There are so many different factors that influence the selection of an appropriate resin. The main thing is to work with your resin supplier, whether it is a distributor or resin manufacturer, to select one that best suits your needs. Creating a list of critical parameters is key to the selection process. Here are some things to consider:

Resin Quantities: One of the first factors is the amount of resin you will purchase. Do you require one or several drums, truckloads or tankers per month? This will determine whether you need to purchase a resin stocked by a distributor in a regional warehouse or one made to order by a resin manufacturer. If you are purchasing a low volume you will likely be limited to resins that local distributors have in inventory for your process and application. 

Manufacturing Process: Next, consider the manufacturing process. Will the product be manufactured by open molding spray-up, resin transfer molding, filament winding, infusion, pultrusion, centrifugal casting, open molding hand lay-up or another process? Each process has general properties like viscosity, gel and cure that resins are commonly set up to meet. If you do more than one process in your shop, select the dominant one or the most sensitive process. 

Application and End Use: After process consideration, the application/end use is the next component to think about. A resin best suited for a heavy truck part will be different than one for a surfboard or shower stall. Suppliers have internal lists of key properties and requirements that resins for various applications are designed to meet, so knowing the end use will narrow the choices. Consider what attributes you might need, such as corrosion or fire resistance.

In addition, you may be guided by certification requirements from organizations such as UL, FM, Lloyds of London, ANSI Z124, CSA International and DNV. Required certifications will dramatically narrow the list of suitable resins further. For instance, having CSA approval on the resin so your product can be sold in Canada may be an important factor in resin selection.

Regulatory Standards: Some of the standards that affect resin selection may apply nationwide, such as the Environmental Protection Agency’s Title V operating permits and Maximum Achievable Control Technology (MACT) standards. Others may be regional, such as the South Coast Air Quality Management District’s Rules 1162 and 1132 in southern California. Be sure to know any applicable state and regional hazardous air pollutant (HAP) and volatile organic compound (VOC) requirements.