Measured Spray Rating Test Methods

 

For those involved in the marine textile or awning industry, the issue of water and how fabric reacts to it is critical as one of the main reasons people use marine and awning fabrics is to keep things dry. The two common water, or "hydro" issues most important to end-users are water resistance and water repellency. Industry people use these terms interchangeably, but they should not. While the terms sound similar, they are by no means the same, as explained by their definitions.

 

Water Resistance is the ability of the fabric to keep water from permeating thru the fabric. Water Repellency is the ability of the fabric to bead the water up and have it roll off, thereby not allowing the water to saturate the fabric. Obviously, if water saturates the fabric, it will eventually permeate thru and leak. Here's the caveat: a poor water repellent fabric can have excellent water resistance and an excellent water repellent fabric can have poor water resistance. In case you're beginning to think, "Okay, this is as clear as mud . . .," here are some thought s that will help resolve this murky issue.

 

A numeric scale to measure Water repellency is something called, "Measured Spray Rating," and is a visual, subjective test. Here's how it works:
 

1、A measured, specific amount of water is poured at a 45-degree angle over the test fabric, which is stretched over a circular frame.
 

2、After the water is poured, the operator performs a visual inspection of the fabric and compares its saturation to benchmarked fabric saturation photos to determine its final rating. The comparison is then made to an industry-standardized AATCC Spray Test Ratings Chart, which equates images of fabric saturation with a number rating, with 100 being the best, and 0 the worst.
 

3、As fabrics are assigned a rating, a higher number means the more the fabric will repel water in real-world situations, such as rain or snow.