Our Treatment Process

This section presents the description of the processes involved in the company’s operation. Each process in the production line has been designed to ensure that high quality standards are maintained. The stages involved are described below.

The first stage of the production process is the reception, debarking and storage of raw poles. Debarked poles are stacked for air-drying to reduce appreciably the level of moisture content. The poles are then given prophylactic treatment to prevent insect attacks whiles undergoing air-drying.

The company has a kiln capacity of 5 * 150cbm which is used for drying and sterilisation of raw poles. The Kiln is powered by a 6T Hot Water Boiler. By Kiln drying, poles are fully sterilised and moisture content reduced to the required level for treatment. The Kiln drying and sterilisation enhances fixation of CCA chemical into the pole cell. This Kiln drying process by Asuboa Wood Treatment is vital for achieving effective preservation of the poles.

After kiln drying, poles are spread on skids. The inner barks and other debris on the poles are removed. Poles are then branded using codes that indicates the buyer, the producer, the location of the treatment plant, month and year of treatment, the species, the kind of preservative and length and class of poles.

The poles are cut to length and holes drilled to allow fixing of bolts, insulators and other attachments in accordance with the buyer’s specifications. All drillings and framings are made before the poles are treated. This is to ensure that the exposed surfaces receive the correct preservative treatment. Prior to treatment, all the poles are offered for inspection. All poles which do not conform to the buyer’s specifications are rejected.

Asuboa Wood Treatment employs the “FULL CELL” process for the treatment of all utility poles. In the “FULL CELL” process, the wood cell cavities are filled with the preservative (CCA Solution). The objective here is to obtain maximum preservative absorption and retention. Poles are loaded onto trams and pushed inside the Pressure Cylinder which measures 2.7m diameter and 21m long. The cylinder is tightly closed and a vacuum applied to remove air trapped in the cylinder and the wood cell cavities. Without releasing the vacuum, the cylinder is flooded with CCA solution. Pressure is then applied to force the CCA solution into the poles. 

Asuboa Wood Treatment is well equipped with a Quality Control Laboratory which forms an integral part of the production process. Before the treatment process begins, the CCA preservative solution is analysed for purity and concentration. After the treatment process, corings are taken from each charge and measured for the depth of penetration and tested for retention with an X-ray Analyser. After each charge of treatment, the strength of the CCA preservative solution is tested and improved where necessary.