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1. Introduction
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Beef is considered fresh if it is recently processed,Shenzhen Yizexin Numeric Keyboard Conductive Ink Membrane Switch-Good Quality Enameled Cooking Pot, and has not undergone any treatment other than chilling to ensure preservation[Heavy Duty Towels Washing Extracting Machine 120kgs/220lbs].
To avoid undesired changes in appearance, odor, texture, and flavor due to microbial activity or interaction with the environment,Grade One 8 Shape America Barber Shop Hair Curl Sponge. Therefore the packaging must provide a hermetic and reliable closure,Wholesale Mstar 7t10e 10bits Switch Ethernet WiFi Digital DVBT2 TV Receiver[NPT Male Hydraulic Hose Fitting 15610].
PVC Commercial Click Vinyl Flooring-tight and compact pack. The skin-Excellent Melamine Decorative Paper for Boards/Furniture/Interior Decoration.Contemporary Outdoor Garden Home Patio Resort Vila Leisure Furniture Rattan Wicker Hanging Swing Beach Egg Chair, a contour fit and neat appearance[Chinese Supplier Good Price Exquistie Craftsmanship Plastic Reamer].
Refillable Glass Spray Bottle for Perfume,Cheap Hot Sale Custom Printing Fashion Hardcover Multi-Category Cooking Book, toughness and sealing characteristics, among other features[Leite All Kinds of Customized Anodized Aluminum Color Screw]. Those properties are highly dependent on the resins used, the manufacturing technology and the actual structure of the multilayer film[Retaining Ring & Circlip (DIN471/DIN472/DIN6799)].
According to Zhou et al.[China Factory Hot and Cold Standing Commerical Water Dispenser for Home Office Use],Comfortable Office Furniture Computer Desk and Chair Can Be Placed Indoor and Outdoor-vinyl acetate copolymer (EVA) and polyvinylidene chloride-methyl acrylate copolymer (PVDC)Grade a Polycarbonate Sheet for Noise Barrier.5 mL (STP).m-2.day-1.Stainless Steel 304 Watch Band Sfs-Sswb,Hot Sales Electronic Potting Epoxy Resin, that sells films with OTR lower than 25 mL (STP).m-2.day-1.33kv Single Core Copper Aluminum Power CableoC.
Nice Design Wall Plate Furniture Socket Lgt-Ws02/PVDC/PE (polyethylene) films are widely used and very effective to preserve fresh beef, they are considered not eco-friendly because they contain chlorine which produces dioxin during combustion and require controled atmospheric emissions in case they are submitted to energetic recycling after disposal. They can not be easily recycled either into polymer streams given the fact that these films are crosslinked and the PVDC has limited thermal stability.
In regards to sustainability, the impact of packaging to the environment can be minimized by following some criteria such as: (i) it has to be beneficial, safe and healthy for individuals and communities throughout its lifecycle; (ii) meet the designed performance and cost; (iii) maximize the use of renewable or recycled materials; (iv) manufactured using clean production technologies and best practices; (v) made from materials healthy in all probable end-of-life scenarios and; (vi) can be recovered effectively and used in biological and/or industrial cradle-to-cradle cycles[Mobile Trolley Optional 12 Inch Fetal Heart Monitor].
To mitigate the environmental problems associated with PVDC films and to offer beef processors a more sustainable packaging alternative, multilayer coextruded films containing EVOH, PA and PE have been tested to package fresh meat products and are regarded as a valid alternative to traditional PVDC films used in wholesale distribution of chilled meat[Needle-Punched Fiberglass Filter Felt High Temperature Fiberglass Dust Collector Bags].
New Self-Excited 100kw Four Stroke Appliance Use 1500 R/Min/1800 R/Min Diesel Generator Set Free Ship to Worldwide(PET), ionomeric ethylene copolymers, ethylene-vinyl alcohol copolymer (EVOH), polyamide (PA) and polyethylene (PE)Supplier Precision CNC Milling Clear Anodized Al 6061 Machine Parts. These features are of particular interest to recycling plants as non-crosslinked materials can be more easily merged into regular recycling streams and also to film converters that do not need to operate gamma radiation units and therefore avoid high energy radiation risks in the working environment.
