Medium Density Coirboards for General Purposes

IS 15491 - Scope: Key Formulas, Tables & Specifications

1. Scope Overview

IS 15491 covers specifications and test methods for Medium Density Coirboard, including physical, mechanical properties, and fire resistance.

2. Key Formulas for Mechanical Properties (Clause 1.3)

3. Physical & Mechanical Requirements (Table 1, Clause 11.9)

IS 15491 Key References, Formulas & Tables Summary

1. Key Formulas (Clause 1.3)

2. Physical & Mechanical Properties (Table 1, Clause 11.9)

• Density: Grade 1 (650-900 kg/m³), Grade 2 & 3 (500-900 kg/m³)
• Moisture Content: 5-15% (±3%)
• Water Absorption (Max %): Varies by thickness and soaking time (e.g., Grade 1 after 2h soaking = 6%)
• Modulus of Rupture (Min, N/mm²): Dry condition up to 20 mm thickness: Avg 31 (Grade 1), Min 27
• Modulus of Elasticity (N/mm²): Up to 12 mm thickness: Avg 2800, Min 2500
• Tensile Strength Perpendicular to Surface (Internal Bond): Avg 0.9 N/mm² (Grade 1)
• Screw & Nail Holding Strength: Face avg 2300 N (Grade 1)

3. Testing Standards & Methods (Annex C, Clause 11.11)

• Resistance to spread of flame tested as per Annex C.
• Accelerated water resistance involves boiling specimens and testing internal bond strength.

4. Referenced IS Standards (Annex A)

IS 15491: Terminology & Key Specifications

1. Terminology (Clause 3.1)

• Definitions specific to this standard apply.
• For other terms, refer to IS 707.

2. Mechanical Properties Formulas (Clause 1.3)

Load-deflection data is used to calculate:

• Deflection readings to nearest 0.02 mm.
• Minimum 12-15 readings before proportional limit.
• Record moisture content and temperature during testing.

3. Sizing Material (Clause 3.3)

• Additives like alum, wax, resin improve water resistance.
• Medium density coirboards graded as:

4. Rounding Off (General)

• Follow IS 2:1960 for rounding numerical results.
• Retain significant figures matching the specified values.

flowchart TD
    A[Load-Deflection Data] --> B[Calculate Modulus of Rupture]
    A --> C[Calculate Modulus of Elasticity]
    B --> D[Use formula: 3P'L/2bh²]
    C --> E[Use formula: PL³/4bh³δ]

This summary covers key terms, formulas, and grading relevant to IS 15491.

IS 15491: Material Composition - Key Formulas, Tables & Specifications

1. Material Composition & Additives (Clause 3.3)

• Sizing materials like alum, wax, resin may be added to medium density coirboards to enhance water resistance.
• Medium density coirboards are classified into 3 grades:

2. Density Requirements (Clause 11.3)

• Density tested per IS 2380 (Part 3)
• Average density must comply with Table 1 (Clause 9) (not provided here).

3. Moisture Content (Clause 11.4)

• Moisture content tested as per IS 2380 (Part 3)
• Must meet limits in Table 1 (Clause 9).

4. Surface Absorption & Expansion (Clause 11.6.2)

• Surface expansion tested per IS 2380 (Part 17)
• Average surface expansion must not exceed limits in Table 1 (Clause 9).

Summary Table (from Clause 9 - Table 1, typically):

For exact numerical limits, refer to Table 1 in Clause 9 of IS 15491.

flowchart LR
    A[Material Composition] --> B[Additives: Alum, Wax, Resin]
    B --> C[Medium Density Coirboards]
    C --> D[Grade 1, Grade 2, Grade 3]
    C --> E[Water Resistance ↑]

    F[Tests] --> G[Density (IS 2380 Pt 3)]
    F --> H[

IS 15491: Dimensions and Tolerances for Medium Density Coirboards

Key Dimensions (Clause 1.83b)

• Standard lengths (m): 5.49, 4.89, 3.66, 3.05, 2.44, 1.83, 1.22
• Tolerance on length & width: ± 0.30 mm per meter

Measurement & Compliance (Clause 10.1.3)

• Boards must be checked for:
  • Straightness of edges
  • Squareness
  • Length, width, thickness (per IS 2380 Part 2)
• Dimensions must comply with requirements in Clause 8 (not detailed here)

Rounding Off (General)

• Follow IS 2:1960 for rounding off test results
• Retain the same number of significant digits as specified in the standard

Summary Table: Dimension Tolerances

Notes:

• Other dimensions can be agreed upon between manufacturer and purchaser.
• Physical and mechanical properties are specified in Table 1 (not included here).

flowchart LR
    A[Select Sample Boards] --> B[Measure Length, Width, Thickness]
    B --> C{Check Tolerances}
    C -->|Within ±0.30 mm/m| D[Pass]
    C -->|Outside Tolerance| E[Reject or Rework]
    D --> F[Proceed to Mechanical Testing]

This ensures dimensional accuracy and quality compliance for coirboards per IS 15491.

