Written by: Bob Lang, Solution Specialist at Billco Manufacturing Inc.
There are many variables that effect glass cleaning such as water quality, maintenance, glass types, plant environment, and upstream processes for example. Therefore, it is important to remember that achieving clean glass can be a moving target from day to day, and plant to plant. The goal is to use as many good practices as possible to achieve consistently clean glass.
1.0 WHAT IS NEEDED FOR OPTIMUM GLASS WASHER PERFORMANCE?
Assuming you have a well designed and constructed glass washing machine, there are four main items that you must provide to achieve consistently clean glass from the machine.
- Heated wash water and detergent
- Good quality rinse water
- A good maintenance program
- Roll covering and brush bristles in good condition
2.0 HEATED WASH WATER AND THE USE OF DETERGENT
The wash section of the machine is understandably a very critical step in the glass cleaning process. When the glass passes from this section, it must be free of all debris and dirt. The only thing that should be on the glass as it passes from this section is trace amounts of detergent and wash water solution that can easily be removed in the rinse sections.
The critical components of the wash section are one or two pairs of brushes, as well as water, detergent and heat.
THERE ARE SEVERAL REQUIREMENTS FOR A GLASS WASHER DETERGENT
- It must be non-foaming and easily rinsed.
- It must be effective in removing cutting oil and Lucite-type packing materials.
- It must not attack or deteriorate the glass, or the metal, rubber, and nylon components of the glass washer. It must also be compatible with any coatings on the glass.
We recommend a liquid or powder type detergent, which is very mildly acidic and non-foaming. You should always consult with your coated glass supplier for their recommendations as well. Depending upon the type of glass and coatings you are cleaning, temperatures of the wash water should be in the 110º F to 140º F range.
Some companies do not use detergent in their washers. If you are achieving clean glass without detergent, that is fine. However, it is our opinion that the use of a heated detergent is the only method to guarantee complete removal of oils from the glass.
3.0 GOOD QUALITY RINSE WATER
After the glass passes through the heated wash section, it will progress into the rinse sections of the washer. As mentioned previously, when the glass enters the rinse sections, it will still have trace amounts of wash solution on it. The first pair of rinse brushes should remove this wash solution. The glass is then rinsed with a final pair of brushes and conveyed to the drying section.
The water that is used in the final rinse must be as clean as possible. Anything that is in the rinse water could contaminate the final product. Contaminates such as minerals could be dried on the glass resulting in visually dirty glass and more importantly cause adhesion problems for any downstream processes.