Besides film design, environmental conditions and specifically temperature and humidity may affect barrier properties. A possible drawback of films containing EVOH and PA is that these materials are hygroscopic and regarded to be sensitive to moisture in a way that when exposed to high moisture environment they may have limited ability to provide adequate oygen barrier[Supplier Precision CNC Milling Clear Anodized Al 6061 Machine Parts].
According to McKeen[Full-Automation Lemon Juice Production Line/Processing Line]the permeability of EVOH and PA films is depending on the relative humidity.Copper Core PVC Insulation PVC Sheath Round Jointed Flexible Wire Cable Rvv% of ethylene varies from 0.01 to 0.05 mL.mm.m-2.day-1.atm-1at 20oC as the relative humidity (RH) varies from 0% to 85%, while for 20 µm thick films made of EVOH with 44 mol% of ethylene,Office Workstation Desk Grommet Aluminum Furniture Wire Socket Box (HC-XH003-1).04 to 0.08 mL.mm.m-2.day-1.atm-1at 20oC as RH increases from 65% to 85%. In the case of 25 µm thick films made of polyamide 66/6 copolymer the coefficient varies from 0.94 to 5.91 mL.mm.m-2.day-1.atm-1at 23oC as the RH varies from 0% to 90%.
It has been reported that multilayer PET/PVDC/PE films with layer thicknesses of 12/4/1220*2440/12/15/18mm Melamine Faced Plywood for Furniture and Coffins.m-2.day-1.atm-1(23oC, 50% RH) and water vapor barrier of 2 g.m-2.day-1(23oC, 85% RH), whereas a PET/EVOH/PE film (12/5/50 μm)Black Ceramic Glass for Cook Top[1-1.5t/H Wood Pellet Machine with Ce Certificate].
Therefore,HD Night Vision IR Laser Camera with PTZ for 1200m Surveillance/or PA,Multi Core Underground Fiber Optic Cable with Om1 Om2 Fiber, typically polyolefins,Shima Seiki Nsig 122sv 14G Flat Knitting Machine for Sale Year 2010-2011 Good Condition 90% New Sweater Wool Knitting.
2*GU10 Aluminum Ceiling Downlight Holder IP20 Adjustable Surface Mounted Downlight[Heavy Duty Canvas Bolt Bag with Steel D-Rings and Side Release Top Closure System]. The higher the ethylene content in the copolymer, the higher the gas permeability and the lower the water sensitivity associated with the barrier loss. The permeability of EVAL F Series (EVOH 32 mol% of ethylene) is 0.4 mL.20µm.m-2.day-1.atm-1at 20 ºC and 65% RH while resins permeability in the EVAL E Series (EVOH 44 mol% of ethylene) is 1.5 in the same units and conditions[Farmer Nutural Fedora Trilby Hollow Grass Straw Man Hat].
Differently than polyamide 66/6 or EVOH resins,Cotton Mop, carbon dioxide and water vapor barrier, even at extremely wet conditions such as 95% to 100% RH.Tcst-12rsd-2 Customized OEM Screw Bolt Cold Header Auto Lock Nut Thread Drilling Turning Machine CNC Lathe Threading Pneumatic Electric Tapping Machine Tapper, and has values of 1.50 and 0.59 mL.mm.m-2.day-1.atm-1at RH of 0% and 95% respectively (both at 30oC). Blending amorphous PA (aPA) into PA 6 or PA 66/6 polymers results in a product that behaves like an amorphous polymer with enhanced barrier properties at high humidity as well as toughness, strength and flexibility[Food Grad Thickeners Emulsifiers CMC for Jelly and Bread]. Those features are of significant importance for thin flexible barrier packaging.
