Fire Retardant Plywood -Specification

IS 5509: Scope & Key Specifications (Fire Retardant Plywood)

Scope (Clause 3.1):

• Applies to fire retardant plywood as defined in IS 707 and IS 5509.
• Covers general requirements, tolerances, and test methods for fire retardant plywood.

Key Tolerances (Clause 8.3)

Squareness Check (Clause 2.1 & Annex A)

• Use a 1200 mm x 1200 mm square applied to one edge.
• Measure the maximum gap between the plywood edge and the square arm.
• Edge straightness and squareness tests follow Annex A procedures.

Summary Diagram of Tolerance Check

flowchart LR
    A[Plywood Board] --> B{Check Dimensions}
    B -->|Length| C[+6 mm / -0 mm]
    B -->|Width| D[+3 mm / -0 mm]
    B -->|Edge Straightness| E[±10% or ±15% or 0.2%]
    B -->|Squareness| F[Use 1200x1200 mm square]

Note: Refer to IS 707 for plywood definitions and IS 5509 for detailed fire retardant specifications.

IS 5509: Normative References & Key Specifications

• Normative References (Clause 3.1):
  Definitions and terms are aligned with IS 707 (Plywood specification) and the standard itself (IS 5509 : 2000, reaffirmed 2006).

• Tolerances on Finished Boards (Clause 8.3, Table 8.3):

• Edge Straightness Tolerances:

• Testing (Annex A):
  Edge straightness and squareness are tested as per Annex A, which details the procedure for measuring deviations along edges and corners.

Summary Diagram of Edge Tolerance Concept

flowchart TD
    A[Start: Finished Board] --> B{Measure Thickness}
    B -->|<6 mm| C[Edge Straightness ±10% or 2 mm/1000 mm]
    B -->|≥6 mm| D[Edge Straightness ±15% or 2 mm/1000 mm]
    C --> E[Check Length +6/-0 mm]
    D --> E
    E --> F[Check Width +3/-0 mm]
    F --> G[Perform Edge Squareness Test (Annex A)]
    G --> H[Pass/Fail]

Use IS 707 for definitions and IS 5509 Annex A for detailed test methods.

IS 5509: Definitions & Key Specifications Summary

• Definitions:
  Per Clause 3.1, definitions follow IS 707 plus additional terms in IS 5509.

• Test Specimens for Rate of Burning (Clause 12.5c):

  • Size: 100 mm × 12.5 mm (full thickness)
  • Number: Three specimens per sample

• Dimensional Tolerances on Finished Boards (Clause 8.3):

• Edge Straightness Tolerance:

  • For thickness < 6 mm: ±10%
  • For thickness ≥ 6 mm: ±15%
  • Or 2 mm per 1000 mm (0.2%)

• Testing Edge Straightness and Squareness:
  Detailed in Annex A (Clause 8.3) with a specified procedure.

Quick Reference: Edge Straightness Tolerance

graph LR
A[Board Thickness] -->|<6 mm| B[±10% Edge Straightness]
A -->|≥6 mm| C[±15% Edge Straightness]
B & C --> D[Max 2 mm deviation per 1000 mm length]

For full definitions, refer to IS 707 and IS 5509 Clause 3.1.

IS 5509: Flame Retardants Key Points

Types of Flame Retardants (Clause 4.1)

• Type 1: Ammonium phosphates
• Type 2: Ammonium sulphate
• Type 3: Boron compounds
• Type 4: Ammonium phosphate + Boron compounds
• Type 5: Ammonium sulphate + Ammonium phosphate

Retention of Fire Retardant Chemicals (Clause 6.2.2)

• Recommended retention: ~50 kg/m³ (for interior/exterior use not subject to leaching)

Conditioning After Treatment (Clause 7)

• Equilibrium moisture content ≤ 20%

Dimensions & Tolerances (Clause 8)

• Follow IS 12049 for dimensions
• Thickness tolerance as per IS 303

Testing Requirements (Clause 11)

Test specimens must be cut 150 mm away from edges.

Definition (Clause 3.2)

Flame retardant: A substance applied to plywood reducing flame spread and penetration.

flowchart TD
    A[Flame Retardant Chemicals] --> B[Type 1: Ammonium Phosphates]
    A --> C[Type 2: Ammonium Sulphate]
    A --> D[Type 3: Boron Compounds]
    A --> E[Type 4: Ammonium Phosphate + Boron]
    A --> F[Type 5: Ammonium Sulphate + Ammonium Phosphate]

For detailed application and testing methods, refer to IS 5509 clauses mentioned above and related IS codes.

