Basic Introduction To Waterproof And Breathable Fabrics And Fabric Structures And Components

The Waterproof and Breathable Fabric keeps you and your layering system dry while allowing sweat to drain during exercise. Water-repellent, breathable fabrics are typically 2-3 layers of fabric, all of which are based on the same principle: These fabrics have pores too small for water to pass through, but large enough to allow body vapors to escape. To achieve waterproof and breathable properties, fabric manufacturers use lamination techniques or coatings.
A laminate is formed when a waterproof breathable membrane is bonded directly to the fabric on the underside of a garment. An analogy for this process is the idea of ​​applying wallpaper to walls. Where membrane (wallpaper) + fabric (wall) = laminate. Paint is a liquid solution that provides waterproof and breathable properties when applied to the front of the clothing, similar to paint applied to walls. All raincoat fabrics are treated with Durable Water Repellent (DWR) for extra protection against water.

Vents typically consist of an outer layer called a fabric (usually made of nylon or polyester) and a laminated film or coating made of ePTFE or PU. A third layer consisting of a backing liner is sometimes added to provide abrasion resistance. The purpose of the fabric is to add color and protection. Although this layer is treated with Durable Water Repellent (DWR), it is not waterproof. The second layer is a waterproof layer, with pores too small to let liquid water in, but large enough to allow water vapor to escape. The last layer of the 3-layer fabric is bonded for comfort. Over the years, most waterproof and breathable fabrics have been very waterproof and suitable for any weather activity but vary in breathability and other sizes.

Waterproof fabric construction

Waterproof fabrics are produced from a structure of fabric and film layers that are fused together with heat and glue to form a fabric laminate. Fabric laminates consist of a top or facing fabric, a film layer, an additional insulating layer, and a backing (or lining) fabric. The number of layers in a fabric laminate creates expectations for the durability, breathability, and overall functionality of the laminate. The most common types of laminates are:

2-layer laminate: Consists of fabric and film. These laminates are paired with insulating and/or drop liners to protect the membrane layers from damage

2.5 Layer Laminate: Similar to 2 Layer Laminate, with printing on the membrane side to protect the membrane from damage

3-layer laminate: Consists of the face fabric, membrane, and backing fabric. 3-ply laminate most commonly found in high-performance rain covers

4-Layer Laminate: Typically used in footwear, a 4-layer laminate construction contains fabric and film, but has an additional layer of foam or felt

Waterproof Garment Components

When waterproof fabric laminates are constructed into apparel, footwear, and accessories, different components are used to lock in moisture and help increase breathability. These components help strengthen any potential weaknesses while still maintaining the intended structure and design:

Seam Sealing/Seam Tape: The waterproof garment will seal the seams with waterproof seam tape to lock in moisture from the edges of each fabric panel

Zippers/fasteners: Zippers and fasteners serve dual purposes in waterproof clothing. They have obvious use in the general construction of any jacket, but some zippers and fasteners also provide some degree of waterproof protection. For jackets with limited breathability, you may find zippers in the armpit area to quickly dissipate body heat and keep the wearer cool