With the continuous tightening of environmental protection policies, especially since VOCs emission charges were widely levied nationwide this year, 15 provinces and cities have issued VOCs charging standards. This will undoubtedly make matters worse for the printing enterprises with sluggish growth, because they have to bear the dual pressure of reducing VOCs emissions and increasing operating costs.
Car wash, as one of the most important raw and auxiliary materials in printing enterprises, is profoundly affecting the economic benefits of printing enterprises. Today, let's talk about car wash. The printing car wash that can't be underestimated - the triple guarantee of quality, environmental protection and safety!
New car wash
Car washing water is indispensable for printing production. When changing the printing operation, version and ink, the printing master needs to clean the rubber blanket, ink roller and other parts. If the cleaning is not clean, it will not only affect the printing of the next live piece, but also damage the blanket and ink roller, reducing the service life of the machine. Before the appearance of car washing water for printing, the printing master often used gasoline or kerosene to clean the machine, because this way of cleaning the ink is efficient and dry quickly, but gasoline and kerosene are volatile solvents, and the VOCs content of 100% will cause environmental pollution, and the smell is pungent, which will harm the operator's body. Not only that, gasoline and kerosene have a low flash point and are also flammable and explosive dangerous chemicals. At present, there are many kinds of environment-friendly car washes on the market, but these environment-friendly car washes may not be really environment-friendly. We need to train a pair of eyes to identify the real environment-friendly car washes. Before identifying the true and false environment-friendly car wash, we should first give you some basic knowledge of car wash.
Is car wash water water?
Car wash water is not water, and there is no water in car wash water. It is petroleum products of hydrocarbons. The environment-friendly car wash is mainly made of environment-friendly solvent and high-efficient emulsifier. When we use it, we can mix it into a certain proportion of concentration to replace gasoline and kerosene. Use car wash water to clean the ink, paper wool and paper powder on the blanket and ink roller. Good car wash water is not easy to make the ink roll crystallize, and it is not easy to cause machine rust, which not only improves the print quality, but also extends the life of the ink roll.
The correct way to use car wash water is to add 0.5 parts of water (no more than 1 part of water at most) to one part of the original solution, and form a water-in-oil solution after mixing evenly. This kind of cleaning effect is the best, and has no adverse effect on the machine. If the printing machine is equipped with an automatic cleaning device, you can use the original solution directly and add water automatically according to the actual needs of the machine.
The relationship between the usability of car wash water and environmental protection and safety in the eyes of workers
In order to make it easier for you to understand, here we want to use a term of science popularization: flash point.
The flash point refers to the lowest temperature at which the mixture of steam and air heated to the liquid surface of the flammable liquid will flash when it contacts with the flame. The higher the flash point, the less flammable and safer the liquid.
At present, many enterprises implement piecework wage. In a unit time, the more the workers produce, the higher the income will be. At present, there are fewer and fewer large-volume long-form printing in printing enterprises, while there are more and more short-form printing with small batch and urgent delivery. This requires the operator to change the printing plate frequently and wash the blanket repeatedly. From the perspective of their own interests, workers must hope that the car wash water will be volatilized as soon as the rubber blanket and ink roll are cleaned, just like gasoline, so as to improve production efficiency and not delay production. This is the so-called convenient car wash in the eyes of the workers. However, this usability does not meet the requirements of environmental protection and safety, because the volatile car wash must be a solvent with a low flash point and a volatile organic content of 100%.
Properties of qualified car wash
1 Security
First of all, for the need of fire safety. The flash point of qualified car wash water used by the offset press must be higher than 55 ℃; The flash point of the thermosetting wheel runner must be higher than 100 ℃. Therefore, when enterprises choose products, products with low flash point have potential safety hazards.
The second is the need for transportation safety. Since the explosion of dangerous chemicals in Tianjin Binhai, the production, storage and transportation of chemicals have been rectified everywhere. According to the national transportation regulations, if the flash point of the product is higher than 61 ℃, it does not belong to dangerous chemicals, and the transportation is treated as ordinary goods; If the flash point is lower than 61 ℃, there are special requirements for its production, storage and transportation, and unqualified individuals and enterprises shall bear corresponding legal responsibilities for production, storage and transportation.
A dealer in the south once had such an accident: because the actual flash point of the car wash it sold was only about 20 ℃, the high temperature in the summer was very volatile, and the iron packaging barrel could not bear the internal pressure, resulting in a barrel explosion accident.
From this, we understand that the flash point of qualified car wash water must be higher than 61 ℃.
In view of this, are the large batches of leather washing water (also known as special detergent for rubber blanket) emerging on the market that are safe, environmentally friendly, volatile, easy to use and cheap? With this question in mind, an experiencer recently made a small experiment after an unannounced interview, and the result was really shocking.
The trademark and instructions of a leather washing water used by a printing enterprise in a certain place indicate that the flash point of the leather washing water is 66 ℃ and the initial boiling point is 190 ℃. According to its logo, this should at least be a safe and problem-free skin wash. However, the truth is that this leather washing water is actually made of 120 # gasoline, with a flash point of about - 10 ℃. From this, we can see that the manufacturer is clearly deliberately deceiving users. The factory had a fire due to the use of this product, but luckily it was put out in time without causing a major disaster.
2 Environmental protection
Is car wash environmentally friendly? Qualified car wash water should be environmentally friendly, with a small odor, and should not contain benzene, toluene, xylene and other aromatics. Because aromatic solvents not only harm people's health, but also expand and corrode the adhesive layer of printing press ink roller and blanket. At present, there are a large number of car washes using 120 # solvent gasoline (containing aromatics), kerosene, alcohols, and paint thinner (aromatic solvent) as raw materials on the market, which are neither environmentally friendly nor safe. The printing enterprises should try to choose the straight-chain alkane solvent without aromatic hydrocarbon as the raw material of car washing water, which is also internationally recognized as an environmentally friendly solvent.
Low quality car wash pursues high volatility. The organic solvent after cleaning will volatilize into the air, and the printing workshop is a sealed space with heat preservation and moisture preservation due to the process requirements. These organic solvents enter the human blood with the human body's breath, seriously threatening human health. What's more, in order to pursue high profits, some manufacturers do not consider whether the raw materials are toxic or environmentally friendly at all, as long as they volatilize quickly and the price is low.
The experiencer bought a car washing water online in Beijing. Its flash point is about 10 ℃. Its chemical composition is very complex, including benzene, toluene, xylene, chloride, ester, ketone, alcohol, etc. It emits a suffocating pungent smell, and it is also very easy to cause fire, which is very dangerous.
3 Low VOCs content
Here, we need to add another term to popular science: volatile organic compounds.
VOC is the abbreviation of volatile organic compounds. Generally speaking, we call those chemicals whose boiling point is equal to or lower than 250 ℃ VOCs, VOCs refer to total volatile organic compounds.
With the continuous progress of VOCs pollution charging process, it is imperative to treat and adopt chemicals with low VOCs content from the source. Jiangsu Danyang Suhu Printing Equipment Co., Ltd. actively responded to the call of the government, complied with the trend of historical development, and timely developed the car wash 80B with zero VOCs content. This car wash water has a 100% emission reduction, is colorless and tasteless, and its flash point is higher than 100 ℃.
Finally, I will give you a simple tip to identify whether the car wash is safe: find a one-kilogram oil cartridge cover, pour a little car wash (no more than 20 ml), and then throw the lighted match into the liquid. Car wash water that can only ignite the liquid without putting out the match must not be used.