Regardless of which analysis must be done, a careful and representative sample preparation is the first step to an unfailing measuring result
The directives 2003/108/EC (WEEE) and 2002/95/EC (RoHS) of the European Union regulate the collection of electronic components by the manufacturer and limit the use of problematic substances such as chromium or mercury in the manufacture of electrical and electronic products.
Compliance with these directives must be verified through appropriate analysis.
Regardless of which analysis must be done, a careful and representative sample preparation is the first step to an unfailing measuring result.
Therefore IEC TC 111 Working Group 3 has published procedures for tests within the framework of RoHS implementation.
According to the 'procedures for the determination of levels of six regulated substances (lead, mercury, hexavalent chromium, polybrominated biphenyls, polybrominated biphenyl ether) in electrotechnical products, chapter 5.4 apparatus / equipment', the use of the following Fritsch mills is recommended:.
a) Coarse grinding or cutting mill with 4 and 1mm or similar stainless steel bottom sieve.
Depending on the application, the cutting mill Pulverisette 15, the universal cutting mill Pulverisette 19 or the power cutting mill Pulverisette 25 should be used.
The procedures permit the use of stainless steel sieves and blades.
However, all cutting mills are also now available with tooled steel chromium-free tools.
The expression 'heavy-metal-free', which is often used here, is incorrect, because such steels do not exist; however, 'chromium-free' is completely satisfactory for this application.
b) Centrifugal mill with 250um tungsten carbide (WC) coated steel sieve, WC-coated rotor, (for uniform plastic material a 1mm steel sieve is appropriate).
In order to avoid any risks of impurities during milling a 1mm Titan variable-speed rotor mill Pulverisette 14 with standard rotor and sieve ring made of stainless steel or TiN-coated rotors and sieves should be used.
c) Freezer bladeless cryogenic impact grinder / mill with self-contained liquid nitrogen tub, insulated case, speed control, programmable timer, and safety interlock.
Many samples like for example: PCB, IC-Chips, LCD glass, electronic parts and plastics are milled with liquid nitrogen in freezing condition by embrittlement.
The vibratory micro mill Pulverisette 0 with Cryo-Box meets exactly these requirements.
Samples, which are brittle enough already by room temperature, like for example glass, electronic chip etc can already been ground without cooling with the vibratory micro mill Pulverisette 0.
Various materials of mortar and ball (WC, ZrO2, Agate, Al2O3, etc) enable milling without contamination of heavy metal, involved in RoHS directives.
The shape of the bowl makes cleaning easy.
Conclusion: The implementation of the above-mentioned EU directives will make the preparation of electrical and electronic scrap necessary in many laboratories.
With the mills described above and the worldwide experience of Fritsch in this field also your sample will be perfectly prepared for the subsequent analysis, says the company.
