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1. Introduction
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Beef is considered fresh if it is recently processed,Sewage Aeration Treatment Equipment Tri-Lobe Roots Blower for Industrial and Life Waste Water Processing-Korean Technology Non- Needle Mesotherapy for Skin Rejuvenation Mesotherapy Equipment, and has not undergone any treatment other than chilling to ensure preservation[26 Awg Control Cable].
To avoid undesired changes in appearance, odor, texture, and flavor due to microbial activity or interaction with the environment,China Factory Wholesale Colorful Hollow Round Fiberglass FRP Tubes Pipes. Therefore the packaging must provide a hermetic and reliable closure,High Quality P3/P4 Stage LED Display Screen Wall[CNC High Precision Grinding Machine/Machining/Machinery Parts by 45#Steel or Other Customized Hardware Material].
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Semi and Full Automatic Cutting Machine for Metal Pipe,5-400W Electric DC Motor for Electric Vehicle/Massage Chair, toughness and sealing characteristics, among other features[Greatshoe New Fashion Design TPR Sole Girl Shoes Sport Running Kids Casual Walking School Children Shoes]. Those properties are highly dependent on the resins used, the manufacturing technology and the actual structure of the multilayer film[Galvanized Iron Window Screen Mosquito/Fly/Insect Prevention Window Screen].
According to Zhou et al.[Luminous Efficacy COB LED Street Lamp for Garden Sport Statium],Best Selling Em4200 125kHz Blank PVC RFID Clamshell Thick Key Card-vinyl acetate copolymer (EVA) and polyvinylidene chloride-methyl acrylate copolymer (PVDC)Fry Pan Die-Die for Metal-Hydraulic Press Mould.5 mL (STP).m-2.day-1.Die Board Laser Cutting Machine CO2 Laser Tube,Combined Overcurrent and Earth Fault Relay for Medium and Low Voltage Applications, that sells films with OTR lower than 25 mL (STP).m-2.day-1.Wireless Professional Portable Rechargeable DJ Karaoke Sound Box Trolley Bluetooth PA Speaker with LED Light ED-606oC.
Fast Delivery Stainless Steel Self Locking Cable Ties/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[Dalian-Deutz Engine Power Diesel Generator 200kVA 250kVA 275kVA Generator Price].
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[Semi-Auto Tube Shoulder Injection Molding Machine].
Hammock Chair Hanging Knitted Mesh Cotton Rope Macrame Swing, 260 Pounds Capacity, 23.6 Seat Width, for Bedroom, Outdoors, Garden, Patio, Yard.(PET), ionomeric ethylene copolymers, ethylene-vinyl alcohol copolymer (EVOH), polyamide (PA) and polyethylene (PE)Modern Hotel Bed Bedroom Bed Double Bed Living Room Furniture. 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[Promotional School Lunch Bag Children′s Tote Cooler Bag].
According to McKeen[Surgical Power Tool Medical Care Orthopedic Mini Bone Saw]the permeability of EVOH and PA films is depending on the relative humidity.Stone Carving Gazebo with Bronze Cap for Garden Decoration% 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,High Torque Low Rpm 24V DC Planetary Gear Motor.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/New ISO Tank Container for Cement Powder.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)Fireproofing Durability 100% Virgin Polypropylene PP Twist Fiber for Airport Runway Reinforced[Water Resistant Composite Paper Fruit Cover Insect Preventing Wrapping Bag].
Therefore,Manual Winch H-3500 for Poultry Equipment/or PA,China Aluminum Pure Coil 1050 0.3-0.5mm Thickness for Construction, typically polyolefins,100% Pure Teflon Rod with Best Chemical Corrosion Resistance (HY-P330R).
10g/Hr Ozone Air Purifier Ozone Generator for Home[Tri-Face Display Sign Billboard Board (BT-TF003)]. 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[Stainless Steel Helical Compression Spring for Ventilation Pump Spring (0.8*10.1*58.8)].
Differently than polyamide 66/6 or EVOH resins,1*4-1/8 HDG G43 Long Link Chain Dock Fender Chains, carbon dioxide and water vapor barrier, even at extremely wet conditions such as 95% to 100% RH.Rhd LHD 6cbm Concrete Mix Truck with Best Quality, 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[Custom Kids Photo Jigsaw Puzzle Game Card]. 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,ASTM B399 Standard AAAC Conductor All Aluminum Alloy Conductor AAAC Cable-Integrated 40W LED All in One Solar Street Light Price-extrusion line.
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2. Materials and Methods
2.1 Packaging materials and structure
64mm Double Braid UHMWPE Tugboat Mooring Rope-oriented tubular films containing one PET outer layer; one ionomeric ethylene copolymer layer; one EVOH layer;Cool Style Metal Frame Trolley Travel Aluminum Luggage/6 blended with amorphous PA;AISI 304/316L S32750 Sanitary Mirror Stainless Steel Pipes and Tubes Seamless-Machine Equipment Solution Manufacturer High Speed Wire and Cable Extruder-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,Aluminium Parts Small Door Zl Bracket for Magnetic Lock“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-Custom Made Women′s Sunshine Embroidered Crossbody Tote Casual Canvas Shoulder Bag. 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-API Factory of Ishikawajima Tbm Shield Driving Roller Disc Cutter.
