The tightening length during the button pull tester experiment is very special!

The Button Pull Tester is used to test the fixing and fixing strength of buttons, buttons, five-pin buckles, snaps, bow ties and other accessories, especially for children\'s clothing. babies and children, to define the responsibilities of clothing manufacturers and ensure that buttons, push-buttons and fasteners can be properly attached to the garment to prevent buttons from becoming detached from the garment, causing a risk of ingestion and suffocation by the baby.

The tightening separation rate of the button pull tester is set to a certain tightening separation rate according to the requirements of relevant standards. For example, the GB/T requirement is (100 ± 10) mm/min.

Place the sample on the tester and adjust the clamp position to maintain the center axis and the direction of the tensile force of the upper part. and consistent lower clamps; place the sample in the center of the clamp to ensure that the sample is longitudinal The central axis passes vertically through the center line of the upper and lower clamps; make sure there is no damage or slippage when placing the sample. Use a tester to record the maximum pulling force. The upper clamp pulls the pieces until they are separated from the garment or damaged. The main damage methods are part damage, attachment method damage, and fabric damage.

The clamping length of the snap tester is short and slippage is likely to occur:

The correct way to use the tester clamp should be that of the clamping length of the specimen. conforms to the teeth of the pliers. When the surface lengths are the same, first use an external force to push the jaws to generate initial friction onthe clamping surface, then load the sample through the movement of the tester beam. When the friction force pulls the jaws (wedge-shaped mouth) due to the action of the inclined surface, the greater the axial pulling force, the greater the clamping force generated. The wedge-shaped operation assembly with two inclined planes on the tester clamp body is designed to accept uniform compressive stress based on the above clamping method.

However, some operators did not perform according to the tester\'s requirements. The clamping length of the sample was short or the sample was processed too short, resulting in uneven stress on the slope of the wedge-shaped mouth and the shape of the wedge. The local stress at the mouth far exceeds the elastic limit of the material, causing plastic deformation and severe valgus of the mouth of the wedge, causing collapse.steepness or wear of the slope of the mouth of the corner. If the pliers continue to be used under these conditions, the corner mouth angle is reduced, which aggravates the stress state of the pliers body and causes slippage.

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