Gas Barrier Coextrusion Composite Film Use Form
DATE：2019/9/5 8:58:46 / READ： / SOURCE：This station
Gas barrier coextrusion composite film use form
Gas barrier coextrusion composite membranes, as categorized by use form:
1 After film formation, heat-sealed into a pouch or packaging film;
2 film for deep drawing processing;
3 a heat-shrinkable film that has been subjected to secondary processing;
4. Body-wound packaging film that has been stretched and reprocessed. The following are explained separately.
(1) Heat-sealed pouch or packaging film
Representative structures are mostly PO/EVOH/PO, PO/PVDC/PO, and have a thickness of 20 to 100 μm. Polyolefins such as EVA, LDPE, LLDPE, and PP can be used. EVA has good low temperature sealing properties. When puncture resistance is required, LLDPE is used. When static strength or impact strength is required, the nylon layer is added to make a structure of PE/PA/EVOH/PA/PE.
(2) Film for deep drawing molding
Co-extruded composite films for deep-drawing vacuum packaging such as ham, sausage, sautéed meat products, processed meat products such as pork roast, or processed in aquatic products require gas barrier properties and good molding processing adaptability. EVOH is used as a barrier material to increase the processing flexibility of the nylon layer. In addition, nylon imparts characteristics to the film in terms of shape and strength. The general structure is PE/EVOH/PE and the thickness is 100 to 150 μm. In addition, there is an EVOH/PA/PE structure with EVOH as the outer layer, and the surface properties are improved. Regardless of the asymmetric structure, wrinkling occurs when the cover material is heat-sealed. To solve this problem, the PET/EVOH/PA/PE structure was studied.
(3) Shrink film
After the shrink film is used to package the product, the packaged product is fixed by heat shrinkage, and in order to obtain shrinkage performance, the film is produced for non-heat setting biaxial stretching, and the food package generally requires the film to shrink at a low temperature and in a short time (allowing shrinkage) The temperature is only 70-90 ° C), the general structure of EVOH shrink film is PO / EVOH / PO, PO / EVOH / PA / PO, PA / EVOH / PO, PO uses EVA, ionic polymer and PP, according to The heat resistance of the packaging material is selected separately, and in order to obtain low-temperature shrinkage properties, the substrate film must be highly stretched at a low temperature. However, EVOH-like films are poorly processed films, and therefore, easy-stretch EVOH has been developed.
PVDC-based co-extruded heat-shrinkable composite film, the structure is EVA/PVDC/EVA, or EVA/PVDC/ionic polymer, used for large bags of frozen beef, small bags for animal processing products.
(4) Skin packaging film
The body-wrap package is a heat-deformable film that is elastically restored to closely conform to the packaged form of the packaged article. The EVOH type body wrap film can be EVA/EVOH/ionic polymer, PA/EVOH/EVA or PVC/EVOH/EVA type. In addition, the PVDC type has a PVC/PVDC/EVA structure and is used for packaging of processed products such as ham, sausage, and meat. The PVC substrate is used because of its good elastic recovery characteristics. Crosslinked polyolefins having rubber-like elasticity at high temperatures are under investigation.
Gas barrier coextrusion composite membranes, as categorized by use form:
1 After film formation, heat-sealed into a pouch or packaging film;
2 film for deep drawing processing;
3 a heat-shrinkable film that has been subjected to secondary processing;
4. Body-wound packaging film that has been stretched and reprocessed. The following are explained separately.
(1) Heat-sealed pouch or packaging film
Representative structures are mostly PO/EVOH/PO, PO/PVDC/PO, and have a thickness of 20 to 100 μm. Polyolefins such as EVA, LDPE, LLDPE, and PP can be used. EVA has good low temperature sealing properties. When puncture resistance is required, LLDPE is used. When static strength or impact strength is required, the nylon layer is added to make a structure of PE/PA/EVOH/PA/PE.
(2) Film for deep drawing molding
Co-extruded composite films for deep-drawing vacuum packaging such as ham, sausage, sautéed meat products, processed meat products such as pork roast, or processed in aquatic products require gas barrier properties and good molding processing adaptability. EVOH is used as a barrier material to increase the processing flexibility of the nylon layer. In addition, nylon imparts characteristics to the film in terms of shape and strength. The general structure is PE/EVOH/PE and the thickness is 100 to 150 μm. In addition, there is an EVOH/PA/PE structure with EVOH as the outer layer, and the surface properties are improved. Regardless of the asymmetric structure, wrinkling occurs when the cover material is heat-sealed. To solve this problem, the PET/EVOH/PA/PE structure was studied.
(3) Shrink film
After the shrink film is used to package the product, the packaged product is fixed by heat shrinkage, and in order to obtain shrinkage performance, the film is produced for non-heat setting biaxial stretching, and the food package generally requires the film to shrink at a low temperature and in a short time (allowing shrinkage) The temperature is only 70-90 ° C), the general structure of EVOH shrink film is PO / EVOH / PO, PO / EVOH / PA / PO, PA / EVOH / PO, PO uses EVA, ionic polymer and PP, according to The heat resistance of the packaging material is selected separately, and in order to obtain low-temperature shrinkage properties, the substrate film must be highly stretched at a low temperature. However, EVOH-like films are poorly processed films, and therefore, easy-stretch EVOH has been developed.
PVDC-based co-extruded heat-shrinkable composite film, the structure is EVA/PVDC/EVA, or EVA/PVDC/ionic polymer, used for large bags of frozen beef, small bags for animal processing products.
(4) Skin packaging film
The body-wrap package is a heat-deformable film that is elastically restored to closely conform to the packaged form of the packaged article. The EVOH type body wrap film can be EVA/EVOH/ionic polymer, PA/EVOH/EVA or PVC/EVOH/EVA type. In addition, the PVDC type has a PVC/PVDC/EVA structure and is used for packaging of processed products such as ham, sausage, and meat. The PVC substrate is used because of its good elastic recovery characteristics. Crosslinked polyolefins having rubber-like elasticity at high temperatures are under investigation.
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