Features and functions of meltblown nonwovens

Meltblown cloth is the most core material of the mask.

Meltblown cloth is mainly made of polypropylene as the main raw material, and the fiber diameter can reach 1~5 microns. With more voids, fluffy structure and good wrinkle resistance, the ultra-fine fibers with unique capillary structure increase the number and surface area of fibers per unit area,

thus making meltblown cloth have good filtering, shielding, adiabatic and oil absorption properties. It can be used in the fields of air and liquid filtration material, isolation material, absorbent material, mask material, warm material, oil absorbent material and wiping cloth, etc.

Meltblown nonwoven fabrics are mainly used as composite materials, filtration materials, warm materials, sanitary products, oil-absorbing materials and clean cloths (wipes), battery separators, etc.

They are widely used in fields such as medical and health care, automotive industry, filtration materials, environmental protection, etc.

In foreign countries, meltblown nonwovens are mainly used as two-step SMS materials and medical and sanitary materials and wrapping materials, in addition to wiping and absorbent materials, filtration and barrier materials are also important uses of meltblown fabrics.

1.Meltblown nonwoven performance characteristics.

1、Comfortable, soft hand feel, direct contact with the skin.

2, fine fiber, porous pore small pore advantage, good solid barrier.

3, environmental health uniformity is good.

4, hydrophobic and lipophilic.

Due to the above-mentioned functions, meltblown nonwoven fabrics are used in a large number of filtration and sanitary materials, especially masks. Meltblown nonwoven has a soft feel like paper,

but its raw material is PP, i.e. polypropylene, like spunbond nonwoven, with the addition of a modifier called IRGATEC CR76, which has its own unique improved properties for meltblown nonwoven, spunbond nonwoven and SMS.

2. Application areas of meltblown nonwoven fabrics.

01. Medical protective equipment

As the meltblown fabric and spunbond composite material has high hydrostatic pressure resistance, good air permeability and filtration effect,

especially the material compounded with membrane, has good barrier performance, and the filtration efficiency of non-oil particles can reach more than 99%.

For example, medical protective clothing made of composite materials with quantitative specifications of 60~100g/m² can effectively block microorganisms, particles and fluids, and have good protection against viruses similar to SARS (size 45nm) and HIV (size 90nm).

02. Materials for air filtration

After electrostatic electret treatment of meltblown composite materials, used for air filtration, with low initial resistance,

large dust capacity, high filtration efficiency [in the state of 32L/min flow, the filtration efficiency of 0.3um particle size up to 99.9%,

the resistance is only 117.7Pa (12mm water column)] and other characteristics, widely used in electronic manufacturing, food, beverage, chemical, airport, hotel and other places of Air purification treatment.

It is widely used in the air purification treatment of electronic manufacturing, food, beverage, chemical industry, airport, hotel, etc. It is also used in the filtration device of various air conditioning equipment, medical high performance mask, dust collector filter bag.

03.Materials for liquid filtration

Meltblown nonwovens can also be used as liquid filtration materials, capable of filtering particles of 0.22 to 10 pm particle size.

Such as bacteria, blood and macromolecular substances. It is mainly used in the filtration of photoresist in the electronics industry, the filtration of pharmaceutical, biological and synthetic plasma products in the pharmaceutical industry,

the filtration of beverage, beer and syrup liquids in the food industry, the fine filtration of electroplating liquids, the filtration of water purification in water plants, the filtration of tap water purification, the filtration device of electrolytic water for hydrogen production, the filtration of environmental wastewater, etc.

PP meltblown nonwoven fabric with hydrophilic properties can be used to make battery separators for cell phones.

04.Thermal insulation material

Meltblown nonwovens are characterized by large specific surface area, small voids (pore size ≤20um) and high porosity (≥75%).

Such as the average diameter of 3um [equivalent to an average fiber density of 0.0638dtex (0.058 denier)] meltblown nonwoven fiber specific surface area of 14617cm/g,

while the average diameter of 15.3um [equivalent to an average fiber density of 1.65dtex (1.5 denier)] spunbond nonwoven fiber specific surface area of only 2883cm*/g.

Since the thermal conductivity of air is much smaller than that of ordinary fibers (Table 1-10), the air inside the pores of meltblown nonwoven makes its thermal conductivity smaller, and the heat loss conducted through the meltblown nonwoven fiber material is very little,

and the stationary air layer on the surface of countless ultra-fine fibers prevents heat exchange due to the flow of air, thus making it a very good heat insulation and warmth retention.

Polypropylene (PP) fiber is the smallest thermal conductivity among the existing fiber materials, and the meltblown warming wadding made of PP fiber with special treatment [such as adding 35% of PET three-dimensional curly fiber] has 1.5 times the warming performance of down and 15 times that of ordinary warm cotton.

It is especially suitable for making ski wear, mountaineering wear, bedding, sleeping bags, thermal underwear, gloves and shoes, etc.

The products with a fixed weight of 65~200g/m have been used to make warm clothing for soldiers in cold areas.

05. Oil-absorbing material

Since PP fiber has good hydrophobicity and lipophilicity, small density (0.91g/cm’), low water absorption (0.01%), moisture regain rate of 0.05%, stable chemical properties such as insoluble in oil and acid and alkali resistance,

it is a very good oil-absorbing material. oil absorption of meltblown nonwoven fabric produced from PP raw material is 15~17 times of its own weight (Table 1-11),

water absorption is 0.07~1 times. It has the characteristics of fast oil absorption speed, can float on the water surface for a long time after oil absorption, and can be reused, etc.

It is the most commonly used oil absorption material at present.

06.Wiping and industrial materials

Meltblown cloth is also an excellent wiping material, and can be used for cleaning and wiping precision instruments and equipment, as well as wiping cloths for home life.

In order to prevent fiber shedding in use, which affects the use, low temperature hot rolling process is often used to increase the surface strength of meltblown cloth.

Meltblown cloth is an excellent sound insulation and cushioning material, and is widely used in construction and automobile fields.