Solvent printer and air quality control

The development of the printing industry has brought about the emergence of large-format solvent-based printing systems. Operators of all sizes realize that the introduction of these types of printing systems can provide a wider range of printing products for their new and existing customers. Taking car body advertisements and outdoor signage as examples only, these two markets are rapidly expanding, resulting in the continued use of solvent-based printing presses and damage to the environment. Some people expect the emergence of UV platform printers may make solvent-based printers replaced, but they all underestimate the power of solvent-based printers. If the sales volume of the machine and the introduction of new machine types are now used as the standard to measure the market share, the solvent-based printing machine is at the forefront.

As we all know, when working with large-format solvent-based printing presses, unpleasant smoke and odors are generated, causing harm to the health of employees and customers, and making them feel uncomfortable. Many employers think they are numb to the smell and feel no more, but the customers who usually walk into their workplaces will be surprised and ask, "How can you bear the smell of the smell all day to work?"

In a harsh working environment, new employees will experience headaches, dry mouth, and acupuncture points until they lose consciousness of the smell. Seriously, they may require medical treatment or simply resign.

Over the years, this operating environment has been accustomed to us, but when we realized that these smells and smoke are not just a nasty problem, our views have changed-they do cause harm to the human body . Whether you are using an environmentally friendly solvent-based printer, a wide-format printer (with a width of 3 meters or 9.8 feet), or an ultra-wide-format printer (with a width of more than 3 meters or 9.8 feet), these injuries will be real. .

Therefore, employers need to properly understand the impact of these gases and preventive measures to provide employees with a safe and healthy working environment. Employers not only need to protect the health of employees, but also protect the company itself from legal liability.

It is worth noting that the presence of harsh smoke and odors in the working environment does not mean that dangerous pollutants are necessarily present. On the contrary, not smelling any bad smell does not mean that there must be no dangerous pollutants. But usually they exist at the same time-the existence of one situation may herald the existence of another situation-employers should not guess whether these two exist at the same time. It is possible to provide a healthy and safe environment. How to reduce the harm to human body caused by air pollutants? Before solving this problem, we need to make more understanding.

The procedure of solvent-based ink printing is very simple. After the ink of mixed solvent is printed on the medium, the solvent volatilizes, and the problem arises. When the concentration of solvent exposure is very high, it will cause harm to human body.

These harsh fumes are called "indoor harmful gases", and the US Occupational Safety and Health Administration (OSHA) has made relevant regulations. For many chemicals used in solvent-based printers, their exposure limit is 20 ppm. Usually, when buying a solvent-based printing machine, you will get a safety data sheet of ink material from the dealer or manufacturer, which contains the product's exposure limit information. If the toxic gas in the room causes employees to become sick or have health problems due to excessive exposure of the product, the employer shall bear the medical expenses of the employees, compensation litigation and OSHA fines.

Understanding indoor harmful gases, volume concentrations, and exposure limits is a complex process that involves lengthy chemical equations. It is impossible for every employer to have a detailed understanding of each element, but simply understanding the exposure limits does not determine whether the operating environment is feasible. Human perception can detect harmful gases in the room, but they cannot discern the extent to which they have reached. To understand the extent of indoor harmful gases produced by these machines, you must go through indoor air quality testing. I know many printer manufacturers. When I asked about the degree of indoor harmful gas generated by their equipment, their typical answer was: "When the machine is operating, there are too many variables to determine the concentration level. In the end, printing Factory employers provide their employees with a safe and qualified working environment. "

It can be seen that printing machine manufacturers attribute the responsibility for indoor harmful gas exposure to end users. According to the manufacturer, they cannot help the end user build a clean and healthy working environment. Between the manufacturer and the end user is the distributor. Most qualified distributors will guide the end user to perform proper air filtration when using the solvent-based printing machine. They will also provide effective solutions to make the end user as possible. Make the best choice and provide employees with the cleanest and healthiest working environment.

These dealers have learned these solutions through learning, so I suggest that end users can use their knowledge and expertise to solve this problem. In fact, I do n’t think dealers should sell air-based printing presses without providing customers with air filtration systems and explaining to them why this system is needed. This should not be the case.

Having said that, in order to ensure that the environment meets the requirements or whether air filtration is necessary, it is impractical and expensive for the end user to hire an indoor air quality testing company. Island Clean Air Inc., based in Vancouver, British Columbia, Canada, realized that end-users had problems in this area and contracted a state-certified air testing company in California to conduct concentration tests on some common printing machines on the market today. , The results are surprising.

Each round of testing is conducted under a relatively common operating environment, with room sizes ranging from 100 square feet [3 meters × 3 meters (10 feet × 10 feet)] to 400 square feet [6 meters × 6 meters (20 feet × 20 feet)]. The printing machine prints at average speed, full frame and full color.

The production speed of each printing press depends on the overall production capacity of the printing press. The printers tested included HP Designjet 9000s, Colorspan Gator 72s, Mimaki JV3-160, and Mimaki JV5-160. In order to avoid cross-contamination and ensure the objectivity of the results, the tests are conducted at different times and locations. During the initial test, the printing press was operated in a closed room without air filters or ventilation equipment.

