Development and application of the hottest nano an

2022-08-09
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Development and application of nano antibacterial high barrier packaging film

the nano antibacterial high barrier packaging film is produced by salivation coextrusion technology. The packaging film has better antibacterial and high barrier properties. Compared with the traditional aluminum plastic composite areca packaging, it can improve the shelf life of areca and reduce the cost

key words: nano antibacterial high barrier composite packaging application

the betel nut industry in Hunan has a history of more than 300 years, but it has developed on a large scale in the past decade, and now it has even become the pillar industry of Xiangtan city. In 2009, the output value of betel nut in Hunan exceeded 2billion, with more than 400000 employees. The packaging of betel nuts was first in paper bags, and then upgraded to polyethylene plastic bags. Now the high-end betel nuts are packaged in dry aluminum plastic composite flexible bags or aluminized plastic composite bags. From the perspective of packaging effect, with the improvement of packaging materials, the quality of packaging is getting higher and higher, but the current widely used aluminum-plastic composite packaging costs higher, and chemical adhesives are used in the composite process. Chemicals are inevitable in the composite packaging film, which has a certain impact on the safety of Areca nuts; Moreover, some composite packaging has residual solvent smell, which seriously affects the taste of areca nut and has adverse effects on the health of consumers; In addition, although the existing aluminum-plastic composite packaging has good barrier property, it does not solve the problem of antibacterial, and the betel nut appears mildew after a long storage time. In order to solve the problems existing in the current areca composite flexible packaging, we used the coextrusion salivation process, combined with nano antibacterial technology, developed a nano antibacterial high barrier packaging film, which was applied to the areca industry in Hunan and achieved good results

experimental part

structure of nano antibacterial high barrier packaging film

because areca nut is a kind of ripe fruit after special treatment, it has a special flavor, and the packaging material is required to have high barrier property. In order to prevent areca nut from mildew during storage and extend the shelf life, the inner layer of co extrusion composite packaging film adopts antibacterial polyethylene layer, and polyethylene has good heat sealing performance, which provides convenience for the later bag making operation, EVOH with good barrier effect is used in the middle layer. This material is ethylene vinyl alcohol copolymer, which is a resin with very good barrier performance. Its function is to provide sufficient barrier performance for the coextrusion composite film, and ordinary polyethylene is used in the outer layer] to maintain a low cost. The bonding layer adopts imported resin with stable performance to ensure the quality of coextrusion composite. Specific structure: pe/ad/evoh/ad/antibacterial PE, film thickness is 120 μ m。

main raw material

nano antibacterial polyethylene, first treat the nano antibacterial agent with dispersant and other additives, then mix it with polyethylene, granulate it with twin-screw extruder to obtain antibacterial masterbatch, and blend the masterbatch with polyethylene resin to obtain nano antibacterial polyethylene for coextrusion composite, self-made]; Ethylene vinyl alcohol copolymer (EVOH), DuPont; Adhesive layer resin (AD), because the tension machine system is a closed-loop system, DuPont bynel series; Polyethylene (PE), ld155, Shanghai Jinshan Petrochemical Co., Ltd

main equipment

coextrusion flat film casting unit of Austrian Lanjing company, model 92f057

screw diameter (mm): machine a φ 55

b machine φ 40

c machine φ 55

d machine φ 55

length diameter ratio: a machine 30/1

b machine 30/1

c machine 30/1

d machine 30/1

screw speed (RPM): a machine 170/270

b machine 170/270

c machine 170/270

d machine 170/270

die head width (mm): 1350

die gap (mm): 0 2

production capacity (kg/h):200

screw pressure (bar): a machine 57

b machine 69

C machine 68

D machine 44

traction speed (m/min):

surface temperature of casting roller (℃):

air knife pressure (PA):

surface tension( μ N/cm):

output (kg/h):

process conditions

trial production process conditions are related to resin characteristic temperature, molecular weight and fluidity, equipment characteristics and other factors. It is the guarantee for the successful trial production of nano antibacterial high barrier packaging film, such as screw speed, processing temperature, cooling setting temperature, air knife temperature, distributor scale, system tension, etc. [5]. After repeated tests, the process conditions are determined as follows: processing temperature (℃), a machine barrel, B machine barrel, C machine barrel, D machine barrel, flange, machine head; Screw speed (RPM): machine a is, machine B is, machine C is, and machine D engineering plastics are generally used in the safety module, electrical module, rotation module, electromechanical coil framework, slide rail and other modules of household appliances

product performance test

test standard

tensile strength is measured according to gb/t, tensile speed is 5 mm/min, and temperature is 25 ℃

tear strength shall be tested according to QB/t standard

the antibacterial property of the film is carried out according to gb/t standard

heat sealing strength shall be tested according to qb/t standard

oxygen transmission shall be tested according to GB/t standard

the water vapor transmission shall be tested according to GB standard

test results

the main performance indexes of the developed antibacterial high barrier packaging film are shown in Table 1. Table 1. Main performance indicators of anti-bacterial high barrier packaging film

areca packaging application

as mentioned above, the finished areca is a product that has been specially processed, and the processing technology of areca from different manufacturers is also different, but the final products must have pure taste and strong aroma. In order to ensure the quality of products for a long time, effective methods in anti-bacterial high barrier packaging technology are adopted. Therefore, we conducted a comparative experiment between the antibacterial barrier packaging and the aluminum-plastic composite packaging widely used at present

two kinds of packaging materials are made into packaging bags, and the specification is common (150 × 110mm), 64 grams per bag. Then store it at room temperature, and observe the appearance, good relationship between China and Malaysia, and the change of flavor

the results of the comparative experiment are shown in Table 2 and table 3. Table 2. Changes of areca appearance with time in nano antibacterial high barrier packaging and traditional aluminum-plastic composite packaging

Table 3. Changes of areca flavor with time

it can be seen from table 2 and table 3 that the shelf life of areca in traditional aluminum-plastic composite packaging is about three months. After upgrading to nano antibacterial high barrier packaging, its shelf life is at least six months, and the problem of mildew of areca due to long storage time is solved. In terms of cost, nano antibacterial high barrier bags also have great advantages over traditional aluminum-plastic composite bags by replacing a good spare part with the same component on the faulty machine. At present, the cost of aluminum-plastic composite bags (64g bags) is 0.15 yuan/piece, while the cost of nano antibacterial high barrier packaging bags after large-scale production is about 0.11 yuan

conclusion

(1) using nano antibacterial technology, nano antibacterial high barrier packaging film can be prepared by coextrusion salivation process, which has excellent antibacterial and high barrier properties

(2) the production process of nano antibacterial high barrier packaging film is simple, the product quality is stable, the product performance index meets the areca packaging requirements, and the production cost is lower than the aluminum-plastic packaging produced by the dry composite method

(3) nano antibacterial high barrier packaging film used in areca packaging can improve the shelf life. (end)

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