Packaging bag process audit is very important, you will understand after reading it

In order to better control product quality and deliver qualified products that meet customer needs to customers, it is necessary to have a comprehensive understanding of various aspects, including the contents of the packaging, the barrier properties of the bag, the placement of items on shelves, the freshness and shelf life of the goods. Then, the flexible packaging factory needs to consider the film properties, inks, adhesives, and various processing technologies comprehensively.

What material combinations can achieve the best effect of preserving the contents? In each production process, what process operations can meet customer needs? This requires a series of consecutive considerations. This is Shunxingyuan Packaging, a professional flexible packaging manufacturer From receiving the order The first thing to do 。

Therefore, Shunxingyuan Packaging, a professional flexible packaging manufacturer, specially established the packaging bag process audit position 。 This position complements the production technology position in the technical quality control of the production process, but it pays more attention to the pre-production consideration and planning of printing plate design, raw and auxiliary material selection, printing, lamination, curing, bag making process parameters, and post-printing processing for single-order products, special products, and new products.

When you don't know how to express your packaging needs you can choose Shunxingyuan Packaging When you no longer need existing packaging and need packaging upgrades you can choose Shunxingyuan Packaging 。” Let's learn about what packaging bag process audit is.

I. Content of process audit and guidance for production

1. Color management

Color is the core of print quality control. In the entire production management of printing enterprises, printing color management should be at the center. A dedicated person should be responsible for the arrangement and control of plate-making colors, and the on-site ink mixing and management.

In addition, in color management, the color analysis of customer samples and the difference between the plate-making proofing color and the actual production color are analyzed. By selecting the appropriate printing color conditions, using professional measuring tools and professional color characteristics, the printing color is automatically controlled and managed to achieve accurate color reproduction, which has an important impact on improving the competitiveness of printing enterprises.

2. Audit of raw (auxiliary) material management

Formulate the type, specifications, characteristics, inspection, and determination of raw materials.

Understand the requirements of food for packaging material performance, such as the different food aroma retention of different composite materials, the post-processing temperature and time of cooked and sterilized food, and understand the characteristics of single-layer film materials and multi-layer composite packaging materials, including materials, thickness, strength, oil resistance, heat resistance, heat sealing, and barrier properties, etc., to find the material combination that meets the packaging contents.

Understand the adsorption and residual solvent content of various films to reduce odor generation. Understand the factors affecting the barrier properties of the film to select excellent material combinations, select suitable inks and adhesives, and ensure that qualified products are delivered to customers.

3. Production and audit of printing plates

a. Understand the relationship between the angle of the electro-engraving knife and the width and depth of the hole. The recesses of the etching process are grid-shaped, while the electro-engraving machine carves an inverted cone shape.

Conical recesses are not easy to clean, and the transfer rate is also less, which is prone to screen hole blockage and unstable coating. The more the number of screen lines, the smaller the depth and volume, and the less the amount of glue.

Generally, cooking bags and freezing bags use 85-100L is better.

b. The selection and processing of gravure rollers include seamless steel pipes and copper-clad pipes. The quality of copper plating is directly related to the quality of image electro-engraving, and the quality of chromium plating is related to the use and printing quality.

Generally, the copper plating hardness HV100-120 Vickers, chromium plating hardness is HV900-1100, chromium plating should not have chromium shedding or peeling, good wear resistance, high India resistance, nickel plating thickness is 10um, copper plating thickness is 60um, and the actual electro-engraving depth does not exceed 40um, chromium plating thickness is 10um.

c. For different types of films, the printing plate rollers have different incremental values in the order of printing colors, but the incremental number of each color plate roller in the same set of plates is the same.

For example, the general diameter increment for nylon film printing is 0.04mm.

d. In the design of printing patterns, the superimposed patterns and positions of different pigments should be evenly distributed, otherwise, uneven pressure will cause misregistration and other abnormal phenomena.

4. Preliminary setting of production process

The production process sheet should specify the type and specifications of raw materials used, the surface corona value, the type and model of ink, the type and model of adhesive, the working concentration, mixing method, coating amount (dry glue amount); the ratio of mixed solvent, ink viscosity, ink drying temperature, bag making basic temperature, curing conditions, etc. Product quality requirements need to be clearly specified in the process sheet. The production process must strictly follow the process content, otherwise, due to arbitrary operation, batch unqualified products will result in losses.

Of course, operators can make appropriate adjustments according to the machine, climate, and actual situation, and report immediately. At the same time, the optimized parameters are recorded and stored in the computer as standard process records.

5. Strict first sample confirmation and self-inspection

First sample confirmation is a very crucial link. The accuracy of the printing layout specifications, color difference, color reproduction, halftone reproduction, screen hole condition, text stroke registration, omission, and indentation are all within the scope of first sample confirmation.

Due to the slow sampling speed and the gap between the ink model concentration and the actual printing, strict first sample confirmation and self-inspection are necessary when production is stable. Note that the samples mentioned are representative under normal process and production conditions.

At the same time, the first sample confirmation is carried out according to the production process and process procedures. Quality control is carried out on each roll of semi-finished products or finished bags, and the first-piece confirmation items and forms are filled out for each process, and the items are checked one by one.

