In terms of the damage function of TPU film in the post bonding process:
Decreased waterproof performance: TPU film itself has good waterproof performance. If there is damage, such as small holes or cracks, it will allow moisture to penetrate into the interior of the fabric through these damaged areas, resulting in a significant reduction in the overall waterproof performance of the composite fabric. For example, fabrics that could have been used to make outdoor waterproof clothing may experience water seepage when exposed to rainwater due to damage to TPU film, which cannot meet the waterproof requirements for outdoor use.
Decreased breathability: Normal TPU film, when combined with knitted fabric, can maintain the breathability of the fabric to a certain extent, making the wearer feel comfortable. But if the TPU film is damaged and its structure changes, it may hinder the flow of gas and affect the breathability of the composite fabric. This will increase the stuffiness and reduce the comfort of wearing the fabric.
In terms of physical performance:
Strength reduction: TPU film has certain strength and toughness, which can enhance the physical properties such as tensile strength and tear resistance of knitted fabrics. However, when TPU film is damaged, its own strength decreases, and its reinforcing effect on knitted fabric will also weaken. During use, fabrics are more prone to tearing, damage, and other issues, which reduces their durability.
Appearance defects: Damage to TPU film may form marks on the surface of the fabric, such as scratches, dents, etc., affecting the appearance quality of the fabric. These defects not only reduce the aesthetics of the fabric, but may also affect the sales and use of the product to some extent. For example, defects on the surface of fabrics are not acceptable when making high-end clothing or household items.
In terms of chemical properties:
Chemical resistance change: TPU film has good chemical resistance, but after damage, its chemical structure may change, leading to a decrease in chemical resistance. When exposed to certain chemicals such as detergents, organic solvents, etc., chemical reactions are more likely to occur, further affecting the performance of the fabric. For example, during the cleaning process, the fabric may experience issues such as fading and deformation.