Plastic zipper and plastic bag provided with the zipper

Abstract

A plastic bag which is made by fusing a material film to have an upper opening portion. A zipper is provided on an inner surface of the opening portion, and the zipper has a groove formed on a base tape and a ridge formed on another base tape, the groove and the ridge being capable of engaging with and disengaging from each other. At least the base tapes are colored differently. The base tapes respectively have parts which serve as flaps, and the flap parts are of different widths. Thereby, the opening portion of the plastic bag has a step.

What is claimed is:  
     
         1 . A plastic zipper comprising: 
 a groove formed on a first base tape and a ridge formed on a second base tape, the groove and the ridge being capable of engaging with and disengaging from each other;    wherein: 
 at least the first base tape and the second base tape are colored differently; and  
 at least a dimension from the groove to one side of the first base tape and at least a dimension from the ridge to one side of the second base tape are different from each other.  
   
     
     
         2 . A plastic bag which is made of a plastic film and which has an opening portion on one side, comprising: 
 a zipper which is provided on an inner surface of the plastic film of the opening portion, the zipper comprising a groove formed on a first base tape and a ridge formed on a second base tape, the groove and the ridge being capable of engaging with and disengaging from each other;    wherein: 
 at least the first base tape and the second base tape of the zipper are colored differently;  
 at least a dimension from the groove to one side of the first base tape and at least a dimension from the ridge to one side of the second base tape are different from each other; and  
 the first base tape and the second base tape are located such that an upper side of the first base tape and an upper side of the second base tape are on different levels.