This page shows (part of) the analysis equipment and techniques available at PTG/e including a brief description of the equipment or technique.
Compounder (twin screw)
A compounder can be used to mix additives into a thermoplastic material or even to perform reactive extrusion.
The equipment used is a ThermoElectron Rheomex OS – PTW 16 twin-screw compounder with a range of heads, such as monofilament, tape (2 cm) and film (10 cm). The screw diameter is 16 mm, the screw structure and L/D ratio are variable (25 or 40) with a maximum temperature of 400 °C.
Once a good recipe has been developed, a sample batch can be compounded at kilogram scale, which can subsequently be broken down into granulate by means of the pelletiser. At the customer’s facility, this granulate can be tested for its suitability for a specific application.
Differential Scanning Calorimetry (DSC)
DSC is used to examine the thermal transitions in a polymeric material (e.g. melting point, Tg and crystallization).
Measurements are carried out with a TA Instruments Q2000, which has a temperature range of -80 to 300 °C. A material sample of as little as 3 mg is sufficient for a measurement.
The results of a DSC measurement can for example be used to determine if a material melts and if so, when. It can also be used to distinguish between a homopolymer, a copolymer and a blend.
Dynamic Mechanical Thermal Analysis (DMTA)
DMTA is a technique used to analyse the viscoelastic behaviour of a material as a function of temperature or frequency. This provides information on the stiffness of the material.
Measurements are carried out with a TA Instruments Q800 DMTA, with a temperature range of -100 to 300 °C. Clamps are available for measuring films (up to 2 mm thick) and a sample specimen (up to 4 mm thick); dual/single cantilever and 3-point bend clamps).
The DMTA measurement results are used for determining the glass transition temperature (Tg). A DMTA diagram shows the modulus of elasticity (E-modulus) as a function of temperature. The E-modulus is a measure of stiffness of a material.
A drawing line is used for stretching films and fibres in one direction. This results in improved mechanical properties of the material in that direction.
The equipment used is a Retech customized drawing line, comprising a draw unit with 5 godet rolls, 3 draw units with 3 godet rolls and 2 convention ovens. The drawing speed can be adjusted per unit. All the rolls and ovens are induction-heated and all temperatures can be regulated separately.
After stretching, the monofilaments or tapes are wound around a cardboard tube for being used at the customer’s facilities.
Gel Permeation Chromatography/Size Exclusion Chromatography (GPC/SEC)
GPC or SEC is used to determine the average molecular weight (Mn and Mw) and the polydispersity index (Mw/Mn) of a polymer material.
Measurements are performed at room temperature using SEC Waters 2695 instruments with various detectors (refractive index, UV-VIS). Various organic solvents may be used as eluent (tetrahydrofuran (THF), N,N-dimethylacetamide (DMA) and hexafluoroisopropanol (HFIP)). A material sample of only 2 mg is sufficient for a measurement.
The average molecular weight and the molecular weight distribution of a polymeric material have a strong influence on the material properties (physical, mechanical and processing properties). The results of a SEC measurement can therefore be useful in explaining certain physical or mechanical properties of a material specimen. Complementary to NMR and Infrared spectroscopy, SEC analysis is an excellent technique for comparing different material batches.