Process for Removal of Films and Coatings
Publication Date: 2003-Oct-18
The IP.com Prior Art Database
A process utilizing heated fluid under moderate pressure has been used to remove polymeric films and coatings from surfaces.
A process utilizing fluid under moderate pressure has been used to remove polymeric films and coatings from surfaces. It uses heat and force to peel the material from the surface. Hot water (the closer to 100°C the better), under pressure, is sprayed against such materials to peel them from substrate surfaces. The water temperature reduces the modulus and adhesion of the material. Water temperatures of about 60°C or greater are preferred. Water temperatures of about 90°C or greater are most preferred.
A small fitting was created to control the temperature, pressure, volume and angle of the spray between the nozzle and the substrate to provide sufficient impact pressure to remove the tape or coating, restrict the proximity of the nozzle from the substrate to avoid damaging the substrate from excessive pressure, and provide splash-back protection for the user. This process works well on materials that are softened by moderate heat or removable by peeling such as tapes, films, paints, sealants and lubricants. It also works to remove foreign materials such as gum, tar or similarly unwanted materials from permanent surfaces.
Tapes or coatings can be removed with systems having any number of combinations of pressure, flow, distance, spray angle, and spray configurations yielding 22 to 40 pounds per square inch (psi) impact pressures at elevated temperature. Off-the-shelf inexpensive sprayers which generated 1500 to 5000 psi internal pressures were used to provide 22 to 40 psi impact pressures at the surface of the coatings. For example, industrial sprayers configured to 3000 psi, 3.5 gallons per minute, 85-100°C water temperature, and a 25° nozzle angle operated particularly well at separation distances of about 2.6 to 5 inches. This yielded impact pressures of about 22 to 40 psi. At distances of 2.5 inches or less the impact pressure increases rap...