PP (polypropylene) non woven bags represent over 90% of the global non woven bag market, making them the industry standard for sustainable packaging. Understanding PP material properties, grades, and specifications is essential for making informed purchasing decisions.
PP non woven bags have become the go-to choice for businesses worldwide seeking sustainable, cost-effective, and durable packaging solutions. Unlike traditional woven fabrics, non woven materials are created by bonding fibers directly together through thermal, chemical, or mechanical processes—skipping the weaving step entirely. This unique manufacturing method results in a fabric that’s lightweight yet strong, making it ideal for shopping bags, promotional items, and retail packaging.
In this comprehensive technical guide, we cover:
PP Material Basics
What polypropylene is and why it dominates the market
Material Properties
Complete physical, mechanical, and thermal characteristics
GSM Grades
Weight selection guide for different applications
Manufacturing Process
From resin to finished bag step by step
Quality Testing
Essential tests and certification standards
Applications & Safety
Industry-specific recommendations and compliance
Whether you’re a procurement professional, quality manager, or business owner, this guide provides the technical knowledge you need to specify and source PP non woven bags confidently.
Understanding PP (Polypropylene)
What is Polypropylene?
Polypropylene (PP) is a thermoplastic polymer made from propylene monomers through polymerization. It’s one of the most versatile and widely used plastics globally, finding applications in packaging, textiles, automotive parts, and consumer goods. First polymerized in 1954 by Italian chemist Giulio Natta, PP has grown to become the second-most produced plastic in the world after polyethylene.
The material’s success stems from its unique balance of properties: it’s lightweight (the least dense commodity plastic), chemically resistant, moisture-proof, and easily recyclable. For non woven bag manufacturing, PP is processed through a spunbond process that creates continuous filaments bonded into a sheet structure—resulting in a fabric that combines strength with breathability.
Chemical Structure: Propylene Monomer: CH₂=CH-CH₃ → Polymerization: [-CH₂-CH(CH₃)-]n
Resin Code: #5 (Recyclable)
Why PP for Non Woven Bags?
When selecting materials for non woven bags, manufacturers weigh multiple factors including cost, performance, environmental impact, and processing characteristics. PP emerges as the clear winner for most applications due to its unique combination of properties that no other single material can match.
| Property | PP | PE (Polyethylene) | PET (Polyester) | Cotton |
|---|---|---|---|---|
| Density | 0.90 g/cm³ | 0.92-0.97 | 1.38 | 1.54 |
| Melting Point | 160-170°C | 105-135°C | 250-260°C | N/A (burns) |
| Tensile Strength | High | Medium | Very High | High |
| Moisture Absorption | <0.01% | <0.01% | 0.4% | 8-10% |
| Chemical Resistance | Excellent | Good | Good | Poor |
| Cost | Low | Low | Medium | High |
| Recyclability | Yes (#5) | Yes (#2, #4) | Yes (#1) | Compostable |
- Lowest density (lightest weight per volume)
- Excellent moisture resistance
- Good chemical resistance
- High melting point (heat sealable)
- Cost-effective production
- Recyclable infrastructure
Types of PP Used in Non Woven Bags
Not all PP is created equal. The specific type of polypropylene used significantly affects the final bag’s performance characteristics. Understanding these differences helps you select the right material for your specific application requirements.
Homopolymer PP
- Pure polypropylene resin
- Higher stiffness
- Better heat resistance
- Lower cost
Best For: Standard shopping bags, promotional bags
Copolymer PP
- PP + ethylene (3-8%)
- Improved impact strength
- Better flexibility
- Enhanced durability
Best For: Heavy-duty bags, bags requiring flexibility
Recycled PP (rPP): Post-industrial or post-consumer recycled content (20-50%). Slightly reduced properties but lower carbon footprint. GRS (Global Recycled Standard) certified options available. Best for eco-conscious brands.
Material Properties Deep Dive
Physical Properties
The physical properties of PP non woven fabric are determined by the spunbond manufacturing process, which creates a network of continuous filaments thermally bonded at intersection points. This structure gives the material its characteristic combination of strength, flexibility, and breathability.
| Property | Value | Test Method |
|---|---|---|
| Density | 0.895-0.92 g/cm³ | ISO 1183 |
| Melt Flow Index (MFI) | 25-40 g/10min | ISO 1133 |
| Tensile Strength (MD) | 20-40 MPa | ISO 527 |
| Tensile Strength (CD) | 15-30 MPa | ISO 527 |
| Elongation at Break | 100-400% | ISO 527 |
| Melting Point | 160-170°C | DSC |
MD = Machine Direction, CD = Cross Direction — Properties vary depending on fiber orientation during manufacturing.