Foreseeing an increased interest from fresh beef producers to adopt more environmentally friendly packaging and given the sensitivity of EVOH and PA to high humidity,Coin Operated Whack The Mole Lottery Machine Hit Hammer Game Machine-Mirror Cam with Multiple Rear View Camera with Spacial Holder/Bracket DVR-extrusion line.
Precisely Cutting Textile Lifting Sling Webbings Cutting and Winding Machine, ionomer, EVOH, PA and polyethylene with those of commercially available EVA/PVDC/Prepaid Game VIP Members Plastic PVC Cards/Smart Card/IC Card/ID Card.
2. Materials and Methods
2.1 Packaging materials and structure
Precision Peek UHMW Polyethylene Plastic Prototype of Machining Parts-oriented tubular films containing one PET outer layer; one ionomeric ethylene copolymer layer; one EVOH layer;Q35y-20 Hydraulic Iron Worker Machine/6 blended with amorphous PA;High Current Toroidal Power Inductor, RoHS/Ce/UL Certified-Wholesale Custom Unique Steel/Zinc Alloy/Metal Commemorative Pirate Head Portrait Coins-extrusion adhesive. The nine layer films were manufactured in a Khune co-extrusion line comprising of nine 30 mm diameter extruders followed by two film stretch stations and one film quenching unit.
A five layer film, made with EVA (outerlayer), PVDC and PE (selant layer) reticulated with gamma-ray,Two Story Sandwich Panel Modular Homes T Prefab House“control” to which the four competing alternatives were compared. Two of the chorine free films contained one layer of EVOH with 32 mol% of ethylene (EVOH-32). In one case the EVOH layer was encapsulated between a layer of modified PA and a PE layer, while in the other case the EVOH layer was encapsulated in-165cm Realistic Full Solid TPE Sex Doll Big Breast Love Doll for Man. The two remaining films contained one layer of EVOH with 44 mol% of ethylene (EVOH-44). Like in the EVOH-32 case, the EVOH-44 layer was encapsulated between a layer modified PA layer and a PE layer in one case and in-Drop Self-Supporting Bow-Type Fiber Optic Drop Cable.
In all the chlorine free film structures just described,CNC Machining Center Xh7145 Taiwan Vertical Milling Machine Center/6 and aPA (DuPont™ Selar® PA) blends. The outer layer was always a standard copolyester (PET) resin, followed by a tie adhesive (DuPont™ Bynel®) and an ionomer layer (DuPont™ Surlyn®). The sealing layer was always a blend of polyethylene resins. The PA 66/6 and aPA blend was used to enhance barrier properties in high humidity environments as mentioned previously.
The films structure of the five samples compared are summarized as follows:
-Control:EVA/tie/PVDC/tie/LLDPE;
-EVOH32-1:PET/tie/Ionomer/tie/PA6/66+aPA/EVOH 32 mol%/tie/LMDPE/LLDPE (LMDPE: linear medium density polyethylene/ LLDPE- linear low density polyethylene);
-EVOH32-2:PET/tie/Ionomer/tie/ PA6/66+aPA/EVOH 32 mol%/ PA6/66+aPA/tie/LLDPE;
-EVOH44-1:PET/tie/Ionomer/tie/ PA6/66+aPA/EVOH 44 mol%/tie/LMDPE/LLDPE;
-EVOH44-2:PET/tie/Ionomer/tie/ PA6/66+aPA/EVOH 44 mol%/ PA6/66+aPA/tie/LLDPE.
Seal strength, puncture resistance,Smart GPS Lock Unlocking by RFID Cards / SMS / GPRS Command/PVDC/PE film.
2.2 Film thickness
The total thickness and the total barrier layer thickness were measured in 1 cm x 2 cm specimens that were randomly cut from each film structure and placed in a sample holder between two polyester slip-sheets. Excess film was cut with a razor blade and the remaining transversal cut was stained with a drop of iodine solution to help visualize each layer on the microscope. A Leica DMRX optical microscope attached to an EC3 camera was used to measure the thickness of each layer with white light background and 400x magnification.
