Resin-treated compressed wood laminates (compregs) - Specification, Part 1: For electrical purposes

IS 3513 Part 1: Scope - Key Specifications & Properties

Physical Properties (Table 1, Clause 8.1)

Mechanical Properties (Table 3, Clause 8.3)

IS 3513 Part 1: Key References & Mechanical Properties

Mechanical Properties (Table 3, Clause 8.3)

Important IS Standards Referenced (Clause 2.1, Annex A)

• IS 1734 (Part 9): Tensile strength test for plywood
• IS 1708 (Parts 8, 9, 11): Compressive & shear strength tests for timber specimens
• IS 1586: Rockwell hardness test methods
• IS 1998: Static bending and impact strength tests
• IS 324: Specification for ordinary denatured spirit
• IS 707: Timber technology glossary
• IS 3396: Volume and surface resistivity tests for insulating materials

Summary

• Use Table 3 (Clause 8.3) for mechanical property limits.
• Refer

IS 3513 Part 1: Definitions & Key Mechanical Properties

Definitions:

• As per Clause 3.1, definitions from IS 707:1976 (Glossary of Timber Terms) apply.
• Refer IS 707 for timber-related terminology essential for understanding compreg materials.

Key Mechanical Properties (Table 8.3, Clause 8.3)

Notes:

• Specimens for compressive strength tests are 20 mm x 20 mm x 20 mm.
• Mechanical properties are directional: parallel/perpendicular to laminae and grain.
• Testing standards referenced ensure uniformity and reliability.

This concise summary helps in understanding the definitions and mechanical specifications for compreg materials as per IS 3513 Part 1. For detailed definitions, consult IS 707:1976.

Types of Compregs (IS 3513 Part 1, Clause 4.2.1):

Key Physical Properties (Table 1, Clause 8.1):

Mechanical Properties (Types V & VI, Clause 8.3):
Refer to IS 3513 Part 1 Table 3 for detailed values (not provided here).

Electrical Properties (Table 2, Clause 8.2):

IS 3513 Part 1 — Key Material Specifications for Compregs

Physical Properties (Clause 8.1 | Table 1)

Mechanical Properties (Clause 8.3 | Table 3)

IS 3513 Part 1: Manufacture of Compreg for Electrical Purposes

Key Specifications (Clause 6.2 - Manufacture)

Mechanical Properties (Clause 8.3 - Table 3)

Physical Properties (Clause 8.1 - Table 1)

IS 3513 Part 1: Dimensions and Tolerances for Finished Compreg Boards

Key Tolerances (Clause 7.1.3)

Additional Specifications

• Clause 7.3.1: Final tolerances must comply with purchaser's drawings.
• Clause 6.6: Purchaser must provide detailed drawings with dimensions and tolerances for machined components.
• Clause 6.7: Edges and surfaces must be coated with insulating varnish per IS 10026 (Part 3/ Sec 1 to 7):1983.

Summary

• Length and width have asymmetric positive tolerance only.
• Thickness tolerance is percentage-based, tighter for thicker boards.
• Protective varnish coating is mandatory on edges and surfaces.

flowchart TD
    A[Purchaser Drawings] --> B[Dimensions & Tolerances]
    B --> C[Length: +6/-0 mm]
    B --> D[Width: +3/-0 mm]
    B --> E[Thickness < 6mm: ±10%]
    B --> F[Thickness ≥ 6mm: ±5%]
    G[Finished Component] --> H[Protective Varnish (IS 10026)]

This ensures dimensional accuracy and durability per IS 3513 Part 1.

IS 3513 Part 1: Key Properties of Compreg for Electrical Purposes

1. Physical Properties

Refer to Table 1 (Clause 8.1) — general physical properties as per IS 3513 Part 1 (not detailed here).

2. Mechanical Properties (Table 3, Clause 8.3)

3. Electrical Properties (Table 2, Clause 8.2)

IS 3513 Part 1: Workmanship and Finish — Key Points

1. Workmanship (Clause 7.3.1)

• Finished components or blanks must adhere to tolerances specified in purchaser's drawings.
• No generic tolerance; strictly as per order documents.

2. Finish Requirements (Clause 14.1)

Purchaser must specify:

• Number and type of boards/components.
• Size and thickness.
• Detailed drawings with tolerances and dimensions.
• Finish type: platten finish or machine finish.
• Surface treatment: oil finish or varnish finish.
• Any special requirements.

3. Protective Coating (Clause 6.7)

• Edges and surfaces must have a protective insulating varnish per IS 10026 (Part 3/ Sec 1 to 7):1983.

