1. Field of the Invention
This invention relates to an inexpensive surface fastener to be used as fasteners for disposable paper diapers or other products, and more particularly to a continuous surface fastener tape having hook-shape engaging portions adapted to be cut into individual surface fastener pieces.
2. Description of the Related Art
FIG. 30 of the accompanying drawings shows a conventional fastener for a diaper, etc. In this fastener, a plastic substrate piece 5' has on one surface an adhesive layer 6' extending from the center to one end and a protective separating portion 7' extending from the center to the other end. On the other surface, the plastic substrate sheet has another adhesive layer 6' and another protective separating portion 7' arranged reversely to the one surface. The plastic substrate sheet 5' is folded double when attaching to one part of a diaper A' in production of diapers, and in use the adhesive layer 6' is peeled off the corresponding protective separating portion 7' and is then attached to a companion part of the diaper A'. This part is exemplified by Japanese Utility Model Publication No. Hei 1-29230.
The concept of using a surface fastener in a disposable diaper is disclosed in Japanese Patent Laid-Open Publication No. Hei 2-5947. In this surface fastener, as shown in FIG. 31 of the accompanying drawings, a multiplicity of elastic engaging elements 4' are arranged on one surface of a thin, very flexible substrate sheet 5', each engaging element 4' having a round-surfaced head 4'-1 and an upright stem 4'-2 standing on the substrate sheet 5'. This surface fastener is fixed to an end portion of a narrow flexible, rectangular high-polymer tab, which is equipped with a low-viscosity pressure-sensitive adhesive agent to keep the tab in folded form so that the tab may be unfolded or peeled off for engagement with a companion surface fastener when the diaper is in use.
With the plastic substrate piece 5' disclosed in the first-named publication, since the diaper A' is fastened by the adhesive layer 6', only a limited degree of attaching strength can be achieved. This plastic substrate piece 5' is difficult either to manufacture continuously or to store in continuous form, causing a laborious inventory management.
The surface fastener disclosed in the second-named publication requires a very complex manufacturing process, which is laborious and time-consuming. Further, since the surface fastener and the high-polymer tab cannot be formed at once by extrusion molding, a high degree of manufacturing efficiency and hence a low price of products cannot be realized.
USPTO Backgrounds
USPTO Backgrounds