With furniture manufacturing, wooden door processing, flooring production, decorative panel manufacturing, various flat panel industries and production lines evolving more in the direction of automation, intelligence, and large-scale production, the traditional modes like manual brushing, manual roller coating, and air spraying are being left behind as they cannot satisfy the overall requirements of product quality, production efficiency, and cost control of the modern manufacturing enterprises. particularly, with the very fast popularization of UV curable coating technology, companies expect not only achieving a more even, a smooth, and a high-gloss coating effect but also minimizing paint wastage through higher efficiency in the use of materials and reduced labor, to mention a few. Thus, the double roller coating machine, with advantages of steady regulation of coating thickness and improved coating consistency, has gradually become one of the core pieces of equipment in modern industrial coating production lines.
From the perspective of furniture manufacture firms, the major components of a complete UV coating production line usually consist of devices for removing dust, a double roller coating machine, a leveling unit, UV curing equipment, an automatically-controlled conveying apparatus, etc . In this regard, the double roller coating machine is very essential in coating of the workpiece surface with UV coat uniformly. Quality of the UV-curing and hence of the UV paint coating, smoothness of product surface, consistency of paint film thickness, and product quality depend very much on the double rollers. Recently, the use of the double roller coating machines in furniture companies has replaced some of the traditional spraying processes as part of the companies' efforts to attain product leadership and reduce the overall production costs through a more accurate coating method.
The high-precision UV paint double roller coating machine by Foshan XMF Machine Manufacturing Company Ltd. can be used for various flat materials, e.g., wood, plastic, glass, metal, and ceramic panels. The machine has various working widths such as the 620mm and the 1320mm, and reaches a maximum conveyor speed of 15m/min.
It is capable of running different process systems like UV paint, PU paint, NC paint, and some water-based coatings and is equipped with paint recycling and high-precision roller coating control features, offering a more efficient option to the modern-day automated coating processes.
Thus, this article would give us a complete explanation on these problems: what is a double roller coating machine, why does it become one of the important equipment in the modern UV coating production, how the companies should select their double roller coating machines?
What is a Double Roller Coating Machine?
A double roller coating machine is an automatic paint coating apparatus using two types of high-precision coating rollers to evenly paint workpiece surfaces one after another.
The technology enables it to be used continuously in a coating production system without the manual painting of the flat products such as the ones mentioned above.
Prior to UV and air spray painting, double roller coating is a method where the paint coating and paint thickness are well controlled by the roller system with the result of less painting waste, excellent surface quality, and product consistency. For modern furniture companies, the double roller coating machine does not just serve as a coating machine but it is the key factor in improving product quality, reducing labor and production costs, and even the whole line of production automation.
With the furniture making industry gradually moving from low to high-end, from ordinary to customized products, double roller machines are playing their part in a big way.
Working Principle Of A Two-Roller Coating Machine
In spite of the fact that there are certain structural dissimilarities between different brands, the underlying operating mechanisms of the machines are essentially the same
When in operation, the coating paint (UV, water-borne, oil-borne, etc.) is distributed evenly on the surface of the coating rollers via the paint supply system. Subsequently, the coating rollers pass the coat to the application rollers. The application rollers make steady contact with the workpiece or boards as being conveyed on the conveyor. With the combination of accurate pressurization as well as synchronization of the rotations of the rollers, the paint gets applied evenly onto the product surface. Owing to the fact that the rollers run with the same speed and pressure and do not rely on the human factor, the entire coating operation remains unaffected by the skill and experience, etc. of operators and so every workpiece will have almost the same thickness.
Once completed, the board is usually transferred to leveling equipment which further smoothenes the paint film or it proceeds to the UV curing stage in the case of UV coating. The whole production cycle allows for continuous feeding and fully automated operation that significantly boosts production efficiency. According to publicly-released product information of XMF, the double roller coating machine of high-quality precision has independent frequency converters for paint roll and work roll and it is fitted with an independent lifting and adjustment mechanism. The feature allows for roller spacing to be adjusted precisely in accordance with board thickness as well as process requirements so as to further enhance coating accuracy and stability of the machine. Such a structure not only meets processing needs of different board sizes but also increases the versatility of the double roller coating machine.
Why have more companies been opting for double roller coating machines?
