General purpose film

An all aromatic polyetherimide is made by Du Pont from reaction of pyromelUtic dianhydride and 4,4 -oxydianiline and is sold as Kapton. It possesses excellent thermal stabiUty, mechanical characteristics, and electrical properties, as indicated in Table 3. The high heat-deflection temperature of the resin limits its processibiUty. Kapton is available as general-purpose film and used in appHcations such as washers and gaskets. Often the resin is not used directly rather, the more tractable polyamide acid intermediate is appHed in solution to a surface and then is thermally imidi2ed as the solvent evaporates. 

The main types of NatureWorks PLA that are available for packaging applications include general purpose film grades, extrusion coating, extrusion and thermoforming grades and injection stretch blow moulding. 

The general purpose film grade is biaxially oriented , a property that gives it stability at temperatures up to 130 °C. They also offer a biaxially oriented film for high temperature applications (150 °C). According to NatureWorks, these resins offer excellent optical properties, good machinability and excellent twist and dead fold characteristics. These polymers are offered in common pellet form, which should allow for rapid adoption with conventional extruders. 

Film Applications These resins can be used as general purpose films for packaging of finits and vegetables, or applied onto a variety of textiles. 

Although general-purpose films are available, they can be varied in composition to meet specific requirements. Such special formations may be superior to standard films in flame resistance, heat sealing characteristics, water absorption, cold resistance, water vapor transmission, light or solvent resistance, etc. 

The PP/PIB blends are used for general-purpose films, boil-in bags, medical over-pouches, industrial sacks and liners. The blends compounded with carbon black served as over-wraps for the manufacture of tarpaulins, photographic films and papers, as well as in a variety of outdoor applications (weatherability of clear grades is poor). 

Film products contain a comonomer (1-butene, 1-hexene or 1-octene) which is used to reduce polymer crystallinity. The type of comonomer used has a significant effect on film toughness properties. 1-butene is used for general purpose film applications and 1-hexene or 1-octene are used for more demanding applications. 

Plasticizer for general purpose film, gaskets and tubing 310 ... 

Recommended for products adhesives, blood bags, cellular rubber goods, film sheeting, gaskets, general purpose film, industrial hose and tubing, low viscosity plastisols, packaging, sealants, PVC film, vinyl foam ... 

General-Purpose Polystyrene. Polystyrene is a high molecular weight M = 2 — 3 x 10 ), crystal-clear thermoplastic that is hard, rigid, and free of odor and taste. Its ease of heat fabrication, thermal stabiUty, low specific gravity, and low cost result in mol dings, extmsions, and films of very low unit cost. In addition, PS materials have excellent thermal and electrical properties that make them useful as low cost insulating materials (see Insulation, ELECTRIC Insulation, thermal). 

Adhesives. Poly(vinyl alcohol) is used as a component in a wide variety of general-purpose adhesives to bond ceUulosic materials, such as paper and paperboard, wood textiles, some metal foils, and porous ceramic surfaces, to each other. It is also an effective binder for pigments and other finely divided powders. Both fully and partially hydrolyzed grades are used. Sensitivity to water increases with decreasing degree of hydrolysis and the addition of plasticizer. Poly(vinyl alcohol) in many appHcations is employed as an additive to other polymer systems to improve the cohesive strength, film flexibiUty, moisture resistance, and other properties. It is incorporated into a wide variety of adhesives through its use as a protective coUoid in emulsion p olymerization. 

The rolled type batteries are general-purpose batteries with high capacity and good characteristics. Thin film power sources have found a number of specific applications in the fields of portable accumulators with high energy density for application in electronic and integral circuits, sensors, monitors and for medicine [3],... 

General-purpose grades of ETFE are whitish and translucent. However, for certain grades in thin widths, for example a film of 0.025 mm, transmittance is about 95%. Refractive indices are roughly 1.407. 

General-purpose grades of cellulosics are transparent or translucent. Certain grades in thick films or sheets, 1.5 mm thick for example, have transmittances superior to 90% with a haze inferior to 8%. Refractive indices are roughly 1.47-1.48. 

The most widely used developer in the world, Kodak D-76, fells under the category of general-purpose developers. D-76 was formulated in 1927 byj. G. Capstaff of Kodak as a black and white movie film developer. However, not long afterwards better movie-film developing formulas were introduced and D-76 found use as a still-film developer. Eventually, it became the standard by which to judge all other developers. It was not that D-76 was the best developer ever formulated. It was more that a standard was needed and D-76 had the best all-around compromise of sharpness to grain with a full tonal range from black to white. 

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