Summary Table: Workmanship & Finish

flowchart TD
    A[Order Specification] --> B{Includes}
    B --> C[Number & Type]
    B --> D[Size & Thickness]
    B --> E[Drawings with Tolerances]
    B --> F[Finish Type: Platten/Machine]
    B --> G[Surface Treatment: Oil/Varnish]
    B --> H[Special Requirements]
    H --> I[Supplier Applies Protective Varnish]

For detailed mechanical properties and test methods, refer to Table 3 (Clause 8.3) in IS 3513 Part 1.

IS 3513 Part 1 (1989) Sampling Summary:

• Sampling Reference:
  Sampling procedures are detailed in IS 3513 Part 4: 1966. Part 1 refers users to Part 4 for sampling methods.

• Test Pieces:
  Test specimens must be cut from the sampled boards and tested as per methods and tables specified in IS 3513 Part 4.

• Related Standards:
  Sampling and testing also align with these relevant IS codes:

  • IS 1708: Testing small clear timber specimens
  • IS 707 Part 1: Moisture content determination
  • IS 1586 Parts 8 & 9: Compressive strength parallel and perpendicular to grain
  • IS 1734 Part 11: Shear strength parallel to grain
  • IS 3513 Part 4: Methods of test for wood laminates (sampling included)

Key Points for Sampling (from IS 3513 Part 4):

• Sample Size: Usually, a representative number of boards are selected from a batch based on lot size (e.g., 5-10% or as specified).
• Test Specimens: Cut clear specimens avoiding defects, with dimensions per test method (e.g., 20 mm × 20 mm × thickness for strength tests).
• Moisture Conditioning: Specimens should be conditioned to specified moisture content before testing (typically 12-15%).

Typical Sampling Flow:

flowchart TD
    A[Batch of Boards] --> B[Select Representative Boards]
    B --> C[Cut Test Specimens]
    C --> D[Condition Specimens (Moisture)]
    D --> E[Perform Tests as per IS 3513 Part 4]

Summary Table: Sampling and Testing References

IS 3513 Part 1 — Key Testing Specifications & Mechanical Properties

Mechanical Properties (Clause 8.3, Table 3)

Electrical Properties (Clause 8.2, Table 2)

IS 3513 Part 1: Marking Specifications for Compreg

Per Clause 12.1, each compreg item must be legibly and indelibly marked with:

• a) Type and finish
• b) Manufacturer's initials or recognized trademark
• c) Year of manufacture
• d) Batch number

If compreg is supplied as boards, each board is marked; if in components, each component or package of small components is marked.

Summary Table for Marking Details

Additional Notes

• Marking must be legible and indelible to ensure durability during handling and use.
• Purchaser may request additional markings at contract time.

flowchart LR
    A[Compreg Supply Form] -->|Board form| B[Mark each Board]
    A -->|Component form| C[Mark each Component]
    A -->|Small Components| D[Mark each Package]
    B --> E[Mark: Type & Finish, Manufacturer, Year, Batch]
    C --> E
    D --> E

This ensures traceability and quality control per IS 3513 Part 1 requirements.

IS 3513 Part 1: Packing and Delivery Key Points

Packing and Delivery (Clause 13)

• Boards/components must be delivered clean, dry, and suitably packed to prevent damage and moisture ingress.
• Packaging should ensure legible, indelible marking on each board/component/package with:
  • Type and finish
  • Manufacturer’s initials/trademark
  • Year of manufacture
  • Batch number
• Additional purchaser-specified marks as per contract.

Information to be Supplied by Purchaser (Clause 14)

• Number of boards/components
• Material type
• Size and thickness
• Detailed drawings with tolerances (for components)
• Finish type (platten/machine)
• Surface finish (oil/varnish)
• Special requirements

Mechanical Properties Summary (Table 8.3)

IS 3513 Part 1 – Information to be Supplied by the Purchaser

Per Clause 14.1, the purchaser must provide the following details clearly with the order:

• Quantity: Number of boards or components
• Material Type: Specify the exact grade/type of material
• Dimensions: Size and thickness of boards/components
• Drawings: Detailed drawings with all dimensions and tolerances for components (Clause 6.6 & 7.3)
• Finish: Whether platen finished or machine finished
• Surface Treatment: Oil finish or varnish finish
• Special Requirements: Any other specific needs or instructions

Additional notes:

• Components must be delivered clean, dry, and suitably packed (Clause 13.1).
• For special shapes (discs, rings, gear blanks), drawings with precise dimensions and tolerances are mandatory.

Summary Table for Purchaser's Information

This ensures clarity and conformity to IS 3513 standards for supply and fabrication.