The sudden outbreak of the novel coronavirus pneumonia makes the professional term "melt-blowout cloth" known to people overnight, and the melt-blowout industry has also developed rapidly. At present, China has become the world's largest melt-blowing cloth production capacity, the most comprehensive equipment category of the country, and mastered the mature whole-process equipment design and manufacturing technology, has exported a large number of melt-blowing equipment and products to the world. However, the process control of melt-blown nonwovens is difficult and has high technical content. The rapid development of the industry causes the urgent demand for talents and technology. Especially after the ebb of the demand for anti-epidemic materials, facing the fierce market competition, industrial enterprises need to make efforts in personnel training and technology, and find a way out in product development and market development.

Because melt-blow spinning is unsteady, the thickness of the fibers varies from position to position. However, no matter in electron microscope or fiber analysis instrument field of view, basically can not see the end of the fiber. If the melt-blown fiber is really short fiber, it should be visible with a high probability, which also proves that the fiber is continuous fiber.

The view of continuous fiber can guide the production practice correctly, and can explain the abnormal phenomenon in the production process visually, and can provide clear ideas and countermeasures for solving the technical problems.

High speed photography of melt-blown spinning fibers

Exxon melt-blow process is the mainstream melt-blow process, also known as single hole spinning process, melt-blow nonwovens are almost all produced by Exxon melt-blow process. The characteristic is that the spinneret is an isosceles (or equilateral) triangular component, and the spinneret holes are arranged at the top of the triangle, with only one line of spinneret holes. The draft air is drawn by high temperature and high speed, and the draft air is ewed from both sides of the spinneret holes at a certain Angle. Compared with other meltblowout processes, the fiber distribution is narrow.

Production technology of melt-blown nonwovens

In addition to the Exxon melt-blowout process, there is another melt-blowout nonwoven fabric production technology in which spinneret holes are distributed in multiple rows and columns. Each spinneret hole is composed of two concentric tubes set together. The spinning melt is expelled from the central tube and the draft air is expelled from the annular channel centered on the melt pipe. It's called the Biax process.

Production technology of multi-row hole melt-blown nonwovens

Single - row hole and multi - row hole two kinds of process compatible melt-blow production line

In the simple melt-blowing production line, the roll receiving mode is used more, and the roll receiving mode can be divided into single roll and double roll receiving mode. The number of receiving rollers has a great influence on the product performance, the same roller receiving, using double roller receiving products have a relatively fluffy structure.