PVDC - the preferred choice for high barrier packaging materials
PVDC is the only plastic with high barrier to both oxygen and water vapor, and it has an unparalleled superiority in odor barrier.
The barrier performance of PVDC to oxygen is equivalent to 1700 times of LDPE, 1000 times of PP, 20 times of PET, and 10 times of PA (test conditions are 23°C, 1atm, relative humidity 75% RH);
The barrier performance of PVDC to water vapor is equivalent to 20 times that of LLDPE, 76 times that of EVOH-32, 30 times that of EVOH-44, and 190 times that of PA;
The barrier performance of PVDC to odor is equivalent to 1000 times that of EVOH, 500 times that of PA, and 17,000 times that of PP and PE.
PVDC's high oxygen barrier performance is not affected by the ambient humidity, and has a distinct advantage over EVOH and PA. The following table shows the comparison of oxygen transmission rates of PVDC and EVOH-38% at different temperatures and humidity (the barrier properties of PA and PVDC and EVOH are not within the same order of magnitude, so no comparison is made).
Destructive test results of PVDC composite film and EVOH multi-layer co-extrusion stretched film:
Experimental conditions: temperature 40°C, humidity 100%
Experimental species: Number of experiments for a certain low-temperature product: 500 pieces each Conclusion: The effect of PVDC composite film on product quality is significantly better than that of EVOH multi-layer co-extrusion stretch film; PVDC composite film must be used for both upper and lower films in order to make full use of PVDC. Excellent high barrier property; PVDC composite film packaging, low temperature products are expected to achieve normal temperature circulation.
New packaging materials:
PVDC multilayer co-extruded high barrier blown film
The PVDC multi-layer co-extruded high-barrier blown film produced by Sino-foreign joint venture Xingtai Weite Plastics Co., Ltd. is a new packaging material with high barrier MA-PVDC as a barrier layer. It uses the characteristics of co-extrusion, the MA-PVDC, PE, EVA, PP, PA and other materials are organically combined with complementary performance and become a high-performance packaging material with excellent overall performance. Because of the high barrier property of MA-PVDC, Witt Plastics can control the oxygen permeability to <1cm3/m2·0.1MPa·d (GB/T1038-2000) and the vapor permeability to <0.7g/, according to the needs of users. M3·d (GB/T1037-1987) can replace aluminum-plastic composite film, EVOH co-extruded film, nylon coextruded composite film and other materials.
The company currently promotes MA-PVDC six-layer co-extruded film transparent substrates and black and white milk films (asymmetrical structures).
The other three layers can be selected on demand. The structure can be flexibly selected for heat sealing in the inner layer or the outer layer according to customers' different requirements for heat-sealing fastness. Therefore, the asymmetrical structure is more practical.
Application area
·Obstacles to cooked meat products and dairy products—Extend the shelf life, stop the vapors—Prevent dehydration, ensure the quality, and prevent odors—Preserve the original flavor, Cold meat, Oxygen resistance of seafood—Extend the shelf life, and keep the color fresh and block steam. - Anti-dehydration and anti-odor - A variety of fresh products can be in the same refrigerated truck or the same refrigerated container, not odor, fruit juice, jelly, canned fruit Oxygen - anti-oxidation, deterrence - anti-dehydration and anti-odor - maintain the original flavor of tea , Oxygen barrier - Anti-mildew, Anti-oxidation, Anti-oxidation, Anti-moisture, Anti-odor - Keep original flavor, Toothpaste, Cosmetics, Blocking steam - Keep moisture, prevent dehydration, Block odor - Keep original odor, Food preservation bag, Oxygen resistance, Mildew resistance , Anti-mosquitoes, Grains, Mouth Resist, Steam, Anti-moisture, Oily, Expanded Foods, Oxygen Blocking, Extending, Shelf-resistance, Steam, Anti-hygroscopic, Metal Rust, Oxygen, Oxygen, Anti-oxidation, Anti-moisture, Other Areas
Environmental protection
In the United States, PVDC is considered safe and non-toxic material and complies with FDA standards; in Germany, the government strongly advocates the use of PVDC and has a “green markâ€; in Japan, it has been confirmed that PVDC incineration is not related to the production of dioxins. The content of PVDC in the PVDC co-extruded film is about 10%, and the packaging bag can be recycled for injection molding. The use of PVDC can save other materials in tens of times and has positive energy saving and environmental protection significance.
Compare with similar products
· Compared with PVDC coating, it has higher barrier performance, no residual solvent, no cracking layer.
Compared with PVDC multi-layer co-extruded cast film, it has better vertical and horizontal strength and is more suitable for packaging bags. The product structure can be made symmetrical or asymmetric.
· Compared with PVDC dry film, it has higher barrier performance, no residual solvent and less delamination.
Compared with EVOH, PVA and PA co-extruded membranes, it has better steam-barrier properties and high oxygen barrier properties are not affected by humidity.
Compared with aluminum-plastic composite film, it has no pinholes and no broken cracks. The product can be made transparent or protected from light. Witton Plastics Co., Ltd. has conducted comparative experiments on PVDC multi-layer co-extruded film and aluminum-plastic composite packaging milk. The thickness of MA-PVDC in PVDC multi-layer co-extruded film is 10 μm, and the thickness of aluminum foil in aluminum-plastic composite material is 9 μm. If milk is packaged in the form of Tetra Pak, the durability of the aluminum-plastic composite is superior to that of the PVDC co-extruded film. If milk is packaged in the form of a Tetra Pillow, the coextrusion of PVDC film is superior to that of aluminum-plastic composites. This shows that in the process of packaging and transporting Tetra Pak inevitably appeared in the aluminum foil cracks, affecting its barrier properties. From this, it can be seen that the manufacture of Tetra Baked packaging, aluminum plastic composite material is the best choice; and production of bag packaging (especially three-dimensional bags), PVDC multi-layer co-extruded film is the best choice. In any case, so far, only PVDC multi-layer co-extruded films can compete with aluminum-plastic composite films in all plastic films.
Witt Plastics is about to launch new products
PVDC multi-layer co-extruded high barrier lower blown stretch film
The outer layer of the product is PP or PA. The water cooling process under the blowing, in addition to maintaining a good vertical and horizontal strength, the transparency can be comparable with the cast film. This product can be used directly on low temperature meat production lines without compounding.
PVDC multi-layer co-extruded high-resistance heat-shrinkable insulation shrink film This product has a heat shrink function and can be used for shrink packaging of cold meat, etc., and can replace PVDC single layer artificial casing film.
PVDC multilayer co-extruded high barrier fresh-keeping self-adhesive film In addition to the product's thermal shrinkage characteristics, the outer layer material is self-adhesive.
PVDC summary:
· VDC and VC copolymers - mainly used for coating and artificial casings · VDC and MA copolymers - mainly for coextrusion compounding
• MA-PVDC, also known as high barrier PVDC, is equivalent to more than 30 times the barrier performance of PVDC for sausage casing.
·PVDC complies with US FDA hygiene standards and can be widely used in the packaging of cold meat, cooked meat, products, milk and dairy products, oily foods, tea, medicines and other products.
Source: "Packaging Materials and Containers"