Specification of veneered wood boards for packing cases

IS 4834: Scope & Key Specifications

• Scope: Covers plywood dimensions, tolerances, and quality for general purposes (refers also to IS 707-1968 for definitions).

Key Dimensions (Clause 7.1)

Tolerances on Dimensions (Clause 7.3)

Additional Notes

• Edge straightness and squareness tested as per Annex A (Clause 7.3).
• Definitions and terms aligned with IS 707-1968.

This ensures plywood panels meet size accuracy for structural and general use.

flowchart TD
    A[IS 4834 Scope] --> B[Dimensions per Clause 7.1]
    B --> C{Selected Sizes}
    C -->|Yes| D[900×600, 900×300, 600×600, 600×300]
    C -->|No| E[1200×600, 1200×300]
    A --> F[Tolerances per Clause 7.3]
    F --> G[Length ±6mm]
    F --> H[Width ±3mm]
    F --> I[Thickness ±0.5mm]
    A --> J[Edge Tests Annex A]

This summary aids in quick reference for plywood sizing and quality control per IS 4834.

IS 4834 Key References: Dimensions, Tolerances & Manufacture

1. Dimensions and Tolerances (Clause 7.3)

2. Manufacture - Veneered-Wood Board Thicknesses (Clause 5.5)

3. Edge Straightness & Squareness (Annex A, Clause 7.3)

• Method of test provided for verifying edge straightness and squareness of plywood.
• Ensures compliance with dimensional tolerances for quality control.

This summary aligns with IS 4834 specifications for plywood general purposes, ensuring dimensional accuracy and manufacturing standards.

IS 4834: Grades, Dimensions & Tolerances for Veneered-Wood Boards

Grades (Clause 3.1)

• Grade 1: For packing cases/boxes used as storage packs.
• Grade 2: For packing cases/boxes used as transit packs.

Dimensions & Tolerances (Clause 7.3)

Nominal Thickness & Veneer Details (Clause 5.5)

Additional Notes

• Thickness testing is mandatory for each specimen (Clause 1.1).
• Tolerances ensure manufacturing precision critical for packing quality.

flowchart LR
    A[Grades] --> B[Grade 1: Storage Packs]
    A --> C[Grade 2: Transit Packs]
    D[Dimensions] --> E[Length ±6mm]
    D --> F[Width ±3mm]
    D --> G[Thickness ±0.5mm]
    H[Thickness Details] --> I[Core Stock]
    H --> J[Veneers for Faces]

This summary aids in selecting the correct grade and ensuring dimensional compliance per IS 4834.

IS 4834: Key Formulas, Tables & Specifications for Materials

1. Tolerances on Dimensions (Clause 7.3)

2. Nominal Thicknesses (Clause 5.5)

3. Test Specimens Conditioning (Clause 9.2)

• Condition specimens at 27° ± 2℃ and 65 ± 5% RH until constant weight.
• Alternatively, 24 hours in a well-ventilated room may suffice.

Additional Notes:

• Thickness testing is mandatory for each specimen (Clause 1.1).
• These controls ensure plywood quality for general purposes.

flowchart LR
    A[Raw Material] --> B[Core Stock Thickness]
    B --> C[Veneers for Faces Thickness]
    C --> D[Assemble Veneered-Wood Board]
    D --> E[Dimension Check with Tolerances]
    E --> F[Conditioning Test Specimen]
    F --> G[Thickness Test & Quality Control]

This summarizes the key material specs and quality control from IS 4834.

IS 4834: Manufacture of Veneered-Wood Boards

Key Specifications (Clause 5.5 & 7.2)

• Nominal Thicknesses (mm):

• Standard thicknesses of veneered-wood boards: 9, 13, 16, 19 mm

Dimensional Tolerances (Clause 7.3)

Conditioning of Test Specimens (Clause 9.2)

• Condition specimens at 27°C ± 2°C and 65% ± 5% RH until weight stabilizes.
• Alternatively, 24 hours in a well-ventilated room may suffice.

This ensures consistent quality and dimensional accuracy during manufacture and testing of veneered wood boards.

IS 4834 - Workmanship and Finish Key Points

1. Workmanship (Clause 6.2)

• Boards must be flat.
• Faces should be reasonably smooth.
• Edges trimmed square within 3 mm tolerance.

