In the selection of main materials for spunbond nonwoven fabrics, polyester (PET, polyethylene terephthalate) is not the only option, but with its “high adaptability” to the process, “comprehensive performance advantages” of the finished product, and “cost sustainability”, it has become the core material accounting for over 60% of the global spunbond production capacity (2024 industry data). When materials such as polypropylene (PP), nylon (PA), and polyethylene (PE) are applied in specific scenarios, polyester can become the “universal preferred” across multiple fields such as medical, geotechnical, and packaging. Essentially, its molecular structure, physical properties, and “full chain fit” with the spunbond process – from melt spinning to mesh reinforcement, from finished product performance to scene adaptation, each step precisely matches the core requirements of the spunbond process.
The “essential requirements for the main materials” of spunbond technology: three core requirements
The process of “melt direct spinning, air flow stretching, and thermal bonding reinforcement” in spunbond technology sets special requirements for the main material that are different from other non-woven fabric processes (such as needle punching and water jet). This is the bottom standard for selecting the optimal main material:
Compatibility of melt spinning: It needs to be stably melted within the range of 200-300 ℃, with controllable melt viscosity (to avoid wire breakage or sticking to the mesh), and can continuously spray to form fine filaments of 1-3dtex (the core of spunbond is “continuous filament forming a mesh”);
Mesh reinforcement adaptability: It needs to withstand the temperature of thermal bonding (120-180 ℃), maintain stable strength between fibers after bonding (without thermal degradation or excessive melting), and be compatible with subsequent processing (such as cutting and composite);
Universality of finished product performance: It is necessary to consider strength (fracture strength ≥ 20N/5cm), weather resistance (outdoor use ≥ 3 years), chemical stability (acid and alkali resistance, organic solvent resistance), and the ability to expand functions through additive modification (such as UV resistance and antibacterial).
These three requirements form a closed loop of “process material application”, and polyester is currently the only material that can simultaneously meet the requirements of “high adaptability+high universality+low cost”.
Polyester vs. Other Materials: “Performance Rolling” in Spunbond Process
Comparing polyester with polypropylene (PP), nylon (PA), and polyethylene (PE) commonly used in spunbond technology, its advantages are reflected in the leading position in the entire chain of spinning, reinforcement, and finished products.
（1） Melt spinning process: the “stability and controllability” of polyester is irreplaceable
The first step of spunbond technology – “melt spinning”, directly determines the quality and production efficiency of the filament. Polyester is superior to other materials in key parameters:
Although polypropylene (PP) has a low melting temperature and low processing energy consumption, its thermal stability is poor (easily degraded above 200 ℃), and the temperature needs to be strictly controlled during spinning. Moreover, fine denier fibers are prone to brittleness after forming, which cannot meet the strength requirements of high-end scenarios such as medical protection;
Nylon 6 (PA6) has strong moisture absorption (equilibrium water absorption rate of 2.5% at 23 ℃), and needs to be dried before spinning (increasing process cost). Moreover, the viscosity fluctuation of the melt leads to uneven filament strength, and the longitudinal and transverse strength ratio of the finished product can reach 2:1 (far exceeding the 1.3:1 of polyester);
Polyethylene (PE) has a low melting point, and after spinning, the long filaments are prone to sticking into a mesh, with extremely low strength (fracture strength only 10-15N/5cm). It can only be used for low-end disposable packaging (such as shopping bag lining) and cannot adapt to mainstream applications of spunbond.
Only polyester, with its linear polyester molecular structure (unbranched, controllable crystallinity), can stably melt over a wide temperature range and accurately control the melt flow rate, achieving “low breakage rate+fine yarn forming” and laying the foundation for efficient production of spunbond technology.
