RoHS Complaint Industrial Control Switches

Posted by admin on July 18, 2010 under Industrial Mechanical | Be the First to Comment

The RoHS directive restricts the use of lead (Pb), mercury (Hg), hexavalent chromium (Cr-Hex), polybrominated biphenyls (PBB) and polybrominated diphenyl ethers (PBDEs) to a maximum of 1000 parts per million and the Cadmium 100 ppm. The restrictions are based on a homogeneous material, which means that they apply mechanically to a single substance, which (theoretically) could be separated.

Prohibited substances have traditionally been used extensively in farm and industrial control found, because they confer resistance, durability and reliability. These are important properties, such as switches often work under difficult conditions, such as in boilers, etc. They are supposed to have a long life and work accurately and reliably. These restrictions should therefore move the industry has been difficult.

While the industry has taken commendable steps to RoHS compliance, efforts have been neither easy nor entirely successful so far. This is not the sincere efforts that have attempted to divert attention. The main problem is the availability of RoHS compliant components and parts have been. The majority of currently available electronic components comprise at least one of the prohibited substances: pigments contain cadmium, mercury in infrared detectors, coatings PBB and PBDE in plastics used as flame retardants, lead in solders and inhibited contain Hex-Cr. (Chromium is passivated by oxygen, forms a thin protective oxide surface prevents oxidation of underlying metal. Oxidation states are six common i. e hexavalent chromium 3 (trivalent chromium i. e ).
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A number of products have been developed to replace the banned substances. However, the long-term reliability, an important parameter for the industry’s switch is not yet determined. Examples of such alternate Hex-Cr, save, trivalent chromium, molybdates, etc. This, however, specific substrate, in other words, they need a certain type of frames coating for grip and protection are applied are the hexagon – Cr did not need. This leads to additional costs, in addition to being less flexible operation. also developed lead-free solders tin-silver-copper were made to replace the traditional tin-copper. However, concerns of durability and reliability are not related. lead-free solders also require a higher reflow temperature. This often leads to costly changes and conversions.

RoHS compliance, is the least, say, a difficult task for any company. This change also applies to the industry. The difficulties to be mainly the requirement, the maximum permissible levels of banned substances in a homogeneous material. This requires the entire material flow from raw materials and components manufacturers in the last step forward. Also included in the standards of compliance are consumables such as labels, glues, paints, etc., which can sometimes introduce unwanted substances in the finished product.

A further complication for manufacturers of switching control many found the army and / or aerospace. No RoHS and space and products with applications that can be considered “Aerospace” should not be RoHS compliant. However, this presents more problems in the maintenance of inventory management and change RoHS compliant non-compliant products for the providers.

Although RoHS full employment is the ultimate goal of industrial control switches manufacturing, managing the transition is the greatest current challenge.