Engineered composite yarns are yarns made with two or more components (i.e Kevlar® and steel). These yarns have allowed glove manufacturers to make gloves with higher levels of cut resistance, without sacrificing comfort or dexterity, than with high-strength fibers, such as Kevlar® or Dyneema® alone.
Cut resistance in knitted gloves is influenced by four factors:
- Strength: Examples of high-strength yarns would be Dyneema® or Kevlar®
- Hardness (dulling): An example of hard yarn would be stainless steel, which is often a primary component in composite yarns.
- Lubricity (slickness): slippery yarns such as Spectra® or Dyneema® allow a blade to slide over their surface without cutting through.
- Rolling action (knit construction): Most knit gloves allow the individual yarns to ‘roll’ as a sharp edge slides over them, producing somewhat of a ball-bearing effect. The edge slides across without cutting through the material.
Typically, the more of these factors that can be engineered into a yarn, the more cut resistant it will be. For example, an engineered yarn may consist of high molecular-weight polyethylene (HMPE) such as Dyneema®, which is both high strength and slick; and stainless steel, which is hard, and then knit in to a seamless glove, which provides ‘rolling’. Taken together, these characteristics result in a material that is far more cut resistant than a material made with only one component.
Further design considerations may be color, grip, moisture management, or other characteristics that engineered yarns can provide in a special-purpose glove.
Engineered yarns are typically used in applications requiring higher levels of cut resistance (ASTM Level 3 or higher), such as sharp or heavy sheet-metal handling, glass handling, or meat processing where sharp blades are used.