Interestingly, within 30 minutes, each printing machine tested exceeded the exposure limit. According to the measurement of different printing machines, the exposure value ranged from 20 ppm to 200 ppm.

The operating time of the printing press exceeded 30 minutes, and the exposure value continued to increase. Remember, the exposure limit can be as low as 20 ppm.

Tests have shown that wide-format solvent-based printers cannot meet the exposure limit requirements, which affects the working environment. Therefore, printing plant employers must install air filtration devices or ventilation equipment to ensure that employees work in a safe environment. Employers have the right to choose and compare filtering or ventilation options. There are four reference schemes for removing indoor harmful gases. [next]

Exhaust Ventilation System: Usually this method is transported by pipeline (direct exhaust of indoor harmful gases) or a filter device installed on the roof (this is a widely recognized method, although it is more effective in removing indoor harmful gases difference). One of the disadvantages of these systems is that the concentration of harmful gases in the room is significantly greater than the concentration of air, so it is difficult to exhaust these gases using only the exhaust method. All air filtration systems have a capture zone, and when the air passes through the filtration system, the pollutants in it are captured. These systems have an impact on overall air quality. However, when the air passes through the filter system, only a small amount of harmful gas is captured, which makes the air environment still higher than the exposure limit.

The exhaust ventilation system is expensive and difficult to maintain, and the Environmental Protection Agency does not want harmful pollutants to be released into the environment. Usually installation of such ventilation equipment also requires a special power connection and building installation permit. In addition, because the installation location of the system is fixed, when you need to rearrange the workshop or add equipment, you will be subject to certain limitations.

Source capture systems: These systems usually consist of a box with a hose that directly connects to the printing press and sucks in the harmful substances discharged from the printing press to prevent these substances from entering the air. This active prevention method is more effective than the exhaust system, but it also has some disadvantages.

It does prevent most harmful gases from entering the air, but it cannot capture these harmful gases 100%. This is because there are many ways to generate exhaust gas during the operation of the printing press. For example, the printed matter output from the printing press will still produce exhaust gas during the drying process on the drying rack. Once harmful gases enter the air, the system cannot exclude them.

In addition, once the printing press stopped, the source capture system also stopped working. Those harmful gases that have not been treated will enter the air. Some people questioned whether the ratio of the system's elimination of indoor harmful gases could make the workshop environment below the OSHA exposure limit. Someone used a brand source capture system and a common solvent-based printing machine to test. The results showed that the printing machine exceeded the exposure limit after just 30 minutes of operation. This shows that the use of source capture systems is not enough to keep the indoor environment below the exposure limit.

Usually, it is necessary to use the source capture system and the air filtration system at the same time. Other problems with source capture systems include: expensive consumables, devices occupying the production floor, and special power requirements.

Air filter devices: These systems are usually stand-alone devices that draw air into the filter system and clean air enters the room through the exhaust port. The key to the efficient operation of these systems is that sufficient air flow allows all air in the room to circulate, which allows all harmful gases to pass through the filter device.

Small equipment may not allow air to circulate adequately and not allow all harmful gases to enter the filtration system. Another disadvantage is that, similar to the source capture system, the system occupies a large area. But the air filter device can be moved more conveniently in the production workshop.

Harmful gases entering the equipment must not be allowed to enter the air 100% before being processed. If the large-scale air filtration device is properly used, the exposure limit of the production workshop can be lower than the specified limit value. The key here is that a sufficiently large air filter must be used. In addition, this device can work 24 hours a day, and can continue to eliminate harmful gases generated during the drying process.

The standard of consumables required for the air filter device is far lower than the source capture system (requires 110 volt standard power). It has been proven that this system is more effective than the source capture system or exhaust system.

Source capture and air filtration system: This system is a dual device and the most effective of all solutions. It can be directly connected to the printing press to remove indoor harmful gases, and can also circulate air to purify indoor air.

This equipment is the best solution to minimize indoor harmful gas values ​​and to be below the exposure limit. The harmful gas is eliminated from the printing press in advance, and the concentration of the harmful gas entering the air is far lower than the value obtained by using the air filtration system alone.

Similarly, by purifying the indoor air through air circulation, indoor harmful gases that are not excluded by the source capture system or the exhaust gas during the drying process will be discharged in a short time, thereby making the operation workshop comply with OSHA standards. It is concluded through testing that the use of this dual filtration system can keep indoor harmful gas values ​​below the exposure limit.

It has to be admitted that not all printing presses can be connected to the source capture system. Although most manufacturers realize the need for exhaust ports on printing presses, many printing presses are still monolithic and cannot be connected to other equipment.

For systems that do not have an exhaust port, a sufficiently large air filtration system is the most effective solution to ensure that it meets OSHA standards.

Determining whether and what standard filtration system is required depends on the following factors:

Room size Press type Press operating speed Media size Gamut used Press operating time Built-in filter / ventilation (HVAC)
Type of ink used
Regardless of the level of harmful gases in the room, it is ultimately the employer ’s responsibility to ensure adequate air filtration. Employers can acquire relevant knowledge and expertise through equipment dealers to ensure that the best solution is selected for air filtration.

Solvent-based printers are an effective tool for expanding products and services. But this effective tool also comes with risks. We should be aware of these risks and eliminate them so that the press operators can work in a healthy and safe environment.

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