IS 5509: Preparation of Plywood for Fire Retardant Treatment

Key Specifications (Clauses 5 & 6)

• Plywood Quality for Treatment (Clause 5.1):

  • Must conform to BWR grade of IS 303.
  • Clean, free from oil/dirt.
  • Moisture content ≤ 15%.
  • For decorative plywood, flame retardant solution must not spoil surface color.
  • ECO-Mark plywood must meet ECO-Mark requirements in IS 303.

• Treatment Method (Clause 6.1.1): Pressure Impregnation After Manufacture

  • Use full cell process.
  • Plywood preferably kept vertical in pressure cylinder.
  • If stacked horizontally, insert spacers/grills for free solution flow.
  • Apply vacuum ≥ 560 mm Hg for 20–30 min.
  • Introduce flame retardant solution under vacuum.
  • Apply pressure: 2 to 12 kg/cm² depending on timber species & thickness.
  • Maintain pressure until required absorption.
  • Break pressure, apply vacuum again for 10–15 min to remove excess solution.

Important Notes

• Degree of penetration depends on veneer permeability (refer IS 401 for heartwood treatability).
• Pressure and temperature must not damage wood structure.
• Proper concentration of flame retardant solution ensures specified absorption and retention.

Summary Table: Pressure Impregnation Parameters

flowchart TD
    A[Plywood Preparation] --> B{Clean & Moisture ≤ 15%}
    B --> C[Place Plywood in Pressure Cylinder]
    C --> D[Apply Vacuum (≥560 mm Hg, 20-30 min)]
    D --> E[Introduce Flame Retardant Solution]
    E --> F[Apply Pressure (2-12 kg/cm²)]
    F --> G[Maintain Pressure until Absorption]
    G

IS 5509: Fire Retardant Treatment - Key Points

1. Fire Retardant Chemical Retention

• Recommended retention: ~50 kg/m³ (for interior/exterior use not exposed to leaching)
• Fire retardants are leachable, so avoid use in wet or rain-exposed conditions.

2. Plywood Requirements Before Treatment

• Grade: BWR grade as per IS 303 (to withstand pressure impregnation)
• Moisture content: ≤ 15%
• Surface: Clean, free from oil/dirt
• Decorative plywood: Ensure solution color does not spoil surface

3. Conditioning After Treatment

• Condition plywood to equilibrium moisture content ≤ 20%

4. Dimensions & Tolerances

• Follow IS 12049 for dimensions
• Thickness tolerance as per IS 303

5. Sampling & Testing

6. Combined Treatment

• For combined flame retardant + preservative, refer IS 12120 for preservative types and retention.

flowchart TD
    A[Plywood (BWR Grade, ≤15% MC)] --> B[Fire Retardant Treatment]
    B --> C[Conditioning (≤20% MC)]
    C --> D[Dimension & Tolerance Check (IS 12049, IS 303)]
    D --> E[Sampling & Testing]
    E --> F{Tests}
    F -->|Flammability| G[6 specimens, 125x125 mm]
    F -->|Flame Penetration| H[3 specimens, 125x125 mm]

Note: Fire retardants are not chemically fixed; avoid use where rain or water may leach chemicals.

IS 5509: Conditioning After Treatment - Key Points

• Types of Treatment (Clause 6.1):

  • 6.1.1 Pressure Impregnation: Post-manufacture treatment using pressure or vacuum-pressure to impregnate plywood with fire retardant chemicals.
  • 6.1.2 Soaking Treatment: Submerging plywood in solution until required absorption is achieved.

• Requirements:

  • Treatment must ensure plywood meets fire retardant standards (Clause 4.3).
  • Pressure and temperature during treatment must not damage wood structure.
  • Veneer permeability affects penetration (refer IS 401 for treatability of heartwood).

Typical Conditioning Parameters for Pressure Impregnation:

Formula for Solution Absorption (Weight Gain %):

[ \text{Weight Gain %} = \frac{W_{treated} - W_{dry}}{W_{dry}} \times 100 ]

• (W_{treated}) = weight after treatment
• (W_{dry}) = oven-dry weight before treatment

flowchart LR
    A[Manufactured Plywood] --> B{Type of Treatment}
    B -->|Pressure Impregnation| C[Vacuum + Pressure Chamber]
    B -->|Soaking| D[Submerge in Solution]
    C --> E[Conditioned Fire Retardant Plywood]
    D --> E

Summary: Conditioning after treatment in IS 5509 involves pressure impregnation or soaking to ensure adequate fire retardant chemical absorption without damaging plywood structure. Use IS 401 for wood permeability reference.

