Testing artificial leather

Methods of testing artificial leather

• The products must be accepted by the technical control service of the manufacturer in accordance with the requirements of the Technical Specifications.
• The artificial leather is accepted in batches.
• A batch of artificial leather is considered an amount of artificial leather of the same color, hue, embossing or printing, made according to one formulation and production technology, one backing item, in the amount of no more than daily production and registered with one quality document.
• For the leather haberdashery industry, the batch volume must be at least 12 rolls and the batch must be formed from rolls of one thickness group.
• Depending on the controlled parameters, the quality of the leather is determined by continuous or selective control.
• With continuous control, the leather is presented in fully formed batches or individual units of production.
• Control of leather quality based on appearance, width, conformity of packing and marking to the requirements of Technical Specifications, Vinisan LLC during sorting and the consumer carry out continuous control of each unit of production before placing leather for cutting.
• It is also possible to carry out continuous quality control of appearance and width directly during the process of technological production.
• In case of selective control, the leather should be presented in fully formed batches.
• Quality control of physical- mechanical parameters and thickness is carried out by periodic sampling control.

Quality control is quite complicated and lengthy process, which includes:

of vinyl artificial leather is performed by inspecting the face side across the width on the cloth-inspection table. Length and width of the roll are also measured at this stage.

Prior to testing, the elemental samples shall be kept in laboratory rooms or special chambers for at least 24 hours at a relative humidity of 65 ± 5% and a temperature of 20 ± 2 °C.

A section 1m long without defects is taken for the test out of each roll selected for testing along the entire width, from which the elemental samples are cut.

For testing of vinyl artificial leather, three elemental samples 100±1 x 100±1 mm in size are cut: two at a distance of 50 mm from the edges and one in the middle of the cut.

Checking the appearance

Testing of physical-mechanical parameters

Determination of mass and thickness

Thickness is measured with a thickness gauge that meets the following requirements:

• diameter of measuring platforms – 10 or 16 mm for monolithic execution;
  16.20 mm – for porous monolithic execution;
• division value is not more than 0.01 mm;
• pressure of the measuring platform on the elemental sample is 0.5-1.5 N for monolithic execution and 0.5-1.0 N for porous monolithic execution.

The elemental sample is placed on the support surface of the machine, the measuring pin is lowered onto the material and left in such a position for 10 sec., then measured and recorded on the scale. The test result is the arithmetic mean of the parallel test results.

is determined on three elemental samples cut in the longitudinal and transverse directions, 50±1 x 200±1 mm in size.

Breaking load and extensibility at break

A tensile test machine is used to test the load with a ±1% relative error.

In the process of stretching the sample, the readings of the load and elongation scales are monitored and their values are fixed at the moment of complete rupture of the elemental sample or polymer coating or backing.

is determined on three elemental samples cut in the longitudinal direction. The length of the working area of the elementary sample is 150±2 mm, the width is 50±1 mm.

The bonding strength of the film coating and the backing

Each elemental sample is length-mapped into three sections:

• first – 50 mm;
• second – 80 mm;
• third – 20 mm;

In the first section, the polyvinyl chloride coating is manually separated from the backing.

Elemental samples are fixed in the clamps of the breaking machine: the backing is fixed in the upper clamp, the coating – in the lower clamp.

The stratification is carried out until the end of the second section. At least 10 values of load are determined on a scale of loads during the test.

The load scale indexes are removed every 10 mm of the elongation scale after the stratification process was stabilized.

is determined on three elemental samples 95±1 x 20±1 mm in size, cut in the longitudinal direction.

Stiffness

A device type ПЖУ-12М is used for testing. Metal balls weighing 0.88 g are used for loading the elemental samples. Distance of falling balls is 26±1 mm

The stiffness, cN, is calculated by multiplying the number of dropped balls by the mass of one ball (0.88 g). The result is rounded to the tenth. The result of the test is the arithmetic mean of the test results of elementary samples.

of vinyl artificial leather is determined by visual assessment of the degree of color change of the elemental sample after light-thermal aging on a 5-point gray scale.

Light resistance

Two elementary samples with a rectangular side not less than 30 mm in size are cut out for the test; one of the samples – the control one – is stored in a sun-protected place, and the other is tested.

Mercury-quartz irradiator DRT-230 and thermometer are used for the test.

Elemental samples are irradiated at 70±3 °C under a mercury-quartz irradiator for 8 hrs.

2.8.4. Light resistance is assessed visually by comparing the contrast between the control sample and the sample tested on a gray scale.

is determined on three elemental samples 200±1 x 200±1 mm in size.

Resistance to petroleum products, oils

The cut samples are folded in the form of an “envelope” with face side inside and hanged on hooks. 2±0.2 cm3 of gasoline or oil with a measuring pipette is dropped and the sample is left under a layer of petroleum at a temperature of 20±1 °C for 24 hours. After that, gasoline or oil is removed with the filter paper and the presence or absence of stains on the back of the sample is visually assessed.

An elemental sample is considered to have passed the test if no gas or oil leakage spots appear on the reverse side.

is determined on two elementary samples 180 x 80 mm in size, cut in longitudinal and transverse directions.

Resistance of front coating to dry and wet friction

When tested for dry friction, the elemental sample is placed on the base of the test device and fixed there. The friction core of the device is tightened with an adjacent fabric 50 x 50 mm in size. The friction surface should be smooth and without folds.

Tests for wet friction are carried out as a test for dry friction, but the adjacent fabric is placed in distilled water for at least 5 minutes before testing. It is then pressed so that the moisture content of it is approximately equal to the weight of the adjacent fabric. The elemental sample must be dry. After the test, the adjacent fabric is dried.

is determined by the method of determining the resistance to destruction of vinyl artificial leather when squeezing and flexing samples in the form of a rhombus.

Vinyl artificial leather is considered to have passed the test when no specimen has micro cracks, cracks of face side, flaking, swelling or complete fracture.

Multiple flexing resistance

We have a certificate of compliance of the measurement system with the requirements of DSTU ISO 10012:2005. This allows us to be confident in our quality of work, and you can be assured of the product compliance.

Quality Assurance