News

Your present location:Home >> News >> Dynamics >> 3 possible problems of low temperature and low pressure technology in China

3 possible problems of low temperature and low pressure technology in China

Number of visits: Date:2016-09-01 15:42:26

Recently, the domestic paper industry is quietly popular "low temperature and low pressure" technology, the development of the technology will give the board of the domestic production of enterprises to bring another technological revolution. At present, the domestic part of the board of directors as a pioneer in the courage to try, the low temperature and low pressure technology pioneered in the daily production. So, what is the "low temperature and low pressure" technology? In addition, cardboard production, the allocation of steam pressure is considered to meet the "low pressure" technology?
Status: domestic low temperature and low pressure technology application is not optimistic
Industry experts have visited a number of domestic use of low temperature and low pressure "technology is a successful enterprise board found" low temperature and low pressure, but obviously "technology application is not optimistic, such as tile line design and the actual production situation are not optimistic, the product quality is not stable. In addition, it was found that when the tile line running for a period of time, the steam pressure to return to the previous high pressure to produce.
Compared with Europe and the United States, there are 3 major problems in China's low temperature and low pressure technology
The experts on the low temperature and low pressure technology, a special visit to the European developed countries, a number of cardboard enterprises. Through the exchange and learning, the basic understanding of the current foreign board of enterprises to master the high-tech, and the domestic board of directors of the proposed "low temperature and low pressure" concept, there are deviations, it is debatable. To this end, the author on the following points to share with colleagues in the industry:
Control the temperature of each layer of paper and paperboard, and control the low temperature and high temperature
The domestic high-speed tile line generally use the "anti bending system" program, through the detection and control of the key points of tile line board temperature, ensure that the board a driving wheel after the temperature control in the reasonable scope, the cardboard flat and not easy to deformation. Therefore, we need to control the temperature of each layer of paper and paperboard, low temperature and high temperature control material.
This is a reminder of the three and five layers of cardboard on the demand for heat is different, if the use of a unified "low pressure" value of the production of cardboard, then the heat supply is not able to meet the demand for cardboard production heat
Each part of the steam pressure is not a unified "low pressure" value
In this paper, the distribution of steam pressure in each part of the tile is given from abroad. It is found that the distribution of the steam pressure is also a key point. As a width of 2500mm, speed 350m/min tile line, the main steam pipe steam pressure 14kgf/cm - the pressure distribution is as follows:
(1) high quantity of cardboard, double machine hot plate pressure 10-12 kgf/ - cm. Kgf/cm - 8 corrugated stick pressure cylinder 4-6 kgf/cm preheating.
(2) low quantitative cardboard, double machine hot plate pressure 6-8 kgf/ - cm. Kgf/cm - 6 corrugated stick pressure cylinder 2-4 kgf/cm preheating.
From the pressure distribution table, we can see that the cardboard quantitative difference, the steam supply pressure is also different. Therefore, in the production process, the various parts of the steam pressure is not a unified "low pressure" value. In particular, the need for "high" tile line, or to use the "high pressure" production, the only way to ensure the efficient production line and cardboard quality.
Can not blindly learn from foreign experience
To a certain extent, for the high speed 300m/min watts line, so the supply of steam pressure is indeed a low pressure for us, but we can not blindly follow the school.
The author analyzes the main reasons are as follows:
<1> foreign high-speed tile line configuration of the tile roller and double machine hot plate, are peripheral heating type, relative to our domestic cavity heating container, its high thermal efficiency, fast temperature conversion, we can not follow suit.
<2> heating equipment for heating the heating temperature of the board in order to meet the heating temperature, the steam pressure is adjusted automatically. At the same time, a lot of arc heaters are installed in the key parts to compensate for the heat.
<3> foreign cardboard factory adhesives technology and the use of raw materials, but also with us there is a big difference. They use wheat starch, gelatinization temperature is generally controlled at around 53 degrees Celsius, and we generally use corn flour or tapioca flour, gelatinization temperature between 56-60 degrees celsius.

TypeInfo: Dynamics

Keywords for the information: