Different types of suits are made for different purposes and for different temperatures. [1] Combinations range from a thin “shortie” (2 mm or less) covering only the upper body to an 8 mm semi-dry neoprene boot, gloves and hood, usually completed. Definition of the name of the Oxford Advanced Learner`s Dictionary combination Hugh Bradner, a physicist at the University of California, Berkeley, invented the modern combination in 1952. Wetsuits became available in the mid-1950s and evolved when the relatively fragile foamed neoprene was first covered with thin sheets of harder material such as nylon or later elastane (also known as lycra) and later sandwiched. Improvements to the way the suits` joints were made by gluing, gluing and blind seams helped the suit stay waterproof and reduce hot flashes, replacing the water trapped between the suit and the body with cold water from the outside. Further improvements to the joints on the neck, wrists, ankles, and zippers resulted in a combination known as “semi-dry.” Originally, wetsuits were made only from foam rubber or neoprene sheets, which had no support material. This type of suit required care when put on, as the foam rubber itself is both fragile and sticky against bare skin. Excessively easy to stretch and pull caused these suits to tear. This was somewhat corrected by carefully spraying the diver`s suit and body with talcum powder so that the rubber could slide more easily. Semi-dry suits are effectively a combination with improved joints on the wrist, neck and ankles, and usually also with a waterproof zipper. Together, these characteristics significantly reduce the amount of water that moves through the suit as the wearer moves through the water. The wearer is wet in a semi-dry suit, but the water that enters is quickly heated and is not “drained” by colder water that penetrates from the outside, so the wearer stays warm longer.
The closed water layer does not contribute significantly to the insulating capacity of the combination. The circulation of residual water beyond the joints still causes heat loss, but this loss is minimized by the more efficient seals. Although more expensive and difficult to put on and take off than a wetsuit (in most cases, help is needed to close the dry zipper that is usually located above the shoulders), semi-dry suits are cheaper and easier than dry suits and do not require any additional skills in the case of diving. They are usually made from thick neoprene (usually 6 mm or more), which provides good thermal insulation at shallow depths, but loses buoyancy and thermal insulation as the gas in neoprene compresses deeply like a regular combination. Early costumes, marketed as “semi-dry” suits, came in a variety of configurations, including a one-piece, full-body suit, or two pieces consisting of “long jeans” and a separate “jacket.” Almost all modern semi-dry suits are one-piece suits, with the zipper usually on the shoulders on the back, but other arrangements have been used. Semi-dry suits usually do not include boots, and most models do not include a hood (as it is difficult to create a good seal around the face), so a separate pair of wetsuit boots, hood and gloves is worn if necessary. They are best suited for use when the water temperature is between 10 and 20°C (50 and 68°F). [Citation needed] These sample sentences are automatically selected from various online information sources to reflect the current use of the word “combination”. The opinions expressed in the examples do not represent the opinion of Merriam-Webster or its editors.
Send us your feedback. The main function of a combination is thermal insulation to keep the wearer warm in conditions where they would otherwise quickly lose body heat due to heat transfer through relatively large amounts of water. Secondary and random functions include buoyancy and protection from certain environmental hazards such as abrasion, sunburn and, to a lesser extent, wind chill. Wetsuits are used for thermal insulation of activities where the user is likely to be immersed in water or frequently sprayed with strong projections, often approaching almost horizontal directions, where normal wet clothing is unlikely to keep the water away. Activities include scuba diving, sailing, sea rescue, surfing, rafting, whitewater kayaking and, in some circumstances, endurance swimming. A wetsuit must be well adjusted in order to work effectively during immersion. An adjustment that is too loose, especially at the openings (wrists, ankles, neck and overlaps), allows cold water to enter from the outside when the wearer moves. [Citation needed] The flexible seals on the wrists of the suit help to avoid heat loss in this way. The elasticity of foamed neoprene and surface textiles allows many people to stretch enough to effectively wear standard sizes, but others need to have their suits customized to get a good fit that isn`t too tight for comfort and safety. Places where the suit passes through a hollow tend to change the volume when the wearer bends that part of the body, and changing the volume of space under the suit acts as a pump to squeeze hot water out of the suit and suck the cold water into the opposite motion. The difference between a suit and a dry suit is that a dry suit allows water to enter the suit, although a good fit limits the flow of water in and out of the suit, while dry suits prevent water from entering.
As a result, underwear remains dry and retains its insulating effectiveness. Wetsuits can provide adequate protection in warm to moderately cold waters. Dry suits are usually more expensive and complex to use, but can be used when protection against lower temperatures or contaminated water is required. [2] Still water (without currents or convection) conducts heat away from the body by diffusion of pure heat, about 20 to 25 times more efficient than stationary air. [1] [3] Water has a thermal conductivity of 0.58 Wm−1K−1, while stationary air has a thermal conductivity of 0.024 Wm−1K−1,[4], so an unprotected person can succumb to hypothermia even in hot water on a hot day. [5] The combinations are made of closed-cell foam neoprene, a synthetic rubber that contains small bubbles of nitrogen gas when used as a combination material (neoprene can also be made without foam for many other applications where insulating properties are not important).