Pencil slats

IS 3084: Scope and Key Specifications

• Scope (Clause 1.1):
  Covers requirements for pencil slats used in pencil manufacturing.

• Relevant Indian Standards (Clause 2.1):

  • IS 1375: Specification for black pencils
  • IS 707: Glossary of timber technology terms
  • IS 2: Rules for rounding off numerical values

• Timber Species for Pencil Manufacture (Clause 4.1, Table 1):

• Rounding Off (IS 2:1960):
  Final test values must be rounded off to the same number of significant digits as specified.

This standard ensures quality timber selection and testing accuracy for pencil slats in pencil manufacturing.

IS 3084: References and Key Specifications

• Referenced Standards (Clause 2.1):

  • IS 1375:1959 — Specification for black pencils.
  • IS 707:1976 — Glossary of terms for timber technology and utilization.
  • IS 2:1960 — Rules for rounding off numerical values (applies for test result reporting).

• Rounding Off (General):

  • Final test values must be rounded as per IS 2:1960.
  • Retain the same number of significant figures as the specified value.

• Timber Species for Pencil Manufacture (Clause 4.1, Table 1):

Summary:
IS 3084 relies on timber species quality and references IS 1375 for pencil specs. Use IS 2 for rounding off test results. The timber species table guides selection for pencil manufacturing.

flowchart TD
    A[IS 3084 Standard] --> B[References]
    B --> IS1375[IS 1375: Black

IS 3084 - Definitions & Key Specifications

• Definitions: As per Clause 3.1, all definitions follow IS 707: 1976 (Glossary of terms applicable to timber technology).

• Species of Timber for Pencil Manufacture (Clause 4.1, Table 1):

• Rounding Off (Clause None): Final test values must be rounded as per IS 2:1960, retaining the same number of significant digits as the specified value.

Summary:

• Refer IS 707:1976 for timber terminology.
• Use the above table for selecting timber species by quality.
• Apply IS 2:1960 rules for numerical rounding in test results.

flowchart TD
    A[IS 3084 Definitions] --> B[IS 707:1976 for Terms]
    A --> C[Timber Species Table]
    A --> D[Rounding Rules (IS 2:1960)]

IS 3084 - Species of Timber for Pencil Manufacture

Key Specifications (Clause 4.1 & Table 1):

Notes:

• Quality I species are preferred for pencil slats due to superior properties like softness, ease of sharpening, and minimal splintering.
• Quality II species are acceptable but generally of lower quality.
• Timber selection per IS 3084 ensures durability and workability in pencil manufacturing.

Reference:

• Definitions as per IS 707 : 1976 apply.
• This classification is based on latest investigations for pencil slat suitability.

flowchart LR
    A[Species of Timber] --> B[Quality I]
    A --> C[Quality II]
    B -->|Examples| ALD[Alder (ALD)]
    B --> CYP[Cypress (CYP)]
    B --> DEO[Deodar (DEO)]
    B --> H

IS 3084 - Dimensions and Tolerances for Pencil Slats

The standard provides specifications for pencil slats, including dimensional tolerances, especially for green or insufficiently seasoned timber.

Key Points on Dimensions and Tolerances:

• Length and Thickness Tolerances (Clause 5.1):
  No extra tolerances beyond those prescribed are required for length and thickness of slats.

• Tolerances for Green/Insufficiently Seasoned Timber (Note 2 below Clause 5):
  Allows for additional dimensional variation due to moisture content and shrinkage.

Typical Dimensional Tolerances (as per IS 3084 and common timber practice):

Recommended Practice:

• Use Annex A for sawing practice to minimize dimensional variation.
• Follow Annex B for waxing and dyeing to stabilize dimensions.

Summary Diagram of Dimensional Tolerances:

graph LR
A[Slat Dimensions] --> B[Length ±1 mm]
A --> C[Thickness ±0.1 mm]
A --> D[Width ±0.2 mm]
B --> E[Green Timber: +1/-2 mm]
C --> F[Green Timber: +0.2/-0.3 mm]
D --> G[Green Timber: +0.3/-0.4 mm]

For detailed specifications, refer to IS 3084 Annexes and related standards IS 707 and IS 1375.

IS 3084: Quality Requirements for Pencil Slats

Key Specifications:

• Rounding Off Values:
  Follow IS 2:1960 for rounding test results.

  • Retain the same number of significant digits as the specified value.

• Timber Species for Pencil Manufacture (Clause 4.1, Table 1):

Additional References:

• IS 1375:1959 – Specification for black pencils
• IS 707:1976 – Glossary of timber technology terms

This ensures pencil slats meet the quality and species standards critical for manufacturing consistent, high-quality pencils.

IS 3084: Treatment and Specifications for Pencil Slats

Key Specifications:

• Moisture Content: Slats must have moisture content ≤ 12% (Clause 6.1).
• Seasoning: Timber must be air-seasoned before sawing to achieve this moisture level.
• Sawing: Logs are first sawn into blocks (Annex A), allowing margin for shrinkage and depending on slat ply.
• Oversize Allowance: For green or insufficiently seasoned timber, oversizes in width must account for shrinkage and sawing tolerances (Clause 5.1).

Treatment of Slats (Clause 7.1 and Annex B):

• Slats may be treated or untreated.
• Waxing: Essential to improve wilting properties before pencil manufacture.
• Dyeing: Optional for color enhancement.
• Annex B details:
  • Two-step waxing and dyeing procedure.
  • Alternative single-step procedure.

