Key points of process control and development tren

2022-07-13
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Key points of process control and development trend of plastic wine bottle cap

release date: Source: Internet editor: lychee browsing times: 1716 copyright and disclaimer

core tip: in the bottle cap packaging industry, wine bottle cap packaging is a huge branch. Compared with other types of bottle caps, it has high profits and large demand. At present, the materials of wine bottle caps on the market mainly include plastic, glass, metal, aluminum plastic, etc. Among them, the cost of plastic wine bottle caps is lower than other types, and they are widely used. Most of their materials are ABS plastic or PP plastic, and the traditional printing process is printing. The correct control of the production process in the mass and rapid production process is an important prerequisite to ensure the stable quality of plastic wine bottle caps and reduce waste or defective products, which requires the operators to have a deep understanding of plate making, printing production process, printing quality problem analysis and other aspects after the company transfers part of the equity of Yongxing new energy to lixinhai. In this regard, the author summarizes some practical experience and shares it with the industry

[China Packaging News] in the bottle cap packaging industry, wine bottle cap packaging is a huge branch. Compared with other types of bottle caps, it has high profits and large demand. At present, the materials of wine bottle caps on the market mainly include plastic, glass, metal, aluminum plastic, etc. Among them, the cost of plastic wine bottle caps is lower than other types, and they are widely used. Most of their materials are ABS plastic or PP plastic, and the traditional printing process is printing. The correct control of the production process in the mass and rapid production process is an important prerequisite to ensure the stability of the quality of plastic wine bottle caps and reduce waste or defective products, which requires operators to have a deep understanding of plate making, printing production process, printing quality problem analysis, etc. In this regard, the author summarizes some practical experience and shares it with the industry

key points of plate making

first, 250 ~ 300 mesh cloth is used for stretching. Since nylon silk cloth is mostly used for plate making, 300 mesh cloth is generally used. If the ink layer thickness needs to be increased in case of special patterns, 250 mesh cloth is used. After the stretched adhesive is completely dried, a layer of photosensitive adhesive with a certain thickness is evenly coated on the cloth surface, and then the photosensitive adhesive is fully dried by air drying or other drying methods. Then put the film and frame on the exposure table, adjust the printing position, cover the shading cloth, and turn on the exposure lamp for exposure. Finally, immerse the exposed version in clean water for 1 ~ 2 minutes, and develop the version with tap water

production process and process control points of plastic wine bottle stamping

1 Printing production process

turn on the heating oven for preheating, and set the heating temperature to 40 ~ 50 ℃. Seal the non pattern areas on the four sides of the frame with adhesive tape, and then install it on the machine, adjust the position and turn on the power supply. Turn on the vacuum pump, put the plastic wine bottle cap to be printed on the fixed mold, and accurately position it by adjusting the position of the frame. The first piece shall be tested and printed first. After the quality is qualified, the automatic upper cover equipment and automatic lower cover equipment shall be adjusted. The batch production can be carried out only after the heating oven reaches the predetermined temperature

2. Key points of process control

the printing production requirements of plastic wine bottle cap are different from those of aluminum plate, paper and other printing materials. Because the plastic parts are easy to deform after heating, and the wine bottle cap has strict dimensional requirements, the oven temperature of the plastic wine bottle cap must be lower than the deformation temperature of the plastic parts, which is generally set at 40 ~ 55 ℃

in addition, ink type, cloth, printing speed, etc. have certain particularity. Most inks use single component quick drying inks. Semi matte quick drying inks are commonly used. Add quick drying or slow drying diluents to adjust the drying speed of inks to adapt to the changes of production environment temperature in winter and summer. Sometimes, quick and slow drying diluents are used to adjust the inking amount of inks to meet the requirements of different production speeds

printing quality requirements for plastic wine bottle caps

1 The clarity of the pattern

requires uniform ink, consistent color, clear pattern, no bottom leakage, no joint offset, no indentation, etc

the thickness and uniformity of the ink layer can be changed by adjusting the number of cloth mesh, the number of plate scraping, the ink viscosity and the scraper speed. In addition, the ink should be fully stirred before production to ensure uniform color and viscosity, which can improve the performance of plastic resin

adjust the joint and width of the whole pattern by adjusting the length and width of the whole film that the impact testing machine can operate normally only driven by the electromechanical. The pattern joint is generally controlled within 1mm. The author suggests that the blank pattern should be selected as the joint as far as possible to achieve the effect of unclear joint

Before using the

version, the blank part of the pattern must be covered with transparent tape to avoid pollution caused by ink dripping

2. The size and height of the printed pattern

the size and height of the pattern of the plastic wine bottle cap should be consistent with that of the standard sample cap, and there is no obvious difference through visual inspection. The size deviation of the pattern should be controlled within ± 0.2mm, and the height deviation of the plastic wine bottle cap pattern should be controlled within ± 0.1mm, which can be measured directly with a vernier caliper

adjust the size of the pattern by adjusting the size of the film, while the scraper pressure and ink viscosity have little effect on the size of the pattern

