In recent years, the social washing industry in China has developed rapidly, and many washing owners have learned more about foreign advanced washing equipment. At the same time, the supporting resources of large washing factories are also becoming more and more perfect, so the washing efficiency is greatly improved than before. With the application of washing machines and integrated washing, the efficiency bottleneck of washing is being broken day by day. As a result, the ironing efficiency, which was temporarily relieved by the application of folding machines, has once again been paid attention to by many washing owners. There is also a place for domestic use. However, China's washing situation is far from that of foreign standardized factories. The selection of these new technologies and new equipment needs to be comprehensively considered. It is the only truth to choose the most suitable one to maximize benefits.


The high-speed screed line is actually composed of several links: feeding, ironing, folding and stacking. Therefore, how to build a high-speed screed line that conforms to the actual situation of the enterprise also needs to be analyzed separately from these links to maximize benefits.


Ironing speed analysis


The primary indicator of high-speed ironing line is ironing speed, only higher ironing speed can get greater benefits. The ironing speed mentioned here refers to the highest speed that the user can reach to dry and iron the linen in actual use, rather than the highest speed that the device can run. Because the maximum operating speed of the equipment is often higher than the actual linen drying speed, in actual production, the equipment runs at a high speed, and the linen cannot be ironed, which is meaningless. At present, the domestic social washing is still dominated by roller ironing machines, and the steam pressure is generally below 5bar. Therefore, in recent years, four-roller and five-roller ironing machines have been more used, and the corresponding ironing speed can reach 30M/min (sheets), 20M/min (quilt cover), so that the ironing through more rollers Machine selection, which can increase ironing speed by more than 40%, some customers have adopted 6-roll ironing machine for higher speed to improve efficiency.

Folder speed analysis


The increase in ironing speed requires that the operating speed of the folding machine also needs to be increased. It should also be noted here that the ironing speed only refers to the speed at the entrance of the ironing machine. Due to the need to ensure the ironing quality, the speed of each roller will be 2~4% higher than that of the previous roller. The more, the higher the speed at the exit of the iron. Taking the ironing speed of 30M/min and the number of ironing rollers as 5 as an example, the outlet speed of the ironing machine can reach 35M/min. In addition, in order to ensure that the linen has accumulated wrinkles on the folding machine, the operating speed of the folding machine must be at least 35M/min. It is 5~8M/min faster than the export speed of the ironing machine, so that the operating speed of the folding machine is selected at 40~43M/min.


In the operation of the folding machine, the speed of one fold and two folds can be adjusted according to the ironing speed, while the running speed of more than three folds is fixed. Therefore, the maximum running speed of the folding machine refers to the linen that can be processed by three folds. speed. At the same time, when the linen is folded in three, there is a stop process on the three-fold table to ensure that the linen enters the four-fold completely, so the actual maximum operating speed of the folding machine is often lower than the maximum operating speed (mechanical speed) of the folding machine. 2M/ Min or so, otherwise it will cause the linen at the three-fold table to be too late to be processed and the gap will be super wide, and the linen will be folded in two.


Based on the above situation, the maximum running speed of the folding machine must be above 50M/min to ensure the basic normal use. If considering the reserved space for the improvement of the ironing speed, the folding machine with the maximum running speed above 55M/min needs to be selected first. .

Feed speed analysis


The feeding speed, also known as the feeding speed, refers to the speed at which the operator feeds the linen into the ironing machine. Since it takes time for the operator to pick up the second linen after sending one linen, there is a gap between the two linen, which directly affects the ironing speed. Another term has been introduced in this profession, called effective ironing speed.


For example, at present, the ironing speed of sheets has reached 20M/min (4bar steam pressure, 4-roll ironing machine usage), and the operator turns around and picks up the next line after sending the linen. To the ironing machine feeding table, the whole process time is about 3 seconds (other personnel arrange the linen for the ironing operator), then there will be a gap of about 1M between the two linens. The existence of the neutral gear does not carry out the actual ironing work, so the overall ironing speed will decrease, and the actual ironing speed of the linen is called the effective ironing speed. Taking the above speed as an example, according to each linen 3M length calculation, the effective ironing speed is 15M/min, which means that if there is no gap in theory, the ironing speed of 20M/min can iron 6.6 pieces of 3M length linen in 1 minute. Only 5 pieces of linen can be ironed, and the effective ironing speed is reduced by 24% compared with the theoretical ironing speed. If the length of the linen is smaller, there will be more gaps, so the efficiency loss will be greater. In actual operation, if the ironing speed is usually lower than 12M/min, the effective ironing speed is basically the same as the ironing speed (usually, when the previous linen has 30cm left, it will not be sorted, and the latter linen will be picked up. ), but as the ironing speed increases, the gap between the effective ironing speed and the ironing speed will be larger, that is to say, if the problem of feeding speed is not solved, the ironing speed will be directly lost, so the number of rollers will be increased. The benefit of increasing the ironing speed is also weakened, and the gap between the linens also leads to an increase in the ineffective use of steam, so the overall economic benefit reaches 70% of the investment. Expectation is very good.

Through the above analysis, usually when the ironing speed reaches 20M/min or more, it is necessary to consider the influence of the linen spacing on the ironing speed. The most effective way is to increase the cloth feeding speed and reduce the linen spacing. Taking the above data as an example, if the operator increases the pick-up time between the previous linen and the next linen to 1 second, the effective ironing speed can be increased to 18M/min. An extra 60 bars can be ironed per hour; if the processing time between the linens is reduced, the effective ironing speed is equal to the ironing speed, the efficiency is maximized, and the return on investment is expected.


