EXTERNAL INFLUENCES ON LIQUID VISCOSITY AND YOUR SPRAY SYSTEM

By Nathan Webb

How often does an operator come to you reporting solvent popping, poor material coverage or orange peeling on your company’s product? These are common problems and can lower production efficiencies, increasing rejects and reworked product on your production lines. One important factor to consider when troubleshooting your spray system is the changes in viscosity due to the varying temperatures of the material being applied.

Change in liquid viscosity primarily affects your spray patterns and the application capacities of the product. Many operators will combat this by changing air or fluid pressures on their spray equipment to get the desired results, but this can negatively impact your system’s efficiency. Liquids with a high viscosity require a higher minimum pressure to begin spray pattern formation, while lower viscosities require less. The result is inconsistent spray patterns and poor coverage of product.

There are several areas to consider when your viscosities are being influenced by outside elements:

  • Spray booth ventilation system function – Check for proper airflow through your spray booth. Verify all equipment and dampers are functioning properly. Is humidity a factor?
  • Temperature of the production area Do the occurrences appear on specific shifts only? Are seasonal changes influencing these areas on your line?
  • Distance from material reservoir to spray equipment Loss of heat during transfer is common and easily remedied. Relocation of reservoirs, in-line heaters or jacketed lines should be considered to maintain a consistent fluid temperature if pipe run is significant.
  • Proper storage and placement of product – The storage and staging of material before it’s used in production can adversely affect viscosity if the containers are not handled correctly. The average time required for a 55 gallon drum of material to return to ambient temperature is TWO days if not stored in an environmentally controlled area.

To assure consistent viscosity of the liquids, one consideration is to maintain a consistent temperature of the material. A KREMLIN AD60 heater is an excellent way to maintain a constant temperature in your fluid lines. By maintaining a lower viscosity, atomization pressures can be reduced, resulting in higher transfer efficiencies and a more consistent finish. For additional information, refer to the EXEL website http://www.kremlinrexson-sames.com/.

Is your plant experiencing spray pattern inconsistency or application inefficiency? The knowledgeable Sales Engineers at OTP Industrial Solutions can help you identify the right solution to drive efficiency into your finishing and fluid handling systems and protect the integrity of your end product.

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