2. Dimensional Tolerances (Clause 7.3)

3. Thickness Specifications (Clause 5.5)

Summary

• Ensure flatness and smooth finish.
• Maintain edge trimming within 3 mm.
• Follow tolerances strictly for length, width, and thickness.
• Use specified veneer and core thicknesses for given board thicknesses.

flowchart TD
    A[Start: Veneered-Wood Board] --> B{Check Thickness}
    B -->|9 mm| C[Core: 6 mm, Veneer: 1.5 mm]
    B -->|13 mm| D[Core: 9 mm, Veneer: 2.0 mm]
    B -->|16 mm| E[Core: 10 mm, Veneer: 3.0 mm]
    B -->|19 mm| F[Core: 13 mm, Veneer: 3.0 mm]
    C --> G[Check Flatness & Smoothness]
    D --> G
    E --> G
    F --> G
    G --> H[Trim Edges within 3 mm]
    H --> I[Check Dimensional Tolerances]
    I --> J[Length ±6 mm, Width ±3 mm, Thickness ±0.5 mm]
    J --> K[End]

This ensures compliance with IS 4834 workmanship and finish requirements.

IS 4834: Dimensions and Tolerances for Plywood

1. Standard Panel Sizes (Clause 7.1)

2. Dimensional Tolerances (Clause 7.3)

3. Additional Specifications

• Edges trimmed square within 3 mm (Clause 6.2)
• Boards must be flat with reasonably smooth faces.
• Edge straightness and squareness tested as per Annex A.

Summary Diagram: Tolerance Limits

graph LR
A[Length] -->|+6 mm / -0 mm| B(Tolerance)
C[Width] -->|+3 mm / -0 mm| B
D[Thickness < 6 mm] -->|±10%| B
E[Thickness ≥ 6 mm] -->|±5%| B
F[Edge Straightness] -->|2 mm / 1000 mm| B
G[Squareness] -->|2 mm / 1000 mm| B

Use these limits to ensure plywood panels conform to IS 4834 standards for quality and fit.

IS 4834: Sampling and Inspection Key Points

Sampling (Clause 8.2)

• Select n veneered-wood boards randomly from a lot of size N for inspection.

Dimensional Tolerances (Clause 7.3)

Inspection & Treatment

• After acceptance, boards undergo momentary dipping in preservative (Clause 10.1).
• Edge straightness and squareness tested as per Annex A (Clause 7.3).

Summary Diagram

flowchart TD
    A[Lot of Veneered-Wood Boards] --> B[Sampling as per Lot Size]
    B --> C[Inspection of Selected Boards]
    C --> D{Accept or Reject}
    D -- Accept --> E[Preservative Dip Treatment]
    D -- Reject --> F[Reject Lot]

This ensures quality control by systematic sampling, dimensional checks, and treatment.

IS 4834 – Key Test Specifications & Procedures

1. Conditioning of Test Specimens (Clause 9.2)

• Specimens must be conditioned before testing.
• Standard conditioning:
  • Exposure for 24 hours in a well-ventilated room.
  • For higher accuracy:
    • Temperature: 27°C ± 2°C
    • Relative Humidity: 65% ± 5%
    • Until weight is substantially constant.

2. Specimen Dimensions (Clause 2.5 c)

• Two specimens of size:
  15 cm x 2.5 cm

3. Thickness Measurement (Clause 1.1 & A-1.1.1)

• Measure thickness in mm with accuracy ±0.02 mm.
• Measuring instrument: flat contacting surfaces, diameter ~6 mm.
• Take 8 readings per specimen:
  • Four corners
  • Midpoints of edges
  • Approximately 20 mm inside edges.

4. Reporting (Clause A-2)

• Report conditioning procedure and test results clearly.

Thickness Measurement Summary Table

flowchart TD
    A[Prepare Specimen] --> B[Condition Specimen]
    B -->|24 hrs at 27°C ±2°C, 65% ±5% RH| C[Measure Thickness]
    C --> D[Take 8 readings]
    D --> E[Calculate Average Thickness]
    E --> F[Report Results]

This ensures standardized testing per IS 4834.

