Application analysis of the hottest BOPP cigarette

2022-07-24
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Application analysis of BOPP cigarette packaging film (I)

basic efficacy and requirements of cigarette packaging film

with the continuous development of new flexible packaging materials and the improvement of packaging technology, it represents the tobacco industry at the forefront of packaging technology and materials, and puts forward higher requirements for cigarette packaging. As the most external packaging of cigarettes, cigarette film has a more prominent positioning on the brand. In addition to meeting the storage and protection needs of cigarettes, we pay special attention to the image effects of the market, including regular folding, smooth hand feel, clear bottom display effect and visual brightness. In recent years, with the successful application of color film, it has been attached with anti-counterfeiting, new product publicity, product integration, improvement and upgrading and other effects, all of which must be based on meeting the operating adaptability of various existing cigarette machines

as a tobacco film which is widely accepted by the market and can be highly praised, it must meet the following performance:

1. It can meet the smooth running of different cigarette machines, packaging speeds and a wide range of heat sealing. It can complete the whole process of unwinding, cutting, unloading, folding, heat sealing and conveying at the machine speed of 100-600 packets/minute, and even stop and start intermittently

2. Good bag copying effect mainly refers to the clamping position of the film on the cigarette bag box skin and the regular geometric shape formed by the folding of the film relative to the cigarette bag

3. A long period of aroma preservation and mildew prevention can prevent the tobacco from moisture absorption and mildew, and prevent the outward loss of tobacco aroma, that is, a small oxygen and moisture permeability, with good barrier

4. Good bottom display effect and visual attraction to ensure low haze and high gloss

5. It can prevent frosting and fogging during storage and transportation, and has good surface abrasion resistance and scratch resistance

6. Long term shape stability, keep the cigarette bag straight and flat after precise measurement, and avoid cigarette bag deformation caused by relaxation, wrinkling or excessive shrinkage. For hard package, it should have certain post shrinkage; For soft packs, the size of the film shall be kept stable, and there shall be no looseness or extrusion deformation of the cigarette pack caused by excessive shrinkage in the later stage

7. It meets the environmental protection and health requirements in the process of processing and consumption, including that the packaging heating process does not produce harmful gas to human body (1. the requirements for the film material of the specified pulse test method), prevent the adsorption of dust during shelf display (small surface accumulated charge), and environmental protection problems after consumption (the film is required to be degradable), etc. If there is no carton, the cigarette film can save paper

8. The cigarette packaging film sold by the vending machine should also have good smoothness

9. The waterproof fog performance of some coated cardboard and vacuum aluminized cardboard cigarette packs, especially the color box leather cigarette packs of the tensile testing machine clamp with carborundum spraying

as a well-known domestic tobacco packaging enterprise, Jiangsu Zhongda New Materials Group Co., Ltd. has launched "jinzhongda" brand cigarette packaging film, which is one of the crystal brands that meet the above requirements

influence of cigarette packaging film index on packaging

bopp cigarette film production is a continuous high-speed process consisting of mixing of various raw materials, extruding, casting, MDO, TDO, winding, aging and slitting packaging. With the deepening of product differentiation and application technology cognition, its process flow should cover storage environment, transportation conditions, etc. In view of the influence of stretching process and raw materials on film properties, such as shrinkage, shrinkage balance, post shrinkage of packaging, charge mobility of film surface and core layer, rigidity of smoke film, smoothness at high temperature, optical properties (including gloss and haze), red and wrinkle resistance, wear resistance, anti fog, etc., continuous in-depth research has been carried out, and more reasonable and more economic raw materials and formulas have been selected, Optimize the process parameters of each process (such as tensile modulus, temperature curve, winding and slitting technology, etc.) to continuously improve the adaptability and grade of products. At present, in addition to the commonly used shrinkable film, semi shrinkable film, micro shrinkable film and ordinary film, there are also a variety of differentiated and personalized products in the market, including high brightness, high transparency, wear-resistant pattern, waterproof fog, color printing anti-counterfeiting, composite color printing carton free strip package and other types of cigarette films. Especially since Chengdu Zhongda's 25000t/a five layer co extruded tobacco film production line was put into operation, the optical and mechanical properties of tobacco film products have been greatly improved, reaching the international leading level

the technical requirements for cigarette packaging film include dimensional deviation, appearance requirements and physical property indexes

size requirements include:

