The factors that determine the quality of printed products

In order to make the product quality stable, standardized and unified to meet customer needs, special inspection of the product. Most printing companies use manual inspections to inspect products for third-level inspections to complete the quality control of manufactured products.

1 Systematic three-level inspection of quality inspection

The third-level inspection is a kind of inspection system that combines self inspection, mutual inspection and special inspection.

1) Self test

Self-inspection is the operator's self-inspection of the products he produces, according to proofs, processes and technical standards, and makes a judgment as to whether the product is qualified. This test fully demonstrates that production workers must be responsible for product quality. Through self-examination, producers are fully aware of the quality problems of the products they produce, and use their brains to find the cause of the problems and take improvement measures.

2) mutual inspection

Mutual inspection means that production workers test each other. It is mainly the next process to carry out spot inspection on the semi-finished products that have been transferred from the previous process; mutual inspections are carried out between the processes and processes; and the team quality personnel or the team leader performs spot checks on the products processed by the group's workers.

3) Special Inspection

Special inspection is conducted by professional inspection personnel. Professional inspection is the ultimate affirmation of product quality. It cannot be replaced by self inspection and mutual inspection. Moreover, the three-level inspection system must be based on special inspections. This is due to the fact that full-time inspectors are more skilled in the product's technical requirements, process knowledge, and inspection skills than the production workers in the production process, and the testing instruments used are also relatively sophisticated. It is more reliable and the inspection efficiency is relatively high. Second, because producers have strict production quotas, they are prone to misdetection and missed inspections. Therefore, special inspections play a decisive role in the quality of products.

2 quality inspection steps

1) According to product technical standards, specify the purpose of inspection and the quality requirements of each product, and provide appropriate inspection methods;

2) Determine the product with the help of electronic equipment;

3) Compare the data obtained from the test with the standard and the specified quality requirements, and judge whether the individual product or batch product is qualified according to the comparison result;

4) Record the obtained data, and feedback the judgment result to relevant departments so as to improve the quality in time.

3 quality inspection error

In the quality inspection, due to the influence of subjective and objective factors, it is difficult to avoid or even occur. According to the information, inspectors' missed detection rates for product defects can sometimes reach as high as 15% to 20%. Inspection errors can be divided into the following categories.

1) Technical error: It refers to the error caused by the lack of inspection skills of inspectors.

2) Emotional error: It refers to the inspection error caused by inaccurate inspection staff and inaccurate work.

3) Procedural error: It refers to the error caused by unbalanced production and management confusion.

4) Knowingly making mistakes: It refers to the inspection error caused by the inspection personnel.

4 Improvement of quality inspection

1) Repeat inspection

How many unqualified and unqualified products out of the qualified products have been tested?

Inspection personnel or technical personnel with higher technical skills shall review and inspect a batch of qualified and unqualified products that have been inspected.

3) Change inspection procedures

In order to understand whether the test is correct, when the inspector checks a batch of products, he can use a higher-accuracy test to perform a re-examination to find the size of the test error caused by the test. Establish standards and compare them with standards to identify defects or errors in the products during the inspection process. Since the assessment methods of inspection quality of inspection personnel vary from company to company, and the situation of each company is different, it is difficult to adopt a unified assessment system.

5 Quality Inspection

In the process of quality inspection, it is necessary to know the quality problems that are likely to appear and exist in the process of the product, and to determine whether the product is accurately qualified or not.

1) Finished "serious waste product" items refer to: unclear printing, white plate, stencil printing, ink spill, stain, ghosting, missed printing, texts without missing strokes, excessive die-cutting size, serious misalignment of bronzing And leak hot, ink line, ink dot, overflow ink (width more than 0.3mm, marginal length of 5mm or more), embossing, bronzing, die cutting dislocation (out of the tolerance range after 0.3mm or more), bronzing off point (0.3mm or more 3 points or more for spotted, uncovered ground dots, exposed base color or missing dots (more than 3 for each 0.1mm dot shape), damage (1mm or more), wrinkles (2mm or more), and barcodes fail to meet national standards Wait.

2) Finished "general waste" items: printing ink lines (width less than 0.3mm), ink dots (width less than 1mm), ink overflow (width less than 0.3mm), overprinting errors (below 0.3mm below the tolerance range), Undercoat color or lost dots (0.1mm dot shape each containing 3 or less), embossing, hot stamping, die cutting misalignment (below 0.3mm below the tolerance range), damage (1mm or less), wrinkles (2mm or less) Wait.

3) Among the inspection sampling quantities, there is a "serious waste product" item, and the batch of finished products is judged as unqualified; there are 2 "general waste products" items, and the batch of finished products is judged as unqualified.

The quality of products cannot be guaranteed by inspection. In the initial stage of product development, the relevant design procedures, quality control methods, and process knowledge in the processes of design, process flow, etc. shall be solved and the quality problems existing in the production process shall be solved. Participate in the process of product quality control. This not only improves the quality of the product, it controls the entire process of product quality and ensures the final quality of the product.

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Ningbo Vinny International Trading Co., Ltd , http://www.vinnystationery.com