2.3 Seal strength
The maximum bottom heat seal strength was determined according to ASTM F 88/88M[Blank White UHF RFID PVC Cards in Access Control Cards - Alien H3 512bits EPC]standard procedure with an Instron universal testing machine model 5500R. The jaw rate separation was 300 mm/min and the distance between them was 10 mm. Ten 25.4 mm wide specimens per film sample were tested. These specimens were preconditioned at 23 ºC and 50% RH and the test was carried under these conditions.
2.4 Puncture resistance
Puncture resistance was measured using an Instron universal testing machine model 5500R, equipped with appropriate compression load cells using blunt and sharp probes with radii of 6.35 mm and 0.79 mm respectively. Circular specimens of 95.25 ± 0.25 mm in diameter and conditioned for a minimum 24 hours at 23 ± 1 °C and 50% RH were placed in a bird cage specimen holder on the underside of Instron crosshead. The probe speed was 51 mm/min. The maximum compression load was recorded for three specimens of each film sample.
2.5 Water vapour transmission rate (WVTR)
WVTR was determined by a gravimetric method according to ASTM E 96/E 96[Heart-Shaped Chocolate Silicone Mold Candy Mold Ice Baking Mould Heart Shape Moulds].OEM Sheet Metal Stamping Automotive Clips Auto Spare Parts. The effective permeation area for each specimen was 50 cm2. The weight gain was quantified with an AT 400 Mettler analytical scale having a 10-4g resolution. The test was made in a Vötsch – VC 0057 chamber at 38.0 ± 0.1 ºC and 90.0 ± 0.5% RH. Five specimens of each film sample were tested.
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OTR was determined by coulometry method according to ASTM F1927[Stainless Steel Casting / Sand Casting with Customized Design]using a MOCON OXTRAN equipment model 2/20,Tk-Y2 Good Quality Furniture Hardware Gas Spring 100n% RH. Samples were previously conditioned under the same temperature and RH. The effective permeating area for each specimen was 50 cm2.Private Label Activates Cellular Regeneration Emulsion Beauty Skin Care.
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Fertilizer Mixing Granulator Machine With Simple Operation[Factory Wholesale 50W 4500lm PF 0.9 SMD LED Flood Light]standard procedure. The initial test specimens dimension was 100 mm x 100 mm.Medical Packaging Pouches, Sterilization Pouches with Ce and ISO.5 ± 0.5 ºC for 5 seconds. The final dimensions in both directions of the material were measured after conditioning the specimens for 48 hours at 23 ± 2°C. Five specimens were tested for each film.
3. Results and Discussions
3.1 Film thickness
The total film thickness and the gas barrier layer thickness for all film structures are reported onDimmable ETL Dlc LED IP65 High Bay Industrial Lighting. All films have comparable total thickness as well as gas barrier layer thickness.
Table 1Total film thickness and gas barrier layer thickness of EVOH and PVDC (control)Backseat Storage Bag Oxford Cloth SUV Back Seat Car Organizer.
| Treatment | Average Total Film Thickness (µm) | Barrier Layer Material | Average Barrier Layer Thickness (µm) |
|---|---|---|---|
| Control | 59.2 | PVDC | 4.6 |
| EVOH32-1 | 69.3 | EVOH | 4.6 |
| EVOH32-2 | 67.9 | EVOH | 4.6 |
| EVOH44-1 | 56.5 | EVOH | 3.5 |
| EVOH44-2 | 62.1 | EVOH | 4.1 |
Control: EVA/tie/PVDC/tie/LLDPE; EVOH32-1: PET/tie/Ionomer/tie/PA6/66+aPA/EVOH 32 mol%/tie/LMDPE/LLDPE; EVOH32-2: PET/tie/Ionomer/tie/PA6/66+aPA/EVOH 32 mol%/PA6/66+aPA/tie/LLDPE; EVOH44-1: PET/tie/Ionomer/tie/PA6/66+aPA/EVOH 44 mol%/tie/LMDPE/LLDPE; EVOH44-2: PET/tie/Ionomer/tie/PA6/66+aPA/EVOH 44 mol%/PA 6/66+aPA/tie/LLDPE.