Mechanical Properties by GSM
| GSM | Tensile (MD) | Tensile (CD) | Elongation | Handle Pull |
|---|---|---|---|---|
| 60 | 18-22 MPa | 12-16 MPa | 100-200% | 8-10 kg |
| 70 | 20-25 MPa | 14-18 MPa | 120-220% | 10-12 kg |
| 80 | 22-28 MPa | 16-20 MPa | 140-240% | 12-14 kg |
| 90 | 25-30 MPa | 18-22 MPa | 150-260% | 14-16 kg |
| 100 | 28-35 MPa | 20-25 MPa | 180-300% | 16-18 kg |
| 110 | 30-38 MPa | 22-28 MPa | 200-320% | 18-20 kg |
| 120 | 32-40 MPa | 24-30 MPa | 220-350% | 20-24 kg |
| 130 | 35-42 MPa | 26-32 MPa | 240-380% | 22-26 kg |
| 140 | 38-45 MPa | 28-35 MPa | 260-400% | 24-28 kg |
| 150 | 40-48 MPa | 30-38 MPa | 280-420% | 26-30 kg |
Chemical Resistance
Excellent Resistance
- Acids (dilute)
- Alkalis
- Oils & Greases
- Alcohols
Poor Resistance
- Chlorinated Hydrocarbons
- Aromatic Hydrocarbons
UV Warning: Outdoor direct sun exposure causes degradation in 6-18 months without UV stabilizers. Add 2-3% UV stabilizers for outdoor applications to extend lifespan to 2-4 years.
GSM Grades Explained
GSM (Grams per Square Meter) measures the weight/thickness of non woven fabric. It’s the primary specification for non woven bags. Higher GSM = thicker fabric = stronger bag = higher cost.
GSM Grade Spectrum
Understanding GSM grades is crucial for selecting the right bag for your needs. The GSM value directly impacts the bag’s strength, durability, appearance, and cost. Below is a visual spectrum showing the complete range of GSM options available for PP non woven bags, from ultra-light promotional grades to premium luxury applications.
50-60 GSM Ultra-light
Price: 100% (Base)
Use: Disposable promotional, single-use events
Durability: 10-20 uses
70-80 GSM Light
Price: 115-130%
Use: Promotional bags, lightweight retail
Durability: 20-40 uses
90-100 GSM Medium
Price: 145-165%
Use: Standard shopping bags, general retail
Durability: 40-70 uses
110-120 GSM Med-Heavy
Price: 180-200%
Use: Quality retail, supermarkets
Durability: 70-100 uses
130-140 GSM Heavy
Price: 220-245%
Use: Premium retail, heavy items
Durability: 100-150 uses
150-160 GSM Extra Heavy
Price: 270-300%
Use: Luxury retail, maximum durability
Durability: 150-200 uses
170-200 GSM Premium
Price: 350-450%
Use: Specialty, canvas alternative
Durability: 200-300+ uses
GSM Selection Guide by Application
| Application | Minimum GSM | Recommended GSM | Premium Option |
|---|---|---|---|
| Promotional Events | 60 | 70-80 | 90 |
| Trade Shows | 70 | 80-90 | 100 |
| Convenience Stores | 70 | 80-90 | 100 |
| Supermarkets | 90 | 100-120 | 130 |
| Clothing Retail | 90 | 100-110 | 120 |
| Department Stores | 100 | 110-120 | 130 |
| Luxury Retail | 120 | 130-140 | 150+ |
| Electronics | 100 | 110-120 | 130 |
| Pharmacy/Cosmetics | 70 | 80-90 | 100 |
| Wine/Spirits | 100 | 110-120 | 130 |
Red Flags: ❌ GSM variance >10% (inconsistent quality) | ❌ Systematic under-weight (cost-cutting) | ❌ No GSM specification on documentation. Industry standard tolerance: ±5%, premium suppliers: ±3%.