（2） Hot bonding reinforcement process: precise matching of polyester’s “temperature adaptability”
The “thermal bonding reinforcement” after spunbond forming is the core step that determines the strength of the finished product. The softening point of polyester perfectly matches the thermal bonding temperature:
Polyester: softening point 220-240 ℃, thermal bonding temperature 120-160 ℃ (below softening point, above glass transition temperature 70 ℃), only the fiber surface slightly melts during bonding, forming a “point bonding” structure – ensuring fracture strength (25-35N/5cm) while retaining fiber toughness, and the bonding point is not easily peeled off after water washing;
Polypropylene: softening point is 140-150 ℃, and the thermal bonding temperature should be controlled at 120-130 ℃ (with a temperature difference of only 10-20 ℃). A slightly higher temperature can cause excessive melting and lead to mesh adhesion (with a decrease in breathability of more than 50%), while a slightly lower temperature can result in weak bonding (with a 30% decrease in strength after washing once);
Nylon 6: softening point 180-190 ℃, thermal bonding requires 160-170 ℃, energy consumption is 20% higher than polyester, and the moisture absorption of the bonded product is still strong (size shrinkage rate of 3% -5% at 90% humidity), affecting application stability;
Polyethylene: The softening point is 80-90 ℃, and the thermal bonding temperature is only 90-100 ℃. The bonding point is prone to softening at low temperatures (such as outdoor use in summer), leading to deformation of the finished product.
Taking the outer layer of medical protective clothing as an example: after being heat bonded at 140 ℃, the polyester spunbond non-woven fabric has a fracture strength of 30N/5cm and a strength retention rate of 80% after 10 water washes; If PP spunbond is used, the strength under the same process is only 22N/5cm, and after 3 washes, the strength is less than 15N/5cm, which cannot meet the GB 19082 standard.
（3） Finished product performance stage: The “universality” of polyester covers all scenarios
The application scenarios of spunbond nonwoven fabrics range from outdoor geotechnical to medical protection, with significant differences in performance requirements. However, polyester, with its “modifiability+high stability”, has become the only material that can cover all scenarios.
Weather resistance: Polyester molecular chains contain benzene rings and have strong resistance to UV degradation. After adding 0.5% UV resistant agent, the strength retention rate for outdoor use is 70% for 5 years; PP without benzene ring structure, outdoor strength decreases by 40% in one year, requiring additional coating protection (cost increases by 30%);
Chemical stability: Polyester is acid and alkali resistant (with a strength retention rate of>90% after soaking in a 5% sulfuric acid/sodium hydroxide solution for 72 hours), suitable for industrial filtration and chemical packaging; PE is acid resistant but not alkali resistant, and PP is alkali resistant but not strong oxidizing acid, both of which have application limitations;
Functional modification potential: Polyester can achieve functional expansion through copolymerization and blending, such as adding antibacterial agents to make medical non-woven fabrics (antibacterial rate>99%), adding flame retardants to make fireproof geotextiles (oxygen index ≥ 32); Although PA6 can also be modified, its cost is 1.5 times that of polyester, and its cost-effectiveness is low;
Strength and toughness balance: The fracture elongation of polyester spunbond non-woven fabric is 20% -30% (PP is only 15% -20%), which can adapt to soil settlement in geotechnical engineering (can still rebound after stretching by 5%) and avoid cracking; Although PE spunbond has a high elongation rate (40% -50%), its strength is too low to bear weight.
Taking outdoor waterproofing membrane base as an example: polyester spunbond non-woven fabric has a UV aging resistance life of 8 years and a soil corrosion resistance (acid alkali alternating environment) life of 5 years; If PP spunbond is used, the lifespan is only 3 years and needs to be replaced every 3 years, with a full lifecycle cost 60% higher than polyester.
Cost and Sustainability: Unparalleled Cost Performance of Polyester
In addition to performance and process adaptation, cost and sustainability are key industrial choices, and polyester also has advantages in these two aspects.