1, film width deviation

2. Thickness limit deviation

3, average thickness deviation

4. Roll length and number and length of joints

appearance requirements include:

1, wrinkles (longitudinal)

2. End winding flatness

3, wrinkle, particle, burst tendon and bubble

4. End face scratch

5. Impurity pollution

6. Film roll paper core

the main physical and technical indexes include: in addition to the above 9 indexes, some manufacturers have added tests for other performance indexes. Such as: minimum heat sealing temperature, surface resistivity, electrostatic half-life, 60 ℃ dynamic friction coefficient, etc

see the table for all physical indexes that have a major impact on the packaging quality of cigarette packets

1. Young's modulus of the film (E). Modulus is an important factor determining the film stiffness. When the film thickness and width b are constant, the film stiffness im=s.b.e3/12. Generally, the transverse modulus of the film is much larger than the longitudinal modulus. The longitudinal value of the film (MD, unit: n/mm) is usually marked during detection. The modulus of high shrinkage smoke film is higher than that of ordinary smoke film. The film has a higher modulus, has a more perfect blade cutting performance, is more conducive to push feeding, is conducive to the high-speed transmission of the film on the smoke machine, and ensures the folding rules of the smoke film and the smoothness and straightness of the smoke bag

2. Thermal shrinkage of the film. Proper thermal shrinkage rate can make the cigarette package compact. In particular, the balanced longitudinal and transverse shrinkage rate (the difference between MD and TD values is about 0.5) can ensure that the film has tighter and more uniform wrapping, and prevent the uneven shrinkage from causing wrinkles on the thermal surface of the cigarette package or wrinkles caused by inconsistent one-way tightness of the cigarette package. Some high shrinkage films still have a post shrinkage of about 0.4% after the cigarette machine is heat sealed and packed. Within 7-15 days after the cigarette bag is off the machine, it can improve the smoothness and tightness of the cigarette bag film packaging, and ensure that the cigarette bag is tight and not loose for a long time

3. Antistatic property. The antistatic property of the low-speed packaging machine cloth is more stringent than that of the high-speed machine (400 packages/minute or above), but the selection and proportion of antistatic agent have a great impact on the haze of the film. Through the process improvement, the electrostatic charge on the film surface is greatly reduced. At the same time, the antistatic agent ensures the outward migration of the core layer charge. Generally, the surface volume resistivity of the film is reduced to 1011n, the electrostatic half-life is shortened, and the attenuation rate is ≥ 20%, The accumulated charge on the surface of the film can be released quickly, and the cross-sectional charge is small, so it has a wider adaptability to the difference of the film device and the bag making manipulator under the speed of different machines, and even has a good effect on the anti dust collection of cigarette packets

4. Optical properties (including gloss and haze). By changing the variety and proportion of antistatic masterbatch and other additives, optimizing the stretching ratio and cooling conditions, the gloss and haze of the film have reached the international leading level. Among them, the gloss of the five layer co extruded common smoke film is 95-97 (45 ℃ angle incidence), and the haze is less than 1.0%; Ys type has a gloss of about 95 (45 ℃ angle incidence) and a haze of about 1%, which ensures the real bottom display effect and visual brightness of the cigarette label

5. Dynamic friction coefficient. The friction coefficient of the film has a great influence on the accurate transportation of the film, the accurate alignment of the film to the cigarette packet, the folding effect of the film and the cigarette packet transportation. Mask a and C have different friction coefficients, which are respectively applicable to the smooth transportation of the film to the flue gas machine channel and the accurate positioning of the cigarette packet card. In particular, the high-speed packaging cigarette machine requires high temperature smoothness on the a side of the film

in a word, Jiangsu Zhongda New Material Group Co., Ltd. will continue to explore according to the development of the smoke film industry and produce films with higher performance and better quality through scientific and technological innovation to meet the needs of the majority of manufacturers

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