Timber Technology And Utilization of Wood, Bamboo and Cane - Glossary of Terms

IS 707: Scope Summary

• Scope Exclusion: Botanical features and purely scientific terms are excluded.

• Reference Standard:

  IS No.	Title
  1708 (Parts 1 to 18) : 1986	Methods of testing small timber specimens (second revision)

• Key Definitions:

  • Forming (3.203): Refer to 3.202 (not detailed here).
  • Spread of Adhesive (3.430): Area covered by 0.5 kg of adhesive mix prepared as per manufacturer’s instructions.

Important Notes:

• The scope mainly covers testing and evaluation methods for timber specimens.
• Adhesive application is quantified by the spread area per 0.5 kg adhesive mix.
• Always refer to the latest edition of IS 1708 for updated testing procedures.

flowchart LR
    A[IS 707 Scope] --> B[Excludes Botanical Features]
    A --> C[References IS 1708 (Timber Testing)]
    A --> D[Defines Forming (3.203)]
    A --> E[Defines Spread of Adhesive (3.430)]

This concise scope ensures focus on timber testing and adhesive application standards under IS 707.

IS 707: General Terms Related to Timber

IS 707 primarily serves as a glossary of terms for timber technology and forest product utilization. It does not provide formulas or tables but defines key terminology essential for understanding timber standards.

Key Definitions (Example):

• Timber (Clause 3.473): Commercial wood, often in converted form.
• Other terms include seasoning, knots, grain, sapwood, heartwood, etc., which are critical for timber quality assessment.

Important Specifications (from typical timber standards):

• Moisture Content: Usually expressed as a percentage of dry weight.
• Density: Mass per unit volume, often in kg/m³.
• Modulus of Elasticity (E): Indicates stiffness, typically in N/mm².
• Allowable Stress: Varies by species and grade.

Common Timber Properties Table (Indicative):

flowchart LR
    A[Timber] --> B[Raw Wood]
    B --> C[Seasoned Timber]
    C --> D[Converted Timber (Planks, Beams)]
    D --> E[Structural Use]

For detailed formulas and tables on strength, seasoning, and grading, refer to IS 1708, IS 287, and IS 883. IS 707 is foundational for terminology only.

IS 707 - Key Terms & Specifications for Wood-Based Panels

Definitions (Clause 3.504)

Wood-based panels include:

• Plywood: Veneers bonded with organic binders under heat/pressure.
• Blockboard: Core of softwood strips sandwiched between veneers.
• Flush Door: Panels with a core (blockboard or particle board) faced with veneers.
• LVL (Laminated Veneer Lumber): Veneers bonded with adhesive under heat/pressure.
• Particle Board: Wood particles bonded with organic resin.
• Fibreboard: Wood fibers bonded either inherently or with binders.

Manufacturing

• Formed using heat and/or pressure.
• Materials: solid wood, veneers, strands, particles, or fibers.
• Bonding agents: organic binders or inherent bonding.

Reference Table for Testing (IS 1708)

Important Notes:

• Thickness and density vary by panel type.
• Bond strength, moisture content, and dimensional stability are key properties.
• Refer IS 1708 for detailed test methods.

flowchart LR
A[Wood-Based Panels] --> B[Plywood]
A --> C[Blockboard]
A --> D[Flush Door]
A --> E[LVL]
A --> F[Particle Board]
A --> G[Fibreboard]
B & C & D & E & F & G --> H[Manufactured with heat/pressure]
H --> I[Bonding agents: Organic binders or inherent]

For detailed mechanical properties and testing, refer to IS 1708 (Parts 1-18).

IS 707: Definitions Pertaining to Bamboo and Cane

IS 707 (2011) primarily serves as a glossary of terms related to timber, bamboo, and cane, focusing on anatomy and utilization. It does not provide design formulas but standardizes terminology essential for structural and utilization purposes.

Key Definitions (Summary)

• Bamboo: A woody grass with hollow cylindrical stems (culms), segmented by nodes.
• Culm: The main stem of bamboo, consisting of internodes (hollow sections) and nodes (solid joints).
• Rattan (Cane): Climbing palms with solid, flexible stems used in furniture and handicrafts.
• Internode: The hollow section between two nodes in bamboo.
• Node: The solid joint in bamboo providing strength and flexibility.
• Anatomy: Bamboo has vascular bundles embedded in a parenchymatous matrix, unlike wood which has growth rings.

Typical Properties (from general knowledge)

Visual: Bamboo Anatomy

graph LR
    A[Culm] --> B[Node]
    A --> C[Internode]
    C --> D[Hollow Section]
    B --> E[Solid Joint]

Note: For structural design, refer to IS 15978 (Bamboo Structures) for strength and design formulas. IS 707 is a terminology reference only.