3. Ink adhesion

the requirements for ink adhesion are as follows: after the ink on the plastic wine bottle cap is completely dry, use a special tool to cross it, paste it with 3M paper tape, roll it back and forth for 3 times with a rubber roller, and after tearing off the 3M paper tape, do not allow the ink to peel and delaminate in a large area, and allow a small area to fall off slightly

in actual production, the safety belt used in the power industry is a personal protective equipment that is placed higher than the operator to fall or hang the operator safely after falling. The author found that the ink adhesion can be adjusted by adjusting the type of ink and the hardness of the coating of the plastic wine bottle cover. For plastic wine bottle caps with special quality requirements such as alcohol immersion resistance or high temperature sterilization resistance, different varnish can be selected according to requirements. For example, it is directly sprayed on the printed plastic wine bottle cap, and then the plastic wine bottle cap is immersed in 50% alcohol for half an hour, dried for 3 minutes, and then the ink adhesion is tested

common printing quality problems and solutions for plastic wine bottle caps

1 Color difference

phenomenon: there are differences between the color batches of the printed pattern of the plastic wine bottle cap or the standard sample cap

cause analysis: as the printing pattern of plastic wine bottle cap is generally small in area and thin in line, color difference meter cannot be used for color comparison, and visual comparison can only be carried out under specific light source. Generally, D65 light source of standard light source box is selected as the light source, which can also be bright and scattered natural light. Color comparison under direct sunlight or dark fluorescent lamp with insufficient light is avoided

solution: try not to use self-adjusting composite color, because there are differences in manual ink mixing technology and ink types, which makes it difficult to adjust the color to be consistent in each batch production. In this regard, the special ink for standard sample caps can be purchased from the ink manufacturer, and the ink quantity required for the production of several batch orders can be ordered according to the size of the production batch of plastic wine bottle caps, so as to ensure the consistency of the printed pattern color of plastic wine bottle caps between batches

it is worth noting that the mesh number of each pattern should not be easily changed. Once the mesh number is changed, it is equivalent to changing the ink amount, which will cause the difference in the ink layer thickness of the printed pattern, and then produce color difference. If the speed and oven temperature are changed during the printing process, the staff should remember to correct and confirm the pattern color again. In addition, starting from the proofing of new products, the standard sample covers are classified as "deep, medium and light" according to the color, and a fluctuation range standard for color difference judgment and dispute is established to avoid large differences due to different standards in color difference judgment

2. A small part of the pattern is missing

phenomenon: the printed pattern of the plastic wine bottle cap is compared with the standard sample cap, and sometimes a small part of the strokes or details are missing

cause analysis: during the printing process of plastic wine bottle caps, ink particles sometimes block the cloth eyes, resulting in less or missing inking at some positions. If the printing pattern of the plastic wine bottle cap is missing compared with the standard sample cap, the normal recognition will not be affected, and the area is less than (2 × 2) Mm2, and not more than two at the same time, it is regarded as qualified product

solution: during the production of plastic wine bottle caps, when there is a long-time shutdown such as shift change and rest, the staff must clean the residual ink in the plate and use a special detergent to clean the plate, so as to avoid blocking the eyes due to the solidification of the ink during the shutdown

the small stroke pattern should be adjusted as much as possible during plate making, that is, the small stroke pattern points should be merged or removed to avoid ink blocking due to a small number of eyes; On the same plate, make several more patterns. When the plate eye is blocked, you can replace other standby patterns to continue production

development trend of automatic high-speed printing production of plastic wine bottle caps

in recent years, in order to meet the requirements of customers for high efficiency, high quality and low cost, the automatic high-speed printing process of multi-color overprint has gradually moved to the market. This process also puts forward high requirements for printing equipment, ink and cloth

at present, the production speed of plastic wine bottle caps has increased from 20 ~ 30 PCS/min manually or semi automatically to 40 ~ 70 PCS/min automatically. The increase of production speed puts forward new requirements for the chain length, drying time and ink amount of the printing equipment oven. In addition, properly reducing the number of cloth mesh and increasing the ink amount can increase the ink layer thickness of the printed pattern, which can solve the problem of insufficient ink amount caused by too fast rotating speed in high-speed production

in order to reduce the cost and reduce the quality problems such as poor ink adhesion and peeling, the ink with low viscosity and high hiding power can be used in the future

in recent years, UV printing ink has been gradually applied in the printing production of plastic wine bottle caps. Under the irradiation of UV lamps, UV printing ink can be quickly cured. It has the advantages of high hardness after the ink layer is cured, fast production speed, and eliminating the need for secondary baking. When used on products sensitive to high temperature, the advantages of UV printing ink are more obvious. At the same time, it also lays a foundation for multi-color overprint on one printing equipment, which can increase the decorative nature of patterns, Improve product added value

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