Polypropylene is a type of thermoplastic that is known for its resistance to chemical solvents, bases, and acids, making it a challenging material to bond with adhesives. However, some epoxies are specifically formulated for bonding to low-surface-energy plastics like polypropylene. One of the best options is a surface-insensitive epoxy designed for plastics, or more specifically, a two-component epoxy system that includes a primer or an adhesion promoter. Brands like 3M and Loctite offer epoxy products that include a treatment step to prepare the polypropylene surface, enhancing the bond strength. It's crucial to follow the manufacturer's instructions for surface preparation and epoxy application to ensure optimal adhesion. These specialized epoxies can create a durable bond suitable for a variety of applications, from industrial repairs to DIY projects.

Yarn elastic, commonly known as elastic yarn, is made by wrapping elastic fibers with other yarns like cotton or polyester. This blend creates a stretchable material, perfect for garments requiring elasticity such as socks, hats, and sportswear. The core of elastic fiber provides resilience and durability, enabling the fabric to return to its original shape after stretching. When selecting yarn elastic for a project, consider the desired elasticity level and washability, as some elastic fibers may degrade with heat or harsh chemicals. It's also essential to test the stretch and recovery of the yarn in a swatch before committing to a larger project to ensure it meets your needs.

TiO2 is a chemical compound composed of titanium atoms Ti and oxygen atoms O2.