Immovable joints

A separate group of inhibited plastics includes such engineering materials as glues, sealants, plastic Cl carriers, multi-purpose lubricants and others (see Chap. 5). Inhibited glues are intended to form tight, nondetachable joints in machine parts operating in hostile media. Sealants are able to prevent permeation of the ambient media and create impermeable immovable joints of machine parts. 

Sealing shells are mostly applied in insufficiently stiff and weakly loaded immovable joints. They are usually made as flat or hollow tubular seals fastened along the packed hole outline (lids, hatches, car and instrument bodies, doorway and window openings, etc). It should be emphasized that the introduction of Cl into sealing compositions is strongly advisable since this is found in the narrow gaps and clearances where the corrosion process intensity is the highest. 

Microencapsulated Cl fixed on the surfaces of metal parts forming immovable joints have found application in various industrial sectors. The interior of the shells is liberated when the parts are brought into contact and the capsules become squashed. This technique is used for antirust protection of rivet joints of the skin of airplanes. Microcapsules with Cl are carried, with minimum outlay, to the demanding corrosion sites of casing and drilling pipe strings at excavation sites of oil and gas deposits. The effective use of inhibited microcapsules has not been fully realized due to a number of reasons, including technical and economic ones. 

The human skeleton consists of both fused and individual bones supported and supplemented by ligaments, tendons, and skeletal muscles. The articular ligaments and tendons are the main parts holding together the joint(s). hr respect to the movement, there are freely moveable, partially moveable, and immovable joints. Synovial joints, the freely moveable ones, allow for a large range of motion and encompass wrists, knees, ankles, shoulders, and hips. 

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