Testing of engineering plastics

Differential Scanning Calorimetry (DSC) is used to determine transition temperatures and enthalpy changes of solid and liquid samples under controlled temperature changes. The analysis can be used to determine the melting, crystallization, and glass transition temperatures and their enthalpies, the material's amorphic and crystalline behavior, hardening and specific heat, material compatibility, and the effect of additives. The temperature range for the measurement is -170 °C to 600 °C, available atmospheres are N₂ and O₂. Please disclose the desired temperature program upon ordering: heating rate(s) (K/min), isotherms, and temperature ranges (min/max). If you have any doubts about these parameters, we are more than happy to help.

In TGA, the sample is heated at a controlled rate or kept at a controlled temperature while its mass is weighed with an extremely precise scale. The analysis provides information about phase transitions, absorption, adsorption, desorption, chemisorption, thermal decomposition, and solid-gas reactions. It can also be used as a characterization and compositional analysis method. As a result of the measurement, you will get the change in mass as a function of temperature and time. A simultaneous thermal analysis (TGA + DSC) can be performed upon request. The type of heating cycle can be tailored to your sample (temperature ranges from 25 °C to 1100 °C), with various options for the surrounding gas atmosphere (air, O₂, and N₂). Please disclose the aim of the measurement and the desired temperature program and atmosphere(s) upon ordering.

Measurement of thermal conductivity and thermal diffusivity of plastic materials according to the ISO 22007-2 standard. Specific heat capacity per unit volume can be determined simultaneously for an extra charge. The method is suitable for materials with thermal conductivity from 0.01 to 500 W/mK and thermal diffusivity from 5×10−7 to 1×10−4 m2s−1. Thermal conductivity can be measured in a specific direction, for example, in-plane (x,y) or thickness direction (z). Testing can be performed at room temperature or in a climate chamber (temperatures from -40 °C to 300°C). Additional preparation cost applies to climate chamber testing. Please specify the desired testing procedure when requesting an offer.

The oxidation induction time (OIT) is a measure of a material's resistance to thermo-oxidative degradation. OIT testing is performed according to the ISO 11357-1 standard using a differential scanning calorimeter (DSC). In the test, the sample is heated under a nitrogen atmosphere to the desired temperature, typically 100 °C to 200 °C. Oxygen is then introduced while the temperature is kept constant isothermally. The time until the material begins to degrade is recorded, and this is called the oxidation induction time. Testing is often used to assess the performance of antioxidants added to polymeric materials.

ISO 5659-2 outlines the procedure for measuring the optical density of smoke produced by a material placed in a closed test cabinet and exposed to thermal radiation. The standard was originally developed for plastics, but it can be applied to a range of other products and materials. In the test, representative specimens of the material are mounted horizontally in a test chamber, and their upper surface is exposed to a specified level of thermal irradiance (usually 25 kW/m2 or 50 kW/m2), with or without a pilot flame. The resulting smoke is collected, and its optical density is measured using a photometric method. Some of the key parameters measured include the maximum specific optical density (Ds,max), the specific optical densities at specified times (Ds(1,5), Ds(4), Ds(10)), and the cumulative specific optical densities during the first 4 minutes of the test (VOF4). A toxicity measurement can also be included to measure toxic gas emissions. Its results are reported as the conventional index of toxicity (CITG). The ISO 5659-2 smoke production test is often required as part of the EN 45545-2 fire safety evaluation of railway materials.

Smoke and toxicity testing by IMO 2010 FTP Code Part 2 is performed on surface materials to assess their suitability for marine use. The specimen is placed in a horizontal position under a cone radiator inside a smoke-density chamber. During the test, the specimen starts to emit smoke, which is collected in the closed chamber. The density of smoke is detected optically. When making toxicity measurements with FTIR, the concentrations of carbon monoxide (CO), hydrogen chloride (HCl), hydrogen bromide (HBr), hydrogen fluoride (HF), hydrogen cyanide (HCN), nitrogen oxides NO_x (NO + NO₂), and sulfur dioxide (SO₂) are measured. Classification criteria for smoke An average (D_m) of the maximum of D_s of three tests at each test condition should be within the following limits: D_m 200 for materials used as the surface of bulkheads, linings, or ceilings, D_m 400 for materials used as a primary deck covering, D_m 500 for materials used as a floor covering , D_m 400 for plastic pipes and electric cables. Classification criteria for toxicity The gas concentrations measured at each test condition should be within the following limits: CO 1450 ppm, HCl 600 ppm, HBr 600 ppm, HF 600 ppm, HCN 140 ppm , NO_x 350 ppm , SO₂ 120 ppm (200 ppm for flooring).

Fire testing according to EN ISO 9239-1 is used to evaluate the ability of flooring to withstand flames and radiant heat. Flame spread, smoke generation, and the lowest radiant heat to sustain burning are measured. The method is primarily used to classify floor coverings according to the European EN 13501-1 fire classification system. Depending on the results, floorings can be categorized as A2fl, Bfl, Cfl, or Dfl. A smoke production classification of s1 or s2 is also provided. Another use case is assessing the burning behavior of floor composites and interior horizontal surfaces used in rail vehicles according to the EN 45545-2 standard. The testing procedure is the following: 1) The test specimen is placed in a horizontal position below a gas-fired radiant panel inclined at 30°, where it is exposed to a defined heat flux. 2) A pilot flame is applied to the hotter end of the specimen. 3) Following ignition, any flame front that develops is noted, and a record is made of the progression of the flame front horizontally along the length of the specimen, measuring the time it takes for the fire to spread to defined distances. 4) Smoke production is recorded as light transmission in the exhaust stack. One specimen is tested in one direction (e.g. production direction) and another in the direction perpendicular to the first specimen. The test that yields the worst results is repeated twice in that direction.

This test measures the ignitability of building materials when exposed to a small flame. The main purpose of the test is to classify building products according to Euroclass B, Bfl, BL, C, Cfl, CL, D, Dfl, DL, E, Efl, or EL as per the European classification standard EN 13501-1. Measurlabs provides individual EN ISO 11925-2 testing as well as other certified tests for EN 13501-1 fire rating classification.