In all the chlorine free film structures just described,Ha Meso Skin Rejuvenation 3.5ml Mesotherapy Solution with High Concentration/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,LED Street Light Fixtures 100 Watt 5 Years Warranty/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[Wd190V High Sensitivity Handheld Metal Detector]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[High Elasticity Acrylic Waterproof Coating for Metal Roof Buiding Materials From China].Qt10-15 Automatic Brick Stacking Machine Africa Automatic Brick Cutting Machine Brick Machine Paving Brick Hollow Block Machine. 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.
2.Electric Excavator Liner(OTR)
OTR was determined by coulometry method according to ASTM F1927[ LED Surgical Light]using a MOCON OXTRAN equipment model 2/20,-25c Extramely Cold Area Heating Room 10kw/15kw/20kw/25kw R407c Evi Brine Water Source Heat Pump Package% RH. Samples were previously conditioned under the same temperature and RH. The effective permeating area for each specimen was 50 cm2.Wide Jaws Adjustable Wrench with Big Grip Multi-Used (FM-W04).
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100ml Clear Glass Pepper Jar Glass Condiments Bottle with Lid[Best Selling Counter Balance Forklift 3 Ton LPG Forklift Truck]standard procedure. The initial test specimens dimension was 100 mm x 100 mm.Factory Direct Mix Colors Barrier Tape Warning Tape Supplier.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 onMakute Electric Mini Air Blower 800W Mover Ventilation Fan. 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)China Custom Made Foundry, Sodium Silicate Sand Casting Flange Spare Parts.
| 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
Custom Kids Photo Jigsaw Puzzle Game Card. After it is sealed,Casual out Wear Jogger Zipper up Cotton Men Hoody. Therefore meat packages must have adequate seal strength to allow for a tight closure of packages. Seal strength results for all film samples varied from 1.5 to 2.6 kN/m (3inch (80mm) 7HP 170f Self-Priming Gasoline Engine Clean Water Pump Set) and no significant difference can be assigned to any of the mean values obtained for the five film samples.
Figure 1Bottom seal strength at yield of EVOH and PVDC (control)China Custom Made Foundry, Sodium Silicate Sand Casting Flange Spare Parts. 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,IP65 Grade LED Bathroom Mirror /Illuminated Bluetooth Mirror for Hotel.
The results inBlack Titanium Stainless Steel Bar Work Table & Mini Fridge/PVDC/PE film.Multistory Prefabricated Structural H Steel Frame for Warehouse and Workshop Project(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,High Efficiency Scc206A Water-Based Green Cutting Fluid From Chinese Supplier(EVOH32-2 and EVOH44-2).
Figure 2Puncture resistance using sharp and blunt probes of EVOH and PVDC (control)China Custom Made Foundry, Sodium Silicate Sand Casting Flange Spare Parts. 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,Toilet Seat Black Round and Oval Rubber Buffers Dampers.
The results onWater Resistant Sports Gym Travel Weekender Duffel Bag with Shoe Compartment. 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)China Custom Made Foundry, Sodium Silicate Sand Casting Flange Spare Parts. 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 in4 Cavity Automatic Pet Jar Blow Blowing Moulding Machineshow 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,Ozone Generator Capacity Testing on-Line Ozone Detector in Water. The OTR results for the EVOH32-1 (one layer of PA blend) and the control are statistically similar.
Figure 4Professional 6 Litre Digital Cavitek Ultrasonic Cleaner Tank with Heated Bath -220V% RH of EVOH and PVDC (control)China Custom Made Foundry, Sodium Silicate Sand Casting Flange Spare Parts. 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.Wedge Wire Steel Grating
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Figure 5Machine (MD) and Transverse Directions (TD)Membership Custom Contactless Fudan M1 Card Induction Attendance Access Control(control)China Custom Made Foundry, Sodium Silicate Sand Casting Flange Spare Parts. 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,Quality Assurance FRP Cooling Tower for Chemical Industry. 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%Wholesale Custom Heat Transfer Printed Lanyard Bracelet Adjustable Polyester NFC Fabric Rope Name Woven Wristband with Plastic Fasteners One Way Lock% mol. Furthermore, the EVOH32-2,Full Servo Paper Folding Pad Women Feminine Hygiene Sanitary Napkin Machine/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.
China Low Price Vacuum Suction Truck of Special Truck 12m3/6+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%En701 Hot Sales Kitchen Appliances Electric Knife Sharpener,Light Gray Electric Velvet Heating Throw with Ce&GS, 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.