IS 4834: Key Points on Preservative Treatment of Plywood

1. Core Timber Specifications (Clause 5.2)

• Moisture content: ≤ 12%
• Core strip dimensions:
  • Width ≥ 80 mm
  • Length ≥ length of board
• Core strips must be of one timber species per board.

2. Preservative Treatment Method (Clause 10.1)

• Treatment by momentary dipping (dip-in-dip-out) in a suitable preservative solution.
• Preservative type and concentration to be agreed between purchaser and supplier.

3. Quality Control & Re-test (Clause 9.7)

• If initial samples fail tests (9.3 to 9.6), a second random sample is tested.
• Failure in the second sample leads to rejection of the entire lot.

4. Additional Test (Clause 1.2 for Grade 2 Boards)

• Soak test specimens in cold water for 24 hours.
• Test by forcibly separating outer layers while still water-soaked.

Summary Table: Core Strip Requirements

Preservation Treatment Flow

flowchart LR
    A[Inspect Boards] --> B[Momentary Dip in Preservative]
    B --> C[Drying & Packaging]
    C --> D[Quality Testing]
    D -->|Pass| E[Dispatch]
    D -->|Fail| F[Retest Samples]
    F -->|Pass| E
    F -->|Fail| G[Reject Lot]

This ensures plywood durability by controlling moisture and applying agreed preservative dip treatment with strict quality checks.

IS 4834 - Marking Specifications (Clause 12.2 & 12.2.1)

• Location: Markings must be placed on the face of the board near one edge.
• ISI Certification Mark:
  • Optional on each board.
  • Indicates compliance with the standard under ISI's quality control system.
  • Use governed by Indian Standards Institution (Certification Marks) Act.
  • Ensures continuous inspection and testing by ISI.
• Additional Notes:
  • For licensing details of ISI mark, contact Indian Standards Institution.
  • Refer to Annex B, C, D for related clauses (formerly Appendices A, B, C).

Summary Table for Marking Location

Key Reference

• Annex A: Method for testing edge straightness and squareness (Clause 7.3).
• IS 707-1968: Definitions related to this standard.

flowchart LR
    A[Board Face] --> B[Marking near one edge]
    B --> C{ISI Certification Mark?}
    C -->|Yes| D[Mark with ISI Mark]
    C -->|No| E[No ISI Mark]

This ensures traceability and quality assurance per IS 4834.

ISI Certification Mark (IS 4834 - Clause 12.2.1)

• The ISI Certification Mark on boards ensures compliance with IS standards via a strict quality control system supervised by ISI.
• Use of the mark is regulated under the Indian Standards Institution (Certification Marks) Act.
• It guarantees:
  • Production under defined inspection and testing.
  • Continuous market surveillance by ISI.
• Manufacturers must obtain a license from ISI to use the mark.

Key Specifications from IS 4834 (Relevant Clauses)

Notes:

• Refer to Annex A for test methods on edge straightness and squareness.
• For licensing details, contact the Indian Standards Institution.

flowchart LR
    A[Manufacturing Process] --> B[Quality Control System]
    B --> C[ISI Supervision & Testing]
    C --> D[ISI Certification Mark Granted]
    D --> E[Market Surveillance by ISI]
    E --> F[Continuous Compliance Assurance]

This flow ensures products with the ISI mark meet IS 4834 requirements consistently.

IS 4834: Method of Test for Edge Straightness and Squareness

Edge Straightness Test (Annex A, Clause 7.3)

• Equipment: Straight edge at least equal to full board length.
• Procedure:
  • Place the straight edge along the edge of the plywood.
  • If edge is convex, position straight edge to give equal gap at both ends.
  • Measure the maximum gap between the edge and straight edge to nearest 1 mm.
• Tolerance:

  Parameter	Tolerance
  Edge Straightness	2 mm per 1000 mm length (0.2%)

Squareness Test (Annex A)

• Procedure:
  • Measure squareness by checking the angle between edges (usually with a square tool).
  • The deviation from 90° should not exceed the tolerance.
• Tolerance:

  Parameter	Tolerance
  Squareness	2 mm per 1000 mm length (0.2%)

Dimensions and Tolerances for Finished Boards (Clause 7.3 Table)

Summary Diagram

flowchart LR
    A[Place straight edge along plywood edge] --> B{Is edge convex?}
    B -- Yes --> C[Position straight edge for equal gaps at ends]
    B -- No --> D[Measure max gap between edge and straight edge]
    C --> D
    D --> E[Record gap (max 2 mm per 1000 mm allowed)]
    F[Check squareness with square tool] --> G[Deviation ≤ 2 mm per 1000 mm]

Key Notes:

• Test specimens: rectangular, cut 15 cm from edges, ±1.5 mm tolerance.
• Edge straightness and squareness are critical for plywood quality control.
• Follow Annex A for detailed test procedure.

