In 1993, the project entitled "Spray Application Technology" was initiated to improve anti-sapstain spray treatment of lumber by British Columbia sawmills. This project has now been completed with the following milestones accomplished: 1) A better understanding of the spray application process was developed through an investigation of liquid atomization and spray transfer to lumber surfaces. 2) Methods were developed for simulating commercial spray systems using pilot plant facilities at Forintek. 3) Improved longitudinal and cross-chain spray systems were developed at Forintek and their capability to evenly apply spray to lumber at target retentions was demonstrated. 4) Spray technology was transferred to a sawmill which involved installing nozzle configurations developed at Forintek into a new cross-chain spray system at a coastal sawmill. Treated lumber was sampled and the results confirmed original performance expectations. During this project we found that simple changes to existing commercial spray systems, involving the set-up and operation of hydraulic nozzles, are sufficient to significantly improve their performance. Guidelines for improving spray system performance are documented in this report in addition to a detailed explanation of the spray application process.
Spraying
Preservatives - Tests
Preservation - Non pressure processes - Brushing and spraying