Developing an Evaluation Program for Lumber Drying Operations in Bolivia

The Bolivian forest products industry has experienced substantial growth during the last ten years. Exports of value-added products have largely replaced logs and green lumber, and raw materials for wood products have shifted to lesser used species. Important investment has taken place in lumber drying capacity, which unfortunately was not always accompanied by sound drying practices. Several non-governmental organizations, with U.S. financial aid, are currently supporting the industry with technical assistance. This project assists these efforts by assembling much needed information regarding lumber drying, and providing tools for performance measurement of drying practices.

A survey was conducted among Bolivian companies to determine lumber drying capacity, technology and practices. Results showed a total drying capacity of 6,104,250 board feet in 167 kilns. Technology and practices used are highly variable. Thirty six percent of kilns are home-made, and 59% are European commercial brands. Upon completion of the survey, a set of analytical tools was developed and tested in six Bolivian firms. These tools were designed to systematically evaluate lumber drying operations and formulate actions for improvement.

Equilibrium moisture content (EMC) during storage, manufacturing and shipping was monitored in plants located in three Bolivian cities and inside containerized shipments of wood products. Findings showed differences between EMC and lumber moisture content from -1% to 7%. Differences between EMC inside dry-lumber storage and processing facilities varied between 0% and 3.6% and were greatly influenced by facility configuration. Climate during shipment of wood products largely depended on packaging materials and methods, which attenuate sharp changes in ambient conditions. Monthly values for outdoor EMC for the main cities of Bolivia were calculated based on historic weather data and are reported.