Feather is proven natural insulation material. With proper maintenance and care it gives its users maximum thermal comfort coupled with low weight, high reliability and long life sleeping bag. Maximum “loft” reach filling with a high percentage of down in conjunction with light and fine materials that do not restrict their loft weights.
Quality feather filling
determines not only the amount of down in the mixture (see figures 90/10, 80/20 or 70/30), but also their overall flexibility and extensibility (ie. The ability to attract maximum volume and loft). This “fullness” (eng. “Fill Power”) is an internationally recognized celebrity and tested system IDBF in special laboratories.
IDBF principle of the test is the measurement of the volume of one ounce (28.35 g) feather mixture, stored in a tall glass graduated cylinder and a lid loaded with a constant weight of 68.4 g. Measurements are made in laboratory conditions at constant temperature and humidity conditions. The measured volume is standard expressed in cubic inches (1 cubic inch (cuin) = 6,387 cm3). High quality pure goose powder (i.e. a mixture which would theoretically give mark 100/0) reaches the filling capacity of 950-1000 cuin. However, this volume occupies relatively slowly, which does not meet the needs of the user sleeping bag that needs to loft manifested as soon as possible after removal of the sleeping bag from the packaging and even if the flexibility of the mixture is limited such as high humidity from the air or from long-term continuous use. Therefore, the down mixed with small feathers which are flexible and do not absorb moisture. This mixture then feather “will acquire” more quickly.
Small feathers but not in itself any significant volume, so by blending into a mixture of feathers with declining fullness and increases the weight load and the amount needed to get the sleeping bag. Therefore, we do not use just one feather blend, but we choose different ratios of down and feathers, depending on what material (what weight and structure), the sleeping bag is constructed and what use is destined.
The most commonly used mixture:
-90/10, 750 cuin-high filling used for expeditionary sleeping bags and when a critical requirement for high insulation capacity with minimum weight
-90/10, 600 cuin-cost-effective yet high-quality sleeping bags
-90 / 10, 900 cuin-extreme fullness for extremely targeted products
Every feather mix to some extent absorbs moisture and it is therefore important-if conditions allow-sleeping properly ventilate and dry. This applies mainly for use at lower altitudes, where there liquid water and sufficient humidity. In contrast, for example, when climbing expeditions, this problem is reduced with increasing altitude, as the atmospheric pressure decreases, the temperature and humidity and sleeping better moisture discards. Moistening significantly reduces the coating material is made of semi-permeable material (eg. Colibri DRY), which dramatically reduces the ingress of moisture from the environment.
All this applies only for quality feathers-must be made of waterfowl (geese, duck, Eider…) and must be chemically stripped natural grease which protects them from moisture. Feather products may not be chemically cleaned!!!