One attribute of Spal fan blades is their material. Instead of being made of a plastic polymer, they are comprised of specially-treated nylon. Nylon is a very effective material for how Spal fan blades work and what they are designed to do. There are three to four different types of blades available for automotive cooling fans and each boasts a distinctive shape. They are also discernible by their purpose. Straight Spal fan blades are often used for high performance vehicles while curved propellers can be used for cars, diesel trucks, and vans.
Nylon works so well because the surface is amenable to moving air with low restriction. It is not only smooth, but also resistant to dust and moisture sticking to it. For applications where a Spal low profile fan is mounted in back of a radiator or engine cooling system, high temperatures are present. When there is damp dust or debris, plastic blades may become heavier, thus rotating less. Nylon is able to withstand the heat while also presenting a strong enough surface that will not be bogged down by particles building up on the Spal low profile fan blades.
Another crucial trait is the filling. Spal low profile fan blades are not solid nylon, but instead filled with glass. They are made this way because glass is both lightweight and strong. It also cuts down on vibration. For an automotive cooling fan that is designated for high performance, the amount of CFMs can be as high as 1,900. With that kind of power, especially for straight blades, it can create a lot of noise and vibration. Spal low profile fans do not have this problem. Between the texture of the nylon surface and the glass filling, they are the quietest automotive cooling fans on the market.
If you are looking to better manage the temperature of your radiator and/or oil cooler, there are many Spal accessories to choose from. The company has developed many sizes and different fan applications with a concentration on the way their blades perform. They can also be used an OEM fan replacement in certain vehicles and for some automakers, actually come as a stock part.