How do Raincoat Fabric Manufacturers' waterproof fabrics work?

waterproof structure

A waterproof membrane or PU membrane is sandwiched between an outer layer (or "fabric") and an inner layer ("scrim") immediately adjacent to the skin. The scrim draws moisture outward and helps protect the film and membrane from contamination. The nature of the inner layer determines whether the fabric is 3-layer, 2.5-layer or 2-layer.

3 layers - outer layer, membrane layer and inner layer are bonded together into one flexible material

2.5 Layers - The outer and membrane layers are bonded together by a very thin inner carbon or an inner textured "half layer"

2 Layers - The outer layer and film are bonded together, but the inner lining is a loosely hanging fabric or mesh

The importance of durable water resistance (DWR)

When water hits a brand new waterproof jacket, it "beads up" and runs off. This is because the surface has a Durable Water Repellent (DWR) coating. Poorly maintained jackets are often "soggy," with water seeping through the fabric. When this happens, the flow of moisture inside is interrupted. The steam cannot escape because it is blocked by water droplets that soak through the fabric. The wearer may feel wet. This feeling is caused by the accumulation of sweat inside the soaked jacket, not by any leakage. The solution is usually as simple as cleaning and re-proofing the fabric with the appropriate product.

seam sealing

You can make a jacket out of a waterproof material, but it will leak quickly unless you seal the seams. Look inside the waterproof jacket and you'll see the seams are covered with strips of tape. This tape does not allow moisture to pass in either direction, so the more tape, the less breathable the jacket will be. It also stiffens the seam area.

measure performance

There are a variety of test and measurement methods that can be used to quantify performance, but none are standardized or industry-wide accepted. It's important to be skeptical of any quoted data you see, and keep in mind that multiple factors -- such as the type of fabric or the pattern of tape used -- can affect the performance of a personal style.

For more product-related information, please click: Oxford Fabric