Polypropylene, a versatile plastic polymer, is characterized by its lightweight and resilient nature. It has a somewhat waxy and smooth texture, often feeling softer than other plastics. This tactile feel makes it comfortable for use in a variety of applications, from automotive parts to textiles and packaging. It doesn't absorb water, which contributes to its slick feel, and it remains stable across different temperature ranges, maintaining its physical properties without becoming brittle or overly soft. The comfort factor and practicality of polypropylene make it a preferred choice for items requiring direct skin contact, like undergarments and diapers, as well as for durable consumer goods.

Polypropylene, a type of thermoplastic polymer, is inherently not flame retardant. It has a relatively low melting point (160-170°C) and can ignite at temperatures around 570°F (300°C). However, it's worth noting that it can be made flame retardant through the addition of chemical flame retardants or by compounding it with other materials that enhance its resistance to flames. These modifications are essential in applications where fire safety is a concern, such as in construction materials, automotive parts, and electrical components. Manufacturers often tailor the flame resistance of polypropylene to meet specific safety standards required for different applications.

A synonym for "yarn" can vary depending on the context. In the context of textiles, synonyms include thread, wool, and fiber. These terms refer to the thin strands of material used for knitting, weaving, and sewing. "Yarn" often implies a thicker, softer strand, particularly used in knitting and crocheting. In another context, "yarn" can mean a long, involved story, often exaggerated for effect. Here, synonyms might include tale, story, or anecdote. This dual meaning of "yarn" underscores the richness of the English language, where one word can carry diverse implications depending on its usage. Thus, the appropriate synonym depends significantly on whether the intended use is within a textile or storytelling setting.