Poison protection

Distributing contaminated food, knowingly or unknowingly, can spell disaster for manufacturers. In addition to the lost value of batches returned, a producers reputation could be irretrievably shattered with buyers moving acquisitions to other competitor sources. However, time and technology has moved on and it is now possible to use modern and competitively priced production equipment that can virtually eliminate contamination in processing. The food, beverage and pharmaceutical industries make special demands regarding hygiene and cleaning in production areas and, that is why machinery design looks to be crevice free to prevent dirt traps and are often manufactured from non-corrosive materials.

Major contamination source Contamination is a major issue in the food and dairy sectors, including the soft cheese industry. Here, manufacturers are confronted with clostridia (spindle shaped bacterial cells). Various strategies exist such as UHT heating, adding salts, pre-melting, or introducing repressive substances such as nisin. But if the raw products used to produce these cheeses are contaminated themselves, even these measures can prove ineffective. Such highly resilient bacteria can then easily accumulate in production equipment. However, traditional conveyor belt drives comprising of the classic geared motor, chain and pulley are still in widespread use in the food, beverage and pharmaceutical process and packaging industries, but they do pose a potential contamination risk to products transported by them. Where guarding and obstacles create limited access to standard geared motors on production lines cleaning cannot be thoroughly undertaken and as a result, it is not uncommon to see cooling ribs completely clogged with product residues or belt lubricants. Even the fan cowling attract process dust and needs frequent removal for effective cleaning. A recent report from Udo Eigenfeld, CEO of BDL Maschinenbau GmbH remarked that a food manufacturer recently became aware of this fact during a recall. Although chain motors are often placed under a protective guard and cover, fine dust particles can still accumulate on the chain. Unfortunately, most covers leave the undersides of the mechanisms exposed and are a far cry from complying with stringent protection standards such as IP65 or IP66. It was found that the source of contamination was actually the grease used to lubricate the chain. Although this substance is physiologically harmless, it can nevertheless accumulate dust. Dust containing protein is the basic foodstuff for germs, bacteria and salmonellae, which occasionally break free from the chain due to normal process vibration and can end up in food. Drum motor drives eliminate the risk of contamination since the entire drive mechanism is located in a sealed unit. The easy to access, space saving and compact drum motor drives, eliminate the risk of contamination, since the electric drive motor and integrated precision gearbox are all combined and enclosed in a crevice free, sealed rotating drum. With maintenance free bearings there is no need to lubricate the drive elements and the absence of chains and cooling fan, has also removed further possible sources for dirt, dust and germs to accumulate. The obvious consequence is that drum motor drives are thus able to comply with the highest standards of hygiene and eliminate the risk of food contamination due to dust accumulation. Drum motor drives offering IP66 protection classification can be cleaned using high pressure hosing without the need for subsequent lubrication or maintenance. This not only reduces the risk of contamination but also the total cost of ownership.

Study confirms problems A study conducted by the 'Frauenhofer Institute for Production Engineering and Automation' confirmed problems with levels of hygiene in food production. More than half (52%) of food manufacturers found hygiene to be inappropriate during production. The main cause for concern was traced back to conveyor belt drives. It was found that older external gearbox drive mechanisms in particular, often had areas that were hardly accessible and were thus difficult to clean. (A copy of the study can be obtained from the Frauenhofer IPA in Stuttgart, Germany. Source: open automation 2/2002, p. 54f) A further option provided in particular for the food, pharmaceutical and cleanroom industries is "burnt-in" identification plates on the end of drum motor covers. These new identification plates are formed by electrolysis. This procedure enriches carbon molecules near the surface of the stainless steel housing, causing a change in colour - similar to the process used on some knife blades. In comparison to the traditional method of attaching a separate stainless steel identification plate to the motor, this method provides considerable greater degree of hygiene. It's now impossible for capillaries to form behind the plate and avoids the plate being ripped off, as can be the case with adhesive identification plates. BDL Drum Motors located at Corby have undertaken various trials in conjunction with customers and OEM's to demonstrate energy saving claims of between 32% (loaded) and 47% (unloaded) in comparison to conventional geared motor drives; clean hygienic profile features of drums with quick changeover and no maintenance requirements; developing new drive solutions for new belting materials, etc. Working closely with industry, BDL have evolved the drum motor to be a serious contender to replace geared motor drives.