Materials for PVC Coated Fabrics: The Difference Between Polyester Flat Yarn and Polyester Round Yarn

Introduction

In the production and application of PVC-coated fabrics, polyester fiber serves as the primary reinforcing material. The choice of its fiber form directly impacts the performance of the final product. Polyester flat yarn and polyester round yarn are two common types, with significant differences in appearance, structure, performance, and application scenarios.

What are polyester flat yarn and polyester round yarn?

Polyester round yarn is a traditional round-cross-section polyester fiber produced using a conventional melt-spinning process. It has a smooth surface and a round or nearly round cross-section.

Polyester flat yarn is a flat polyester fiber with a rectangular or oval cross-section, produced through a specialized spinning and drawing process.

Morphological and Structural Differences

Cross-sectional Shape:

Round Yarn: Round or nearly round

Tap Yarn: Flat, typically with a width at least four times its thickness

Surface Characteristics:

Round Yarn: Smooth, cylindrical

Tap Yarn: Large flat surface area, surface treatments available

Performance Comparison

Polyester Round Yarn Characteristics:

Mechanical Properties: High strength, good abrasion resistance, isotropic (similar properties in all directions)

Processing: Easy to spin and weave, bonds well with PVC coatings

Application Characteristics: Suitable for fabrics requiring uniform strength, providing excellent overall coverage

Unique Advantages of Polyester Tape Yarn

Large Coverage: 30-50% more coverage than round yarn at the same weight, reducing material usage and costs

Tear Resistance Performance: The flat structure offers improved tear propagation resistance, making it particularly suitable for applications requiring high tear resistance.

Coating Adhesion: The flat surface provides a larger bonding area, ensuring a stronger bond with the PVC coating and resisting peeling.

Flexibility: The low flexural stiffness makes the fabric more flexible, making it suitable for items that require frequent folding or rolling.

UV Resistance: The flat structure provides improved UV shielding, extending the product's outdoor life.

Application Differences

Polyester round yarn is more suitable for:

High-strength conveyor belts

Heavy-duty tarpaulins

Structural materials requiring uniform load distribution

Polyester tape yarn is more suitable for:

Truck tarpaulins

Storage canvas

Outdoor awnings

Inflatable products

Flexible containers

Development Trends

With technological advances, the application range of polyester tape yarn is continuously expanding. Modern spinning technology has enabled the production of tape yarns with a variety of width-to-thickness ratios to meet specific application requirements. Furthermore, hybrid products (combining tape and round yarns) are becoming increasingly popular, balancing performance and cost.

Conclusion

Polyester tape and round yarn each have their advantages in PVC-coated fabrics, and understanding their differences is crucial for selecting the right material. Flat wire, with its superior coverage, tear resistance, and cost-effectiveness, is gradually replacing traditional round wire in many applications. However, round wire still maintains its irreplaceable position in certain specific areas. When making a choice, consider product performance requirements, production costs, and processing conditions to make the most reasonable decision.