High density polyethylene films

Table 6 shows the sales estimates for principal film and sheet products for the year 1990 (14). Low density polyethylene films dominate the market in volume, followed by polystyrene and the vinyls. High density polyethylene, poly(ethylene terephthalate), and polypropylene are close in market share and complete the primary products. A number of specialty resins are used to produce 25,000—100,000 t of film or sheet, and then there are a large number of high priced, high performance materials that serve niche markets. The original clear film product, ceUophane, has faUen to about 25,000 t in the United States, with only one domestic producer. Table 7 Hsts some of the principal film and sheet material manufacturers in the United States.

Plastic materials represent less than 10% by weight of all packagiag materials. They have a value of over 7 biUion including composite flexible packagiag about half is for film and half for botties, jars, cups, tubs, and trays. The principal materials used are high density polyethylene (HDPE) for botties, low density polyethylene for film, polypropylene (PP) for film, and polyester for both botties and films. Plastic resias are manufactured by petrochemical companies, eg. Union Carbide and Mobil Chemical for low density polyethylene (LDPE), Solvay for high density polyethylene, Himont for polypropylene, and Shell and Eastman for polyester. 

EiaaHy, a new aluminum fire-resistant paneling consists of a composite design that iacludes a soHd thermoplastic compound core covered with a high density polyethylene adhesive film and an aluminum skin. The product is easily formable. It has sound deadening abiHties, and an optional poly(vinyHdene fluoride) resia coatiag provides damage resistance. 

Polyethylene films as packaging material "plastic" squeeze bottles are molded from high-density polyethylene. 

Akhtar has studied the morphology and physical properties of NR and high-density polyethylene blends prepared in Brabender plasticorder at 150°C at a rotor speed of 60 rpm [53]. Films were molded between two chromium plates at a pressure of 0.34 MPa. The films along with mold were... 

Low-density polyethylene (LDPE) film for food packaging, etc. High-density polyethylene (HDPE) blow molded into bottles and containers... 

On the other hand, there is no evidence to support the assertion that polyethylene vapor berries deteriorate with exposure to soil chemicals. Construction film is a low-density polyethylene. High-density polyethylenes are used for the storage and transportation of an array of chemicals. Polyethylene is chemically stable, but may be adversely affected by aliphatic hydrocarbons (such as hexane, octane, and butane) and chlorinated solvents. It does not appear to be reactive with the acids and salts likely to be encountered in soil and concrete. 

High density extruded planks, 23 404 High density lipoproteins (HDLs), 5 135-137 10 829 niacin and, 25 798 High density polyethylene (HDPE), 10 596-595 11 225 16 21 17 724 20 149-179 24 267, 268. See also HDPE entries analysis of, 19 566 as barrier polymer, 3 377 bimodal reactor technology for, 20 170 blow molding of, 20 171-172 blown film applications, 20 173-174 catalysts used for, 20 152-155 chemical resistance of, 20 166 commercial applications of,... 

In order to illustrate the utility of model parameter interpretation, a data set containing NIR transmission spectra of a series of polymer films will be used [85]. In this example, films were extruded from seven different polymer blends, each of which was formulated using a different ratio of high-density polyethylene (HDPE) and low-density polyethylene (LDPE) where the blend compositions were 0, 2.5, 5,10, 25, 50 and 100% HDPE. NIR spectra were then obtained for four or five replicate film samples at each blend composition. Figure 12.18 shows the NIR spectra that were obtained. 

Figure 12.22 The regression coefficient spectrum for the PCR model of high-density polyethylene content in the polyethylene blend films.

A significant fraction, more than 25%, of the low-density polyethylene (LDPE) (Sec. 3-14a) produced by radical polymerization consists of various copolymers of ethylene. LDPE has come under increasing economic pressure in recent years because of a combination of factors [Doak, 1986]. High-density polyethylene (HDPE) has displaced LDPE in applications such as blow-molded bottles and thin films where the increased strength of HDPE is preferred over the clarity of LDPE. Linear low-density polyethylene (LLDPE) (Sec. 8-1 lc) competes effectively with LDPE in terms of both cost and properties. New producers of ethylene have entered the LDPE market because of a lack of alternatives for their feedstocks. Many LDPE producers use copolymerization as a strategy to obtain products more resistant to displacement by HDPE and LLDPE. 

Focusing collectors are usually cast acrylic Fresnel lenses, or mirrors of aluminized polyester film in frames of aluminum. These reflectors are either enclosed in a bubble of poly(vinyl fluoride) film, or under polycarbonate glazing, which may be covered with a fluorocarbon film to reduce the reflectivity. The absorbers for active systems are copper or aluminum since the temperatures are too high (325—370°C) for plastics. The frames, however, can be molded ABS, high density polyethylene or polyurethane, either solid or structural foam. Polybutylene or chlorinated PVC can be used for piping hot water, and tanks can be made of either reinforced polyester or blow- or rotational-molded, high density polyethylene (12—15). 

Fig. 18. Induced open-circuit voltage in elongation plotted against amplitude at the end of film for as-cast films polypropylene (PP), high-density polyethylene (PE(H)), low-density polyethylene(PE(L)), polystyrene PS), and poly(methyl methacrylate) (PMMA). Span length = 3.6 cm. Electrode area=2.5 x 2.5 cm2. Film thickness =0.5 mm. Reproduced from Furukawa and others [J. Appl. Polym. Sci. 12, 2675 (1968)] by permission of John Wiley Sons, Inc.

Film -use of microbial polysaccharides [MICROBIAL POLYSACCHARIDES] (Vol 16) -cellulose esters m [CELLULOSE ESTERS - ORGANIC ESTERS] (Vol 5) -drying of [DRYING] (Vol 8) -by extrusion [PLASTIC PROCESSING] (Vol 19) -ITOPE [OLEFIN POLYMERS - POLYETHYLENE - HIGH DENSITY POLYETHYLENE] (Vol 17) -from LDPE [OLEFIN POLYMERS - POLYETHYLENE - LOW DENSITY POLYETHYLENE] (Vol 17) -of LLDPE [OLEFIN POLYMERS - POLYETHYLENE - LINEAR LOW DENSITY POLYETHYLENE] (Vol 17) -of polyethylene oxide) [POLYETHERS - ETHYLENE OXIDE POLYMERS] (Vol 19) -of polystyrene [STYRENE PLASTICS] (Vol 22) -m printing processes [PRINTING PROCESSES] (Vol 20)... 

HDPE film - [OLEFINPOLYMERS - POLYETHYLENE - HIGH DENSITY POLYETHYLENE] (Vol 17)... 

Recently, Ramamurthy and Weiss and their coworkers reported the photo-Fries rearrangement of three 1-naphthyl phenylacelates (Fig. 36) in cation-ex-changed zeolite Y and high-density polyethylene films [193], When the substrates were irradiated in hexane to <30% conversion, the eight photoproducts in Fig. 36 were detected. The photoproduct distributions from polyethylene or a Y-zeolite are drastically different from those in solution. Cage-escape products (54 and 55) are absent in both constrained media, and in zeolite Y, only 49 was detected. The... 

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