IS 5509: Dimensions and Tolerances for Fire Retardant Plywood

1. Nominal Sizes Tolerances (Clause 8.3, Table 8.3)

• Thickness options (Clause 8.2): 3, 4, 5, 6, 8, 9, 12, 15, 19, 22, 25 mm.
• Other sizes can be agreed upon between manufacturer and purchaser.

2. Edge Straightness

• Tolerance: ±10% for thickness < 6 mm, ±15% for thickness ≥ 6 mm.
• Equivalent to 2 mm per 1000 mm length or 0.2%.

3. Squareness Test (Annex A)

• Use a 1200 mm × 1200 mm square.
• Place one arm on plywood edge; measure max gap between plywood edge and square arm.
• Max gap recorded is the measure of squareness deviation.

4. Edge Straightness Test Procedure

• Use a straight edge at least equal to plywood length.
• Measure the largest gap between plywood edge and straight edge.
• If edge is convex, hold straight edge to create equal gaps at both ends.

flowchart TD
    A[Plywood Edge] --> B{Straight Edge}
    B -->|Measure gap| C[Max Gap]
    C --> D{Is gap ≤ tolerance?}
    D -->|Yes| E[Accept]
    D -->|No| F[Reject or Rework]

Summary:

• Length tolerance: +6 mm / -0 mm
• Width tolerance: +3 mm / -0 mm
• Edge straightness: max 2 mm per 1000 mm
• Squareness checked with 1200 mm square, max gap recorded

These ensure dimensional accuracy and quality in fire retardant plywood per IS 5509.

IS 5509: Workmanship and Finish - Key Specifications

1. Tolerances on Finished Boards (Clause 8.3, Table 8.3)

• Edge straightness:
  • For thickness < 6 mm: ±10% or 2 mm per 1000 mm (0.2%)
  • For thickness ≥ 6 mm: ±15% or 2 mm per 1000 mm (0.2%)

2. Edge Straightness & Squareness Testing (Annex A)

• Edge Straightness:
  Use a straight edge equal to board length; measure max gap between edge and straight edge.

• Squareness:
  Check with a 1200 mm × 1200 mm square; record max gap between square arm and board edge.

3. Workmanship & Finish (Clause 9)

• Finished plywood must be clean, free from dirt and stains, except uniform flame retardant coloration.
• Sampling and conformity criteria per IS 7638.

4. Additional Notes

• Conditioning after treatment to moisture content ≤ 20% (Clause 7).
• Dimensions conform to IS 12049; thickness tolerance per IS 303.

flowchart TD
    A[Finished Board] --> B{Check Dimensions}
    B -->|Length +6/-0 mm| C[Accept]
    B -->|Width +3/-0 mm| C
    B -->|Outside tolerance| D[Reject]
    A --> E{Check Edge Straightness}
    E -->|Gap ≤ 2 mm/1000 mm| C
    E -->|Gap > 2 mm/1000 mm| D
    A --> F{Check Squareness}
    F -->|Gap ≤ allowed| C
    F -->|Gap > allowed| D

This ensures compliance with IS 5509 workmanship and finish requirements.

IS 5509: Sampling & Test Specimens

• Sampling for Rate of Burning (Clause 12.5 c):
  Take 3 test specimens of size 100 mm × 12.5 mm (full thickness) from each sample.

Tolerances on Finished Boards (Clause 8.3, Table 8.3)

• Edge Straightness:
  • For thickness < 6 mm: ±10%
  • For thickness ≥ 6 mm: ±15%
  • Max deviation: 2 mm per 1000 mm (0.2%)

Edge Straightness & Squareness Testing (Annex A)

• Use a straightedge or measuring device along the edge.
• Measure deviations; ensure within tolerance limits above.

Summary Diagram of Sampling Specimen

flowchart LR
    Sample[Sample Board] -->|Cut 3 specimens| Specimen1[100mm x 12.5mm]
    Sample --> Specimen2[100mm x 12.5mm]
    Sample --> Specimen3[100mm x 12.5mm]

This ensures consistent sampling and dimensional control per IS 5509 standards.