IS 15491: Physical Requirements Summary

1. Density Test (Clause 11.3)

• Test specimens per IS 2380 (Part 3).
• Average density must comply with Table 1 (Clause 9).

2. Moisture Content Test (Clause 11.4)

• Tested as per IS 2380 (Part 3).
• Average moisture content must meet Table 1 requirements.

3. Mechanical Properties (Clause 1.3)

• Load-deflection data used to calculate:

• Deflection readings to nearest 0.02 mm.
• Minimum 12-15 readings up to proportional limit.
• Record moisture content and temperature during testing.

4. Flame Spread Resistance (Annex C, Clause 11.11)

• Follow specified test method for flame spread resistance.

flowchart LR
    A[Test Specimen] --> B[Density Test (IS 2380 Pt 3)]
    A --> C[Moisture Content Test (IS 2380 Pt 3)]
    A --> D[Load-Deflection Test]
    D --> E[Calculate Modulus of Rupture]
    D --> F[Calculate Modulus of Elasticity]
    A --> G[Flame Spread Resistance Test]

Note: Refer Table 1 (Clause 9) in IS 15491 for exact density and moisture limits.

IS 15491: Mechanical Requirements Summary

Key Tests & Specifications

Key Formulas (Clause 1.3)

Notes:

• Deflection readings must be recorded to 0.02 mm accuracy.
• Minimum 12 to 15 load-deflection readings up to proportional limit.
• Moisture content and temperature during testing must be recorded.
• Resistance to spread of flame test method is detailed in Annex C (Clause 11.11).

flowchart LR
    A[Load Application] --> B[Measure Deflection]
    B --> C{Calculate}
    C --> D[Modulus of Rupture]
    C --> E[Modulus of Elasticity]

This concise summary equips you with the essential mechanical test requirements and formulas per IS 15491.

IS 15491: Sampling and Inspection Key Points

1. Scale of Sampling (Clause 10.1)

• Sampling is done as per prescribed scale (details in 10.1.3).
• Samples are selected for dimensional checks and testing.

2. Criteria for Conformity (Clause 10.3)

• Lot acceptance: All samples must meet requirements (Clause 11).
• If any sample fails:
  • Take double the number of samples from the lot.
  • Lot passes if all these additional samples conform.

3. Testing of Samples (Clause 11 & 10.1.3)

• Measure:
  • Straightness of edges
  • Squareness of boards
  • Length, width, thickness (as per IS 2380 Part 2)
• Dimensions must comply with Clause 8 requirements.

4. Rounding Off (IS 2:1960)

• Final test values rounded per IS 2 rules.
• Retain significant digits equal to specified values.

Summary Table: Sampling & Acceptance

flowchart TD
    A[Select Initial Samples] --> B[Test Samples]
    B -->|All Pass| C[Lot Accepted]
    B -->|Any Fail| D[Double Samples Taken]
    D --> E[Test Additional Samples]
    E -->|All Pass| C
    E -->|Any Fail| F[Lot Rejected]

This ensures quality control through progressive sampling and strict dimensional checks.

IS 15491: Key Test Methods & Formulas

1. Test Specimen & Number of Tests (Clause 10.2)

• Specimens must follow size and conditioning per Clause 10.2.
• Minimum 12 to 15 load-deflection readings up to proportional limit.
• Record moisture content and temperature during test.

2. Important Formulas (Clause 1.3, Table B-1.3)

• Deflection readings to nearest 0.02 mm.

3. Test for Modulus of Elasticity & Rupture (Clause 11.7)

• Average and minimum values must meet Table I (Clause 9).
• Tests per Annex B.

4. Resistance to Spread of Flame (Annex C, Clause 11.11)

• Follow specified test method for flame spread resistance.

flowchart TD
    A[Test Specimen Preparation] --> B[Load-Deflection Test]
    B --> C[Record Load & Deflection]
    C --> D[Calculate Modulus of Rupture & Elasticity]
    D --> E[Compare with Table I Values]
    E --> F{Meets Requirements?}
    F -- Yes --> G[Pass]
    F -- No --> H[Fail]

Summary: Use the above formulas with precise load-deflection data, maintain environmental conditions, and ensure results meet specified minimums per IS 15491.

IS 15491: Resistance to Spread of Flame - Key Points

Test Setup (Annex C, Clause 11.11)

• Specimen size: 150 mm × 25 mm
• Orientation: Flat surface at 45° to horizontal
• Flame source: Luminous batswing flame from Bunsen burner, 25 mm wide
• Application cycle:
  • Flame applied for 30 seconds
  • Removed for 30 seconds
  • Reapplied for 30 seconds
  • Removed again

Acceptance Criteria

• Medium density coirboards must pass this test as per Clause 9 and 11.11.

