TPU
TPU is a thermoplastic polyurethane that softens when heated and can be molded. It is a material that makes use of its elasticity, abrasion resistance, and flexibility, and is used for films, coatings, parts, and more.
Contents6 sections
Definition and Overview
TPU is a resin material that refers to thermoplastic polyurethane. It softens when heated and stabilizes in shape when cooled. It is used not only as a fiber material itself, but also as film, sheet, coating, and molded parts for apparel and garment accessories.
There are grades ranging from soft, highly stretchable types to relatively hard types, and they are designed according to the intended application. For this reason, the name TPU alone does not indicate specifications such as thickness, hardness, transparency, stretchability, or water resistance.
Features and Appearance
TPU is characterized by having both rubber-like elasticity and resin-like abrasion resistance. When used as a transparent or semi-transparent film, it tends to have a glossy, smooth appearance, and its look can be changed by coloring or surface finishing.
When made into film or coating, it is also used for applications that make it harder for water to pass through. However, waterproofness, moisture permeability, yellowing, weather resistance, and hydrolysis resistance vary depending on product design and processing structure, so it is important to confirm the required performance tests.
- It is a material that makes it easy to take advantage of elasticity and stretch recovery.
- It is used in areas where resistance to rubbing and wear is required.
- Transparency, gloss, and hardness vary depending on the grade and thickness.
- Flexibility in low-temperature environments and chemical resistance should also be checked according to the application.
Main Applications
In apparel, it is used for films and laminate layers in rainwear and outdoor clothing, reinforcement and design parts in sportswear, and auxiliary materials that require stretchability. In areas that are likely to be exposed to water or friction, it is adopted in consideration of the combination with the outer fabric.
In bags, shoes, and belts, it is used for transparent windows, reinforcing materials, parts, and surface materials. From lightweight transparent items for spring and summer to layered materials intended for windproofing and waterproofing in autumn and winter, seasonality is determined by the fabric construction rather than by TPU alone.
Selection and Handling Notes
When selecting, check the hardness, thickness, transparency, stretchability, adhesion, and abrasion resistance required for the application. For film and laminated fabrics, it is reassuring to evaluate adhesion to the outer fabric, whitening or cracking due to bending, and appearance changes after washing during the prototyping stage.
Not only dimensional changes in the TPU itself, but also shrinkage in the bonded outer fabric and lining affect product dimensions. Suitability for washing, drying, and dry cleaning differs depending on the grade and lamination, so follow the handling conditions provided by the material supplier and conduct washing tests before mass production.
During sewing, needle holes may be noticeable, and feeding may cause scratches or scuffing on the surface. Use a thin needle and appropriate presser foot, and for products that require seam waterproofing, separately consider water-sealing specifications such as seam tape. High-temperature irons and pressing may cause deformation, changes in gloss, or sticking.
Differences from Similar Terms
Polyurethane is a broad term for materials that have urethane bonds. TPU refers to thermoplastic polyurethane that softens with heat and is easy to remold. On the other hand, polyurethane in the context of apparel stretch blends may refer to the material used as an elastic fiber.
Synthetic leather is a material that has a resin layer on a base fabric to give it an appearance and performance similar to natural leather. TPU may be used as the surface resin or film of synthetic leather, but TPU itself does not necessarily mean synthetic leather.
Frequently Asked Questions
Are TPU and polyurethane the same?
TPU is a type of polyurethane, but it refers to a thermoplastic material that softens with heat and is easy to mold. Materials generally described as polyurethane also include elastic fibers, foams, and coatings, so the intended use and form need to be checked as well.
Can TPU be machine washed at home?
Whether it can be washed depends on the type of TPU, the structure of the film or coating, and the fabric it is bonded to. High-temperature drying, strong heat, or solvents may cause deformation or peeling, so check the washing instructions and material specifications for each product.
What should be noted when sewing TPU film?
Needle holes can remain easily, and the surface can be scratched by the presser foot or feed dogs, so check the needle, thread, presser foot, and seam through trial sewing. If waterproofness is required, sewing alone cannot prevent needle holes, so consider treatments such as seam tape.
