| 摘要 |
<p>A plastic zipper comprising a male hook and a pair of female hooks that are engaged with each other to form a combination thereof, the plastic zipper being characterized in that, when an opening force is applied to the plastic zipper from an opening side thereof, the pair of female hooks is provided on a flange, a portion of which, being defined by base portions of two female hooks on an opening and content side, becomes flexible, is disclosed. The above-described plastic zipper is favorably used for containers for packaging, since it permits resistance to opening on the opening side to consistently hold a low value of from about 0.9 kg/5 cm to about 1.2 kg/5 cm while permitting resistance to opening on the content side to hold an enough strength of from about 7 kg/5 cm to about 8 kg/5 cm, permits the resistance to opening on both opening and content sides to remain within a specified range of resistance to opening even after opening/closing operations have been executed 100 times or more and, further, has solved a deficiency of the conventional zipper that a resin become brittle by a low temperature causes a problem in the engagement, or the engagement function becomes inoperable after several times of opening/closing operations at an elevated temperature. <IMAGE></p> |
