Heat-sealing plastics

Plastic sandwich boxes make good containers for blot washing, but often have a much larger base area than the size of the membrane. It is useful to have a few containers that have a base of similar dimensions to the membrane, so that incubations can be carried out in as small a volume as possible. Incubations with antibody solutions can be performed in heat-sealed plastic bags (see Note 11), but this is not practical for other steps, particularly incubations with visualization solutions Lids from pipet tip holders make suitable containers for small blots from mimgels... 

The volume of antibody solution required depends on the size of the blot and the container in which the incubation will occur Incubation in heat-sealed plastic bags can significantly reduce the required volume, with a blot from a minigel (8.5 x 5 5 cm) needing only 5 mL of primary antibody solution when incubated in this way If you are unsure of what volume is required, then seal the membrane (or one of the same size) in a plastic bag with a volume of TST, and check that there is enough fluid to cover the membrane... 

Equilibrate membrane in appropriate blocking buffer in heat-sealed plastic bag with constant agitation using an orbital shaker or rocking platform. For nitrocellulose and PVDF, incubate 30 to 60 min at room temperature. For nylon, incubate >2 hr at 37°C. 

Although the principle of a dot-blot apparatus is the same, we recommend the use of a slot-shaped manifold for quantitative determinations, because this shape enables more uniform immobilization of DNA We use rectangular plastic containers and sufficient solution to cover the Biters evenly for all incubations. To save on reagent, Nehls et al. (3) suggested the use of heat-sealed plastic bags. 

It may be packaged in heat sealed plastic bags and placed on the bottoms of pickle barrels, fuel tanks of planes, boats or cars. Small vials of the oil can be concealed in fountain pens or jewelry. 

Cone sleeves are made from a laminate of aluminium foil and paper. The top of the sleeve is crimped down over a cardboard disc to form a lid after product assembly is completed. Tubes are made from cardboard coated on both sides with polyethylene. The base is heat-sealed to make it leak-proof and the top is rolled to make a rim, onto which the lid is heat-sealed. Plastic tubs and containers are used for ice cream and... 

As far as matches are concerned, a heat-sealed plastic envelope will protect a book or box of matches from getting soaked in rain and... 

Depending on the structure of the barrier film and the materials used, gas ingress can preferentially take place through the whole surface of the barrier film (permeation through the surface) or through the heat-sealed plastic VIP flanges (permeation at the edges), or both. 

Attempts have been made to perform thermal retorting ia a gas barrier flexible pouch or tray. The retort pouch, under development for many years, has a higher surface-to-volume ratio than a can and employs a heat seal rather than a mechanical closure. Similarly, plastic retort trays have higher surface-to-volume ratios and are usually heat seal closed. Plastic cans iatended for microwave reheating are composed of bodies fabricated from multilayer plastic including a high oxygen barrier material, plus double-seam aluminum closures. 

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. 

Vinylidene Chloride Copolymer Latex. Vinyhdene chloride polymers are often made in emulsion, but usuaUy are isolated, dried, and used as conventional resins. Stable latices have been prepared and can be used direcdy for coatings (171—176). The principal apphcations for these materials are as barrier coatings on paper products and, more recently, on plastic films. The heat-seal characteristics of VDC copolymer coatings are equaUy valuable in many apphcations. They are also used as binders for paints and nonwoven fabrics (177). The use of special VDC copolymer latices for barrier laminating adhesives is growing, and the use of vinyhdene chloride copolymers in flame-resistant carpet backing is weU known (178—181). VDC latices can also be used to coat poly(ethylene terephthalate) (PET) bottles to retain carbon dioxide (182). 

In the adhesives area, thermoplastic, fatty polyamides are used in hot-melt and heat-seal adhesives for leather, paper, plastic and metal. Blends of EDA- and DETA-based polyamides are suggested for use in metal can seam sealants with improved toughness (234) pressure sensitive adhesives have been formulated with DETA-based polyamides (235) and anionic and cationic suspensoid adhesives are used as heat-seal coatings in paper converting (236). PIP and certain PIP derivatives are used with EDA in some appHcations (237). 

Biological wastes Sealed plastic bags 120 L Heat sterilization prior to bagging special heavy-duty bags... 

To reduce the permeation of specific compounds through plastic sheets, barriers are introduced in multi-layer structures. Each layer provides its own performance in terms of heat sealing, barrier properties, chemical resistance, stiffness, etc., and... 

BAG PLASTIC 39"HT 36"W SING WALL HEAT SEAL 44GAL CAPACITY 20QS S105012708749 PG 84.74 ... 

BAG PLASTIC A4 FLAT 12IN X 12IN HEAT SEAL CLEAR 8105008377757 BX 34.53 ... 

The above results suggest a potential for utilizing surface fluorinated plastics for modified atmosphere and vacuum packaging applications. If needed, the barrier properties can be improved further by vacuum metalization. Excellent adhesion was found for vacuum-deposited aluminum on this new fluorinated layer, achieving an adhesion index of 10 using the classical cross-hatch method. With this treatment method it was also possible to heat-seal PP or PE onto PET. 

Uses Manufacture of esters for use in perfumes, flavors, soaps, lotions, ointments photographic developer for color movie films dying nylon filament, textiles, and sheet plastics solvent for dyestuffs, cellulose, esters, casein, waxes, etc. heat-sealing polyethylene films bacteriostat, insect repellant emulsions ballpoint pen inks and stencil inks surfactant. 

By far the most studied PolyHIPE system is the styrene/divinylbenzene (DVB) material. This was the main subject of Barby and Haq s patent to Unilever in 1982 [128], HIPEs of an aqueous phase in a mixture of styrene, DVB and nonionic surfactant were prepared. Both water-soluble (e.g. potassium persulphate) and oil-soluble (2,2 -azo-bis-isobutyronitrile, AIBN) initiators were employed, and polymerisation was carried out by heating the emulsion in a sealed plastic container, typically for 24 hours at 50°C. This yielded a solid, crosslinked, monolithic polymer material, with the aqueous dispersed phase retained inside the porous microstructure. On exhaustive extraction of the material in a Soxhlet with a lower alcohol, followed by drying in vacuo, a low-density polystyrene foam was produced, with a permanent, macroporous, open-cellular structure of very high porosity (Fig. 11). 

For sealing membranes into bags it is easiest to cut two sheets of plastic and place one underneath and one on top of the membrane Heat seal around three sides to make a bag, add the incubation solution, remove any air bubbles and seal the fourth side... 

The alternative to using a dish is to form the material into a bag and this so-called pouch or sachet method is often used for plastics films. The advantages are that a larger surface area is exposed, leaks through the wax seal are eliminated, and the conditions are more similar to packaging applications. It is less attractive for rubbers because they are not often used in that sort of packaging application and an alternative to heat sealing the pouch would be necessary. 

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