Cleanliness Control
01 September 2016

Cleanliness Control

As with cleanroom operations, cleanliness is a four-part equation: environment, process, tools, and people. How stringent clean manufacturing guidelines need to be is based on the products and customer requirements.

Controlling air temperature and humidity levels in all work areas is a good first step in clean manufacturing. It may eliminate the need to open windows, which would admit outdoor airborne dirt.

Training staff on preventive maintenance procedures and determining wardrobe guidelines are the next steps in cleanliness control. All operators should understand their individual role in maintaining a clean facility, know what they can and cannot wear on the production floor, and know how their individual work areas should be maintained.

For greater cleanliness control, manufacturing facilities can be segmented into "dirty" and "clean" work areas. The "dirty" work areas, such as toolroom operations, should be placed far away from cleaner, product-assembly sites. Stringent manufacturing areas should be in the middle of the building-the easiest space to keep clean.

In very stringent clean manufacturing sites, production materials are stored in central material handling facilities and conveyed to assembly rooms as needed, via a closed-loop system. This approach eliminates dirty boxes and containers from the production floor. Equipment that produces heavy exhaust should be fitted with pressure-controlled exhaust systems to remove exhaust from the production area.

Equally important as maintaining equipment is determining how any new process, lubricant, or procedure will affect the cleanliness of the finished product.

Use of spray lubricants, for example, which produce airborne particulates, may need to be eliminated. Consider using a lubricant only if its residue can be easily removed from the product with isopropyl alcohol. Silicon-based lubricants may require cleanup with hexane or benzene. In cases where extreme cleanliness is needed, use of such a lubricant should be considered only if it does not come into contact with the product. Avoid over-lubrication, since using extra oil on equipment will only increase the likelihood of contaminating supposedly clean products.

Both cleanrooms and clean manufacturing require a solid commitment from all staff. The benefits include cleaner products and manufacturing facilities, potential new markets for products, and the opportunity to present the production facility as a selling point to customers.