Summary Table (Moisture & Treatment)

flowchart TD
    A[Log] --> B[Saw into Blocks]
    B --> C[Air Seasoning (Moisture ≤12%)]
    C --> D[Final Sawing into Slats]
    D --> E{Treatment?}
    E -->|Yes| F[Waxing + Optional Dyeing]
    E -->|No| G[Untreated Slats]
    F --> H[Pencil Manufacture]
    G --> H

This ensures dimensional stability and surface quality for pencil slats.

IS 3084 - Packaging Specifications for Pencil Slats

Key Packaging Marking Requirements (Clause 9.1)

Each bundle of pencil slats must be clearly and indelibly marked with:

• Quantity packed: Number of slats and ply
• Manufacturer's identification: Name, initials, or recognized trademark
• Species of timber used
• Treatment status: Whether treated or untreated
• Year of manufacture

Sawing and Storage (Annex A)

• Air season green sawn blocks to proper moisture content before sawing.
• Use precision saws (band or circular) with accurate settings to avoid taper.
• Stack slats with restraint during storage to prevent warping.
• Final moisture content should be below 12% before packaging.

Waxing and Dyeing Treatment (Annex B, Clause 1.2.1)

• Wax absorption: 8-15% of dry weight.
• Use vacuum-pressure impregnation with heated wax emulsion.
• Final kiln drying and conditioning at 70-80°C.

Summary Table: Packaging Marking

This ensures traceability, quality control, and compliance with IS 3084 packaging standards.

IS 3084: Marking Specifications for Pencil Slats (Clause 9.1)

Each bundle of pencil slats must be legibly and indelibly marked with:

• Quantity packed: Number of slats and ply
• Manufacturer's identification: Name, initials, or recognized trade-mark
• Species of timber used
• Treatment status: Whether treatment (e.g., waxing/dyeing) is given or not
• Year of manufacture

Additional Key Points:

• Marking ensures traceability and quality assurance under BIS.
• Marking must be durable to withstand handling and storage.
• The Standard Mark use is governed by the Bureau of Indian Standards Act, 1986.

Related Process (Annex B):

• Waxing and dyeing may be done in a single-step or two-step process.
• Wax absorption target: 8% to 15% of dry weight.
• Vacuum-pressure treatment with heated wax emulsion is recommended.

Summary Table for Marking Requirements:

If you need details on waxing/dyeing or sawing procedures, refer to Annex B and Annex A respectively.

IS 3084: Sawing Procedure for Pencil Slats — Key Points & Specifications

Sawing Procedure (Annex A, Clause 5.1)

• Step 1: Convert logs into pencil slat blocks of adequate thickness, considering:
  • Margin for shrinkage during drying.
  • Desired ply thickness of slats.
• Step 2: Air season the blocks to reduce moisture content before final sawing.
• Step 3: Saw slats precisely using well-maintained band or circular saws to avoid tapering.
• Step 4: Stack sawn slats with restraint to prevent warping.
• Step 5: Final drying to moisture content ≤ 12% (Clause 6.1).

Dimensional Tolerances (For green or insufficiently seasoned timber)

• Oversize allowance in width to accommodate:
  • Shrinkage during drying.
  • Sawing tolerances (exact values in Annex A, Note 2).

Moisture Content

Marking Requirements (Clause 9.1)

Each bundle must be marked with:

• Quantity & ply number
• Manufacturer’s name/trademark
• Timber species
• Treatment status
• Year of manufacture

flowchart TD
    A[Log] --> B[Cut into Pencil Slat Blocks]
    B --> C[Air Season Blocks (reduce moisture)]
    C --> D[Precision Sawing of Slats]
    D --> E[Stack & Restrain Slats]
    E --> F[Final Drying to ≤ 12% Moisture]
    F --> G[Bundle & Mark Slats]

Summary:
Air seasoning before sawing and precise cutting with allowances for shrinkage ensure quality slats with minimal warping and correct dimensions. Final moisture content must be ≤12% for durability.

IS 3084 - Waxing and Dyeing Treatment for Slats

Key Specifications & Procedures:

1. Two-Step Process (Clause 1.1 & 1.2.2)

• Step 1: Dye slats and dry to 12% moisture content (air or kiln).
• Step 2: Dip in molten paraffin wax at 80-100°C.
• Wax absorption: 8-15% of dry weight (species dependent).
• Final heat treatment: kiln at 70-80°C for 12-24 hours for uniform wax penetration.

2. Single-Step Process (Clause 1.2.1, Table B-1.3)

• Use wax emulsion or dispersion with dye.
• Wax absorption: 8-15% of dry weight.
• Vacuum-pressure impregnation with heated solution (above wax melting point).
• Final kiln drying and conditioning at 70-80°C.

Summary Table for Wax Absorption & Temperature

Notes:

• Wax absorption ensures moisture resistance and durability.
• Final heat treatment promotes uniform wax penetration.
• Vacuum-pressure method enhances impregnation efficiency in single-step.

flowchart TD
    A[Dyeing] --> B[Dry to 12% Moisture]
    B --> C[Wax Dipping at 80-100°C]
    C --> D[Cool & Wax Absorption 8-15%]
    D --> E[Heat Treatment at 70-80°C for 12-24 hrs]
    E --> F[Finished Slats]

    G[Single-Step Wax Emulsion + Dye] --> H[Vacuum-Pressure Treatment]
    H --> I[Wax Absorption 8-15%]
    I --> J[Final Kiln Drying at 70-80°C]
    J --> F

This ensures