The characteristics of Baijiu in bags printed with

Characteristics of Baijiu in plastic flexible packaging printing bags

Baijiu has a long history and culture. Since ancient times, the packaging of Baijiu cannot be separated from containers such as ceramics, glass, clay pots, etc. They have low permeability. Good sealing. It has the advantages of strong corrosion resistance and long-term storage of Baijiu, but it also has some insurmountable shortcomings. First of all, it is impossible to get accurate experimental results, which is not resistant to impact and easy to break; Secondly, it is inconvenient to carry, mainly because of its large size. Only a few bottles occupy a lot of space, which also leads to the increase of its storage and transportation costs; Moreover, the price of wine bottles is high, which becomes a burden after use. In recent years, plastic bottled Baijiu has also appeared in the market. It overcomes the problems of glass bottles that are easy to break and small volume to weight ratio, but it cannot overcome the problem of small volume to volume ratio. Moreover, its sealing performance is not as good as that of glass bottles. Taking the composite flexible packaging bag as the packaging of Baijiu solves the problem of small volume ratio of bottled Baijiu on the premise of ensuring the tightness. Therefore, although bottled Baijiu is still the mainstream in the market, Baijiu packed in plastic flexible packaging and printing bags has gradually shown its vigorous vitality

Baijiu in plastic flexible packaging and printing bags has the following characteristics

(1) strong barrier and good fragrance retention effect. As long as a suitable substrate is selected, it can be air tight, moisture tight, odor tight and solvent tight

(2) it is easy to carry, not easy to break, and even stronger than plastic bottles. It will not break when squeezed, impacted or dropped

(3) low cost

(4) beautiful appearance. It is easy to use, and its shape, specification and structural design can be diversified. According to people's living needs, a series of packages such as oneortwo, twoortwo, and half a kilo can be designed, which is more convenient to use

based on the above advantages of Baijiu plastic flexible packaging printing bags, Baijiu in flexible packaging bags will be gradually promoted in the market, and the development of Baijiu flexible packaging printing has broad market prospects

the main component of Baijiu is ethanol, which contains at least 79000 tons of plastic alcohol, which is highly corrosive and permeable. It will damage the composite packaging and cause the lamination of the composite film, which will lead to the loss of liquor flavor and the reduction of liquor concentration, "he said. Deterioration of Baijiu, etc. Therefore, composite materials with strong barrier shall be selected when printing Baijiu soft packaging bags. Adhesives, inks, etc. are very important

I. selection of composite substrate

1. Selection of outer materials (printing layer)

in order to improve the barrier property of Baijiu soft packaging bags, it is recommended to use BOPET, BOPA or kpet, kPa and other materials as the surface printing layer to improve the barrier property and prevent the fragrance from emitting. PVDC coating materials will turn yellow after long-term storage. Therefore, PVDC coating materials are generally less used in packages with high requirements for appearance quality

2. selection of inner material (heat sealing layer)

the heat sealing layer of plastic flexible packaging usually adopts PE film and CPP film, and Baijiu in soft packaging bags is usually packaged by automatic packaging machine, which puts forward higher requirements for heat sealing layer materials. First of all, the heat sealing layer material should have good heat sealing adaptability (heat sealing strength, low temperature heat sealing, anti pollution heat sealing, heat sealing temperature range and heat viscosity strength, etc.); Secondly, the compound adaptability is good; Finally, it must have good film walking property of automatic packaging, that is to say, the thermal surface finish of the material must meet the requirements of the automatic packaging machine and have an appropriate friction coefficient (the surface friction coefficient can be selected from the type and content of resin opening agent and smoothing agent)

(1) good heat sealing strength and heat sealing range

compared with CPP film, PE film has the advantages of wide heat sealing range, low heat sealing temperature and soft texture, while CPP film is generally brittle and has high heat sealing temperature, especially for thicker CPP film. Therefore, for Baijiu packaging bags with automatic packaging. PE film is more suitable than CPP film

(2) anti pollution and low temperature heat sealing

when ordinary PE film is used to pack Baijiu, its heat sealing conditions are harsh and the bag leakage rate is high. Therefore, in order to ensure good heat sealing in the packaging process, modified polyethylene such as MPE must be selected. MPE has higher anti pollution heat sealing property than ordinary PE, less affected by Baijiu pollution, higher tensile strength, large toughness and high transparency. Using MPE as heat sealing layer is a better choice

(3) composite adaptability and automatic packaging adaptability

in order to meet the requirements of automatic packaging, polyethylene film is usually produced by coextrusion, so that the composite layer has low principle opacity and smoothness, ensuring high composite strength; At the same time, make the heat sealing layer have high smoothness, so as to obtain a low friction coefficient (usually required to be about 0.2) and ensure good film walking performance of automatic packaging

for example, at present, Metallocene Linear low density polyethylene (mLLDPE) with a certain proportion is usually used in the market to modify the single-layer heat sealing substrate to improve the heat sealing performance and physical properties of the composite, but the cost per ton of modified heat sealing substrate will rise more. In order to achieve the same performance of single-layer modified heat sealing substrate, if multi-layer coextrusion composite substrate is used, the cost rise per ton of material is much smaller. The reason is that the multi-layer coextrusion composite substrate can be modified only by blending on one heat sealing layer, and the resin with lower cost can also be used in the middle layer

for another example, packaging resins contain a certain amount of opening agents and smoothing agents to improve processing performance and increase the smoothness of the film surface, but these additives will react chemically or physically with the binder after migrating to the film surface, causing the composite strength to decline. This is also the confusion that many manufacturers often encounter. In order to solve this problem, in addition to allowing the adhesive manufacturers to continuously improve the anti additive ability of the adhesive, choosing multi-layer coextrusion heat sealing substrate is a relatively economical and simple method. That is, the resin without or less containing opening agent and smoothing agent is used on the composite surface of multi-layer coextrusion heat sealing substrate to minimize the precipitation of surface additives in the composite layer, while the high smoothing resin is selected on the heat sealing surface to ensure that the film has sufficient smoothness