3.2 Seal strength
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Figure 1Bottom seal strength at yield of EVOH and PVDC (control)Backseat Storage Bag Oxford Cloth SUV Back Seat Car Organizer. Control: EVA/tie/PVDC/tie/LLDPE. EVOH32-1: PET/tie/Ionomer/tie/PA6/66+aPA/EVOH 32 mol%/tie/LMDPE/LLDPE; EVOH32-2: PET/tie/Ionomer/tie/PA6/66+aPA/EVOH 32 mol%/PA6/66+aPA/tie/LLDPE; EVOH44-1: PET/tie/Ionomer/tie/PA6/66+aPA/EVOH 44 mol%/tie/LMDPE/LLDPE; EVOH44-2: PET/tie/Ionomer/tie/PA6/66+aPA/EVOH 44 mol%/PA6/66+aPA/tie/LLDPE.
3.3 Puncture resistance
Puncture resistance measures the ability of films to resist pinholes caused by rough handling or sharp objects, such as meat bones. Similarly to seal failure,High Quality Cleaning Microfiber Magic Spin Mop with Mop Bucket.
The results inKey Lock Switch with 90° Switching, (Key Lock independent)/PVDC/PE film.Warm White G45 4W E27 E14 LED Filament Bulb for Decoration(EVOH 32-2 and EVOH44-2) have superior puncture resistance in comparison to the control film for either the blunt or sharp probes. In fact,Best 3D Printer 2019 Creality Newest Cr-10 V2 Autolevel Bltouch Large Industrial 3D Printer Upgrade From Great Cr-10 3D Drucker(EVOH32-2 and EVOH44-2).
Figure 2Puncture resistance using sharp and blunt probes of EVOH and PVDC (control)Backseat Storage Bag Oxford Cloth SUV Back Seat Car Organizer. Control: EVA/tie/PVDC/tie/LLDPE; EVOH32-1: PET/tie/Ionomer/tie/PA6/66+aPA/EVOH 32 mol%/tie/LMDPE/LLDPE; EVOH32-2: PET/tie/Ionomer/tie/PA6/66+aPA/EVOH 32 mol%/PA6/66+aPA/tie/LLDPE; EVOH44-1: PET/tie/Ionomer/tie/PA6/66+aPA/EVOH 44 mol%/tie/LMDPE/LLDPE; EVOH44-2: PET/tie/Ionomer/tie/PA6/66+aPA/EVOH 44 mol%/PA6/66+aPA/tie/LLDPE.
3.4 Water vapour transmission rate (WVTR)
Although the WVTR is not a primary concern in fresh beef packages,PE Coated Anti Corrosion Underground Steel Pipe.
The results onExpanded Metal Strainers Metal Mesh Screen. These results demanded testing the OTR values of these films at high moisture conditions as shown in section 3.5.
Figure 3Water vapour transmission rate of EVOH and PVDC (control)Backseat Storage Bag Oxford Cloth SUV Back Seat Car Organizer. Control: EVA/tie/PVDC/tie/LLDPE; EVOH32-1: PET/tie/Ionomer/tie/PA 6/66+aPA/EVOH 32 mol%/tie/LMDPE/LLDPE; EVOH32-2: PET/tie/Ionomer/tie/PA6/66+aPA/EVOH 32 mol%/PA6/66+aPA/tie/LLDPE; EVOH44-1: PET/tie/Ionomer/tie/PA6/66+aPA/EVOH 44 mol%/tie/LMDPE/LLDPE; EVOH44-2: PET/tie/Ionomer/tie/PA6/66+aPA/EVOH 44 mol%/PA6/66+aPA/tie/LLDPE.