Manufacturing Process
Complete Production Flow
The manufacturing process for PP non woven bags involves multiple sophisticated stages, each carefully controlled to ensure consistent quality and performance. The spunbond process is the most common method used, offering excellent efficiency and material properties. Understanding this process helps you appreciate the engineering behind your bags and identify quality indicators.
Raw Material PreparationInput: PP resin pellets (virgin or recycled). Additives including UV stabilizers, colorants, and fillers are blended. Material is dried to remove moisture for consistent processing. Homogeneous mixture ensures uniform fiber quality.
Extrusion ProcessTemperature: 200-220°C. PP resin is melted and homogenized. Filtration systems remove contaminants. Metering pump maintains consistent flow rate to spinneret for uniform fiber formation.
Filament SpinningFiber Diameter: 15-35 microns. Molten PP is extruded through spinneret holes (hundreds of microscopic openings). Air quenching rapidly cools filaments. Drawing process orients molecules to increase tensile strength.
Web FormationKey Output: GSM determined here. Continuous filaments are laid on moving conveyor belt with random distribution for isotropic (uniform in all directions) properties. Web thickness controlled by line speed (100-400 m/min).
Thermal Bonding (Spunbond)Temperature: 140-160°C, Pressure: 40-80 bar. Thermal calendering bonds fibers at intersection points using heat and pressure. Bonding points cover 15-25% of surface area. Pattern options: diamond, square, or custom designs.
Roll WindingRoll Width: 160-320cm, Weight: 50-200 kg. Finished fabric is wound into large rolls. Slitting to required width. Quality inspection includes GSM verification, tensile testing, and visual defect detection.
Bag ManufacturingProcesses: Print → Cut → Weld → Inspect. Fabric unwinding, printing (screen, heat transfer, or laminated), optional lamination for waterproofing, ultrasonic cutting, handle attachment, side seaming, bottom folding, final QC inspection, and packaging.
Key Process Parameters
| Stage | Parameter | Control Range | Impact |
|---|---|---|---|
| Extrusion | Temperature | 200-220°C | Fiber quality, MFI |
| Spinning | Air velocity | 3000-6000 m/min | Fiber diameter |
| Web Formation | Line speed | 100-400 m/min | GSM, uniformity |
| Bonding | Calender temp | 140-160°C | Bond strength |
| Bonding | Pressure | 40-80 bar | Fabric integrity |
| Printing | Curing temp | 120-150°C | Print adhesion |
| Welding | Ultrasonic freq | 20-40 kHz | Seam strength |
Quality Indicators & Testing
Essential Quality Tests
Rigorous quality testing is essential to ensure that PP non woven bags perform as expected in real-world use. Professional manufacturers implement comprehensive testing protocols at multiple stages of production. Below are the seven critical tests that every batch should undergo.
GSM VerificationCut 5 samples (100 cm² each), weigh on precision scale, calculate average GSM. Acceptance: ±5% of specified value.
Tensile StrengthTest in MD and CD, sample size: 50mm × 200mm, test speed: 100 mm/min. Acceptance: Meet minimum values for GSM grade.
Handle Pull TestFill bag with standard weight based on GSM, hang for 1 minute. Acceptance: No tearing, deformation <10%.
Seam StrengthApply force to side seams. Acceptance: No separation at 15-25 kg (depending on GSM).
Print AdhesionApply adhesive tape to printed area, peel off rapidly. Acceptance: <5% ink removal (Class 4-5).
Color FastnessExpose to xenon arc lamp, rate color change after 20-40 hours. Acceptance: Grade 4+ (minimal change).
Water ResistanceMeasure water pressure resistance. Acceptance: >50 cm H₂O (unlaminated), >500 cm H₂O (laminated).
Quality Certification Standards
ISO 9001
Quality Management – Manufacturer capability
REACH
Chemical Safety (EU) – EU market compliance
OEKO-TEX
Standard 100 – Harmful substances testing
FDA 21 CFR
Food Contact – Food packaging applications
Common Quality Defects: GSM variation (inconsistent web formation), weak bonds (low calender temperature/pressure), print smudging (insufficient curing), handle tearing (poor ultrasonic welding), uneven cutting (dull blades), fabric holes (contaminants), odor (low-quality resin).
PP vs. Alternative Materials
PP Non Woven vs. Cotton
The debate between PP non woven and cotton bags often centers on environmental impact. While cotton is natural and biodegradable, its production requires enormous amounts of water and energy. PP non woven bags, though synthetic, have a significantly lower production footprint and are fully recyclable. The key question is: how many times will the bag be used?
