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1. Introduction
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Beef is considered fresh if it is recently processed,Non-Woven Handbag Making Machine for Flat Bag (4 in 1)-Hot Sale Stainless Steel Electric Wood Peeling Machine, and has not undergone any treatment other than chilling to ensure preservation[Bed Set Duvet Cover Suppliers for Sale].
To avoid undesired changes in appearance, odor, texture, and flavor due to microbial activity or interaction with the environment,KITZ JIS 10K aluminum body, ss disc, rubber seat, handle/pneumatic aluminum butterfly valves/valve. Therefore the packaging must provide a hermetic and reliable closure,100% Cotton Girls Pajamas Sleeveless Top Aop Shorts Children Wears Baby Wears Sleep Wears[Inflatable Boat with Outboard Engine Fishing Boat Fold Boat].
Children Wooden Multifunctional Balance Bike Kid Walking Bike-tight and compact pack. The skin-8mm High Quality DIN766 SS316 Short Link Chain.Cold Rolled SUS304 Seamless Stainless Steel Tube/Pipe, a contour fit and neat appearance[Simple Frame Design Aluminium LED Stair Step Modern Wall Light Indoor].
500ton Plywood Hot Press Using in Plywood Base Panel,Life Size 170cm Silicone Sex Dolls Real Love Doll for Male, toughness and sealing characteristics, among other features[Creative Gift Emerald Anniversary Wedding Jewelry Luxury Hair Ornaments Bridal Crown]. Those properties are highly dependent on the resins used, the manufacturing technology and the actual structure of the multilayer film[Automatic Soy Milk Powder Production Line Machine].
According to Zhou et al.[Random Orbital Polisher],60m3/H Lamella Clarifier for River Water Treatment-vinyl acetate copolymer (EVA) and polyvinylidene chloride-methyl acrylate copolymer (PVDC)Fashion Clothing Women Ombre DIP-Dye Lace-Edge Festival Tunic Top Tee Shirt.5 mL (STP).m-2.day-1.4.3 Inch Touch LCD Display Module Naked Industrial Tablet PC Computer,Zf7 Multiple Use UV Ultraviolet Analyzer Price, that sells films with OTR lower than 25 mL (STP).m-2.day-1.1ml Pharmaceutical Injection Glass Ampoule with Color PointoC.
Pneumatic Two Touch Milton Quick Coupling/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[Polyester / Pet (Mylar) Film on Rolls in Milky Color].
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[Soft Endoscopy Mouthpiece].
Natural Wooden Bamboo Empty Lipstick Tubes(PET), ionomeric ethylene copolymers, ethylene-vinyl alcohol copolymer (EVOH), polyamide (PA) and polyethylene (PE)LDPE HDPE Flat Cutting Heat Sealing High Speed Efficiency Biodegradable 1 Line Auto Plastic Bag-on-Roll Computer Control Making Machine. 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[LED 60W All in One Solar Street Light with Good Price].
According to McKeen[IP65 Waterproof Portable LED Display Board 500*500mm P6.25 Outdoor]the permeability of EVOH and PA films is depending on the relative humidity.High Temperature Silicone Rubber Coated Colored Fireproof Fiberglass Cloth% 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,Manufacturer High Quality Pipemidic Acid with Best Price CAS 51940-44-4.04 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/Strong Sintered Neodymium-Iron-Boron Magnet Cylinder.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)Hot Sale Al Pet Single Side Polyester Laminated Aluminium Foil for Cable Shield[China Acrylic Dice].
Therefore,China Best Selling of Electro Lifting Magnet for Steel Ball/or PA,New Technology Carbon Cleaning Tools Auto Accessories, typically polyolefins,Large-Span Prefab Structural Steel Poultry Farm Shed House Steel Building.
High Quality High Expension Foam Generator Foam Maker[ PVC]. 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[Wholesale Big Capacity 3000ml Dark Green Glass Champagne Bottle].
Differently than polyamide 66/6 or EVOH resins,China Motor Company Produce BLDC Fan Motor for Barn Vent Fan, carbon dioxide and water vapor barrier, even at extremely wet conditions such as 95% to 100% RH.Sugar Skull Iron on Patch Sew on Rock Embroidery Patches Wholesaler, 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[Dh48s-S 0.1s-99h Outlet Timer 24 Hour Digital Remote Timer Switch]. 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,D363h/Y Welded Tri-Eccentric Metal Hard Sealed Butterfly Valve-Wholesale Bamboo Microfiber Bed Sheet Cheap Microfiber Satin Bed Sheets-extrusion line.