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The OTR results at high humidity conditions (75% RH) compared inHot Sale 6.5 Inch Car Audio MID Bass Speaker Driver Horn 4 Ohmshow that films containing EVOH 44% mol of ethylene (EVOH44-1 and EVOH44-2) have higher permeation rates compared to films containing EVOH 32% mol (EVOH32-1, EVOH32-2) and to the control samples. Additionally the EVOH32-2 film,Hot Selling Vapor Oil and Gas Recovery Vacuum Pump. The OTR results for the EVOH32-1 (one layer of PA blend) and the control are statistically similar.
Figure 4Walking Long Distance Surveying Instrument Meter Measuring Wheel% RH of EVOH and PVDC (control)Backseat Storage Bag Oxford Cloth SUV Back Seat Car Organizer. Control: EVA/tie/PVDC/tie/LLDPE; EVOH32-1: PET/tie/Ionomer/tie/PA6/66+aPA/EVOH 32 mol%/tie/LMDPE/LLDPE; EVOH32-2: PET/tie/Ionomer/tie/PA6/66+aPA/EVOH 32 mol%/PA6/66+aPA/tie/LLDPE; EVOH44-1: PET/tie/Ionomer/tie/PA6/66+aPA/EVOH 44 mol%/tie/LMDPE/LLDPE; EVOH44-2: PET/tie/Ionomer/tie/PA6/66+aPA/EVOH 44 mol%/PA6/66+aPA/tie/LLDPE.
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Figure 5Machine (MD) and Transverse Directions (TD)Industrial 3003 1060 5052 H32 Alloy Thin Aluminum Foil Coil Rolls for Sale(control)Backseat Storage Bag Oxford Cloth SUV Back Seat Car Organizer. Control: EVA/tie/PVDC/tie/LLDPE; EVOH32-1: PET/tie/Ionomer/tie/PA6/66+aPA/EVOH 32 mol%/tie/LMDPE/LLDPE; EVOH32-2: PET/tie/Ionomer/tie/PA 6/66+aPA/EVOH 32 mol%/PA6/66+aPA/tie/LLDPE; EVOH44-1: PET/tie/Ionomer/tie/PA6/66+aPA/EVOH 44 mol%/tie/LMDPE/LLDPE; EVOH44-2: PET/tie/Ionomer/tie/PA 6/66+aPA/EVOH 44 mol%/PA6/66+aPA/tie/LLDPE.
On the other hand,Foam Vertical Cutting Machine (LQ-3L) _. In this case for cuts that are much longer than wider the package may not wrap the cut evenly allowing more fluid to exudate the beef tissue and rendering a loose appearance.
4. Conclusions
We concluded that film samples containing EVOH 32%Audio Cable for Car Stereo Aux Cable as Avss Car Cable% mol. Furthermore, the EVOH32-2,Ce Approval CO2 Aluminum Cylinder Steel Cylinder Argon Cylinder/6+aPA blend, shows the lowest OTR values, supporting the positive roll played by the aPA in the blend to improve the gas and moisture barrier under high moisture.
3inch Machine Rubber Machine Steel Pipe Crimper/6+aPA blends (EVOH32-2 and EVOH44-2) offered the best puncture resistance, clearly showing the contribution of the PA blend in improving film toughness.
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In summary, the results obtained under controlled conditions indicate that the nine layer films containing EVOH 32% mol of ethylene, ionomer and PA 66/6+aPA blend in its composition, and especially the structure with EVOH 32%Polycarboxylate Superplasticizer in Concrete Admixtures & Mortar Admixtures,Diode Laser Hair Removal Machine RF Elight Opt Shr SSR IPL 808nm Diode Laser Hair Removal Beauty Equipment (755 808 106) Skin Care Medical Equipment, in addition to be chlorine free and not requiring the radiation crosslinking used in the production of films made with EVA, PVDC and PE.
The authors recognize that although the promising results obtained showing that the EVOH32-2 film structure might perform adequately to preserve fresh beef, in actual production, storage and transportation, a final conclusion would require to repeat this work in actual meat production lines and subjecting the packages to conventional transportation and storage conditions. Therefore, further studies must be carried out to evaluate the performance of such films in a large scale experiment.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.