The effect of low-melting-point fiber ratio on the properties of nonwoven fabrics
- dkfiber2004
- Oct 25
- 2 min read
Nonwoven fabrics are industrial materials manufactured by mechanically or thermally bonding fibers without weaving them into yarns.
In this process, the structural strength and physical properties of nonwovens can vary significantly depending on the ratio of binder fibers.
In this article, we will examine how the content of low-melting-point polyester binder fibers affects the thickness, density, and tensile strength of nonwovens.
The role of binder fibers
Binder fibers (low-melting fibers) are special polyester fibers with a low-melting sheath/core structure. When heat is applied, the sheath (outer layer) melts and bonds the core (inner layer) with surrounding fibers.
Through this process, bonding points are created between fibers, enabling the production of nonwovens with high strength and stability without the need for additional chemical binders.
Application in the manufacturing process
When binder fibers are used in nonwoven production, they are generally applied through the process of Carding → Needle Punching → Thermal Bonding.
Carding – Fibers are evenly opened and laid into a web.
Needle Punching – Fibers are mechanically entangled using barbed needles for structural cohesion.
Thermal Bonding – Heat is applied to melt the sheath portion of the binder fibers, bonding them with surrounding fibers.
Nonwovens manufactured through this process exhibit improved durability and dimensional stability, making them widely used in automotive interiors, sound-absorbing materials, and mattress fillings.
Binder fibers are typically blended with regular polyester staple fibers at a ratio of 5–50%, with property changes becoming noticeably significant when the content exceeds 30%.
Results of nonwovens according to the ratio of low-melting binder fibers
So, how does the ratio of binder fibers affect nonwovens?
According to experiments conducted at Marmara University, as the blending ratio of staple polyester fibers and low-melting binder fibers increases, the following results were observed:
Binder Fiber Content | Tensile Strength (MD) | Tensile Strength (CD) | Thickness (mm) | Density (g/cm³) |
5% | 2.99 cN/tex | 0.85 cN/tex | 0.79 | 0.459 |
30% | 3.82 cN/tex | 1.90 cN/tex | 0.67 | 0.687 |
50% | 5.22 cN/tex | 2.57 cN/tex | 0.49 | 0.773 |
As the proportion of binder fibers increases, the tensile strength of nonwovens more than doubles, while the thickness decreases by approximately 40%. In addition, the study confirmed that the density of nonwovens consistently increased.
In other words, a higher binder fiber content leads to more bonding points between fibers, enhancing structural stability. This effect becomes especially pronounced when the blending ratio exceeds 30%, resulting in a significant improvement in the mechanical strength of nonwovens.
The ratio of binder fibers is not just a simple blending proportion, but a critical variable that determines the strength, thickness, density, and durability of nonwovens.
An optimal binder fiber ratio maximizes product performance and serves as an eco-friendly solution that replaces chemical binders with a technology based on physical bonding.
