Crimping metal tubes

Crimping. Squeezing a metal tube round a plug, fuse, or similar body to secure the latter firmly. 

Semi-solid products have been traditionally packed in collapsible tin tubes. Metal tubes are a potential source of metal particles in ophthalmic products, and so the tubes have to be cleaned carefully prior to sterilisation. Also, the final product must meet limits for the number of metal particles found. Plastic tubes are not suitable because of their non-collapsible nature, which causes air to enter the tube after withdrawal of each dose. However, collapsible tubes made from laminates of plastic, aluminium foil and paper are a good alternative to tin tubes. Laminated tubes fitted with polypropylene caps can be sterilised by autoclaving, whereas tubes fitted with polyethylene caps are sterilised by gamma irradiation. The tubes are usually filled aseptically, sealed with an adhesive and then crimped. 

Although metal columns are not as popular as in the past, they still are used. In addition, short lengths of metal tubing are sometimes used to connect parts of the apparatus. Place the tubing on the wheel where the bend is desired. The handles are squeezed together to make the bend. This prevents crimping of the tubing. 

Metal reactors were inspected by breaking the tubes, which were often brittle from carburization. The ends were crimped longitudinally and often pieces of the deposited carbon layer broke loose. Normally,... 

Crimping—shaping, folding and crimping, e.g. collapsible tubes (metal). Aerosol valves for glass bottles. Overseals for injection vials. 

Fig. 2. Some tantalum seals and apparatus. (A) Crimped and welded (B) capped and welded (C) apparatus for biphasic, isopiestic equilibrations (D) thermal analysis container (E) tantalum tube to be welded under vacuum [tube is brazed to metal-to-glass seal and closed with joint and stopcock at top) not shown)] (F) sublimation container with reservoir or condenser swaged or flared to fit (G) reaction container sealed in silica jacket under vacuum.

A ground system is only as good as the methods used to interconnect the component parts [9]. Do not use soldered-only connections outside the equipment building. Crimped/brazed and exothermic Cadwelded) connections are preferred. (Cadweld is a registered trademark of Erico Corp.) To make a proper bond, all metal surfaces must be cleaned, any finish removed to bare metal, and surface preparation compound applied. Protect all connections from moisture by appropriate means, usually sealing compound and heat-shrink tubing. 

Each cell comprises a pure lithium anode, a solid cupric oxide/graphite cathode and a porous non-woven glass separator. The electrolyte is lithium perchlorate dissolved in 1,3 dioxolane. Cells are available in a bobbin cylindrical cell formal in which an electrolyte filled central tube (lithium anode) is wrapped in the separator and surrounded by an annular cathode (cupric oxide). The cell is sealed with a crimp-sealed polypropylene joint or glass to metal seals. 

ASTM FI 807 Standard Specification for Metal Insert Fittings Utilizing a Copper Crimp Ring for SDR9 Cross-Linked Polyethylene (PEX) Tubing, ASTM International, USA (2005). 

---