Specification for Synthetic Resin Adhesives For Construction Work (Non-Structural) in Wood

IS 851: Scope - Key Points, Formulas & Tables

1. Scope Overview (Clause 5.3.1, 0.6 - 0.8)

• Allows user options for selection per requirements at order placement.
• Harmonized with international standards and local practices.
• Results/tests must be rounded per IS 2:1960 rules, retaining significant figures as per specified values.

2. Definitions (Clause 2.1)

• Uses definitions from IS 707:1976 plus additional specific terms.

3. Types of Adhesives (Clause 3.1 Table)

4. Methods of Use (Clause A-1.5 Guidance)

• Moisture content range of wood.
• Surface preparation.
• Application methods: single/double spread.
• Normal glue spread amount per line.
• Open/closed assembly time limits.
• Pressure range: N/m² (kg/cm²).
• Post-treatment processes.
• Cleaning procedures.

5. Rounding Off Values (IS 2:1960)

• Round off final test/analysis values to the same decimal places as specified.

Summary Diagram of Adhesive Types:

graph LR
    A[Adhesive Types] --> B[BWP: Boiling Water Proof]
    A --> C[BWR: Boiling Water Resistance]
    A --> D[WWR: Warm Water Resistance]
    A --> E[CWR: Cold Water Resistance]

For detailed formulas or tables on glue spread, pressure, or assembly times, refer to respective clauses or annexures in IS 851.

IS 851: Definitions & Key Specifications

• Reference Definitions: Clause 2.1 refers to IS 707-1976 for fundamental wood adhesive terms.

• Adhesive Types (Clause 3.1):

• Rounding Off (Clause 0.8): Final test/analysis values must be rounded per IS 2-1960, maintaining the same significant figures as specified.

• User Options (Clause 5.3.1): Allows selection flexibility per user requirements during order placement.

• Methods of Use (Clause 1.5): Guidance includes moisture content range, surface prep, application methods (single/double spread), glue spread amounts, assembly times, pressure range (N/m² or kg/cm²), post-treatment, and cleaning.

Typical Pressure Range for Gluing (from IS 851 guidance):

This summary aids in understanding adhesive types, testing, and application norms per IS 851.

Classification of Adhesives (IS 851)

Types & Symbols (Clause 3.1.1)

Test Requirements (Clause 5.3, Table 1 & 5.3.1)

• Gap-filling adhesives: Tested on gap and close-contact joints.
• Close-contact adhesives: Tested only on close-contact joints.
• Routine tests include dry and wet tests at specified temperatures.
• BWP, BWR, WWR types may require cold water tests if purchaser demands.

Key Test Load Values (Mean Failing Load, kg, Minimum)

Notes

• Tests marked with * are done only if purchaser requires.
• Adhesives must meet keeping qualities and resistance according to their classification.

flowchart TD
    A[Adhesive Types] --> B[Gap-Filling Adhesive]
    A --> C[Close Contact Adhesive]
    B --> BWP_GF[Boiling Water Proof (BWP/GF)]
    B --> BWR_GF[Boiling Water Resistance (BWR/GF)]
    B --> WWR_GF[Warm Water Resistance (WWR/GF)]
    B --> CWR_GF[Cold Water Resistance (CWR/GF)]
    C --> BWP_CC[Boiling Water Proof (BWP/CC)]
    C --> BWR_CC[Boiling Water Resistance (BWR/

IS 851: Keeping Qualities of Adhesives

Key Points on Keeping Qualities (Clause 4)

• Keeping qualities refer to the adhesive's ability to retain its properties during storage.
• Adhesives are classified as Gap-Filling (GF) or Close Contact (CC), and by their water resistance:
  • BWP: Boiling Water Proof
  • BWR: Boiling Water Resistant
  • WWR: Warm Water Resistant
  • CWR: Cold Water Resistant

Specifications Summary:

Important Guidelines (Clauses 1.3, 1.5):

• Storage Conditions: Maintain recommended temperature and humidity to avoid degradation.
• Preparation: Mix resin, hardener, and additives as specified; use recommended mixing apparatus.
• Application: Follow specified moisture content, glue spread, assembly times, and pressure ranges.
• Testing: Check viscosity and bonding strength periodically to ensure adhesive quality.

Rounding Off Test Results (Clause 0.8):

• Use IS 2-1960 rounding rules.
• Retain significant figures equal to those in the standard's specified values.

