Barrier properties water vapor transmission rate

In order to improve the water vapor barrier property of Ecoflex or Ecovio , a wax-based masterbatch can be used. Depending on the concentration, this masterbatch reduces the water vapor transmission rates of Ecoflex films by up to... 

Barrier Properties Exact Plastomers create controllable gas-permeable films for modified atmospheres, as well as gas-permeable films and packaging for such items as fresh vegetables, fhiits, flowers, and a growing range of other horticultural products. Users can select carbon dioxide and oxygen transmission rates (OTR) that meet their needs, with low water vapor transmission rates (WVTR) and high levels of clarity and gloss. " ... 

Both treatments improve the water barrier properties of paper-board by decreasing the water vapor transmission rate by 77-78%. The results suggest that the surface coating by biodegradable polymers may be utilized for the manufacture of paperboard containers even in industrial applications (26). 

The CNCs improve the barrier properties like oxygen transmission rate (OTR) and water vapor transmission rate (WVTR) as well as mechanical properties like young s modulus and strength of PLA matrix (Okastnan et al., 2006). 

Barrier properties needed (that is permeability of individual gases and gas ratios when more than one gas is used, water vapor transmission rate, and so on),... 

The water vapor transmission rate (WVTR], often erroneously called water vapor permeability (WVP], is defined as a mass of water vapor transmitted through a unit area in a unit time under specified conditions of temperature and humidity. The water vapor barrier properties for the packaged product, whose physical or chemical deterioration is related to its equilibrium moisture content, are of great importance for maintaining or extending its shelf life. The water vapor barrier is quantified by the water vapor permeability coefficients (WVPC] which indicate the amount of water vapor that permeates per unit of area and time in packaging materials (kgm/m s Pa] (Bangyekan etal., 2006]. 

Retort is a high temperature sterilization process that is used to prolong the shelf life of military rations. Ethylene co-vinyl alcohol (EVOH) /montmorillonite layered silicate (MLS) nanocomposites were co-extruded with retort grade polypropylene (PP) into a multilayer cast fdm to determine if the addition of MLS to EVOH improved barrier, mechanical, thermal and retort properties. The PP/EVOH-MLS/PP structure showed an improvement in some properties such as water vapor transmission rate. Young s modulus, and seal strength before retort in comparison to the PP/EVOH/PP structure however, the improvement in properties was lost after the retort process. 

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