Crimped Wool - The Best Natural Mattress Spring
The benefits of wool in a mattress are many. For one, it can be bent back on itself more than 20,000 times without breaking, compared to about 3,000 times for cotton & 2,000 times for silk therefore it is resistant to tearing and helps add years of life to your mattress. The outside of wool is a protective layer of scales called Cuticle Cells. They overlap each other like tiles on a roof. The exposed edges of the cells face away from the root end so there's more friction when you rub the fibre in one direction than the other. This helps wool expel dirt and gives it the ability to felt.
Wool felts when fibers are aligned in opposite directions and they become entangled. The scales have a waxy coating which stop water from penetrating the fiber, but allows for absorption of water vapor. This makes wool water-repellant and resistant to water-based stains. The interior of the wool fiber is called the Cortex and make up about 90% of the fiber. It is made up of long tapering cells that overlap and are surrounded by the cell membrane complex. There are 2 main types of cells in the cortex
- The Orthocortical
- The Paracortical
Each one has a slightly different chemical composition. In finer fibers, these cells are arranged in 2 distinct halves. In coarser fibers, the arrangement is less distinct. These are the cells that create the crimp in wool. The 2 types of cell expand differently when they absorb moisture, which causes the fibers to bend. When the cells are arranged in 2 distinct halves, there is more crimp. The more random these 2 types of cells are arranged, the coarser the fiber because it creates less crimp. Crimp relates directly to fiber diameter. The crimp in wool fibers makes it soft and springy to touch. Crimp will also add bulk and trap a large volume of air between the fibers, which give wool good insulation properties. Finer wools with more crimp create fabrics that drape better than coarser wool fibers with less crimp.
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