The present invention is directed generally to a mattress tape and, in particular, to a knitted mattress tape suited to provide a french seam at the edges of the mattress that produces a minimum amount of wrinkling.
Mattress tape is known in the art as exemplified in U.S. Pat. No. 3,889,305 (Goldberg) . This prior art heat barrier textile material is directed to a mattress tape formed of at least 50% by weight of filament yarn and, optionally, the balance spun yarn, the filament yarn and spun yarn being made from a synthetic fiber forming polymer such as a poly (ethyleneglycol terephthalate) .
It is noted that as used in this patent "mattress" refers to all types of mattresses and box springs, while "mattress tape" refers to the fabric tape used to finish and close the edges of "mattresses".
In the past, mattress tape has always been woven. Many different patterns of woven mattress tape have been made and many different yarns have been used in the weaves. Yarns ranging from cotton to polyester to nylon to polypropylene have been used. Thus, many different weights of mattress tape have been created using the different yarns.
The prior art mattress tapes have been satisfactory. However, they suffer from the disadvantage of being limited in the designs of the thicknesses, rigidity or shape holding ability. All woven tapes must be of uniform thickness, rigidity, and shape holding capability throughout the width of the tape thereby limiting the degree of shape holding ability that may be obtained by the tape. If the tape is designed too stiff in the edges it will not hold in the track of the mattress binding machines and if the tape is not designed stiff enough in the center it will not be capable of holding its shape without wrinkling. Thus, there is a limit to how firm the tape can be and still sew properly. Further, to achieve the desired shape holding capability in a prior art woven tape, an excess of yarn must be utilized in the edge regions, increasing the cost of the mattress tape.
It is desirable to have a tape that is sewn neatly on the edges and holds in track well while being stiff enough to hold its shape and define a smooth and aesthetically pleasing mattress edge. Further, it is desirable to provide a mattress tape which can achieve the desired appearance and utility while permitting use of less yarn per yard of tape than comparable prior art tapes. Accordingly, it is desirable to provide a mattress tape which overcomes the shortcomings of the prior art configuration described above.