Sealing process

Although there have been few changes in the basic anodising practices, and sulphuric acid is the electrolyte used in most plants, there have been many developments in the pretreatment, colouring and sealing processes associated with anodising. 

The cylindrical-type sealing process for strip packaging does not usually have a cooling cycle or quench surface, hence any pull on the seal ply will tend to weaken the seal while the sealant is still pliable. Therefore, it is desirable that the sealant have good hot tack or a high melt viscosity at processing temperatures. Hot tack is generally accepted to mean the adhesion quality of the sealant from the moment it leaves the seal head and the time it returns to its set or permanent condition. 

There are two basic ways of using this form, fill seal process with laminates, films, or sheets in reel form. 

Using two stock reels to form the two sides of the pouch (usually used in vertical form, fill, seal process). 

Depending on the thermal stability of the dye, the duration of the seal-ing/lamination step and the sealing material, dye coloration (process step 6) can also be carried out after sealing (process step 7) by flushing the cell with dye-containing solution through the filling holes. 

A tubular furnace (not shown) is now slipped over the combustion tube, and the metal is oxidized at 450-500° for a period of 12 hr. The products which sublime out of the heated zone and condense in the cold region of the combustion tube are now resublimed as follows. The boat is first sealed off from the combustion products which are then isolated in a 30-cm section of the combustion tube by a second sealing process. 

Caution. In order to seal off sections of the combustion tube, the oxygen pressure in the system must be about 50 torr below atmospheric pressure. Failure to reduce the internal pressure will prevent a good end seal and may cause a hole to develop during the sealing process. 

The blow/fill/seal process is a complete packaging technique that integrates the extrusion or IBM and container filling steps. This can provide for aseptic filling of the hot as-blown container and is used for pharmaceutical, food, and cosmetic products. The process employs a two-part mold in which the container body mold cavity blocks are separate from the neck-forming members. 

Filling and packaging by blow/fill/seal technology has gained wider acceptance for use in the biotechnology industry in the past decade. The blow/fill/ seal process is one continual, integrated operation in which the container is formed by blowing a molten... 

Jones, D. Topping, P. Sharp, J. Environmental challenges to an aseptic blow-fill-seal process a practical study. J. Pharm. Sci. Tech. 1995, 49 (5), 226-234. 

Fulljames, J.R., Zijerveld, L.J.J., Franssen, R.C.M.W., Ingram, G.M. and Richard, P.D. 1997. Fault seal processes. In P. Mpller-Pedersen and A.G. Koestler (Editors), Hydrocarbon Seals Importance for Exploration and Production, NPF Special Publication 7. Elsevier, Singapore, pp. 51-59. 

Fault seal processes systematic analysis of fault seals over geological and production time scales... 

Fig. 1. Classification of fault seal processes. Fault seals are divided into two types juxtaposition fault seals and fault gouge seals (e.g., cataclasis and clay smear). One fault may have a combination of different sealing processes affecting its sealing capacity.

Fig. 2. Strategy for the analysis of fault seals over geological time scales. Based on a fault juxtaposition diagram, the effects of the different fault seal processes are assessed in a systematic manner for their seal capacity due to clay smear, brittle fault sealing and juxtaposition fault seal.

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