Based on the above analysis, it is necessary to choose a cloth feeder if the ironing speed is above 20M/min.




The choice of the cloth feeder


At present, there are two types of equipments in China that can achieve increased feeding speed, multi-station spreader and cloth feeder. The efficiency improvement is that when the cloth feeder automatically processes the previous linen, because no manual intervention is required, the operator can save time to fetch the next linen, thereby reducing the waiting time for sorting between the front and rear linens. The vacant distance between two pieces of linen is directly reduced, so that the amount of ironed linen per unit time is increased without increasing the ironing speed, and the ironing efficiency is improved.


The efficiency of the multi-station spreader is that the user's ironing lines are classified, such as one ironing line for ironing sheets, one ironing line for ironing quilt covers, and another ironing line for ironing small pieces and irregular linen. In addition, the multi-station spreader currently produced in China is not equipped with a manual feeding channel, so once the domestic multi-station spreader is used, the entire ironing line can only iron the linen that can be fed by the spreader, and other linens. Not available. Due to the large scale of foreign washing factories, they are usually equipped with multiple ironing lines, and more trough ironing machines are used to obtain higher ironing speed through higher steam pressure, usually above 45M/min. , This kind of working conditions makes the multi-station spreader have a place to use. In the current situation of domestic social washing, its efficiency cannot be maximized, and it can only reach about 1/3~1/2 efficiency. That is to say, since the speed of the ironing machine is about 20M/min, the three-station spreader only needs to activate 1~2 stations.


The cloth feeder is a title defined in China to distinguish it from the multi-station spreader. Its main function is to increase the feeding speed, reduce the gap between the linen, and at the same time, it has the functions of fluffing, unfolding and flattening some linen. Due to the limitation of its structure, the flattening effect is not as perfect as that of the spreader, but it is much improved compared to manual flattening. In foreign countries, it is divided into two categories: independent type and direct-connected type. The so-called independent type means that the cloth feeder is an independent device that can be matched with any other ironing machine, while the direct-connected type can often be directly connected to the ironing machine. , so that the cloth feeding mechanism of the ironing machine is omitted, thereby occupying a smaller area, but there is also the defect of a small matching range. The running speed of the cloth feeder can be synchronized with the ironing machine, thereby reducing the cumbersome control after adding equipment, and the running speed range of maximizing efficiency is 20~35M/min.


At present, the application of domestic ironing machines and folding machines has been popularized, but the cloth feeder has just entered the market. Therefore, when choosing a cloth feeder, it is necessary to find out the matching with the existing ironing machine, the floor space and energy configuration of the cloth feeder. And other auxiliary packages to use the equipment with minimal cost. Under the same circumstances, preference should be given to a cloth feeder that occupies a small area, only has power supply, no other auxiliary facilities, and can move flexibly.

A wrong perception needs to be corrected here: the configuration of the cloth feeder and spreader is not to increase the ironing speed, but to increase the effective ironing speed, because increasing the ironing speed (because the equipment is all frequency conversion control, theoretically can increase frequency to make the machine run faster), the linen is no longer dry. Therefore, when choosing the cloth feeding equipment, first of all, it is necessary to confirm whether the gap between the two linens before and after ironing is large. According to actual experience, if the distance between the two linen gaps exceeds 80cm, then the cloth feeding equipment will bring you Visible efficiency improvement; if the neutral distance is less than 30cm (the ironing speed itself is not high), then the maximum benefit of the cloth feeding equipment cannot be realized, and only the auxiliary benefit of smoother linen can be realized. Not cost-effective, at least not worth it if the ironing speed is not improved, and the user needs to make a rational choice.


Note: Visual analysis of screed efficiency improvement

The above has objectively explained the equipment configuration of the high-speed screed line and the key points to consider when selecting it, so how to distinguish the improvement efficiency of the screed line? It is actually very simple. We already know that the running speed of the entire ironing line is actually determined by the ironing machine, and the running speed of the cloth feeder and the folding machine is matched with the ironing speed. Usually, the cloth feeder The running speed is 3~5M/min lower than the ironing speed, and the folding machine speed is 5~8M/min higher than the ironing speed. After the linen is fed from the cloth feeder, it is ironed and ironed, then folded, and finally exited from the folding machine. Therefore, for the user, the efficiency of the ironing line is the quantity of qualified linen that can come out at the exit of the folding machine per unit time. For example, the current ironing speed is 20M/min, and the linen length is 2.8 meters. Since there is a gap of 1M, the number of qualified linen at the exit of the folding machine is 5.3 pieces/min; The speed is still 20M/min, the linen spacing is reduced to 10m, and the number of qualified linen at the exit of the folding machine is 6.9 pieces/min. Even if there is still a gap of 20 cm, the number of qualified linen at the exit of the folding machine is still It can reach 6.6 pieces/min, so the efficiency of the ironing line is increased by 24.5%. This not only reduces the working time of the operator, but also reduces the running time of the screed line equipment, and also greatly reduces the empty space of steam, thus achieving the goal of saving costs in terms of steam, power and manpower.


1*: The above speed data is based on the fact that the steam pressure of most domestic social washing factories is 4~5bar, and the sheets are washed and dehydrated by a single machine as an example. The author visited Jiangsu, Zhejiang and Shanghai.


The average income obtained after sampling from more than 20 washing factories.