Meltblown nonwoven fabric

24 Apr 2020

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The production process of melt-blown non-woven material is shorter, but the whole process is more complicated, which affects the final melt-blown non-woven material.

There are many process parameters of product quality and performance, such as the nature and structure of the polymer, the melt index of the slice, the extrusion of the polymer melt

Volume, hot air velocity, screw extruder temperature, web structure, spinneret structure and spinneret hole shape, hot air temperature,

The distance between the spinneret hole and the net curtain, reinforcement method, etc. These parameters not only have many variables, but also interact with each other.

The production process parameter control of the spray-laid non-woven fabric material is relatively complicated and needs to be considered comprehensively. PP is now used as the raw material to discuss the main work

The influence of artistic parameters.

(1) PP slice

       

The PP chip's own structure directly affects the spinnability. Since PP resin behaves more as a non-Newtonian behavior, it must be strict in production.

The molecular weight and its distribution are controlled by the grid. The molecular weight distribution coefficient is generally less than 4, and the impurity content of the slice must be less than 0.025% in order to reduce

Poor phenomena such as low wool yarn and injection head yarn. In order to ensure that the slice melts evenly in the screw, the appearance size of the slice should be uniform.

(2) Functional additives

       

Functional additives can effectively improve the spinnability of P, increase the functionality of the product, and increase the added value of the product. Currently, commonly used

The functional additives include flame retardant modifier, antistatic modifier, anti-aging modifier, cooling masterbatch, coloring masterbatch, whitening masterbatch, etc.

However, the mixing ratio of these functional additives should be strictly controlled because most of these additives contain inorganic substances.

The facts show that all non-substance substances added in the production will affect the normal spinning, and the mixing amount of these functional slices

Generally not more than 5%.

(3) Melt index

       

The melt index MI is commonly used in production to characterize melt rheological properties. The size of MFI directly reflects the molecular weight of P resin

Size and distribution. Generally, the higher the melt flow rate, the lower the viscosity of the melt, and the easier it is to draw into fine fibers for melting.

The MFI of the spray nonwoven fabric material is 400-1000g1min. Since the ultra-fine short fiber web is obtained by the melt-blown process,

Among the raw materials used in the production of the melt-blown method, polypropylene resin with a high melt index is the first to be promoted because of its good fluidity. M∏I

The molecular weight of the larger polypropylene resin is smaller, and the melt-blown spinning temperature can be reduced accordingly.