The fierce competition among the manufacturers has led to the companies placing more attention on the total value of the equipment investment. One of the fastest-growing reasons for companies having double roller coating machines is that these machines are able to contribute to the upgrading of the production in multiple areas.
To begin with, the use of double roller coating machines results in much better quality control over a large number. With the help of traditional paint spraying methods, paint quality would differ from time to time even under the same conditions. There are a number of factors like paint gun's position, distance, angle of paint spraying, paint gun pressure, etc. that a skilled person must handle, which is very difficult to keep consistent from one operator to another. Thus, there are many chances that a batch may look different from other batches, or worse, the final product might not fulfill the design requirement of the customer. With the use of double roller coating machines, paint is applied by a roller, not by hand, so the parameters of the paint application are the exact same for each piece of product. Therefore human elements such as inconsistency will be very unlikely.
Next, it is the efficiency of the production that is very impressive. As it is a continuous conveyor system, painting is being done on the moving board with no delays or interruptions at all. So, it is the perfect match for modern high-tech automatic manufacturing lines.
Largely, companies have started to realize the significance of paint reuse in an effective way when it comes to materials such as UV and wood which are not very cheap to start with. In fact, the only drawback of the spraying machines that they can’t be used again is the paint that they have been spraying and also a great quantity has already been lost through the air. That, of course, has made material costs high, plus the company has to worry about cleaning up the waste gases that are being produced in a large quantity.
The double roller coaters, on the other hand, work through physical touching and they are much more efficient at transferring the paint to the product surface. The paint is mostly being applied to the product, the rest of the paint gets collected in the circulation system and is then re-used. This, in effect, results very much a higher utilization efficiency of the paint than was possible with the old processes.
That means for relatively expensive industrial paints, such as UV paints, better use of materials means companies can reduce unit production costs further. That in terms of economics, this has a huge advantage, especially considering the long- term.
What kind of industries and products can double roller coaters work best for?
Several companies have come to believe that two-roller coating machines are mostly used in the furniture industry; however, the use of them goes way beyond the traditional furniture manufacturers.
Now, the two-roller coating machines have found their way into numerous industries and products like furniture panels, solid wood furniture, kitchen cupboarddoors, wardrobe doors, wooden doors, flooring, bamboo flooring, decorative panels, waterproof board, PVC panel, etc.
It's mentioned in XMF's promotional material that this double roller coating machine line has application flexibility on flat boards of different materials like wood, plastics, glass, metal, and ceramic, and it is able to make high smoothness and full coatings. Therefore, this machine is not only furniture industry friendly but also can be used for building materials decoration, new energy materials, and industrial sheet processing.
When the furniture is to be as smooth as mirror and the surface requirement is very high, the use of double roller coater with its excellent thickness control ensures not only the smoothness of the furniture, but also helps in the quality of UV curing and polish at the subsequent step.
What are the types of coating that two-roller coating machines can work with?
A lot of companies when buying machines pay attention only to whether two-roller coating machines are restricted to UV coating. However, in reality, the majority of mainstream industrial two-roller coating machines nowadays offer compatibility with various coatings.
Product data available to public indicates that the high-accuracy pair of double rollers together with their coating machine not only support the use of UV涂料, but also PU coats, NC coats, and some water-based coatings as well.
However as different kinds of paint have different requirements on roller materials, paint supply system, viscosity control, and cleaning etc., companies are recommended to talk over with machine manufacturers for their confirmation on equipment configuration so as to meet production requirements before making a decision to purchase a machine.
For a company's long-distance planning, two-roller coating machines versatile between various coatings do not only help save the cost through a higher equipment utilization, but allow also the company the liberty to switch its product processes according to what's the most competitive on a particular market.
Advantages of Double-Roller Coating Machines Compared to Traditional Spraying
Double roller coaters surpass traditional spraying in the sense of film thickness control, paint utilization, degree of automatization, product consistency, etc.
First of all, the thickness of the paint film can be better controlled since with precise control of pressure and roller spacing, double roller coating machine can deliver more even and consistent coatings which greatly reduce the issues like sagging, orange peel, and paint build-up on localized areas.
The second advantage, is paint utilization is higher. As, with physical paint roller transferring the paint, paint mist distribution is reduced and most of the paint sticks to the product surface hence material waste and exhaust gas treatment is minimized to a large extent
In the third place, it is much higher automatization level. The modern double roller coater can combine with an automatic conveying system, leveling device, and UV curing equipment to form a full production line. A single operator can take charge of the equipment and adjust the parameters and reduce dependence on manual labor significantly.
