Wrapped package surfaces

Figure 3. Computer graphic of the I-WP minimal surface, together with its two associated graphs. The lighter graph is the T, or BCC, graph, and the heavier graph is the WP or wrapped package graph. The space group is 229.

Degradation of stored polymeric composites should be minimised, especially in poor environments. Protection of materials and manufactured units should be provided, with separation between surfaces to avoid direct contact or frictional damage. Wrapping, packaging and crates may be used as separators. 

Separators. Coated surfaces should preferably not be in contact. Wrapping, packaging, or crates used to reduce damage whilst items are in transit may perform this function. For large items, timber packings should be specified. 

Basic dyestuffs are usually used for dyeing of unbleached pulp in mechanical pulp such as wrapping paper, kraft paper, box board, news, and other inexpensive packaging papers. Their strong and brilliant shades also make them suitable for calendar staining and surface coloring where lightfastness is not critical. 

Pills continue to be sold mainly in loose tablet form. Sometimes sold in small plastic bags, prescription bottles, plastic wrap, coin rolls, or tinfoil, more creative packaging occasionally surfaces. For instance, in St. Louis, large quantities are sold in cigarette packs. 

The term film is also applied to sheets of cellophane, polyethylene, polyvinylidene chloride, etc., used for wrapping and packaging of food products, meats, and poultry (especially shrink films that are stretched before application). These function as a moisture vapor harrier. Plaslic lilms are also used as slip surfaces in concrete structures such as airstrips, ice rinks, and highways. Photographic film is made from cellulose acetate. 

Efflorescent crystals and crystals which absorb carbon dioxide should be quickly pressed between paper towels until as much as possible of the liquid is soaked up, and then they should be wrapped in a tight package in several layers of fresh paper towels and left in the cupboard for not more than 24 hours. The liquid is drawn by capillarity into the paper and evaporates from the outer surface, but the paper so impedes the circulation of air that water vapor does not escape, and the crystals will not effloresce unless left for more than a day. With preparations that react with carbon dioxide (such as barium hydroxide) the solution which soaks into the paper retains all the carbon dioxide which might otherwise contaminate the product. 

Warehouse drying is normally accomplished by providing an intermediate packaging that breaths. In the case of a rubber bale, the packaging may consist of polyethylene perforated film wrap that enables the surface moisture to evaporate through the film wrap and achieve an acceptable moisture spec (typically less than 0.5 weight percent for products like EPDM or butyl rubber). 

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