IS 707 - Wood Pulp and Fiber Terminology: Key Points

• Pulp (Clause 3.363): Fibrous material from wood, lignocellulosic materials, or waste paper, processed mechanically or chemically for paper/paperboard manufacture. Includes knot, reject, and fluff pulp.

• Pulp from Non-Wood Fibers (Clause 3.363.7): Pulp (except dissolving grades) from non-wood fibrous lignocellulosic materials. Can be bleached or unbleached.

• Sulphate and Soda Pulp (Clause 3.363.4): Wood pulp from coniferous/non-coniferous wood chips cooked chemically:

  • Soda pulp: Sodium hydroxide cooking liquor.
  • Sulphate pulp (Kraft): Sodium hydroxide + sodium sulphide.
  • May be unbleached, partly bleached, or bleached.

• Dissolving Pulp (Clause 3.363.6.1): Special pulp from wood for chemical processing (e.g., viscose).

Typical Chemical Cooking Process Summary

Conceptual Flow of Pulp Production

flowchart LR
    Wood/WastePaper -->|Mechanical/Chemical| Pulp
    Pulp -->|Cooking with NaOH| SodaPulp
    Pulp -->|Cooking with NaOH + Na2S| SulphatePulp
    Pulp -->|Special Treatment| DissolvingPulp
    SodaPulp --> Bleaching{Bleached?}
    SulphatePulp --> Bleaching
    DissolvingPulp --> Bleaching

This summary aligns with IS 707 terminology and classification for wood pulp and fiber types.

IS 707: Machining and Cutting Terminology Key Points

• Cutting Speed (V):
  Speed at which timber is cut, usually in m/min or m/s.
  ( V = \pi \times D \times N / 1000 )
  where:

  • (D) = Diameter of cutter head (mm)
  • (N) = Cutter head speed (rpm)

• Cutter Head Speed (N):
  Revolutions per minute of the cutter head.

• Feed Rate (F):
  Rate at which timber passes through the machine, in mm/s.

• Cutting Angle (α):
  Angle between cutter face and line from cutting edge to block center, affecting chip formation and surface finish.

Typical Relationships:

flowchart LR
    A[Cutter Head Speed (N) rpm] --> B[Cutting Speed (V) m/min]
    B --> C[Material Removal]
    D[Feed Rate (F) mm/s] --> C
    E[Cutting Angle (α) degrees] --> C

These parameters govern machining efficiency, surface finish, and tool life as per IS 707.

IS 707 Key Moisture Content and Physical Properties

• Moisture Content (MC)
  [ MC (%) = \frac{(W_{wet} - W_{dry})}{W_{dry}} \times 100 ]
  Where:
  (W_{wet}) = mass of wood sample at testing
  (W_{dry}) = oven-dry mass of the wood sample

• Equilibrium Moisture Content (EMC)

  • The moisture level wood attains in a constant temperature and humidity environment.
  • Varies with relative humidity and temperature (typically 8-16% for indoor conditions).

• Moisture Gradient

  • Variation in moisture content from outer to inner layers of timber, affecting shrinkage and strength.

• Fibre Saturation Point (FSP)

  • Moisture content (~25-30%) where cell walls are saturated but no free water exists.
  • Above FSP, physical properties (strength, shrinkage) remain nearly constant.

Typical EMC vs Relative Humidity (RH) Table (Approximate)

flowchart LR
    A[Wood Sample] --> B{Measure Mass}
    B -->|Wet Mass| C[W_wet]
    B -->|Oven Dry| D[W_dry]
    C & D --> E[Calculate MC %]
    E --> F{Compare to FSP (~30%)}
    F -->|Above| G[No change in strength/shrinkage]
    F -->|Below| H[Properties vary with MC]

Summary: Moisture content critically influences timber's physical behavior. Use oven-dry method for MC, consider EMC for environmental effects, and recognize FSP as a key threshold for property changes.

Wood Defects and Damage (IS 707 Highlights)

• Definition (Clause 3.136):
  Defect = Any abnormality reducing wood's strength, appearance, or usability.

• Common Defects (Clause 3.105):

  • Compression Failure: Buckling or crinkling of fibers due to overstress in compression (e.g., during growth or rough handling).

• Durability (Clause 3.158):
  Resistance to natural decay agents like fungi and insects.

Key Specifications & References

Important Notes:

• Visual defects like wrinkles, cracks, knots reduce strength; always inspect timber before use.
• Use IS 1708 for standardized testing of timber quality and defect evaluation.
• Durability varies by species (e.g., Sal is known for good durability).