Related Formulas (Clause 1.3, Table B-1.3)

Notes

• Deflection readings to nearest 0.02 mm
• Minimum 12 to 15 load-deflection readings to proportional limit
• Record moisture content and temperature during test

flowchart LR
    A[Test Specimen 150x25 mm] --> B[Hold at 45° angle]
    B --> C[Apply 25 mm batswing flame for 30s]
    C --> D[Remove flame for 30s]
    D --> E[Reapply flame for 30s]
    E --> F[Remove flame]
    F --> G[Observe flame spread]
    G --> H{Pass/Fail}

This test ensures the board's flame resistance per IS 15491 standards.

IS 15491: Marking and Labelling Key Points

Marking Requirements (Clause 12.1.4)

Each Medium Density Coirboard must be legibly marked near any corner with:

• Manufacturer's name
• Grade of the coirboard
• Dimensions and thickness
• Date of manufacture
• ECO-Mark criteria (if applicable)

Packaging materials must be recyclable, reusable, or biodegradable, with documentary evidence provided.

Labelling (Clause 12.1.3)

The product or packaging may briefly display the environment-friendly criteria for ECO-Mark labelling.

Related Physical & Mechanical Properties (Table 1 Summary)

Important Formulas (Clause 1.3)

• Modulus of Rupture (N/mm²):
  [ f_r = \frac{3 P' L}{2 b h^2} ]
• Modulus of Elasticity (N/mm²):
  [ E = \frac{P L^3}{4 b h^3 \delta} ]

Where:

• (P) = Load at proportional limit (N)
• (P') = Maximum load (N)
• (L) = Span (mm)
• (b) = Width (mm)
• (h) = Thickness (mm)
• (\delta) = Deflection at proportional limit (mm)

flowchart TD
    A[Medium Density Coirboard

IS 15491: Eco-Mark Requirements for Medium Density Coirboard

Key Specifications:

• Packaging Material: Must be recyclable, reusable, or biodegradable.
• Documentation: Manufacturer must provide certificates/declarations confirming eco-friendly packaging to BIS.

Marking Requirements on Coirboard:

• Manufacturer's name
• Grade of medium density coirboard
• Dimensions and thickness
• Date of manufacture
• ECO-Mark criteria fulfilled

BIS ECO-Mark Scheme:

• Administered by BIS under the BIS Act, 1986.
• ECO-Mark combines ISI Mark + Eco logo.
• Product must meet additional environment-friendly criteria besides ISI standards.
• Use of ECO-Mark is optional; ISI Mark alone is allowed.

Flame Resistance Test:

• Medium density coirboard must pass flame spread resistance as per Annex C of IS 15491.

Summary Table for ECO-Mark Eligibility

If you need detailed test procedures or marking formats, refer to IS 15491 Annexures and BIS guidelines.

IS 15491 Quality Assurance: Key Specifications & Formulas

1. Rounding Off (IS 2:1960)

   • Final test/analysis values must be rounded to the same number of significant digits as the specified value in IS 15491.

2. Moisture Content (Clause 11.4)

   • Test as per IS 2380 (Part 3).
   • Average moisture content must comply with Table 1 limits (refer Clause 9).

3. Density (Clause 11.3)

   • Test as per IS 2380 (Part 3).
   • Average density must meet Table 1 requirements.

4. Surface Expansion due to Absorption (Clause 11.6.2)

   • Test as per IS 2380 (Part 17).
   • Average surface expansion must not exceed Table 1 limits.

Table 1 (Summary of Limits)

Notes:

• Always use average values from multiple specimens.
• Follow IS 2380 test procedures strictly for consistency.
• Refer Clause 9 in IS 15491 for exact numeric limits in Table 1.

flowchart TD
    A[Start Quality Assurance] --> B[Test Specimens]
    B --> C{Test Type}
    C -->|Moisture Content| D[IS 2380 Part 3]
    C -->|Density| D
    C -->|Surface Expansion| E[IS 2380 Part 17]
    D --> F[Compare Average Value with Table 1 Limits]
    E --> F
    F --> G{Pass Limits?}
    G -->|Yes| H[Accept Material]
    G -->|No| I[Reject Material / Re-test]

This ensures compliance with IS 15491 quality standards

IS 15491: Committee Composition - Key Details

Committee Composition is detailed in Annex D and Annex M of IS 15491. The committee includes representatives from:

• Research Institutes (e.g., Indian Plywood Industries Research and Training Institute)
• Government Departments (e.g., Central Public Works Department, Ministry of Defence)
• Industry Associations (e.g., Federation of Indian Plywood & Panel Industry)
• Testing and Standardization Bodies (e.g., National Test House, Directorate of Standardization)
• Private Companies and Personal Capacities

Summary Table of Key Representatives

Notes:

• The committee ensures representation from technical experts, government, industry, and research organizations.
• It guides the formulation and revision of standards related to wood and lignocellulosic products.
• Alternate members are nominated for each representative to ensure continuity.

graph TD
    A[IS 15491 Committee] --> B[Research Institutes]
    A --> C[Government Departments]
    A --> D[Industry Associations]
    A --> E[Testing & Standardization Bodies]
    A --> F[Private Companies & Individuals]

This structure ensures a multi-disciplinary approach in standard development.