Search results
Results from the WOW.Com Content Network
Spandex fibers are produced by several spinning technologies. Typically, a concentrated solution of the polymer is drawn through spinnerets at temperatures where the solvent evaporates. [6] Chemical route to polyurethane polymer used in production of spandex. Spandex is mainly composed of a polyurea derived from the reaction of a diol and a ...
Industrial Insulation. Rigid polyurethane foam is used in various industries to provide thermal insulation to installations and pipes. In particular, the piping for district heating systems in Europe is primarily insulated using a pre-insulated pipes sandwich assembly composed of a steel heat service pipe, an insulating layer (polyurethane foam) and a polyethylene (PE) casing, which are bonded ...
A cross-linked polyethylene (PEX) pipe. Cross-linked polyethylene, commonly abbreviated PEX, XPE or XLPE, is a form of polyethylene with cross-links.It is used predominantly in building services pipework systems, hydronic radiant heating and cooling systems, domestic water piping, insulation for high tension (high voltage) electrical cables, and baby play mats.
Screen gutter guards are among the most common and most effective. They can be snapped on or mounted, made of metal or plastic. Micromesh gutter guards provide the most protection from small and large debris. [33] PVC type gutter guards are a less costly option, however, they tend to quickly become brittle due to sun exposure.
When coated with a 50–100 nanometer layer of aluminum oxide, the material was able to withstand loads of as much as 280 megapascals, stronger than any other known material whose density was less than 1,000 kilograms per cubic metre (1,700 lb/cu yd), that of water. [1] [2]
Polyvinyl chloride is formed in flat sheets in a variety of thicknesses and colors. As flat sheets, PVC is often expanded to create voids in the interior of the material, providing additional thickness without additional weight and minimal extra cost (see closed-cell PVC foamboard). Sheets are cut using saws and rotary cutting equipment.
The high-temperature properties of the polymer are improved, its flow is reduced, and its chemical resistance is enhanced. PEX is used in some potable-water plumbing systems because tubes made of the material can be expanded to fit over a metal nipple and it will slowly return to its original shape, forming a permanent, water-tight connection.
HDPE is known for its high strength-to-density ratio. [4] The density of HDPE ranges from 930 to 970 kg/m 3. [5] Although the density of HDPE is only marginally higher than that of low-density polyethylene, HDPE has little branching, giving it stronger intermolecular forces and tensile strength (38 MPa versus 21 MPa) than LDPE. [6]