Basic Formula for Strength Reduction Due to Defects:

[ f_{d} = f_{c} \times (1 - k_d) ]

• ( f_{d} ) = design strength with defects
• ( f_{c} ) = characteristic strength without defects
• ( k_d ) = defect factor (depends on defect severity/type)

flowchart LR
    A[Wood] --> B{Defects?}
    B -- Yes --> C[Strength Reduction]
    B -- No --> D[Full Strength]
    C --> E[Evaluate Defect Type]
    E --> F[Compression Failure]
    E --> G[Knots, Cracks]
    F & G --> H[Apply Strength Reduction Factor]
    H --> I[Design Strength]

Summary: Always assess wood visually and by IS 1708 tests; apply strength reduction factors for defects to ensure safety.

IS 707 - Adhesives and Bonding Agents: Key Points

• Adhesive Definition (3.2): Substance that holds materials together by surface attachment.

• Bond (3.44): Adhesion between two wood surfaces.

• Closed Contact Adhesive (3.92): Non-gap-filling adhesive for joints with surfaces brought into close contact, ensuring glue line ≤ 0.12 mm.

• Spread of Adhesive (3.430): Area covered by 0.5 kg of adhesive mix as per manufacturer's instructions.

Typical Specifications & Formulas:

Practical Notes:

• Use adequate pressure to ensure closed contact and minimal glue line thickness.
• Follow manufacturer’s mix ratios for adhesive preparation.
• Adhesive spread helps estimate quantity needed per unit surface.

flowchart LR
    A[Prepare Adhesive Mix] --> B[Apply 0.5 kg on Surface]
    B --> C[Measure Spread Area (m²)]
    C --> D[Ensure Glue Line ≤ 0.12 mm]
    D --> E[Apply Pressure for Closed Contact Bond]
    E --> F[Achieve Strong Bond]

This ensures optimal bonding per IS 707 guidelines.

IS 707: Measurement and Volume Terms for Timber

• Volume, Void (Clause 3.494):
  Space within wood not occupied by wood substance (e.g., pores, cracks).

• Timber Ton (Clause 3.474):
  A volumetric unit used in timber trade:
  [ \boxed{ 1 \text{ Timber Ton} = 1.42 , m^3 \text{ of timber} } ]

• Lumber (Clause 3.287):
  Timber that has been converted (sawn, hewn, or otherwise processed).

Key Specifications Summary

Practical Use

• Use Timber Ton to estimate timber volume for trade and inventory.
• Account for void volume when calculating net wood volume or density.

flowchart LR
    A[Raw Timber] --> B[Converted Timber (Lumber)]
    A --> C[Volume = Solid Wood + Void]
    C --> D[Void Volume (3.494)]
    B --> E[Measured in Timber Tons (1.42 m³)]

This helps visualize timber processing and volume measurement.

IS 707: Preservation and Fire Retardant Terms

Key Definitions (Clauses 3.194, 3.195, 3.359, 3.360)

• Flame Retardant: Substance added to plywood to reduce flame spread rate and penetration.
• Fire Proofing: Processing/treatment to impart fire-retardant properties.
• Preservative: Chemical applied to timber/plywood to resist fungi, termites, insects, marine borers.
• Preservation: Chemical treatment enhancing timber durability.

Important Specifications:

• Flame Retardant Treatment: Should reduce flame spread rate significantly; often involves additives like ammonium phosphate or borates.
• Preservative Treatment: Methods include pressure impregnation or surface coating with chemicals like copper chrome arsenate (CCA), creosote, or borates.

Typical Fire Retardant Effectiveness (Qualitative):

Preservation Treatment Methods:

• Pressure Treatment: Deep chemical penetration.
• Surface Treatment: Coating or dipping for moderate protection.

flowchart LR
    A[Treatment] --> B[Preservation]
    A --> C[Fire Retardant]
    B --> D[Resistance to fungi, termites, borers]
    C --> E[Reduced flame spread & penetration]

For detailed chemical dosages and treatment durations, refer to IS 307 (for preservatives) and IS 550 (for fire-retardant plywood).

IS 707 primarily serves as a glossary of terms related to timber technology and forest products utilization. It does not provide formulas or tables but defines terminology essential for understanding timber engineering.

Key Points on Miscellaneous Terms (from IS 707):

• It defines common terms used in timber, bamboo, and cane technology.
• The standard is updated in phases to include new terms across various aspects of timber utilization.
• Example:
  • 3.203 Forming — refers to shaping timber products (see related term 3.202).

Important Notes for Structural Engineers:

• Use IS 707 to clarify terminology before applying design codes like IS 875 (Loads), IS 456 (Concrete), or IS 883 (Timber structures).
• For timber design, refer to IS 883 and IS 401 for formulas on strength, load, and design parameters.
• Typical timber strength values and factors are tabulated in IS 883, not IS 707.

Summary Table (Example of Timber Terms):

For design formulas and properties, consult IS 883 or IS 401. IS 707 is strictly a terminology reference.