Physical properties of pp nonwoven fabrics produced by non-woven fabric 

Polypropylene is a non-toxic, odorless, odorless, milky, highly crystalline polymer with a density of only 0.90--"0. 91g/rm, which is one of the lightest of all plastics in the world today. It remains unchanged from water. The water absorption rate in water is only 0. O1%, and the molecular weight is about 80,000 to 150,000. The moldability is good, but the shortening rate is large (1% to 2.5%). With high parts, it is difficult to reach the request, and the product profile is glossy and easy to color.[4]

Physical properties of pp nonwoven fabrics produced by non-woven fabric 
Mechanical properties
Polypropylene has a high degree of crystallinity and regular structure, so there is excellent mechanical properties. The absolute value of the mechanical properties of polypropylene is higher than that of polyethylene, but it is still a relatively low grade in plastic materials, and its tensile strength can only reach a level of 30 MPa or slightly higher. Higher isotactic index polypropylene has higher tensile
Intensity, but as the isotactic index advances, the impact strength of the material has dropped, but it does not change after falling to a certain value.

Physical properties of pp nonwoven fabrics produced by non-woven fabric 
Temperature and loading speed have a great influence on the toughness of polypropylene. When the temperature is higher than the glass transition temperature, the impact damage is ductile fracture, and it is brittle fracture below the glass transition temperature, and the impact strength value drops significantly. Advancing the loading speed can increase the temperature at which the ductile fracture transitions to the brittle fracture. Polypropylene has excellent resistance to discarding and discarding, and its products can be bent 106 times at room temperature without breaking.
However, at room temperature, due to the high degree of regularity of the molecular structure, the impact strength is poor. The most prominent property of polypropylene is its resistance to discarding and discarding. [5]
Thermal performance

Physical properties of pp nonwoven fabrics produced by non-woven fabric 
Polypropylene has excellent heat resistance. Products can be disinfected and sterilized at a temperature of 100°C or higher, and they are not deformed at 150°C without external force. The embrittlement temperature is -35°C, and embrittlement will occur below -35°C. Cold resistance is inferior to polyethylene. Reports on the glass transition temperature of polypropylene have a value of 18qC, OqC, 5°C, etc. This is also due to the fact that people use bifurcated specimens in which the ratio of the crystal phase to the amorphous phase is different, and the chain lengths of the amorphous portions in the molecular chain are bifurcated. And to. Melting temperature of polypropylene is about 40-50% higher than polyethylene, about 164-170°C, 100% isotactic polypropylene
The melting point is 176°C. [5]
Chemical invariance

Physical properties of pp nonwoven fabrics produced by non-woven fabric 
Polypropylene is chemically invariable, except for being attacked by concentrated sulphuric acid and concentrated nitric acid, it is invariable for other chemical reagents; but low molecular weight aliphatic, aromatic and chlorinated hydrocarbons can make polypropylene. Softening and swelling, while its chemical invariance along with the growth of crystallinity has progressed, so polypropylene suitable for the construction of various types of chemical pipelines and accessories, anti-corrosion the end result of brilliant.
Electrical properties
It has a higher dielectric coefficient and can be used to build heated electrical insulation products as the temperature rises. Its breakdown voltage is also very high, and it is used as electrical accessories. The resistance to voltage and arc resistance is good, but the degree of static electricity is high and it is easy to age with contact with copper.
Weather resistance

Physical properties of pp nonwoven fabrics produced by non-woven fabric 
Polypropylene is very sensitive to ultraviolet rays, and it can improve its aging resistance by inserting zinc oxide, chlorinated dipropionate, carbon black or similar milky fillers.
Hydrophobicity parameter for reference (XlogP): 3.32, Number of hydrogen bond donors: 03, Number of hydrogen bond acceptors: 34, Number of changeable transition bonds: 15, Number of tautomers: 6, Topological molecule polarity profile Product (TPSA): 29.5 to prevent strong oxidants, chlorine, potassium permanganate sealed, kept in a cool dry place, to ensure a good ventilation.