Bottles multilayer

In Europe, industry has pressed for harmonised EU contols on recycling since the early 1990s. However, till now no such recycling directive exists, which means that the individual Member States of the European Union are responsible for any laws within their territories. Eor PET bottles, multilayer... 

To enhance water-vapor- or gas-barrier properties, layers of different plastics may be injected together or sequentially. Multilayer injection-molded pieces may be prepared as packaging or for blowing into bottle or jar shapes. 

Multilayer blown-film extrusion, VDC copolymers in, 25 725, 729—733 Multilayer bottles, 20 52—53 Multilayer capacitors (MLCs),... 

The other severe problem in the application of PET regarding food containers or bottles is that these products cannot be hot-filled. This limitation is caused by the low Tg of PET, which causes shrinkage during hot-filling. Alternatively, multilayer containers can overcome the problems, but, however, at higher manufacturing costs. PET in combination with an intermediate layer of poly(ethylene-co-vinyl alcohol) (PEVOH) or polybutylene has been used in such... 

Based on the above general principles, quite a number of models have been developed to estimate pore size distributions.29,30,31-32,33 They are based on different pore models (cylindrical, ink bottle, packed sphere,. ..). Even the so-called modelless calculation methods do need a pore model in the end to convert the results into an actual pore size distribution. Very often, the exact pore shape is not known, or the pores are very irregular, which makes the choice of the model rather arbitrary. The model of Barett, Joyner and Halenda34 (BJH model) is based on calculation methods for cylindrical pores. The method uses the desorption branch of the isotherm. The desorbed amount of gas is due either to the evaporation of the liquid core, or to the desorption of a multilayer. Both phenomena are related to the relative pressure, by means of the Kelvin and the Halsey equation. The exact computer algorithms35 are not discussed here. The calculations are rather tedious, but straightforward. 

Franz R, Huber M, Piringer O G, Damant A P, Jickells S M and Castle L, 1996, Study of Functional Barrier Properties of Multilayer Recycled Poly(ethylene terephthalate) Bottles for Soft Drinks. J. Agric. Food Chem. 44, 892-897. 

As we will see in Chapter 9, multilayer blow molding is sometimes used as a way to incorporate recycled polymer in food-grade bottles. For safety reasons the use of recycled plastics in packaging that comes in direct contact... 

R. FRANZ, M. HUBER, O. G. PIRINGER, A. P. DAMANT, S. M. JICKELLS, L. CASTLE, Study of functional barrier properties of multilayer recycled poly(ethylene terephthalate) bottles for soft drinks. Journal of Agricultural and Food Chemistry, 1996, 44, 892-897. 

Plastic bottles are a common form of primary packaging for tablets in many regions because they are lower in weight and less fragile. They may be used as the pure resins or multilayered to reduce their moisture and gas permeability. 

Because LDPE is so pliable, it is not typically used for rigid containers or for films. HDPE is much more rigid, but both compounds are often employed in squeeze bottles and other flexible applications. PE may be used as a moisture-impermeable layer of a multilayer film for sealing blister containers. It may also be used for producing sealable envelopes in which pharmacists can dispense moisture-sensitive powders or tablets. Care should be taken to assure that PE additives do not leach into the pharmaceutical substance. ... 

Harvest cells when confluent (5-6 days) by removing the medium and trypsinizing in the conventional way. After adding trypsin, roll the bottles at speeds of 20-60 rph until cells detach. Cell yields will be similar to or up to two-fold higher than in stationary cultures, and multilayering (non-diploid cell lines) will occur. 

In the last few years, a rapid expansion in the use of high gas barrier plastic structures for food packaging has taken place. These structures include multilayer films, trays, bottles and cups, "bag in the box" and "bag in the barrel" type packages and laminated cartons. 

There are also a number of other fairly obvious stereoisomeric possibilities (i.e., ones transparent to graph theory) that have as yet received no attention, e.g., multiple toroidal rings (or Klein bottles) with a catenane type of interlocking knots tied in the torus tube concentric multilayered toroidal tubes. 

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