Solvent welding refers to a process in which a solvent or solvent blend with no dissolved polymer is used to create a joint between two thermoplastic parts. Solvent welding and solvent cementing are simple and inexpensive processes that produce durable, hermetic joints. Compared with mechanical fastening, the joint may be lighter in weight, does not need additional components, and can be quicker to assemble. The solvent processes also avoid the stress concentrations usually found at mechanical fastenings. Both processes give a joint with low or zero visibility, and unlike adhesive bonding, there is no additional phase at the joint. A wide range of joint designs can be used and, compared with most thermoplastic welding techniques, these processes can be used to assemble relatively large components containing irregular joints. Solvent welding and solvent cementing can produce welds with very little or no weld flashes, giving a better appearance than the welding techniques that use heat or friction, and, compared with frictional techniques, there is no risk of producing particulate debris. Solvent welding is used for assembly of toys and for tamper-proof housings, for example, for utility meters. Other applications include fabrication of hermetic seals in medical devices, and assembly of joints in applications where the final appearance is important, such as with acrylic or polycarbonate display cases and isolation glove boxes.