Down is an excellent natural product which cannot be substituted by synthetic fiber in any form. Various downs are from ducks, geese or eider birds. Sleeping bags filled with high down quality are characterized by their high insulation quality and long life. Every down fill contains a certain portion of small feathers which is necessary since the down itself does not have a quill and would be crushed completely. By way of adding small feathers, the down fill is stabilized and the air pockets necessary for the insulation retained. All sleeping bags bearing the Lestra down label have at least 70% down. It is always new product (original product). Annually approx. 600 tons of feathers and down from various regions are processed and used. In a modern laboratory the quality, purity and sanitary condition of the down used in the Lestra sleeping bags are tested. These tests include loft, presence of foreign particles, maturity, composition and type of down. Loft: Very often loft, which is essential for a long product life, is not stated. LESTRA indicates loft of the down in the US norm “cuin”, (cubic inches per ounce). The loft of the Lestra down blend is stated in the following fashion: original down 80% down, 20% feathers = 540 cuin; original quality geese down 90% down 20% feather = 650 cuin; original quality duck down 70% down 30% feather = 480 cuin; original quality down 80% down 20% feather = 520 cuin; original quality duck down, Teflon® treated and therefore waterproof properties and better loft with same insulation, 85% down, 15% feathers = 600 cuin. The higher the cuin value, the higher the loft of the respective down. Foreign particles: Down is an animal product which might contain substances causing allergies. Lestra avoids this problem by washing, sterilizing and cleaning the dust out of all down qualities. Maturrity: The geographic origin, the feed, size and age of the animal as well the time the animal was plucked is of importance for the down quality. An important quality indicator is the size of the individual down and the loft. The down quality depends on the age of the animal and its habitat. There is a big difference between an animal raised in the warm climate of Southern China or the colder regions of Eastern Europe or the Pyrenees. A fully grown bird from a cold region has substantially a larger and stronger down than a bird from warmer regions. The best downs comes from eastern Europe, the Pyrenees and Canada; reason for this is above all the low temperature and the non-industrial raising of the animals. Compostion: When there is breakage, dust or fiber in the down, the insulation deteriorates. To ensure a constant quality, it is necessary to have control over the processing of the down. Although there is no official norm, Lestra always states the composition of the down used in a clear manner. Down type: The test is extended by a check of the stated type of down (geese or duck) and if the given fill qualities are correct. Lestra makes it a point of importance that the quality of the used down is always stated in a clear and understandable fashion.
Teflon treated down and feathers
There are many reasons to prefer down and feathers to other fill materials. Noticeable characteristics are the excellent insulation properties, low weight, excellent breathability and the singular ability to regain volume. These extraordinary characteristics, however, have so far hidden one disadvantage: washed down or feathers lost their waterproof properties. The down lump when wet and need a long time for drying. To overcome this disadvantage, Interplume developed a process that helps down to regain its waterproof characteristic and at the same time improves its natural properties: treatment with Teflon®. As an industrial process, this treatment ensures the waterproof properties of the down and feathers and creates an invisible protection coat which keeps the natural characteristics over a long time. Regained waterproof property: The waterresistance regained by way of Teflon® treatment is the most noticeable advantage. The feathers repel any water trying to penetrate from the outside. Sleeping bags exposed to extreme weather conditions keep their full insulation properties. Keeping breathability: Teflon® treatment does not compromise the natural breathability of the down. Although it prevents the uptake of water it also helps a quick moisture transfer to the outside. Optimum Loft: Teflon® treatment improves loft of down and feathers. This makes reduction of fill weight possible without affecting the volume. Easy washing and drying: Teflon® treated down fills are easy to wash. If following the wash instructions closely, the fill will stay as good as new even after repeated washing. The water-resistant property allows for a quick drying where tumble-drying reactivates the Teflon® treatment. Odor and dust protection: Teflon® treatment results in efficient odor and dust repellent properties in down and feathers. Therefore an anti-bacterial treatment is not necessary. Environmentally friendly: Teflon® treatment is more environmentally friendly than the conventional process. Teflon® is FCC free and tested dermatologically. Easier filling: Teflon®-treated down allows for an easier automatic filling. Longer life: Teflon® treatment reduces friction among plume and keeps it healthy. This fill-is used with most of the Lestra down filled sleeping bags.
Quality features of a good sleeping bag also include thermally-stitched zips with cover bands which prevent cold bridges at the seams. A two-way nylon zip is also an absolute standard. The same is true for the quality of the zips. The upscale Lestra sleeping bags almost always feature YKK zips at constant quality.
Meets the highest demands.
AREAS OF USE AND TEMPERATURE RANGES The temperature range given should be understood as a reference only. Too many factors hinder a classification. Physical shape of the user comes into play as well as the mat used. Of importance is above all the humidity. For example, a temperature of –20°C with low humidity might be experienced as more pleasant than zero degrees with high humidity. The use of a sleeping bag is affected strongly by the weather and behavior of the user. Lestra offers three temperature ranges (comfort range, intermediate range, extreme range) and divides the sleeping bags into spring, summer, fall and winter sleeping bags. In the comfort range, sleeping without sweating or freezing is possible. In the comfort limit range, the more sensitive person might start to shiver. In the extreme range, additional clothing is required to be protected from hypothermia. Even then, sensitive people or less trained res. exhausted people might be cold. The extreme range is considered the minimum survival temperature! The temperature ranges stated have been determined and documented by laboratory tests at the “Institut International Textile de France (ITF)”. In expeditions, the extreme temperatures were sometimes valued higher with the same products. This, however, applies only to healthy, well trained people. Since the 2003 collection Lestra tests and specifies the temperature ranges of all new sleeping bags according to the European Standard prEN 13537. This newly developped standard (2002) is way stricter than other standards when it comes to the thermical testing of sleeping bags. For each of the four decisive values of the temperature range a set of parameters is defined: ambient temperature, average skin temperature of the user and the metabolic warmth production in the resting position as well as body movement and shivering caused by the cold. The temperature values will be defined according to the sleeping bag’s thermic and vapor. Nevertheless, besides a standardized temperature testing other influences must be considered as well. High humidity, strong winds and personal factors can strongly influence the user’s feeling of the temperature.
Especially for sleeping bag fillings Lestra developped its own custom made Microfibre fill, Lestra Micro Thermo. This is a highly performant technical fibre combining lightweight, durability and good insulation performance. And at the same time it provides high tear and abrasion resistance giving your sleeping bag a long life.