Packages Bi-layer

Bi-layer Package Recycled Polymer-Functional Barrier... 

The scheme of the bi-layer package is shown in Figure 2.1, which consists of a virgin layer and of a layer made of recycled polymer. 

Bi-layer Package with Various Relative Thicknesses 2.3.1 Mathematical Treatment of the Process [1, 8]... 

The mathematical treatment made in Section 2.1.1, leading to the Equations (2.1) to (2.6) can be used for any bi-layer package with various thicknesses. 

Bi-layer Package with Complex Situations Different Diffusivities and Factor Coefficient Different from One... 

As shown in Figure 2.1, for a bi-layer package, the following assumptions are made in order to clarify the process of mass transfer ... 

Bi-layer Packages Made of a Recycled and a Virgin Polymer Layer, by Neglecting the Co-extrusion Potential Effect... 

Mass Transfer in Food with a Co-extruded Bi-layer Package... 

The scheme of the process is shown in Figure 4 17, where the mass transfer is controlled either by diffusion through the thickness of the bi-layer package or by convection into the liquid, while there is no transfer on the external surface of the package. 

Figure 4.17. Scheme of the bi-layer package made of a recycled layer and a virgin layer in contact with liquid food, by taking into account the transfer of the diffusing substance during the co-extrusion stage. 

Figure 4.18. Profiles of concentration of the diffusing substance developed through the bi-layer package in contact w ith the liquid food of finite volume with a = 55.3, for various values of the dimensionless time D-t/L, with R = 5. The initial concentration at time 0 is that attained at the end of the co-extrusion stage.

Figure 4.19 Kinetics of transfer of diffusing substance in the liquid food of volume such as a = 55.3, in the case of the bi-layer package shown in Figure 4.18, with various values of the dimensionless number R. Dimensionless numbers are used in the co-ordinates.

Perez-Gago, M. B. and Krochta, J. M. (2005). Emulsion and bi-layer edible films. In "Innovations in Food Packaging" (J. H. Han, Ed.), pp. 384-402. Elsevier Academic Press, San Diego, CA. 

The problem of bi-layer systems is also examined, when the package consists of the layer made of the recycled polymer bound to the virgin polymer layer. As this virgin layer is placed in contact with the food, it plays the role of a functional barrier. The effect of the various parameters is determined, without forgetting the effect of the mass transfer taking place between these two layers during the stage of co-extrusion. 

Let us notice that generally, and fortunately for the consumers, the concentration of the additives in the polymer used as a package is very low, so that their concentration in the liquid do not exceed their solubility in the food liquid. The same fact occurs at the interface of the two layers of a package, the one made of a recycled polymer and the other of a virgin polymer in the bi-layer system, it is obvious that the partition factor K is equal to 1 when these two layers in perfect contact in the package are made of the same polymer. 

The initial distribution of the pollutant. This factor appearing essentially in the case of bi-layer or tri-layer package made of recycled and virgin layers co-extruded. 

Metal thin films deposited on polymers are widely used in various industrial domains such as microelectronics (capacitors), magnetic recording, packaging, etc. Despite much attention that has been paid in the recent literature on the adhesive properties of metals films on polyimide (PI)( 1 - 5 ) and polyethyleneterephtalate (PET)((L) it appears that a better knowledge of the metal/polymer interface is needed. In this paper we focus ourself on the relationship between the adhesion and the structural properties of the aluminum films evaporated (or sputtered) on commercial bi-axially stretched PET (Du Pont de Nemours (Luxembourg) S.A.). A variety of treatment (corona, fluorine,etc.) have been applied in order to improve the adhesion of the metallic layer to the polymer. The crystallographic... 

The user layer of the bi-objective optimization system is developed in c language of the. net architecture. The underlying layer is developed by using the NetworkX Library of Python and directly calling the packaged Dijkskra algorithm. The data can be imported from EXCEL or dynamically read from the database (ZHOU Y F LIU M 2011, ZHOU Y D 2008). 

A common multilayer PP product is bi-axially oriented polypropylene (BOPP), produced on a line including a machine direction orientation unit, and a tenter frame for transverse orientation. This process commonly uses a three-manifold die that allows thin skin layers of copolymer to be applied on either side of a homopolymer base layer. The copolymer is used in this product so the film can be sealed, which is a requirement in packaging applications. Typically, the skin layer thickness is 5% of the total film thickness. The adhesive property of the copol3mier makes it difficult for the film to be processed through a tenter frame, because the film would stick to the tenter frame clips. The multimanifold die can be designed with narrower width flow channels for the skin layers, to keep the adhesive out of contact with the tenter clips, allowing the product to be extruded successfully. 

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