Most varicose and spider veins appear in the legs due to the pressure of body weight, force of gravity, and task of carrying blood from the bottom of the body up to the heart. Compared with other veins in the body, leg veins have the toughest job of carrying blood back to the heart. They endure the most pressure.
Curing a thermosetting resin transforms it into a plastic, or elastomer by crosslinking or chain extension through the formation of covalent bonds between individual chains of the polymer. Crosslink density varies depending on the monomer or prepolymer mix, and the mechanism of crosslinking:
More Wear-Resistant Concrete: Well-cured concrete (28 day curing period) will develop a surface twice as wear resistant as a surface that is cured for only three days. Proper curing prevents dusting and means less cracking, crazing, and spalling of the concrete.ecommended practice calls for a minimum of seven days curing or the time necessary to attain 70% of the specified compressive or flexural strength, whichever period is less. (Refer to ACI - 308, Standard Practice for Curing Concrete.).