In this blog post, we examine the structure and manufacturing principles of microfiber and scientifically explore how effectively this material can actually block dust mites and dust.
Have you heard about bedding that prevents dust mites and dust? It’s a new technology gaining attention in the clothing and bedding industries. Anyone who’s ever browsed through various products while shopping for bedding or clothing has likely heard about this product and its material, microfiber.
Ultra-fine fibers refer to fibers one-hundredth the thickness of a human hair. When used in products, they create air pockets smaller than fine dust or dust mites but larger than air molecules. This allows the fiber products to maintain breathability while providing a barrier effect that prevents dust and mites from penetrating. This functionality is particularly beneficial for allergy sufferers and those with sensitive skin. Since the fabric possesses breathability akin to pottery while preventing fine dust adhesion or dust mite habitation, it is widely used in functional bedding and clothing. So, how is this fiber, 100 times finer than a human hair, made?
Conventional yarn is produced by filling a hollow cylindrical tube with a liquid polymer material, applying pressure, and extruding strands one by one, much like making noodles. However, creating microfiber using this same method requires first manufacturing tubes with diameters of tens of nanometers, which is technically extremely difficult. Therefore, microfibers are primarily manufactured using electrospinning, which employs an electric field rather than mechanical manipulation.
Electrospinning is a method that applies a high voltage to a liquid raw material, causing the molecules forming the substance to repel each other. Matter is composed of countless particles called molecules. When a high voltage is applied to the material, these molecules are affected and become electrically charged. It’s similar to how your voice naturally gets louder in noisy places like concert halls or markets. In a strongly electrified area, molecules also become electrically charged, creating an electrostatic phenomenon. Molecules acquire the same charge, and like charges repel each other. Consequently, they push away. Conversely, in a liquid state, molecules also possess an attractive force between them. This is due to surface tension, which causes molecules to cluster together to minimize surface area. When the repulsive force caused by the charges becomes stronger than the surface tension that wants the molecules to stay clustered, the liquid can no longer remain clustered and is sprayed out. This is why it is sprayed out in the form of liquid droplets. These sprayed liquid droplets gradually solidify as they pass through the air. As they pass through the air, they transfer their charge to the atmosphere and gradually lose their own charge. Once they lose a sufficient amount of charge, the flow of these droplets becomes unstable. Consequently, the flow twists into a spiral and elongates into a thread-like shape. This is how the thread is born, much like the shape drawn by a ribbon gymnast’s ribbon. This phenomenon continues until the droplet reaches a high-voltage plate positioned a certain distance from the location where the liquid was electrically charged.
The process of creating nanofibers via electrospinning possesses remarkable properties. When spinning yarn with conventional machinery, different machines with varying specifications must be introduced to produce yarns of different thicknesses. However, electrospinning eliminates this need entirely. In electrospinning, the filament thickness is controlled solely by adjusting the applied voltage. Higher voltage yields finer filaments because greater voltage delivers more energy. This is analogous to dropping a fragile object from a greater height, causing it to shatter into smaller pieces. Liquid receiving high energy from the voltage carries a stronger charge and experiences greater repulsion. This strong repulsion overcomes the forces that cause liquids to clump together, allowing them to disperse into smaller droplets.
Another advantage of electrospinning is its ability to combine various materials to impart new functionalities. For example, creating nanofibers with added antimicrobial agents can suppress the growth of bacteria and fungi, as well as house dust mites. These fibers, combining diverse materials and functionalities, find extensive applications beyond bedding—from medical materials and sportswear to industrial filters. They play a vital role in enhancing our quality of life.
We unconsciously use many microfiber products in daily life. They are utilized in various functional products, from dust mite-resistant bedding and functional sportswear to dust-removing towels. All these functional products originated from a small shift in thinking: converting physical force into electrical force. Seeing this makes one wonder how the world might change if more groundbreaking methods are developed in the future, leading to even finer and more specialized yarns. Advances in science and technology bring innovation even to the smallest parts of our daily lives, and new materials like microfiber will continue to prove their value across diverse fields.
