Sealing aluminum foil

AlEt2Cl/CoX2NR3/(MeOH)/Butadiene. All polymerizations were carried out in 250-ml. crown-capped pressure bottles with perbunan/aluminum foil seals. The bottles were dried before use by heating overnight at 120° C. and... 

The storage temperatures used were 6.6°, —12.2°, —23.4°, and — 29.0° C. The wraps were (1) glassine, (unsealed), (2) double glassine, (unsealed) and (3) sulfite paper laminated aluminum foil (sealed). The details of the thawing and curing procedures are shown in Table XVIII. 

FIGURE 7.31 Aluminum foil sealing machine. (From Leader Tech United. Available at http //www.ltucompany.com.)... 

Hard sugar candies have very low moisture content. They are sealed in low water vapor-transmission packaging such as aluminum foil or oriented polypropylene film. 

Polyester. Poly(ethylene terephthalate) [25038-59-9] (PET) polyester film has intermediate gas- and water- vapor barrier properties, very high tensile and impact strengths, and high temperature resistance (see Polyesters, thermoplastic). AppHcations include use as an outer web in laminations to protect aluminum foil. It is coated with PVDC to function as the flat or sealing web for vacuum/gas flush packaged processed meat, cheese, or fresh pasta. 

Saran film is used to wrap cheese and occasionally for vertical form/fiU/seal chub packaging of sausage and ground red meat. Mostly it is used as the high barrier component of laminations not containing aluminum foil. It is rarely used alone in commercial packaging because it is difficult to seal. 

In a variant of the horizontal form/fill/seal operation, the material, moving in a horizontal direction, is folded on itself vertically. Vertical sections of the two faces are heat-sealed to each other to form a pouch, which may then be filled. The pouch, usually made from film or paper bonded to aluminum foil plus a plastic laminant and heat sealant, is closed by a heat seal. This type of pouch gives high moisture and oxygen protection and is used for moisture-and flavor-sensitive condiments and beverage mixes. 

In contrast to most extmsion processes, extmsion coating involves a hot melt, ca 340°C. The thin web cools rapidly between the die and nip even at high linear rates. Both mechanical and chemical bonding to substrates are involved. Mechanical locking of resin around fibers contributes to the resin s adhesion to paper. Some oxidation of the melt takes place in the air gap, thereby providing sites for chemical bonding to aluminum foil. Excessive oxidation causes poor heat-sealing characteristics. 

The disbonding rate decreases with time [35], which can be attributed to the consumption of OH" ions by reaction with adhesive groups. This consumption is obviously partly compensated for by the formation of OH" ions through oxygen reduction these permeate inward from the outer surface of the coating. If this permeation is hindered by an aluminum foil gas seal, the disbonding rate falls off... 

Fignre 27.3 shows a typical spectroelectrochemical cell for in sitn XRD on battery electrode materials. The interior of the cell has a construction similar to a coin cell. It consists of a thin Al203-coated LiCo02 cathode on an aluminum foil current collector, a lithium foil anode, a microporous polypropylene separator, and a nonaqueous electrolyte (IMLiPFg in a 1 1 ethylene carbonate/dimethylcarbonate solvent). The cell had Mylar windows, an aluminum housing, and was hermetically sealed in a glove box. 

Another available product has two faces of aluminum foil over a core of glass scrim webbing it is coated with asphalt. The membrane is 0.012 in. thick. This material has not been tested as a barrier against diffusive flow of radon, but its performance should be similar to that of other foil-faced products. Seams are sealed with aluminum tape. 

We use extrusion coating to apply thin layers of polymer to the surface of non-polymeric substrates such as cardboard or aluminum foil. Extrusion coated materials are extensively used in food packaging. Products include the coated cardboard used to make milk cartons and the coated aluminum foil used to seal dairy product tubs. The process of extrusion coating has much in common with film casting. 

C and 5 hrs at 177°C under vacuum. Specimens were sealed in evacuated aluminum foil bags and irradiated with 0.5 HeV electrons at six different dose levels, viz. 1000, 2000, 3000, 4000, 5000 and 10,000 Mrads. 

The most common forms of flexible packaging are the blister package and the pouch. A blister package usually consists of a lid material and a forming film. The lid material is usually a laminate, which includes a barrier layer (e.g., aluminum foil) with a print primer on one side and a sealing agent (e.g., a heat-sealing lacquer) on the other side. 

Seal each plate with an aluminum foil lid. 

Calcium chloride is available from chemical supply houses, or as "Damp-Rid" refills, from most hardware stores. Place a sufficient amount of calcium chloride in the bottom of a polyethylene container. Place a piece of aluminum foil over but not touching the CaC12, and place the leaves to be dried on top of foil. Curling up the edges of the foil, should prevent the leaves from touching the CaC12. Then seal the container. The leaves should be dry in about two days. 

The lithium phenoxide may be prepared in larger quantities and may be stored for some time sealed under nitrogen and protected from light by wrapping the flask with aluminum foil. Traces of water lead to a gummy salt, while traces of oxygen cause a purple coloration. Quite badly discolored salt has been used successfully in the alkylation procedure, but yields tend to be reduced by tar formation. 

There are two types of lidding push through and peel and push. Lidding material may be of aluminum foil, paper, or plastic that is coated or laminated to enable sealing to the material of the blister pack. 

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