Leather Vamp Flexing Extensibility Testing Machine

Vamp Flexing Tester is used to determine the propensity for materials to crack or otherwise fail at flexing creases, but can also be used to assess whether leathers are likely to produce salt spue. In particular the test simulates conditions in the vamp part of footwear during walking. The test can be conducted with either wet or dry specimens at room temperature. The method is applicable to all flexible materials and in particular those used to manufacture outers and linings of footwear uppers such as leathers, coated fabrics and textiles.

Principle

A square specimen of the material is folded over two inverted V-shaped clamps. The clamps are able to move relative to one another so that as they become closer the specimen is flexed to produce one downward crease surrounded by four upward creases. During the test the clamps oscillate at a constant speed so that the specimen is repeatedly flexed. After a predetermined number of cycles the test is stopped and the specimen is visually examined for signs of damage or salt square.

Application

(1) Footwear upper leather testing to evaluate resistance against repeated bending and stretching during walking conditions.

(2) Coated fabric flexing evaluation for checking cracking, peeling, or surface damage after repeated deformation.

(3) Textile material flexibility testing for footwear uppers, linings, and related flexible materials.

(4) Leather quality control to compare different leather types and verify material durability.

(5) New material development for footwear manufacturers and material suppliers.

Standards

EN ISO 20344-2004 Section 6.5.2

EN ISO 22288

ISO 5423 section 5.2

SATRA TM25

GB/T 20991 Section 6.5.2

GB/T 20991 Section 6.5.2

AS/NZS 2210.2 Section 6.5.2

Parameter

Stretching distance：(19±0.5) mm

Scaling speed：(300±30) CPM

Specimen size：(64×64) mm

Number of samples：12pcs

Fixture：40°V v-shape6.4mm (R)

Counter：6-digit LCD digital display

Power supply：1 Φ, AC 220 v, 2 a

Volume：approx. (55x35x30) cm

Weight：approx. 60kg

FAQ

(1) What materials can be tested by the Leather Vamp Flexing Tester?

The tester is suitable for flexible footwear materials including natural leather, synthetic leather, coated fabrics, and textiles. It helps evaluate whether materials develop cracks, wrinkles, or other damage after repeated bending conditions.

(2) What is the purpose of simulating footwear walking conditions?

During walking, shoe upper materials experience continuous bending and stretching forces. The tester reproduces these movements to assess material durability and identify potential quality problems before mass production.

(3) How are Flexibility of shoe vamps measured?

ISO5423 shoe upper leather stretching and bending testing machine, this machine simulates the shoes in the process of walking, the different parts of the shoe upper leather will be subjected to forces such as stretching, squeezing, bending, etc., resulting in scratches, wrinkles or damage to the shoe material. The machine is simulating this test as a reference for the quality improvement or purchase of upper materials, and it has a power-off memory function.

(4) Can the test be performed with wet leather samples?

Yes. The instrument supports both wet and dry specimen testing according to relevant test requirements. This allows laboratories to evaluate material performance under different usage conditions.

(5) How can I select the correct configuration for my footwear material testing needs?

Selection depends on material type, required standards, specimen conditions, and testing volume. QINSUN engineers can provide professional selection guidance, customized solutions, calibration support, and more application cases according to your requirements.