IS 5509: Test Specimen and Number of Tests

Key Specifications (Clause 11 & 12.5c)

• Flammability Test:
  • 6 specimens per sample
  • Size: 125 mm × 125 mm, full thickness
• Flame Penetration Test:
  • 3 specimens per sample
  • Size: 125 mm × 125 mm, full thickness
• Rate of Burning Test:
  • 3 specimens per sample
  • Size: 100 mm × 12.5 mm, full thickness

Specimen Preparation

• Specimens must be cut 150 mm away from edges (Clause 11)
• Thickness as per IS 12049 and IS 303 (Clause 8)
• Thickness options: 3, 4, 5, 6, 8, 9, 12, 15, 19, 22, 25 mm

Additional Notes

• Conditioning after treatment to moisture content ≤ 20% (Clause 7)
• Fire retardant chemical retention: ~50 kg/m³ (Clause 6.2.2)

Summary Table

This ensures representative and standardized testing for fire retardant plywood as per IS 5509.

IS 5509: Test Requirements Summary

Specimen Dimensions for Rate of Burning (Clause 12.5 c)

• Specimen size: 100 mm × 12.5 mm (full thickness)
• Number of specimens: 3 from each sample

General Test Procedure (Clause 12.1)

• Test specimens prepared as per Clause 11.
• Tests to be conducted as per Clauses 12.2 to 12.4 (not detailed here).

Tolerances on Finished Boards (Clause 8.3, Table 8.3)

• Edge straightness tolerance:
  • For thickness < 6 mm: ±10%
  • For thickness ≥ 6 mm: ±15%
• Maximum deviation: 2 mm per 1000 mm length (0.2%)

Edge Straightness & Squareness Testing (Annex A)

• Method detailed in Annex A (Clause 8.3) involves measuring deviations along edges using straight edges or gauges.

Key Notes:

• Specimen preparation and testing ensure consistency in rate of burning and dimensional accuracy.
• Edge straightness and squareness are critical for board quality control.

flowchart TD
    A[Sample Material] --> B[Cut 3 Specimens 100x12.5 mm]
    B --> C[Conduct Rate of Burning Test]
    A --> D[Measure Finished Board Dimensions]
    D --> E{Check Tolerances}
    E -->|Within Limits| F[Accept Board]
    E -->|Out of Limits| G[Reject Board]
    D --> H[Check Edge Straightness & Squareness]
    H --> I{Within 2mm/1000mm?}
    I -->|Yes| F
    I -->|No| G

Let me know if you need formulas or detailed test methods from Clauses 12.2-12.4!

IS 5509: Optional Requirements for ECO-Mark (Clause 13)

• Quality & Performance: Plywood must meet both IS 5509 and ECO-Mark requirements per IS 303 (BWR grade).
• Tests Required (Clause 12.4):
  • Glue shear strength (dry state)
  • Mycological test
  • Water resistance
  • Other mechanical tests mutually agreed upon
• Environmental Compliance (Clause 13.1.2):
  • Obtain environmental consent clearance from State Pollution Control Board under:
    • Water (Prevention and Control of Pollution) Act, 1974
    • Air (Prevention and Control of Pollution) Act, 1981
    • Water Cess Act, 1977
  • Authorization under Environment (Protection) Act, 1986 if required
  • Compliance with Forest Department rules
• Documentation (Clause 13.2): Manufacturer must submit certificates/declarations to BIS when applying for ECO-Mark.

Summary Table: ECO-Mark Requirements for Plywood

This ensures plywood is both high quality and environmentally compliant for ECO-Mark certification.

IS 5509: Marking and Certification for Plywood

Key Specifications (Clauses 14.1 & 14.2)

• Marking on Each Board (Clause 14.1):

  • Manufacturer's name, initials, or trademark
  • Year of manufacture
  • Type of treatment (e.g., chemical, fire-retardant)
  • ECO-Mark labeling criteria

• BIS Standard Mark (Clause 14.2.1):

  • Each board may carry the BIS Standard Mark as certification.

Certification Requirements (Clause 13.2)

• Plywood must meet ECO-Mark specific requirements.
• Manufacturer must submit documentary evidence (certificate/declaration) to BIS for ECO-Mark approval.

Summary Table for Marking Requirements

This ensures traceability, quality assurance, and compliance with environmental standards.