Historically, string mop yarns have been manufactured by spinning cotton wastes on an abbreviated version of a cotton spinning system. Over time, it was determined that the mopping properties of such cotton string mops could be enhanced by blending the cotton fibers with various synthetic and man-made fibers. Such cotton-synthetic fiber blends have included a blending of cotton fibers with acrylic, rayon, and/or polyester fibers. Such fibers generally are produced in deniers typically in the range of 1.5 denier per filament to 3.0 denier per filament for blending with the cotton fibers. Such cotton-synthetic fiber blends, when compared to 100% cotton mop yarns, were found to provide improved water absorbency with reduced break-in, reduced shrinkage, less linting on the floor, longer life, and faster drying of the mop yarns, whether the yarns were dried via air-drying or were dried in a commercial clothes drier.
More recently, 100% synthetic microfiber flat mops have become increasingly popular for light duty wet mopping versus the use of more traditional string yarn mops. These microfiber flat mops generally are made from extruded bundles of microfiber filament yarns that are knitted or tufted into a fabric scrim or fabric bundle, which then can be treated chemically to split the fabric bundle into wedge-shaped microdenier fibers. The fabric bundle of the split microfibers then further typically is combined with an absorbent pad or backing material and sewn into an elongated pad or carrier.
Such microfiber flat mops have been found to be effective in light dusting, damp mopping, and disinfecting of smooth floors, with their use generally being most widespread in the healthcare industry and home use. However, these mops have been proven to be somewhat impractical for larger scale and/or heavier duty cleaning applications, due to the tendency of the fine denier continuous filaments to catch on surface protrusions and pull away and break from the parent strand, thus damaging the mop. As a result, many janitorial applications that involve the cleaning of larger, more highly soiled surfaces still must be cleaned by larger, traditional string yarn mops made from spun staple fibers. Examples of such janitorial applications include gymnasium floors, restaurants, public restrooms, schools, and buildings, which constitute a significant majority of the hard surface floors that require frequent cleaning in commercial buildings. In addition, while microdenier filaments have been found to efficient at channeling water, they generally are inefficient at absorbing water and thus tend to leave water streaks on clean surfaces. Such limited uses and disadvantages inherent in microfilament mop yarns, as well as their significantly higher cost versus even the highest quality spun stable fiber blended mop yarns, has tended to render such microdenier fibers impractical for most widespread cleaning applications.
Attempts also have been made to combine microfibers with spun yarns, such as by twisting strands of microdenier filament yarns with strands of yarns spun from staple fibers. For example, a yarn has been marketed that contains two plies of microdenier filament yarns and two plies of spun yarns twisted together. While this would appear to be an improvement over the problems inherent in the 100% filament mop yarn approach, the same problems of snagging, splitting, and streaking have been experienced. Thus, there remains a need for a commercial mop yarn for commercial cleaning applications, such as in the healthcare industry, that will not shrink significantly and can be rapidly dried, and which further can hold up to frequent laundering, being subjected to as many as one hundred laundry cycles during its lifetime.