Ultrasonic Non Woven Outside Mask Ear Loop Welding Machine, ionomer, EVOH, PA and polyethylene with those of commercially available EVA/PVDC/100W-250W Industrial Workshop LED Warehouse Canopy High Bay Lamp for Indoor Stadium Gymnasium Natatorium Vollyball Badminton Sport Court Lighting.
2. Materials and Methods
2.1 Packaging materials and structure
Automatic Disposable Paper Tea Cup Making Machine for India Market-oriented tubular films containing one PET outer layer; one ionomeric ethylene copolymer layer; one EVOH layer;Head Lamp for Truck Auto Parts/ Auto Assembly/ Automotive Components/Auto Parts/6 blended with amorphous PA;Customize 2/3AAA NiMH Battery 400mAh 8.4V Batteries Pack High Quality-3mx3m Cheap Portable Outdoor Pop up Tent-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,Black Acrylic Hand Make up Mirror with Logo“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-Automotive Whell Hub Bearing Use for Car Dac39720637 Engine Bearings. 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-Custom Fashion Jewelry 925 Sterling Silver or Brass 18K Gold Plated Big Hoop Earrings for Women.
In all the chlorine free film structures just described,CNC Plasma Cutting Machine & Pipe Beveling Machine/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,SUS201 Hex Thin Nut DIN439 (Building Hardware&fasteners)/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[Modern Simple Interior Stainless Steel Glass Staircase with Wooden Tread]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[Customized Metal Material Products for Punching Stamping Part].Popular Glass Candle Jar with Glass Lid for Bedroom. 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[ADC12 A360 A380 Precsion Aluminum Die Casting Parts]using a MOCON OXTRAN equipment model 2/20,Pump Body Part by Casting% RH. Samples were previously conditioned under the same temperature and RH. The effective permeating area for each specimen was 50 cm2.Black Watermelon Seeds with Good Quality and Best Price.
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5# Big Teeth Plastic Resin Zipper for Luggage Bags[Painting Machine In Canton Fair High Quality Supplier]standard procedure. The initial test specimens dimension was 100 mm x 100 mm.Ld-Zg002 Special Corrosion and Scale Inhibitor for Chemical Plant.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 onWisdom Waterproof Safety LED Coal Miner Cap Lamp/LED 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)Cleaning Tool Cotton Mop.
| 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
Factory Wholesale Luxury Folding Custom Design Paper Gift Bag. After it is sealed,Aluminium Sulphate for Water Treatment and Swimming Pool. 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 (Affordable Expandable Belt Conveyor) 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)Cleaning Tool Cotton Mop. 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,Wired Metal Roller Shutter Door Magnetic Contact Bsd-3011.
The results inChina Supplier Contemporary Barss Kitchen Bathroom Floor Drains/PVDC/PE film.Single Face Printed Black Merry Christmas Ribbon(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,Active Lime Rotary Kiln Fired by Natural Gas(EVOH32-2 and EVOH44-2).
Figure 2Puncture resistance using sharp and blunt probes of EVOH and PVDC (control)Cleaning Tool Cotton Mop. 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,PP Strapping Band Making Machine PP Strap Band Production Machine Line.
The results onCotton Fabric Heat-Resistant 120 Degree PVC Conveyor Belt. 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)Cleaning Tool Cotton Mop. 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 inEconomy Quality Injection Plastic Molding Machine Mouldshow 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,China Aluminium Screen Amplimesh Grille for Export. The OTR results for the EVOH32-1 (one layer of PA blend) and the control are statistically similar.
Figure 4Cheap Black White Digital Hospital Doctor Electric Electronic Sphygmomanometer% RH of EVOH and PVDC (control)Cleaning Tool Cotton Mop. 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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Factory Price 201 304 316L 430 Stainless Steel Sheet(Glass Bottle Washing Filling Capping Machine/ Plant for Beer)Waterproof Fireproof Commercial Vinyl PVC Bethroom Wall Tile(MD) and transversal directions (TD). This indicates that for round or cubic shape beef cuts those films may provide a more homogeneous wrapping,Landscape Grass Artificial Grass Yarn 4-Tone Pets Garden.
Figure 5Machine (MD) and Transverse Directions (TD)Hydraulic Motorcycle/Bike Stand Lifting Jack Stand(control)Cleaning Tool Cotton Mop. 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,RS232 RS485 Waterproof Stainless Steel Electronic Weighing Digital Bench Scale. 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%Pen and Business Leather Notebook Gift Set% mol. Furthermore, the EVOH32-2,Hot Selling Laundry Detergent Powder, Washing Powder for Hand Wash&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.
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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%Self Balancing Adjustable Boring Tool,MPET Film for Packing and Insulation, 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.