What is EVOH material?
What is EVOH material?
EVOH is an Ethylene-Vinyl Alcohol Copolymer mainly composed of carbon, oxygen and hydrogen. It has no toxic gases when burned, and its combustion heat is only half that of polyethylene, causing little harm to the environment.
Does EVOH absorb water?
However, and despite the severe plasticization of EVOH exposed to water, the water uptake by EVOH is very low compared to PVOH, chitosan or other hydrocolloids and ranges between 9 and 12% for all EVOH grades (Mokwena, Tang, & Laborie, 2011) .
Is EVOH crystalline?
Ethylene–vinyl alcohol (EVOH) is a copolymer of ethylene and vinyl alcohol. These materials are highly crystalline and are produced with various levels of ethylene content. Figure 10.4. The structure of EVOH copolymer.
Is EVOH biodegradable?
Other Biodegradable Polymers There are two primary water-soluble polymer types: polyvinyl alcohol (PVOH) and ethylene vinyl alcohol (EVOH). PVOH is readily biodegradable and water soluble. EVOH is another water-soluble synthetic polymer, often used as an oxygen barrier layer in multilayer film packaging.
Is EVOH a plastic?
EVOH stands for Ethylene-vinyl alcohol copolymer and is a flexible, crystal clear, glossy thermoplastic copolymer. This material has excellent flex-crack resistance, and exhibits a high resistance to hydrocarbons, oils and organic solvents.
Where is EVOH used?
atmosphere packaging
EVOH is extensively used for atmosphere packaging where a certain atmosphere is needed inside the package to improve the shelf life of food products. In other words, EVOH film is frequently used for fresh produce when minimal permeability is needed.
What is the effect of orientation on the pet’s gas and water vapor barrier properties?
Improvements in the barrier properties of plastic can be obtained by biaxial orientation processes. Biaxial orientation results in increased toughness, increased stiffness, enhanced clarity, improved oil and grease resistance, and enhanced barrier properties to water vapour and oxygen5,6.
What is the density of EVOH?
1.12 – 1.24 g/cc
| Physical Properties | Metric |
|---|---|
| Density | 1.12 – 1.24 g/cc |
| Moisture Absorption at Equilibrium | 1.5 – 8.5 % |
| Moisture Vapor Transmission | 0.360 – 3.10 cc-mm/m²-24hr-atm |
| Water Vapor Transmission | 14.28 – 217.1 g/m²/day @Temperature 37.8 – 37.8 °C |
Can EVOH be recycled?
EVOH films are also difficult to recycle because the EVOH oxygen barrier layer sandwiched between two or more PE layers has a tendency to gum up when reprocessed, resulting in holes in the recycled PE film. On the upside, EVOH waste does not produce toxic or harmful by-products when properly incinerated.
What is PVDC used for?
The major applications of PVDC include packaging of poultry, cured meats, cheese, snack foods, tea, coffee and confectionery and modified atmosphere packaging of food products.
Are adhesives biodegradable?
However, some adhesives are derived from natural materials, making them both sustainable and biodegradable. Plant-based liquid glues can be made from a variety of starches like corn, wheat, and potato. Other biodegradable adhesives can be sourced from gelatin netting.
Is EVOH a good water barrier?
When compared to other common films, EVOH is considered to have superior barrier properties. For this reason, EVOH is often used in a multilayer co-extruded film structure with materials such as HDPE, PP and PET, all of which have superior moisture barrier properties.
What are the properties of eval EVOH resins?
EVAL™ EVOH combines the excellent gas barrier properties and resistance to organic solvents of polyvinyl-alcohol with the easy processing and water resistance of polyethylene. EVAL™ is commercially available as granules for coextrusion and coinjection, or as monolayer film for lamination.
What are the properties of PVOH and EVOH?
Briefly the properties of EVOH vary with the relative amounts of the two components, polyvinyl alcohol (PVOH) and polyethylene (PE). As the mol% of ethylene increases, the properties of EVOH become more like that of polyethylene, and conversely as mol% ethylene decreases the material behaves more like PVOH.
How is the melting point of EVASIN determined?
EVASIN ® EVOH Grades Ethylene content Melt Index (g/10min) Melt Index (g/10min) Melting point (°C) (%mol) 190°C, 2.16kg 210°C, 2.16kg EV2951F 29 – 2.5 188 EV3201F 32 1.7 – 183 EV3251F 32 1.7 4.0 183
What can EVOH be used for in packaging?
EVOH has some of the best barrier properties to gases such as oxygen, nitrogen, and carbon dioxide, thus making it especially suited for packaging of food, drugs, cosmetics and other perishable or delicate products to extend shelf life.