Dry goods sharing, the reason why the melt-blown cloth becomes brittle the next dayDry goods sharing, the reason why the melt-blown cloth becomes brittle the next day
The new pneumonia epidemic is both a crisis and a big exam. With the rapid spread of the New Crown epidemic, meltblown fabrics have grown from obscure mask raw materials to the hot "cloth gold" in just a few months. Many manufacturers have the problem of becoming brittle the next day after the meltblown fabric is produced. The following is an analysis of the cause of this problem organized by the editors of Sino-Singapore Huamei. We share the experience of many industry professionals for your reference.
First, meltblown materials must be purchased through regular channels. It is recommended to use our high melt index polypropylene melt blown PP material with a melt index of 1500. At the same time, it passes Rohs 2.0 non-metallic, reach-205, halogen, melt index, ash, volatile matter, molecular weight distribution, peroxide residue. Eight third-party tests. In this way, it can ensure that it achieves environmental protection, narrow molecular weight distribution, low ash content, no other product residues, excellent spinning performance and other excellent characteristics, and meets the standards of the number and surface area of fibers in the core area of medical masks.
Qingdao Zhongxin Huamei Mask Melt Blown Polypropylene Special Material
If you buy melt-blown cloth raw materials that strictly comply with the standard through regular channels, then the control of the melt-blown cloth production and processing process is particularly important, because the production process and parameter settings will directly determine the quality of the melt-blown cloth, the processing process is not out The problem, then, the filter grade of the meltblown cloth must be the standard.
Meltblown fabrics become brittle the next day after production, probably because:
1. Uneven spinning, insufficient air flow from the cooler, resulting in uneven heat dissipation, internal stress and embrittlement. This can be improved by adjusting the melt volume of the extruder, adjusting the temperature of the hot blower, and increasing the air flow of the cooler.
2. From the analysis of materials, it should be that the 2040 low-melting finger 38 spinneret is used, the wire is thick, and it will become brittle after 24 hours to 48 hours of complete crystallization. Melt finger 1500's melt-blown material is thin, soft and evenly distributed, so the cloth is soft. The melting index is too high, for example, the melting index of 3000, so the spraying process is like catkins, and the material has little strength.
3. This phenomenon is related to the high temperature of raw materials and processing technology. After the fiber comes out, there is a secondary crystallization rearrangement process inside the PP, which is actually heated inside the screw, which has caused severe thermal degradation. If the residual control of the initiator of the melt-blown peroxide process is not good, it is easy to cause such problems. The most important thing in the melt-blown peroxide process is how to complete the molecular chain breakage termination before the screw extrusion is completed, to prevent the secondary residue from running to the user's non-woven screw to continue the reaction. This will test the screw equipment combination and formulation control. .
Selection of N95 masks meltblown cloth production equipment and process reference
4. As soon as it is made, the melt-blown cloth still has temperature, especially the melt-blown cloth machine that the large drum is collecting, even the fan, the temperature of the melt-blown cloth after winding is high, the plastic is soft under high temperature environment, The greater the toughness, the more brittle after cooling.
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