corrosion resistant polyes- ter powder coating has excellent chemical resistance to a wide variety of chemicals including acids, caustic, solvents, and high moisture. It is far superior to standard 8-10 mil liquid epoxy that is more subject to running or sagging, is manually applied and has a non-uniform coverage over the surface. Standard finish color is M.K. Plastics light gray, and comes with a two year (2) warranty.
All steel surfaces are cleaned and prepared using a multi-stage process that includes phosphate washing to increase corrosion resistance, surface area and improve paint adhesion.
Coatings consist of a 70% zinc rich polyester primer and a polyester powder resin top coat that is electrostatically applied and cured. Final coating thickness is a minimum 4-6 mil for superior corrosion resistance, and includes UV inhibitors to prevent chalking from sunlight.
M.K. Plastics Polyester Powder Coating System is fully cured at 390ºF, and a final pencil hardness of 2H+, has high humidity resistance (Humidity ASTM-D2247 = 4,000 hrs), and the coating also exceeds 4,000 hrs ASTM-B117 Salt Spray Test.
The Corrosion Resistance Guide on the following pages lists many different chemicals and compounds that can be used in HVAC exhaust applications. The guide is intended to assist the User or Engineer in properly selecting the most suitable corrosion protection or material for the air moving equipment. The information below is a compilation of chemical resistance characteristics claimed by the manufacturers of the coatings and resins.
The guide is based on six main materials that the exhaust can come in contact with –
- FRP – Fiberglass Reinforced Polymer
- PVC – PolyVinyl Chloride
- Polyester Powder Coating
- 304 Stainless Steel
- 316 Stainless Steel
All concentrations are 100% or saturated solutions unless otherwise stated. For FRP and PVC the ratings are based on recommended temperature limitations.
To the best of our knowledge the information contained herein is accurate. However, M.K. Plastics Corporation assumes no liability whatsoever for the accuracy or completeness of the information contained herein. Final determination of the suitability of any information or material for the use contemplated, manner of use, and whether there is any infringement of patents is the sole responsibility of the user.
Nichole joined Flow Tech in 2013 as Director of Marketing. She leads our marketing communication initiatives including content marketing development, coordinating events and training, maintaining our digital presence and recruiting, as well as, some business development and office support. Nichole resides in Vernon with her husband Brian and son Roman. She enjoys hosting parties, cooking and lounging on the beach.