（1） Raw material cost: scale reduction of costs+adaptation to recycled materials
Raw material cost: In 2024, the average price of raw PET slices is 8200 yuan/ton, PP pellets are 8500 yuan/ton, PA6 slices are 13000 yuan/ton, and PE pellets are 9000 yuan/ton – the cost of polyester raw materials is lower than that of PP, PE, and PA6, and the global PET production capacity exceeds 100 million tons (PP is about 80 million tons), with higher procurement stability;
Recycled material cost: Polyester can be processed into recycled slices by recycling PET bottles (average price of 5800 yuan/ton), and the proportion of recycled materials can reach 70% (still able to meet the needs of ordinary packaging and geotextiles); Although PP recycled material is also cheap (5500 yuan/ton), its strength decreases by 20% after recycling (polyester only decreases by 8%), which limits its application; The cost of PA6 recycled material is high (8000 yuan/ton), and its performance fluctuates greatly, making it difficult to use on a large scale.
Taking a spunbond non-woven fabric enterprise with an annual output of 10000 tons as an example: using 50% recycled PET chips, the raw material cost is 1.2 million yuan/year lower than that of fully virgin PP and 4.5 million yuan/year lower than that of fully virgin PA6.
（2） Sustainability: Adaptation to circular economy+low-carbon processing
Recyclability: Polyester spunbond non-woven fabric can be broken and remelted after disposal to produce recycled PET slices (recovery rate>90%), forming a closed loop of “production use recycling reproduction”;
Although PP can also be recycled, it can only be recycled 3 times (polyester can be recycled up to 5 times), and the strength of each regeneration decreases more significantly;
Processing energy consumption: The comprehensive energy consumption of polyester spunbond (including melting, spinning, and thermal bonding) is about 800 degrees per ton, while PP is about 750 degrees per ton (only 6% lower), but PP products require additional coating (such as UV resistant layer), resulting in a total energy consumption that exceeds polyester by 15%; PA6 has an energy consumption of up to 1200 degrees per ton, which is 1.5 times that of polyester;
Environmental compliance: The polyester spinning process has no toxic gas emissions (PP high-temperature processing can easily produce trace VOCs, which require the installation of treatment equipment), and recycled polyester can reduce carbon emissions by 30%, in line with the global “dual carbon” trend (such as the EU carbon border tax policy).
Exception scenario: “niche living space” of other materials
Not all spunbond scenarios prefer polyester. Under the requirements of “extremely low cost” or “special function”, other materials still have applications, but none of them can shake the mainstream position of polyester:
PP spunbond: used for disposable low-end products (such as express bag liners and disposable tablecloths), occupying about 15% of the market with “slightly lower processing energy consumption+no need for weather resistance for short-term use”, but unable to enter core fields such as medical and outdoor;
PE spunbond: only used for ultra-thin disposable packaging (such as fruit bagging), with a market share of less than 5% due to low strength and poor weather resistance;
PA6 spunbond: used in high-end special scenarios (such as high-temperature resistant filter bags, which need to withstand temperatures above 200 ℃), due to its high cost, its market share is only 3%, and it can be replaced by “high-temperature resistant modified polyester” (adding aromatic copolymer units).
Conclusion: Polyester is the “optimal solution” for spunbond technology, not the “only solution”
Polyester has become the optimal main material for the spunbond process, which is not accidental – its molecular structure determines “melt spinning stability+suitable thermal bonding matching+universal product performance”, and its industrial scale has achieved “low cost+sustainability”, ultimately finding a perfect balance point in the “process performance cost” triangle model.
When we see a dense polyester spunbond layer on medical protective clothing, feel the tough polyester spun clay geotextile in the roadbed, and feel the smooth polyester spunbond surface on shopping bags, it is essentially a “two-way rush” between polyester and spunbond technology – the process requires a material that can produce stably and has comprehensive performance, and polyester precisely meets this demand. In the future, with the maturity of bio based polyester technology (such as corn based PET), the advantages of polyester in spunbond technology will be further expanded, and its position as the “optimal main material” will continue to be consolidated.
Dongguan Liansheng Non woven Technology Co., Ltd. was established in May 2020. It is a large-scale non-woven fabric production enterprise integrating research and development, production, and sales. It can produce various colors of PP spunbond non-woven fabrics with a width of less than 3.2 meters from 9 grams to 300 grams.
Post time: Sep-15-2025