Kerafol useful information
Determination of electrical properties
The electrical insulation effect of the heat-conducting films is characterized by their dielectric strength. The higher the breakdown voltage, the better the insulation behaviour. Measurements are performed with an AC high-voltage detector.
Determination of mechanical properties
State-of-the-art equipment and measurement devices facilitate the batch-wise determination of tensile strength and elongation of the films . In addition to this, the peel strength of adhesive coated materials is determined on the basis of the "Final Test Method No.1“ (180°).
YOUNGS MODULUS studies
Kerafol analyses the behaviour of flexible films under pressure, using the method described in ASTM D 575-91, to determine the so-called YOUNGS MODULUS. The sample geometry of the individual film types is 30x30mm at 2.5 mm thickness, and pressure is applied with a constant traverse path of 1mm/min (0.04 in/min). The pressure dependence of the films is shown on the graphs.
Determination of flame class
The available KERATHERM® products have been certified and categorized into classes with regard to their inflammability by the American institute "Underwriters Laboratories Inc.“ (UL). In addition to this, the company KERAFOL® endeavours to test its products on the basis of the latest findings in research and development.
Further information regarding the UL identifiers of Kerafol® products is available on the UL website. Visit http//www.ul.com and select the category “Online Certifications Directory”. From there you can search for the Kerafol file under the following file number:
QMFZ2E140693: Plastics-Component. This category contains all Kerafol® products.
Tolerances
In terms of geometry, as well as position and shape of the parts or holes to be punched or relevant recesses and outlines, the tolerances are fixed at a minimum of 0.1 mm in accordance with DIN ISO 2768-m. Regarding the thickness, a deviation from the required dimension of +/- 10% of the total thickness is allowed .Dimensions are measured with a Quick-Scope (QSPAK 3.0) image processing measurement system, or using a dial gauge or measuring microscope. All tools and punching are qualified by means of the first piece inspection report.
Batchwise determination of thermal properties
An equi-area measurement sample (4 cm² base area) is placed between a heatable upper die and a cooled lower die. The lower die is pressed against the upper one by means of a pneumatic pressure cylinder. The pressure dependance of the thermal resistance of the samples is derived from the variation in contact pressure. After approx. 20 minutes, the resultant temperature gradient above the sample is determined via Pt-100 sensors. The thermal resistance (Rth) and the thermal conductivity (l ) are calculated on the basis of this temperature gradient, the heating power passed through the sample, and the sample geometry.