The fourth advantage, product consistency, is better. Mechanical rollers ensure smooth long-term operation resulting in high consistency of mass-produced goods. This is an added value for companies exporting their furniture, producing bespoke or branded furniture pieces, i.e., they are expected to deliver goods of one and only quality. Of course, double roller coating machines cannot work with irregular workpieces or complex curvatures and carved surfaces, for which traditional spray painting machine remains the more adaptable solution. As a result, many big firms of the furniture manufacturing utilize both systems, i.e., double roller coating machines and automatic spray equipment, depending on product structural design, to achieve best possible results.
How should companies select an appropriate double roller coater?
Owing to the existence of many types and models of double roller coater on the market when it comes to the acquisition stage, a company should not just consider equipment price alone, the purchasing decision should be made against the actual production needs of the company.
Firstly, select the most suitable working width for the major production dimensions of the company, for example, 620mm is used on smaller furniture and 1320mm is suitable for wider furniture panels. Different working widths are suitable respectively to the different board sizes and the equipment can usually accommodate one or more standard sizes.
Secondly, one also should find out the minimum and maximum thicknesses of the boards the machine can handle, the furniture boards in different companies are of various thicknesses thus it is necessary to check if in the future, through the introduction of new product models, the double roller coating machine will satisfy the needs of the company’s production line.
Furthermore, factors like conveyor speed, roller processing accuracy, frequency conversion control system, paint supply cycling system, lifting and adjustment mechanism, and equipment upkeep should be closely examined. For a continuously working production line of long duration, the reliability of the equipment is the very important matter, therefore, the equipment speed alone is insufficient.
Along with that, another important aspect which can hardly be ignored by manufacturing enterprises is the capacity of the supplier to carry out after-sales services. The two-roller coating machine is the piece of equipment used in continuous production processes on the industrial level. Therefore, manufacturers are advised to select partners who can provide technological training, the fine-tuning of the equipment, spare parts, and the supply service in the long run, thereby minimizing risks of problems in equipment operation after purchase.
FAQ
Which products are double roller coating machines mainly suitable for?
Two-roller coating machines are mainly suitable for various flat materials of furniture such as furniture panels, cabinet doors, wooden doors, laminate flooring, PVC board, PET board, glass, metal sheet, ceramic sheet, and decorative panel. In particular, they are more suitable for a product that requires a flat surface as well as a uniformly applied paint film. (You can read this as a separate topic if you find it difficult.)
Can a two-roller coating machine only be used for UV paints?
Not at all. The majority of the industrial-grade double-roller coating equipment now can be employed with the use of UV coatings. Besides them, they can also be used with a number of coatings, such as, the PU coatings, the NC coatings, and the water-based coatings, etc., as well.
However, each type of coating has different requirements for the equipment configuration. Therefore, you have to confirm that point with a supplier before you make a purchase.
What is the biggest advantage of two-roller coating machines compared to traditional spraying?
Two-roller coating machines produce significantly better, and more even, paint films on flat surface workpieces, with a much higher paint utilization rate, and with significantly, and consistently, higher quality product and production, while significantly at the cost of much less environmental polluting through the elimination of paint overspray waste. (You are free to translate this into another language.)
What key considerations should enterprises focus on when purchasing two-roller coating machines?
The company should mainly pay attention to those factors:
width
type of board that can be processed
speed of the conveyor belt
accuracy in production of the rollers
control system of a frequency converter
system of paint supplying circulation
mechanism of lifting and adjusting
the ease of the repairs
In fact, the choice of a double roller coating machine is a very important decision made by enterprises. In addition, enterprises will also refer to their present or future product specifications as well as their production capacity planning.
Future development direction of double roller coating machine?
In the near future, double roller coating machines are expected to be much more intelligent, digital, and energy-efficient. Equipped with online inspection, auto-control, the integration of the manufacturing enterprise system MES, and intelligent data analysis, they will constantly elevate the coating quality, the efficiency of production, and the resource utilization.
Thus, the double roller coating machines will offer a complete solution for the modern coating industry, not just for paint but also for various other coatings, and even the whole industry chain related coatings.