Application example of hanging spraying process in

Application example of hanging spraying process in steel barrel production

in the past, when the metal packaging company subordinate to the company group produced two kinds of 200 liter steel barrels for two purposes, because the coating colors of the two kinds of steel barrels were very different, and the production of the two kinds of steel barrels was cross carried out by two sets of middle section equipment and one set of spraying equipment. Conflicts often occur in the production process: first, there are large differences in coating colors, which interfere with each other; Second, the two products are needed at the same time, and it is difficult to ensure supply at the same time. Secondly, it is important that due to too many process changes and serious bumps, the appearance quality of the steel barrel is greatly affected, which is difficult to meet the quality standard requirements of customers

in this regard, through analysis and demonstration, it is determined that an investment of 1.5 million yuan has been invested to introduce a complete set of suspension spraying equipment produced by Shanghai Jianya electrostatic equipment Co., Ltd. (including a pretreatment line, four drying channels, two spraying rooms and two sets of chain conveying devices), forming two complete steel barrel production lines, which can simultaneously produce two kinds of packaging barrels (paint spraying and powder spraying) or two barrel types (external coating and internal coating). In this way, the requirements for ensuring product output and appearance quality have been fundamentally improved. The specific implementation projects are as follows:

first, change the past rolling transmission track transportation to rotary upper transmission suspension transportation coating

adopt the rotary upper transmission suspension transportation coating method, which is to suspend the barrel body and the barrel bottom cover or the barrel body on the rotary conveyor chain with a special hook for operation, and the main purpose is to solve the following problems:

1. Overturning and rolling collision during process conversion in barrel production, It causes deformation in the production of steel barrels and affects the appearance quality of finished steel barrels

2. The rolling down drive is mostly a combination of mechanical and pneumatic transmission. Frequent impact and collision are inevitable in the process of conveying, which is easy to cause damage to the mechanism components (especially the bucket turnover frame and spraying drive mechanism) and affect the normal production

3. When the lower transmission track is used for conveying and spraying, the rotation of the steel barrel is driven by the supporting barrel wheel. In this way, there are inevitably spraying defects on the edge of the lower barrel, which also affects the appearance quality of the steel barrel. It is usually treated by supplementary spraying, which virtually increases the process labor

the above three problems have achieved the expected purpose and achieved good results by changing the transmission mode and using it for one year

II. Improvement and implementation of pretreatment line

the length of pretreatment degreasing, phosphating and cleaning lines used in the past is generally more than 30 meters, so there are two problems: one is the cost of equipment, and the other is the large floor area. The length of the newly-built pretreatment line is 26 meters. By appropriately increasing the flow of water pumps and the number of nozzles, the degreasing, phosphating and cleaning effects of the barrel body and barrel bottom cover are ensured

III. improvement and implementation of drying channel structure

the pre-treatment drying channel, leak test drying channel, internal coating drying channel and external coating drying channel used in the past are arranged in a long line in sequence, and there are the following problems:

1. High equipment cost

2. Large floor area

3, large heat loss

4. Most of the air induction system devices and combustion system devices of the drying channel are set on the top or side of the drying channel, which is difficult to maintain

now this new set of drying channels adopts the touch key operation mode and adopts the parallel setting, that is, the pretreatment drying channel and leakage test drying channel are set on the left and right sides, and the internal coating drying channel is set in the middle between the external coating drying channel and the external coating drying channel. According to the actual use, the length of the pretreatment drying channel and leakage test drying channel is shorter than that of the external coating drying channel and internal coating drying channel. In addition, the induced draft combustion devices of all drying channels are placed under the overhead parallel drying channels. Through the implementation and application verification, the above problems have been well solved, and the heating rate of the drying channel has significantly accelerated the market range created by other industries to reach $7 trillion. Generally, it can rise to 200 ℃ in only 15 minutes, improving work efficiency by 50%

IV. configuration of new external spraying room

in order to adapt to the supporting and practical use of the rotary upper drive suspension conveying, we have taken the following corresponding measures:

1. The speed of the rotary upper drive suspension conveying is adjustable according to the production speed demand, and it is difficult to realize the paint film spraying thickness only by driving the steel drum rotation by the walking of the suspension conveying chain, For this reason, an adjustable mechanical drive mechanism controlled by frequency converter is set. In order to avoid rocking caused by the rotation of the steel barrel and affecting the spraying quality of the steel barrel, a transition drive mechanism should be set at the front end of the spraying

2. Since windform XT 2.0 is a top-level laser sintering material hung on the hanging conveyor chain, there can be defects. In order to realize the automatic control purpose of spraying with barrels and spraying without barrels, an electronic induction memory sensing system controlled by PLC is specially set up, which is conducive to reducing the waste and loss of paint. In order to prevent the electronic sensor from affecting the induction effect due to paint mist covering, a sub auxiliary blocking mechanism is set to ensure the normal operation of automatic spraying

3. Considering the configuration of economical and applicable external spraying equipment, we selected the mechanical conversion spraying machine produced by a factory in Chongqing for supporting use. After trial, it achieved good results, and its performance can be compared with that of imported equipment, which is very stable

4. Due to the continuous adjustment, improvement and improvement of the spraying method, on the premise of ensuring the coating quality of the pulley qb/t 3892 ⑴ 999 for spraying push-pull aluminum alloy doors and windows, the volatilization of paint mist is reduced as much as possible. By adding a special filter cloth, the original water curtain facilities are cancelled, thereby simplifying the heavy waste paint cleaning work

through the implementation and use of the newly-built external spraying room, all the spraying indicators have met the requirements of relevant technical standards, and have the characteristics of stable performance, high degree of automation, few faults, low production cost and so on

v. reasonable layout of the whole coating line

it is necessary to use the original conditions as much as possible to set up a complete set of steel barrel coating line, and it must meet the requirements of process quality and production efficiency. Therefore, it is necessary to reasonably set and layout the pretreatment, drying channel, cover leakage test, internal and external spraying rooms and other lower sequence facilities in the coating line. In the process of implementation, in addition to setting the pretreatment facilities and four hanging conveying devices as described above, the hanging conveying device is also set with variable line, that is, when the inner spraying room is rarely used, the inner spraying room is avoided by changing the line through track flexible pressing, so that the barrel rotation speed is accelerated, which is conducive to improving production efficiency. The painting line after implementation covers an area of only 600 square meters (workshop area), and the setting of facilities is compact and small, which makes full use of the effective space

at present, after the new coating line is used together with the adjusted barrel making equipment, the shift production of oil packaging barrels is increased from 800 in the past to 1200 (which can also be increased); The appearance quality of the steel barrel fully meets the quality standards provided by users and has been highly praised. From this point of view, this new coating line brings many benefits to the enterprise. (end)