Testing of material properties

Testing of mechanical strength

The tests of mechanical strength characteristics, such as: tension, bending, compression, inter-layer shearing and de-lamination are made on the INSTRON 4465 and on  FPZ-100/1 strength-testing machines.

The INSTRON 4465 machine with the maximum tensile and compressive forces applied of 5 kN, is equipped with:

• thermal chamber with temperature range from 0°C to 350°C
• extensometer with a base of 50 mm, allowing accurate measurement of strain and determining of elasticity moduli, and  testing of creep processes, stress relaxation at constant and cyclically variable load
• BLUEHILL modern software being  used to record and process the results of tests.

The strength-testing machine FPZ-100/1 with extensometers with a magnification of 10 to 2000 times, and the range of the measured tensile and compressive forces from 1 N to 100 kN also allows to study of rigidity and of peripheral elasticity.

Friction factor

The apparatus used for measurement of the coefficient of friction allows to measure, in quick and easy way, the coefficient of friction between two surfaces with simultaneous registration of its value in the form of a graph. There s a  possibility to measure the coefficient of static and kinetic friction.

• Range  of measurement the coefficient of friction 0,10÷1,00
• Accuracy of measurement 0,02

Resistance to abrasion

Tests are carried out in the APGi- type apparatus for determining the abrasion resistance by using the Schopper’s method. The device is used for the determination of abrasion resistance with the use of rotating drum with abrasive paper.

Tests are carried out according to standard PN-ISO 4649:

• by using the method of non-rotating sample 
• by using the method of rotating sample 

Melt Flow Index MFI

To detrrmine the melt flow rate of thermoplastics, the Department applies the device of the Hammel Maskin Fabrik company – weight plastometer, type MFI CFR-91.

The plastometer is characterized by the following parameters:

• maximum temperature 330 ⁰C
• maximum load 21,6 kg
• standard die 2,095 x 8 mm

Oxygene index

The test is carried out according to PN-EN ISO 4589-2 standard. The method is designed to test a variety of materials, solid and porous retaining stiffness in the vertical position, as well as flexible plates and foils supported in the vertical position.

The oxygene index is a measure of relative combustibility of materials and remains one of the most important tools of supervision and quality control in the plastics industry. The higher is the value of oxygene index, the harder the material ignites. In the electrotechnical industry, the value of fire resistance  of 27%[V/V] is assumed to be a criterion.

Testing the combustibility of plastics in accordancw with UL 94

This device allows to perform the combustibility tests of polymer materials combustibility, according to  UL 94 standard

Some methods are equivalent to the standardized methods for combustibility testing, published in the Polish, European or international standards.

• Horizontal Burning Test; HB; (PN-EN 60695-11-10 method A) – test of burning of horizontally situated samples
• 50 W Vertical Burning Test; V-0, V-1, V-2; (PN-EN 60695-11-10  method B) - test of burning of vertically situated samples
• 500 W Vertical Burning Test; 5VA, 5VB; PN-EN 60695-11-20 
• Thin Material Vertical Burning Test; VTM-0, VTM-1, VTM-2; (PN-EN ISO 9773)  - test of plastics combustibility (thin foils and fabrics), which are shrinking in the flame.
• Horizontal Burning Foamed Material Test; HBF, HB-1, HB-2; (ISO 9772; there is no Polish equivalent for this method) – testing the combustibility of  the light foams .

The tests conducted in the UL94 chamber are aimed at determining the so- called class (category) of combustbility of materials on the basis of criteria included in the UL 94 standard, and in the rest of standards. 

Thermal analysis

The tests on thermal properties of materials are carried out by thermogravimetry and differential scanning calorimetry, on the stand equipped with the thermogravimeter and scanning calorimeter of the Mettler-Toledo company.

The stand makes it possible to perform thermal analysis, TG and DSC, in a wide range of temperatures (even negative) in the different temperature programs, and many gas media.  The thermogravimeter is coupled with an infrared spectrometer FTIR of the THERMO company, which enables simultaneous TGA tests and analysis of gas decomposition products. The apparatus works with a PC allowing the registration and processing of acquired data.

Tests on polymers

The tests on polymers are performed by using an optical microscope and infrared spectrometer coupled with an infrared microscope.

The optical microscope of Carl-Zeiss Jena with the following parameters:

• magnification up to 1000 x
• backlight upper, lower and mixed
• interchangeable magnifying eyepieces
• attachment Olympus for geometrical measurements with an accuracy of 0.02 mm
• attachment to carry out photographic documentation
• xenon or halogen lights

Cone calorimeter

Testing performed using the cone calorimeter allow to determine most combustibility parameters: ignitability, rate and intensity of burning and smoke production, as well as amount and composition of toxic gases. The tests may be conducted under different conditions of exposure, with intensities of heat radiation in the range from 0 kW/m² to 100 kW/m². The cone calorimeter allows to perform tests according to ISO 5660. The most important parameters determined during a single test in the cone calorimeter are as follows:

•  time of ignition
•  average and maximum rate of  heat emission and  the total amount emitted heat and smoke, the effective heat of combustion
• loss and speed of  mass loss

The cone Calorimeter is an excellent tool, especially in testing of materials, which are subject to modification of flammable properties.

Spectrometric tests

The Fourier’s infrared spectrometer Nicolet 380 FTIR (measuring range7500÷370 cm^-1) equipped with  an infrared microscope IR Centaurus (range4000÷740 cm^-1). Supplementary equipment is a photoacoustic, reflection attachment and ATR attachment.

The infrared spectrometer is applied for:

• identification of various chemical compounds with the particular emphasis on polymer materials (waste materials, mixtures, composites):
  • a comparison of spectrum analyzed with computer spectral libraries
  • identification of functional groups, needed to determine the compound structure

• quantitative and qualitative analysis of gases emitted during combustion of polymer materials and plastics in the thermal analysis (TGA attachment TGA / IR)
• monitoring the process of polymeric material aging under UV radiation, temperature ( destruction of the bonds and the formation of new bonds of a different nature)
• structure determination and the studies of conformance changes of molecular systems
• research on  the impact of intra- and intermolecular influence in oscillation spectra