IS 4834 – Test for Variation in Thickness (Clause 9.3 & Appendix A)

Key Specifications:

• Measurement Accuracy: ±0.02 mm
• Measuring Instrument: Flat contacting surfaces, diameter ≈ 6 mm
• Test Points: 8 readings per specimen:
  • 4 corners (~20 mm inside edges)
  • 4 midpoints of edges (~20 mm inside edges)

Procedure:

• Measure thickness at specified points.
• Calculate variation = Maximum thickness – Minimum thickness.
• Variation must be within tolerance limits as per Clause 7.3 (refer to IS 4834 for exact limits).

Summary Table:

flowchart LR
    A[Select Test Specimen] --> B[Measure Thickness at 8 Points]
    B --> C[Calculate Max - Min Thickness]
    C --> D{Variation ≤ Tolerance (Clause 7.3)?}
    D -->|Yes| E[Pass]
    D -->|No| F[Fail]

This ensures uniformity and quality control of thickness in the tested material.

IS 4834: Test for Resistance to Water (Clause 9.5 & Appendix B)

Test Procedure:

• Specimens: Thickness measured at multiple points; report mean thickness (Clause 2.1).
• Grade 1 Boards:
  • Submerge specimens in cold water (no contact with pan bottom).
  • Heat water to 60 ± 2°C and maintain for 3 hours.
  • Immediately plunge specimens into cold water.
  • While still water-soaked, forcibly separate outer layers with a prising knife.
• Grade 2 Boards:
  • Submerge specimens in cold water for 24 hours.
  • Test similarly by forcibly separating outer layers while still wet.

Acceptance Criteria:

• Specimens shall satisfy requirements of Clause 9.4 (typically no delamination or failure).

Summary Table:

Notes:

• Thickness measurement is critical for accurate results.
• Ensure specimens do not touch pan bottom during submersion.
• Peel test checks bonding integrity after water exposure.

flowchart TD
    A[Prepare Specimens] --> B[Measure Thickness at 8+ points]
    B --> C{Board Grade?}
    C -->|Grade 1| D[Submerge in cold water]
    D --> E[Heat water to 60±2°C for 3 hours]
    E --> F[Plunge into cold water immediately]
    F --> G[Peel test while wet]
    C -->|Grade 2| H[Submerge in cold water for 24 hours]
    H --> G
    G --> I{Pass/Fail}

This test ensures the board's resistance to water-induced delamination per IS 4834 standards.

IS 4834: Mycological Test Key Points

Objective:

Ensure no appreciable separation at edges of test specimens after fungal exposure.

Test Setup (Appendix C):

• Test Dish: Flat rectangular dish (enameled iron, glass, or porcelain), filled to ~25 mm depth with sawdust of non-durable timber (e.g., Semul).
• Sawdust Preparation: Moisten sawdust with aqueous solution containing 12 g cane sugar per litre of water. Amount of solution just enough to moisten without excess.
• Fungal Spores: Sawdust charged with spores of common Indian fungi.
• Specimen Placement: Test pieces pressed into sawdust so upper surface is level with sawdust top.

Procedure (Clause 1.2):

• Submerge specimens in cold water for 24 hours (no contact with container bottom).
• Remove while still water-soaked.
• Test by forcibly separating outer layers with prising knife.
• Specimens must show no appreciable edge separation.

Summary Table:

flowchart LR
    A[Prepare Sawdust] --> B[Moisten with sugar solution]
    B --> C[Charge with fungal spores]
    C --> D[Press test specimens into sawdust]
    D --> E[Submerge specimens in cold water (24h)]
    E --> F[Remove and test separation]
    F --> G{No appreciable separation?}
    G -- Yes --> H[Pass]
    G -- No --> I[Fail]

This test ensures durability against fungal attack per IS 4834 Clause 9.6 and Appendix C.