Polypropylene nonwoven fabrics have become a common sight in our world, used in a wide range of applications from face masks and protective equipment to baby diapers and car filters. The reason polypropylene nonwovens are so popular comes down to their desirable properties and versatility of manufacturing.
Manufacturing Methods Of Nonwoven Fabrics
Polypropylene nonwoven fabrics are typically made using one of three main methods:
• Spunbond: In the spunbond process, polypropylene filaments are extruded through fine holes and drawn or “spun” onto a moving belt using high-speed air. The filaments become randomly laid and entangled, forming a lightweight nonwoven fabric known as spunbonded polypropylene. Spunbond fabrics are strong, flexible, and breathable.
• Spunlace: Spunlacing or hydroentanglement uses high-pressure water jets to entangle and fuse the polypropylene fibers, forming a nonwoven fabric known as a spunlace nonwoven. This process results in fabrics with good tensile strength, softness, and absorbency.
• Meltblown: In meltblowing, molten polypropylene is extruded through fine holes into high-speed air streams that draw and attenuate the fibers into very fine microfibers. These microfibers are deposited randomly onto a moving belt, becoming entangled. Meltblown nonwovens are highly absorbent.
Material Properties Of Polypropylene Non-woven Fabric
Some of the beneficial properties of polypropylene nonwoven fabrics come from characteristics inherent to polypropylene itself:
• Chemical resistance: Polypropylene is resistant to most acids, alkalis, and solvents except strong oxidizing agents.
• Temperature resistance: Polypropylene can withstand temperatures from -40 to 165°F.
• Inertness: Polypropylene is nonreactive and chemically inert.
• Light weight: Polypropylene is lighter weight than alternative materials.
When made into a nonwoven fabric using any of the methods above, the resulting material also possesses:
• Breathability: Polypropylene nonwovens are inherently breathable fabrics due to their open structure.
• Flexibility: The nonwoven structure gives flexibility and drapability.
• Absorbency: Meltblown and spunlace polypropylene nonwovens can absorb liquids well.
• Strength: Polypropylene nonwovens can have good tensile and tear strength depending on manufacturing method and basis weight.
Example Applications Of Nonwoven Fabrics
Polypropylene nonwoven fabrics find use in applications requiring:
• Barrier performance: Face masks, PPE, diapers
• Absorbency: Sanitary napkins, wet wipes
• Filtration: Vacuum bags, air and liquid filters
• Insulation: Thermal and acoustic insulation
• Reinforcement: Geotextiles, napkins
• Liner: Furnishing and automotive liners