6. Management of food packaging safety and hygiene

Familiar with commonly used standards in the production of plastic flexible packaging, including national product standards, industry standards, product hygiene standards, standard characteristics of various types of plastic films, and their testing standards and methods.

Understand the characteristics of food itself and the protection conditions required, as well as the sensitive factors affecting the main components and nutrients in food. Only by mastering the biochemical and physical properties and sensitive factors of the food to be packaged, and the protection conditions, can the material combination, packaging process and operation be selected to achieve its protective function. Understand the distinction between aromatic and aliphatic isocyanates in polyurethane adhesives. Because aromatic isocyanate adhesives will release aromatic amines, which have carcinogenic effects, during high-temperature sterilization, they are not suitable for retort pouches. FDA food packaging material regulations.

Understand the required AW value for microorganisms to cause food spoilage, so as to find the corresponding moisture resistance of the material combination. If the AW value is below 0.6, the reproduction of microorganisms is impossible. Only such a material combination can meet the food packaging safety.

II. Quality control of raw (auxiliary) materials, printing plates and various production processes

1. Formulation of acceptance standards for raw materials

a. Formulate material combinations and requirements for different contents and requirements.

b. Accept according to various raw material standards. Those with special requirements must be strictly tested according to special requirements. For example, for high-temperature retort pouches, their heat resistance and oxygen barrier properties are more strictly required. The oxygen barrier properties must not only be measured under normal conditions, but also under high humidity and high temperature (130 degrees, 90% humidity) to meet the requirements of high-temperature retort pouches.

c. Understand the characteristics of formamide and ethylene glycol ethyl ether, and prepare the test solution for the surface tension of the film according to the GB/T13541-92 standard.

Correctly understand the difference between the dyne pen and the dyne solution to provide a guarantee for film acceptance and use.

2. Basic requirements for the quality acceptance of printing plates

a. Generally, the surface finish of the printing plate is mirror-like grade 7 or grade 8. The electro-engraving quality must not have any missing screen walls or incomplete screen holes under a magnifying glass.

b. The cylindricity and roundness of the printing plate can be determined according to the actual process conditions according to the H-grade standard stipulated in HG/T3079. The roundness tolerance of the outer circle of the printing plate is ±0.01mm, the dynamic balance is less than 50g, and the coaxiality tolerance between the outer circle of the printing plate and the two end shafts is ±0.02mm.

c. The static and dynamic balance of the printing roller and printing plate can be accepted according to GB/T9293.1.

d. Check whether the plate shaft of the printing plate meets the requirements, the balance of the printing plate, whether the keyway and the plug are matched, and whether the plate roller jumps normally during operation.

3. Analysis of color and determination of ink type quality

a. Technical performance indicators of gravure plastic film composite ink - GB/T2024-2012 standard, including: color, coloring power, fineness, adhesion fastness, surface tension, etc.

The content also strictly requires the total amount of solvent residue < 10mg/㎡.

b. Various types of resin inks correspond to various films with different characteristics. They cannot be misused, misused, or different types of inks are printed on each other, otherwise major quality problems will occur.

c. Different types of resins have their corresponding solvents. It is necessary to distinguish which ink corresponds to its true solvent and false solvent, and to clearly understand the solubility parameters of the solvent and resin to avoid problems when adding mixed solvents.

d. Understand the printability of various inks on plastic films, such as: pigment dispersion, coloring power, hiding power, specific volume, oil absorption, etc.

e. Reasonable arrangement of printing color sequence, especially the arrangement of gold, silver, transparent and special colors.

4. Acceptance and matters needing attention of adhesive varieties

a. The solid content of the purchased adhesive should be checked in detail to ensure that it meets the standard, which is the key to ensuring the quality of the composite.

b. During compounding, different types of adhesives should not be mixed, otherwise the ideal compounding effect cannot be obtained.

c. The colloiding order has a scientific basis and cannot be operated arbitrarily. At the same time, it is necessary to clearly understand the adjustment of the curing agent ratio, the amount of glue, and the control of the working concentration of the glue.

5. Adjust the production process according to different climatic conditions

a. Control of humidity and dew point changes in high humidity and high temperature weather and adjustment of process parameters of glue and solvent.

b. Adjustment of the working concentration and matching amount of glue at the turn of spring and summer and the turn of winter and spring.

c. Adjustment of the working concentration and matching amount of glue and the ratio of ink mixed solvent in the rainy season.

III. Standardization and standardization of process audit

1. Analysis of samples

Fully understand the product specifications, material combination, thickness, tensile properties, peel strength, friction coefficient, heat sealing temperature curve, and formulate heat sealing strength, and find the material combination that matches these properties.

For special products, additional test items should be added. For example, retort pouches should add tests for their gas barrier properties and high-temperature shrinkage resistance, and record and file the relevant parameters to form a standard technical process document for the product.

2. Collection and transmission of product technical information

Further understand and collect information on product usage, placement, transportation, quality assurance, and post-processing parameters to provide scientific parameter support for further improvements in the manufacturing process.

3. Standardized and normalized management

Following the process operation procedures, gradually achieve standardized and normalized operations, and form technical document data of good operating parameters to provide process parameters for production assurance.

4. Combine the production process system with the requirements of the quality system

According to the printing production enterprise Effectively combine the “Six Governance” management method, continuously enrich, verify, and improve it in production practice, and ensure smooth production in standardized and normalized production.

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