PP Non Woven
- Cost: $0.30-0.80 per bag
- Weight: 30-60g
- Production energy: 60-75 MJ/kg
- Water usage: 15-25 L/kg
- Carbon footprint: 2.5-3.2 kg CO2e/kg
- Durability: 50-150 uses
- Recyclable: Yes (#5)
Cotton Canvas
- Cost: $3-8 per bag
- Weight: 150-300g
- Production energy: 180-220 MJ/kg
- Water usage: 9,500-11,000 L/kg
- Carbon footprint: 8.5-12 kg CO2e/kg
- Durability: 200-500+ uses
- Compostable: Yes
Verdict: PP non woven offers better environmental profile for most applications (lower production impact, adequate durability). Break-even uses: 10-15 for PP vs 150-200 for cotton.
Quick Comparison Overview
| Factor | PP Non Woven | Paper | PET Non Woven | Jute |
|---|---|---|---|---|
| Cost per bag | $0.30-0.80 | $0.20-0.50 | Higher (+20-40%) | $0.80-1.50 |
| Durability | 50-150 uses | 1-5 uses | 100-200 uses | 100-200 uses |
| Water resistance | Good | Poor | Good | Poor |
| Print quality | Excellent | Excellent | Good | Fair |
| Biodegradability | No | Yes | No | Yes |
Application-Specific Recommendations
Choosing the right specification for your specific application is crucial for balancing cost, performance, and brand image. Below are detailed recommendations for the most common use cases, based on years of industry experience and customer feedback.
Retail Shopping
GSM: 100-120
Handle: Soft loop or W-cut
Size: M & L
Printing: Screen or heat transfer
Supermarket/Grocery
GSM: 120-140
Handle: Soft loop (reinforced)
Size: L
Features: Lamination, reinforced bottom
Promotional Events
GSM: 70-90
Handle: D-cut or U-cut
Size: M
Printing: Screen (1-3 colors)
Corporate Gifts
GSM: 130-150
Handle: Patch handle or webbing
Features: Zipper, pockets, premium finish
Food Packaging
GSM: 100-120
Certifications: FDA, LFGB
Features: Lamination for barrier properties
Storage & Organization
GSM: 120-140
Handle: Soft loop (long)
Features: Drawstring closure, gusseted
Environmental & Safety Considerations
Environmental Profile
Understanding the environmental impact of PP non woven bags requires looking at the complete lifecycle—from raw material extraction through manufacturing, distribution, use, and end-of-life disposal. While PP is petroleum-based, its lightweight nature and reusability significantly reduce its overall environmental footprint compared to many alternatives.
Energy (MJ)
CO2e (kg)
Water (L)
CO2e/use (75 uses)
Lifecycle Assessment (per 100g bag): Raw Material: 45-55 MJ, 1.8-2.2 kg CO2e | Manufacturing: 15-20 MJ, 0.5-0.7 kg CO2e | Transport: 5-10 MJ, 0.2-0.3 kg CO2e | End of Life: 2-5 MJ, 0.1-0.2 kg CO2e
PP Recycling Process
PP recycling has grown significantly in recent years, driven by improved collection infrastructure and increasing demand for recycled content. The recycling process transforms used bags into clean pellets that can be manufactured into new products, reducing waste and carbon footprint by 30-50% compared to virgin material.
📦 Used Bag CollectionUsed PP bags collected from recycling programs, collection points, or take-back schemes. Bags should be free of contaminants for best recycling results.
🔍 Material SortingMaterials sorted by resin type (#5 PP) and color. Non-PP components like zippers, metal parts, and paper labels removed during this stage.
💧 Thorough CleaningThorough washing to remove dirt, residues, and surface contaminants. Clean material ensures high-quality recycled pellets with consistent properties.
✂️ Shredding into FlakesClean PP material shredded into small flakes (5-10mm). Increased surface area improves melting efficiency in subsequent processing stages.
🔥 Melting ProcessTemperature: 200-220°C. PP flakes melted and homogenized. Filtration removes remaining impurities. Melt quality checked for consistency before pelletizing.
⚙️ PelletizingMolten PP extruded through die and cut into uniform pellets. Cooled and dried. Ready for manufacturing new products with 30-50% lower carbon footprint.
