Poly thermoforming

Thermoform able sheet may be mono- or multilayer with the latter produced by lamination or coextmsion. Multilayers are employed to incorporate high oxygen-barrier materials between stmctural or high water-vapor barrier plastics. Both ethylene vinyl alcohol copolymers and poly(vinyhdene chloride) (less often) are used as high oxygen-barrier interior layers with polystyrene or polypropylene as the stmctural layers, and polyolefin on the exterior for sealing. 

The resulting poly(oxy-1,4-phenylene sulfonyl-1,4-phenylene) (PES), CAS 25667-42-9, is a valuable polymer used to make various household appliances, medical devices, automotive parts, etc. The polymer can be shaped by thermoforming and is used in various composite materials. It has good fire safety characteristics and meets the requirements for direct food contact. Other polyethersulfones with structures similar to PES also have important practical applications and are used for the manufacturing of different appliances, cookware, automotive and aerospace components, etc. 

Poly- carbonate Plastics 1959 H-M VG G-F G-F F F All molding methods, thermoforming, fluidized bed coating Street light globes centrifuge bottles, high-temperature lenses, hot dish handles... 

Polycarbonate is being blended with ABS to lower the Vicat softening temperature and to make it more thermoformable (46). It is also blended with poly(butylene terephthalate) to increase stress-crack resistance. 

PPE with poly(hexafluoro propylene- thermoformable, high HDT, Snodgrass Lauchlan,... 

BAK 1095 (Bayer A.-G.) Poly ester-amide with properties similar to LDPE, is suitable for injection molding, blow molding, thermoform-ing, fibers and films. 

V., Dow Chem. Co., Mitsui Toatsu Chem., Ltd., Neste Oy) Poly-lactic acid (PLA) for thermoforming, blow molding, extrusion of fibers and films. The available products include compostable bags, food containers, cafeteria plates, cutlery, medical and pharmaceutical articles,... 

Poly(ethylene terephtlialate) (PET) has become a major synthetic polymer during the past forty years. Significant cotnmercial markets [1] have been developed for its application in textile and industrial fibers, films, and foamed articles, containers for carbonated beverages, water and otlier liquids, and thermoformed applications (e.g. dual ovetiable containers). 

An important factor with thermoforming is that the polymer should show a pronounced rubbery region on the temperature scale. For this reason, amorphous polymers such as PVC, PS, poly(methyl methacrylate) (PMMA), polycarbonate (PC), acrylonitrile butadiene styrene (ABS), etc. are well suited for thermo forming. With semicrystalline polymers, the rubbery region is largely masked by the crystallinity (Fig. 23.19). With PE and polypropylene (PP), thermoforming is, therefore, a critical operation, in which the processing conditions should be very carefully controlled. 

Only high-molecular grades show sufficient rubbery behavior above their melting point to enable a thermoforming process. PA, PET, and poly(butylene terephthalate) (PBT), however, will be very difficult to shape using this technique. 

Since fully cured thermoset sheets cannot be resoftened, forming is not appKcable to them. Common materials subjected to thermoforming are thermoplastics such as polystyrene, cellulose acetate, cellulose acetate butyrate, PVC, ABS, poly(methyl methacrylate), low- and high-density polyethylene, and polypropylene. The bulk of the forming is done with extruded sheets, although cast, calendered, or laminated sheets can also be formed. 

Poly(ether imidejs (PEI)s are a particular class of PI which combine the high-temperature characteristics of PI but still have sufficient melt processability to be easily formed by conventional molding techniques such as compression molding, gas assist molding, profile extrusion, thermoforming and injection molding." ... 

PPE with poly (hexafluoropropylene-co-vinylidene fluoride) Thermoformable, high HDT, and flame resistance Snodgrass and Lauchlan 1972... 

II. Plastic behavior. J Polym Sci Part B Polym Phys 38 383-392 Chen G, Dufresne A, Huang J et al (2009) A novel thermoformable bionanocomposite based on cellulose nanocrystal-graft-poly(e-caprolactone). Macromol Mater Eng 294 59-67 Choi Y, Simonsen J (2006) Cellulose nanocrystal-filled carboxymethyl cellulose nanocomposites. J Nanosci Nanotechnol 6 633-639... 

Poly(butylene adipate-co-terephthalate) (PBAT) Some of its main applications are films (mulch, containers, bags), filaments, thermoformed and injection moulded products, and blown bottles. Two products in the market are Ecoflex (BASF, 14,000 t per year) and MaterBi (former EasterBio/Eastman, now Novamont, 15,0001 per year). For some applications, PBAT has a very low stiffness, and may be mixed with PITB or PEA, for example. It may also be mixed with thermoplastic starch [69, 71]. 

Poly(butylene succinate-co-terephthalate (PBST) Some of its main applications are blown films, filaments, blown and injection moulded containers, thermoformable cups and trays, paper coating, etc. A product in the market is Sorona/Biomax). PBST has good mechanical properties, reasonable processing and biodegrades slowly [69, 72]. 

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