We examine sleeping bags from these factors: the type and texture of fillers; the texture of internal and external materials; functional design; packaging and accessories.
There are two main types of sleeping bag fillers, down and chemical fiber cotton, in addition to single-layer fleece sleeping bags.
Down is divided into duck down and goose down. Under the same conditions, the warmth of goose down is slightly higher than that of duck down. There are three main performance indicators for down: the first indicator is the filling weight, such as 400 grams of goose down sleeping bag, 1100 grams of duck down sleeping bag, this weight is not to say the weight of the sleeping bag, the net weight of the twenty-finger filled down; the second indicator is the containing velvet The feather is composed of feather pieces and velvet. The feather pieces have a supporting effect, and the warmth comes mainly from the fine velvet. The velvet content is expressed as a percentage. For example, 80 velvet means that the velvet content in 100 weight units is 80 units. The maximum down content of duck down is 85 to 90, and the down content of goose down is 90 to 95; the third indicator is the degree of swelling of the down, and the degree of expansion (Fillpower) refers to how many cubic meters an ounce of down has under the pressure of 68.4 grams Inch, the higher the degree of expansion of the down, the better the thermal insulation performance of the down. Generally, the expansion of domestic duck down is about 450, and the expansion of domestic goose down is from 450 to 600. The Andean Goose down imported from the United States can have a velvet content of about 95 and a maximum expansion of 700 to 800.
Sometimes you can find particularly cheap down products on the market, such as a down jacket for 100 yuan and a duck down sleeping bag for 150 yuan. Such products are generally not available. Because down has two other indicators that ordinary people cannot check on site: oxygen consumption index and cleanliness. Down has to go through multiple professional cleaning and degreasing procedures.
There are many types of chemical fiber cotton, and the quality is uneven. The filling density is expressed in grams per meter square, such as 260 grams/meter square, 320 grams/meter square. Compared with the two fillings of down and chemical fiber cotton, the down thermal insulation is higher, and the weight can be the lightest under the same degree of thermal insulation; the thermal insulation of chemical fiber cotton is relatively low, the packaging volume is large, and the compressibility is low; Moisture will lose almost all of its ability to keep warm, and it is not easy to dry, so in harsh mountaineering environments, materials with water permeability are often used as the outer material of down sleeping bags. Chemical fiber cotton has a certain water-repellent performance. And the drying speed is fast; the service life of down products is very long, good maintenance can be used for more than 10 years, and the life span of chemical fiber cotton sleeping bags is only 3 or 4 years.
Fleece sleeping bags are sewn with fleece and can be used as summer sleeping bags or hygienic sleeping bags alone. It can also be used with other sleeping bags in winter to enhance the warmth effect. According to time experience, a -3 degree sleeping bag, plus fleece sleeping bag to keep warm effect can reach about -10 degrees.
Internal and external materials
Ordinary cotton sleeping bags use polyester or nylon materials, and polyester nylon cloth has differences in density and texture, so I won't go into details here. Down sleeping bags have very high requirements on internal and external materials. It is necessary to ensure that nylon materials with a density of more than 230T are required to ensure the anti-velvet. Many domestic nylon fabrics are not dense enough to prevent fleece, and manufacturers use a coating method to prevent fleece, which is very unscientific. Because the inner and outer materials of the down sleeping bag need to have good breathability, otherwise the moisture emitted will gather in the sleeping bag, which greatly reduces the warmth of the down. High-woven pure cotton or polyester cotton can also prevent down, but it is heavy and has poor compression. It is generally not used in high-end sleeping bags.
The design of the sleeping bag is also important. Let's talk about the shape first. Common sleeping bags come in three shapes, Mummy, envelope, and mixed. Mummy style is also called mummy style or mummy style. This sleeping bag has wide shoulders and narrow feet, shoulder width is generally 75 to 85 cm, and foot width is 45 to 55 cm. The Mami sleeping bag is the shape of the sleeping bag that can achieve the best warmth under the same weight, suitable for cold seasons; the envelope type sleeping bag, as the name suggests, the shoulder cloth is as wide as the feet, like an envelope, this sleeping bag is looser, suitable for the warm summer season For people with large body shape; the combination of the first two of the mixed sleeping bag type, the foot width is 55 to 65 cm.
The internationally popular sleeping bag is a small square cap, streamlined (the widest part is not at the neckline, but at the shoulder and elbow). The previous large round cap not only added weight, but was not conducive to keeping warm.
Other functional designs of sleeping bags:
Double slider zipper;
Zipper anti-trap (a thin and hard PP belt inside the zipper to prevent the zipper from eating cloth);
Zipper ventilation inter-layer (cotton windproof inter-layer inside the zipper to prevent cold wind from entering the zipper);
Chest collar (or partition collar, tighten the collar), after tightening, you can place cold air into the neck;
The design of the left and right zippers, the same type of sleeping bag is divided into left and right zippers, which can be combined into a double sleeping bag;
The size of the sleeping bag: L, M, S and other numbers to facilitate people of different heights.
Packaging and accessories
Sleeping bags are packed with Oxford cloth compression bags, which can be large or small, strong and durable.