Polypropylene for Spunbond Nonwovens: Properties and Applications / Articles

Polypropylene for Nonwoven Materials (Spunbond) - Complete Overview

What is Polypropylene for Spunbond?

Polypropylene for spunbond is a special homopolymer grade of polypropylene designed for the production of nonwoven materials by continuous filament extrusion with subsequent laying and bonding (spunbond technology). Unlike general-purpose polypropylene, these grades have strictly controlled rheological characteristics: high melt flow rate, narrow molecular weight distribution, and special stabilizing additives that ensure stable fiber formation and high quality of the finished web.

Spunbond is one of the leading and fastest-growing nonwoven materials. It is used both for disposable hygiene products and for reusable technical applications. The global spunbond market was valued at approximately $13.2 billion in 2024, with an expected average annual demand growth of 6.4%.

What is Spunbond?

Spunbond (from English spunbond, spunlaid) is a technology for producing nonwoven material from a polymer melt by the spinneret method. The essence of the spinneret method is as follows: the polymer melt is extruded through spinnerets in the form of thin continuous filaments, which are then drawn in an air stream and, laid on a moving conveyor, form a textile web.

In the professional environment, the term "spunbond" refers to both the technology itself and the material produced by this technology. Polypropylene is most often used for spunbond production because it allows the densest distribution of fibers in the web and ensures high fiber output per kilogram of raw material.

The main raw material for production is polypropylene - a polymer with high heat resistance, chemical stability, and environmental safety.

How is Polypropylene for Spunbond Produced?

Polypropylene for spunbond is produced from propylene homopolymer using modern catalytic systems and special stabilization formulations. Key features of these grades:

Narrow molecular weight distribution - ensures fiber uniformity and process stability.
High melt flow rate - typically 25-40 g/10 min (at 230 °C, 2.16 kg), ensuring good processability.
Special stabilizing additives - protect fibers from discoloration and undesirable color change (gas fading).
Phthalate-free catalyst systems - modern grades do not contain phthalates.

Controlled rheology and special catalysts ensuring high stereoregularity of the polymer are used in production. Some grades, such as SABIC PP 511A, have a specially developed anti-gas-fading formulation to minimize fiber discoloration.

Spunbond Nonwoven Production Process

The spunbond web formation process includes the following main stages:

Preparation and feeding of polymer raw materials - polymer pellets are fed into the extruder.

Polymer melting and melt filtration - melting occurs in the extruder at about 220-250 °C.

Melt supply to the spinneret assembly - the molten polymer is forced through special holes - spinnerets, forming endless filaments. The diameter of the holes in the spinneret can vary from 250 to 1200 microns.

Fiber formation - filaments are formed with a diameter of 15 to 40 microns.

Aerodynamic drawing and cooling - the filaments undergo drawing under the action of high-speed air, cool down, and gain strength.

Fiber laying on the conveyor - cooled filaments are laid on a moving conveyor, forming a web.

Bonding (calendering) - the fibers are bonded together. There are different bonding technologies:

Thermal calendering - fibers are passed through hot rollers, where they partially melt and firmly adhere under pressure. The method gives the web smoothness and softness.
Needlepunching - mechanical bonding using needles that create micro-punctures and fiber entanglement, creating a material with increased strength and wear resistance.
Chemical impregnation - application of binders to adapt the web for non-standard operating conditions.
Hydroentanglement - high-speed water jets entangle the fibers, giving the material increased elasticity, breathability, and bulk.
Through-air bonding - fibers are joined under the action of heated air, creating more uniform structures.

Key Properties of Polypropylene for Spunbond

Polypropylene for spunbond has the following key characteristics:

Density - 0.900-0.910 g/cm³.

Melt Flow Rate (MFR) - 25-40 g/10 min (at 230 °C, 2.16 kg).

Tensile strength at yield - 30-35 MPa.

Tensile modulus - 1300-1550 MPa.

Flexural modulus - 1200-1250 MPa.

Elongation at yield - 8-11%.

Vicat softening temperature - 152-155 °C.

Rockwell hardness - R 91-106.

Applications of Polypropylene Nonwovens

Polypropylene nonwovens (spunbond), thanks to their unique properties, have found the widest application in various industries.

Medicine and healthcare - one of the key areas. Spunbond is used to produce disposable medical products: surgical masks, caps, shoe covers, gowns, sleeves, surgical drapes, disposable clothing for medical personnel.

Hygiene products - production of diapers, sanitary pads, baby diapers, wet wipes.

Agriculture - protective covers, agrotextiles, mulching covers, greenhouse materials.

Construction - geotextiles, insulation materials, waterproofing, road construction.

Light industry - packaging, bags, covers, shoe and sewing materials.

Filtration - filter materials for industry and household.

Automotive industry - car mats, upholstery, sound insulation.

Major Producing Countries of Polypropylene for Spunbond

The world's leading producers of polypropylene for spunbond are based in the United States, Saudi Arabia, Western Europe, South Korea, and China.

Among the largest manufacturers:

ExxonMobil Chemical (USA) - produces Exceed™ PP3155E5 and PP3684 grades, specially designed for spunbond.
SABIC (Saudi Arabia) - SABIC® PP 511A grade, one of the most well-known for spunbond.
LyondellBasell (Netherlands/USA) - Moplen HP561X, HP562T, HP563S grades for fine fibers.
LG Chem (South Korea) - PP H7700 grade.
Borealis (Austria)
INEOS (UK)

In China, the main producers are Sinopec, CNPC, as well as major private companies. China is the world's largest producer and consumer of polypropylene nonwovens.

In Russia and the CIS countries, polypropylene for spunbond is produced by:

Stavrolen LLC (Russia) - PPG1380-20 grade.
SOCAR Polymer (Azerbaijan) - HB 2662 FS grade.
SIBUR (Russia) - PP H263 FF and other grades.
Nizhnekamskneftekhim (Russia)

Also present on the market are Tatren HT2511 (Slovnaft Petrochemicals) and PP 6202 (Exxon) grades.

Conclusion

Polypropylene for nonwovens is one of the most important segments of the polymer industry, providing the production of a wide range of products - from medical masks and hygiene products to geotextiles and agricultural materials. Special homopolymer grades with high melt flow rate and narrow molecular weight distribution allow the production of high-quality nonwoven materials with specified characteristics. Growing global demand for nonwovens, especially in the medical and hygiene sectors, makes this segment one of the most promising in the polymer industry.