Tree Conversion
Tree Conversion <ul><li>Trees are cut down during winter as there is less growth, therefore less sap </li></ul><ul><li>Aft...
Through and Through Sawing <ul><li>This is one of the most popular methods of sawing. The log is cut in parallel cuts in t...
<ul><li>Advantages </li></ul><ul><ul><li>Low cost and fast </li></ul></ul><ul><ul><li>Maximum width of planks obtained fro...
Tangential Sawing <ul><li>The cut is made at a tangent to the annual rings of the log.  </li></ul><ul><li>Log must be turn...
<ul><li>Advantages </li></ul><ul><ul><li>Produce board with flame figure </li></ul></ul><ul><ul><li>Tangential boards are ...
Quarter Sawing <ul><li>This method leaves the annual rings of the converted timber meeting the face of the board at 45 º o...
<ul><li>Advantages   </li></ul><ul><ul><li>An attractive grain pattern is produced </li></ul></ul><ul><ul><li>Boards are m...
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4. tree conversion

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4. tree conversion

  1. 1. Tree Conversion
  2. 2. Tree Conversion <ul><li>Trees are cut down during winter as there is less growth, therefore less sap </li></ul><ul><li>After felling trees are transported to sawmills to be cut into boards </li></ul><ul><li>This process of converting logs to boards is known as conversion </li></ul><ul><li>There is 3 methods of conversion </li></ul><ul><ul><li>Through and through sawing </li></ul></ul><ul><ul><li>Tangential sawing </li></ul></ul><ul><ul><li>Quarter sawing </li></ul></ul>
  3. 3. Through and Through Sawing <ul><li>This is one of the most popular methods of sawing. The log is cut in parallel cuts in the direction of the grain. </li></ul>
  4. 4. <ul><li>Advantages </li></ul><ul><ul><li>Low cost and fast </li></ul></ul><ul><ul><li>Maximum width of planks obtained from log. </li></ul></ul><ul><ul><li>Little wastage. </li></ul></ul><ul><ul><li>Reveals attractive grain pattern, especially in softwoods. </li></ul></ul><ul><li>Disadvantages </li></ul><ul><ul><li>Not suitable for structural timber </li></ul></ul><ul><ul><li>With this method cupping caused by tangential shrinkage is a problem (cupping is the warping of the plank away from the heart of the tree) </li></ul></ul>
  5. 5. Tangential Sawing <ul><li>The cut is made at a tangent to the annual rings of the log. </li></ul><ul><li>Log must be turned 90º after each cut. </li></ul><ul><li>Timber will display a flame figure </li></ul>
  6. 6. <ul><li>Advantages </li></ul><ul><ul><li>Produce board with flame figure </li></ul></ul><ul><ul><li>Tangential boards are strong boards, used for beams and joists </li></ul></ul><ul><ul><li>Heartwood and sapwood are easily separated </li></ul></ul><ul><ul><li>These boards can take a nail without splitting because of the position of their annual rings </li></ul></ul><ul><li>Disadvantages </li></ul><ul><ul><li>Prone to shrinkage (Cupping) </li></ul></ul><ul><ul><li>It is expensive as the log is turned 90 º for each cut </li></ul></ul>
  7. 7. Quarter Sawing <ul><li>This method leaves the annual rings of the converted timber meeting the face of the board at 45 º or more. </li></ul><ul><li>It is important to note that the log must be rotated each time a cut is taken. </li></ul><ul><li>This method can bring the best features in wood as it produces silver grain which has clearly defined medullary rays </li></ul>
  8. 8. <ul><li>Advantages </li></ul><ul><ul><li>An attractive grain pattern is produced </li></ul></ul><ul><ul><li>Boards are more stable and shrink less </li></ul></ul><ul><ul><li>Boards wear more evenly,important for flooring </li></ul></ul><ul><li>Disadvantage </li></ul><ul><ul><li>Expensive, as the log has to be first quartered then turned for every cut. </li></ul></ul><ul><ul><li>Because the log is quartered then cut again narrower boards are produced </li></ul></ul>
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