Chapas y tablero contrachapado (I parte)
The Evolution and Process of Wood Veneer Production
Historical Context of Wood Veneer
- The technology for obtaining wood veneer is ancient, with origins traced back to Egyptian times around 100 BC.
- Over centuries, the technique evolved significantly, leading to industrial production in the early 20th century in the United States.
- In 1930, Portland Manufacturing Company pioneered advanced technology using phenolic adhesives, reducing reliance on solid wood.
Preparation and Storage of Wood
- Mature trees from plantations are harvested after approximately 20 years and transported to factories for processing.
- In Spain, wood is typically stored in dry patios rather than water pools; stacks can reach heights of up to 6 meters.
- To prevent biological damage during storage, fungicidal sprays are often used.
Processing Techniques
- Logs are prepared by removing irregularities and cutting them to appropriate lengths before further processing.
- Logs undergo steaming or boiling to soften the wood for easier cutting; this treatment can enhance yield by up to 20%.
- Treatment duration varies based on wood species; excessive treatment can make wood difficult to work with.
Cutting and Drying Process
- After steaming, logs are positioned for precise cutting against a blade that determines veneer thickness.
- Obtained veneers are dried in hot air at temperatures between 120°C and 170°C until moisture content reaches about 6%.
Finalizing Veneer Quality
- Dried veneers are bundled in order of cutting to maintain grain continuity for later use.
- High-quality veneers are used for fine cabinetry; they undergo gluing processes with fast-setting adhesives before being finished through trimming and sanding.
Alternative Production Method: Rotary Cutting
- An alternative method involves rotary cutting where logs are centered using laser technology for maximum efficiency.
The Process of Wood Unrolling and Cylinder Formation
Overview of the Unrolling Process
- The unrolling process occurs at speeds around 120 meters per minute, resulting in a seemingly simple appearance but involves complex technology.
- At the end of this process, a perfect wooden cylinder is produced, referred to as "curro" or "bolo," which can be utilized in various wood industries depending on the type of wood.
Mechanisms Involved
- The operation employs a combination of a cutting blade and a pressure bar; the blade cuts while the pressure bar compresses the wood ahead of it during unrolling.
- Machine stability is crucial for producing high-quality veneer; significant forces generated during this operation necessitate great rigidity and inertia to prevent harmful vibrations.
Post-Unrolling Processing