SDL Atlas and Tinius Olsen have a well developed understanding of zipper testing, supported by our technologist Sylvia Hillier who was a member of the Working Group for the recently revised BS 3048:2006 Slider Testing. We are proud to have supplied testing systems to YKK, SGS, Intertek and others, who are now reaping the benefits of this understanding in the form of specialty grips that we have developed.

Sylvia Hillier notes "The growing interest in zipper testing among retailers and their suppliers is part of the industry's greater commitment to testing of components, accessories and garment embellishments for quality, performance and safety, especially when associated with childrenswear. These types of tests go well beyond the traditional basic tests for woven and knitted fabrics."

SDL Atlas and Tinius Olsen technologists are at the forefront of such testing and have developed specialist grips and test procedures to meet the requirements of these new testing procedures. As in real life, zips are pulled in all sorts of directions, with all sorts of forces, so a range of tests to simulate these kinds of rigors, but in a controlled, repeatable way, have been developed. Examples of these are illustrated here and photographs of individual tests are available upon request: -

1. BS3084 Annex G: Lateral Strength of fastener, ASTM D2061 Chain Crosswise Strength - grip ref. S413
   In this test, also referred to as a lateral strength test, the grips are attached to a section of the closed zip and a 1 inch length is tested in tensile mode until it is completely separated. The faces of these grips are profiled with a raised 1 inch serrated area and can be used on all zipper types.
2. Element Slippage Lengthwise - grip ref. S700
   This test is performed primarily in the USA and is similar to the closed end pull off test. The test is conducted with profiled forks that locate between the elements. The test is then run in a tensile mode with the forks exerting force on the elements until they break from the specimen.
3. Element Pull Off - grip reference S435
   In this test, the forceps that pull the element from the zipper are profiled to the shape of the element to ensure that slippage doesn't occur. Due to different element size and profile, a different set of forceps is required for each type of zipper. This test is also performed primarily in the USA.
4. BS3084 Annex D: Strength of Top Stop Holder, ASTM D 2061 - grip ref. HT23 & S411 faces
   In this test, the zipper is clamped at the bottom and the puller is hooked onto the top hook arrangement. The puller is located at the "top stop" end of the zipper. A different top hook may be required for different sizes and profiles of puller. Additionally, a set of profiled faces specific to each zipper type will be supplied for the bottom clamping arrangement to ensure the specimen doesn't slip.
5. Bottom Stop Holder - Slider
   Using the same top hook grip attachment as above, the zipper is arranged with the bottom stopper and puller in this arrangement. Again profiled bottom clamping faces are supplied to prevent slippage.
6. BS3084 Annex H: Lateral Strength Of Open-End Attachment, ASTM D2061 Bottom Stop Holding - Crosswise Test
   In this setup, the bottom stop is clamped in a crosswise direction. Tinius Olsen will supply profiled clamping faces to prevent slippage.
7. BS 3084 Annex C: Strength of closed-end, ASTM D2061 Bottom Stop Holding - Stringer Separation
   The same profiled faces that are used for the "Bridge Top Stop - Stringer Separation" can be used to conduct this test but with the "bridge top stop" located centrally between the grips. Again each profiled set of faces will be tailored to each different type of zipper.
8. Separable Pin - Pull Off - grip reference S827
   The stringer is separated so that one side can be tested. The separable pin (located at the bottom of the stringer) is then placed into the testing attachment that is located as the top grip. The bottom grip will have the same arrangement as described in the "Bottom Stop Holding - Stringer Separation" (?) to ensure that no slippage occurs. The top testing attachment then will be arranged so that the separable pin fits snugly into a fixed notch arrangement to enable the pull off of the separable pin. The test is conducted until either the separable pin pulls off; until the tape breaks; or a rupture of some other kind occurs.
9. BS 3084 Annex E: Strength of Open-End Fastener Box, ASTM D 2061 Retainer Pull Off - grip ref. S412
   Similar to the "Element Slippage Lengthwise Test" (2) a profiled fork is used as the top griping attachment and this is located under the bottom edge of the fixed retainer. The specimen is then clamped at the bottom by a profiled clamping face to prevent slippage with the zipper loaded horizontally between the upper and lower grips.
10. Separating Unit - Crosswise - grip ref. S413
    This test is similar to the "Bottom Stop Holding - Crosswise Test" (6). The difference is in the zipper type and again profiled jaws would be provided for the specific zip type.
11. Resistance to Cushioned Compression - grip ref. S824
    This is a compression test using a simple set of compression platens. The bottom platen has 1/4" thick neoprene affixed to give the cushioned compression.
12. BS3084 annex B Strength of puller attachment, ASTM D2061 Resistance to Pull-Off of Slider Pull - grip ref. S415
    The slider is located in the bottom arrangement with the puller placed vertically through the cross. The cross is profiled to the shape of the puller so that both the bail and puller are clear and unrestricted. The top arrangement consists of a pin that locates through the puller to exert the tensile force on the specimen.
13. Resistance to Angular pull-off of Slider Pull - grip ref. S415-1
    The grips are arranged similarly as above, the only difference is that the bottom cross arrangement is at an angle. This test is also performed primarily in the USA.
14. BS3084 Annex I: Strength of Slider Locking Device, ASTM D2061 Holding Strength of Slider Lock - grip ref. S411 or Crosshatch
    The zipper would be held in the same equipment as per the "Bottom Stop" and "Top Stop" gripping. The zipper is then arranged with the slider located midway down the chain.
15. BS3084 Open-End Fastener Single Stringer Slider Retention - grip ref. HT23 & S411 faces
    In this test, one side of the zipper is clamped at the bottom and the puller is hooked onto the top hook arrangement. The puller is located at the "top stop" end of the zipper.