♻️ New Product ManufacturingRecycled PP pellets used to manufacture new bags, containers, automotive parts, or plastic lumber. Quality suitable for most non-food applications.
Best Practices
- Maximize reuse: 50-100+ uses
- Clean before recycling
- Check local recycling guidelines
- Consider take-back programs
Avoid
- Don’t litter – PP persists 50-100 years
- Don’t burn – releases toxic fumes
- Don’t contaminate – affects recycling
Recycling Rates by Region
Frequently Asked Questions
We’ve compiled answers to the questions we hear most frequently from customers. If you don’t find what you’re looking for here, feel free to contact our technical support team directly.
What does GSM stand for and why does it matter?
GSM = Grams per Square Meter, measuring fabric weight/thickness. Higher GSM means stronger, more durable bags but also higher cost. Quick guide: 70-80 GSM for lightweight promotional, 90-100 GSM for standard retail, 110-120 GSM for quality retail and supermarkets, 130-150 GSM for premium heavy-duty use.
Is PP non woven fabric safe for food contact?
Yes, when manufactured with food-grade materials. PP is FDA-approved under 21 CFR 177.1520. Look for FDA, LFGB (EU), or GB 4806 (China) certifications. Always request food contact certification from your supplier and ensure food-safe inks and adhesives are used.
Can PP non woven bags be recycled?
Yes, PP is recyclable (#5 plastic). Check local recycling programs, clean bags before recycling, and remove non-PP components like zippers or metal parts. Reality: Recycling infrastructure varies by region; reuse is the best environmental option with 50-150+ uses before disposal.
How long do PP non woven bags last?
Lifespan by GSM: 70-80 GSM: 20-40 uses (3-6 months), 90-100 GSM: 40-70 uses (6-12 months), 110-120 GSM: 70-100 uses (1-2 years), 130-150 GSM: 100-150+ uses (2-3 years). Factors affecting lifespan include load weight, handle type and attachment quality, storage conditions (UV exposure), and care/cleaning practices.
Are PP non woven bags waterproof?
Unlaminated: Water-resistant (not waterproof), repels light moisture for 30+ minutes but not suitable for wet items or rain. Laminated: 100% waterproof with PP film coating providing complete water barrier, suitable for frozen items, produce, and outdoor use.
What’s the difference between virgin and recycled PP?
Virgin PP: From petroleum refining, consistent high quality, can be any color, standard cost, higher carbon footprint. Recycled PP: From post-industrial/consumer waste, slightly variable quality, often gray/off-white, 5-15% lower cost, 30-50% lower carbon footprint. Best practice: Blend of virgin + recycled (20-50% rPP) balances quality and sustainability.
Can PP non woven bags be washed?
Yes, with proper care. Hand wash with mild soap and lukewarm water, air dry only. Machine wash not recommended (can damage bonds). No tumble dry. Low heat ironing if needed. Print durability: Screen printing lasts 50+ washes, heat transfer 30-40 washes, laminated bags wipe clean only.
What certifications should I look for?
Essential: ISO 9001 (quality management), REACH compliance (EU chemical safety), Prop 65 compliance (California). Application-Specific: FDA/LFGB (food contact), OEKO-TEX (consumer safety), GRS (recycled content), BPI (compostable options). Always request documentation from suppliers.
Conclusion
PP non woven bags dominate the sustainable packaging market for good reason: they offer the optimal balance of cost, performance, and environmental profile for most applications. With proper GSM selection, quality manufacturing, and responsible end-of-life management, they provide an excellent solution for businesses seeking to reduce their environmental impact without compromising on functionality or brand image.
The key to success lies in understanding your specific requirements, selecting the appropriate material specification, and partnering with a reputable supplier who can provide consistent quality and technical support. Use this guide as your reference for making informed decisions about PP non woven bags.
Key Selection Criteria
| Factor | Recommendation |
|---|---|
| GSM | Match to application (90-120 for most retail) |
| Handle Type | Soft loop for comfort, D-cut for economy |
| Certifications | ISO 9001, REACH, application-specific |
| Quality | ±5% GSM tolerance, AQL 2.5 inspection |
| Supplier | Verified, audited, good references |
- Specify GSM clearly with ±5% tolerance
- Request test reports to verify claims
- Approve samples before bulk production
- Consider total cost, not just unit price
- Plan for reuse: design for 50+ uses
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