Practical Note:

• Adhesive viscosity and bond strength are primary indicators of keeping quality.
• Store adhesives in airtight containers and avoid temperature extremes.

flowchart LR
    A[Adhesive Types] --> B[Gap-Filling (GF)]
    A --> C[Close Contact (CC)]
    B --> D[BWP/GF, BWR/GF, WWR/GF, CWR/GF]
    C --> E[BWP/CC, BWR/CC, WWR/CC, CWR/CC]
    D & E --> F[Check Keeping Qualities]
    F --> G[Viscosity]
    F --> H[Bond Strength]
    F --> I[Storage Conditions]

For detailed values on spread rates, pressures

IS 851: Key Requirements Summary

1. Test Requirements (Clause 5.3)

• Adhesives tested as per Table 1:
  • Gap-filling adhesives: Tested on both gap joints and close-contact joints.
  • Close-contact adhesives: Tested only on close-contact joints.

2. Types of Adhesives (Clause 3.1)

3. Methods of Use (Clause 1.5)

• Moisture content range of wood.
• Surface preparation.
• Application methods (single/double spread).
• Normal glue spread per glue line.
• Open and closed assembly times (max/min).
• Recommended pressures: N/m² (kg/cm²).
• Post-treatment of the product.
• Cleaning of containers and test procedures.

4. Rounding Off (Clause 0.8)

• Final test values rounded per IS 2:1960.
• Maintain same significant figures as specified.

Typical Pressure Range (Example)

flowchart TD
    A[Adhesive Type] -->|Gap-filling| B[Gap & Close-contact Tests]
    A -->|Close-contact| C[Close-contact Tests only]
    B --> D[Test Results]
    C --> D
    D --> E[Rounding off per IS 2:1960]

This concise overview helps ensure compliance with IS 851 adhesive requirements. For detailed tables and values, refer to the full standard document.

IS 851 - Marking and Labelling Key Points

Marking Requirements (Clause 6.1)

Each adhesive container shall be marked legibly and indelibly with:

• Manufacturer's name or distinguishing mark
• Description of material (refer IS 851 Clause 3)
• Manufacturer's reference number
• Batch number
• Date of manufacture
• Expiry date (date beyond which adhesive should not be used under recommended storage)
• Reference to manufacturer's instructions for use
• The phrase "to be stored in a cool dry place"

Use of Standard Mark (Clauses 6.1.1 & 6.1.2)

• The product may carry the Standard Mark.
• Use of this mark is governed by the Bureau of Indian Standards Act, 1986.
• Licensing details for use of the Standard Mark are available from BIS.

Additional Notes

• Marking must comply with IS:2-1960 rounding off rules.
• Manufacturer must provide storage and usage instructions clearly.

Summary Table for Marking Information

flowchart LR
    A[Adhesive Container] --> B[Marking]
    B --> C[Manufacturer's Name/Mark]
    B --> D[Material Description]
    B --> E[Reference Number]
    B --> F[Batch Number]
    B --> G[Date of Manufacture]
    B --> H[Expiry Date]
    B --> I[Instructions Reference]
    B --> J[Storage Instruction]

This ensures traceability, safety, and compliance with IS 851.

IS 851: Guidance Regarding Use of Adhesives

Based on Clause 1.5 and related notes, key points for adhesive use on wood are:

• Moisture Content of Wood: Typically 8% to 12% for optimal bonding.
• Surface Preparation: Surfaces must be clean, dry, and free from dust, grease, or loose fibers.
• Application Methods: Single or double spread; double spread often improves bond strength.
• Spread Amount (Single Glue Line): Usually 150-250 g/m² depending on adhesive and wood type.
• Assembly Times:
  • Open Assembly Time: Max 5-10 minutes (time adhesive remains tacky before joining).
  • Closed Assembly Time: Min 15-30 minutes (time under pressure to develop bond).
• Pressure Range: Recommended pressure is 0.7 to 1.5 N/mm² (7 to 15 kg/cm²).
• Post-Treatment: Curing at ambient or elevated temperature as per adhesive type.
• Cleaning: Use recommended solvents immediately after use; clean test equipment regularly.

Additional Notes:

• Follow manufacturer instructions for resin, hardener, fillers.
• Round off test results per IS 2-1960.
• Use of Standard Mark governed by BIS Act 1986.

Summary Table: Adhesive Use Parameters

flowchart TD
    A[Wood Surface] --> B[Surface Preparation]
    B --> C[Adhesive Application]
    C --> D[Open Assembly Time]
    D --> E[Join Surfaces]
    E --> F[Apply Pressure (0.7-1.5 N/mm²)]
    F --> G[Closed Assembly Time]
    G --> H[Post Treatment & Curing]
    H --> I[Finished Product Cleaning & Testing]

This ensures strong, durable adhesive bonds in wood products per IS 851

IS 851: Veneers for Test Pieces (Appendix B)

Key Specifications for Veneers:

• Material: Canarium spp. veneer
• Dimensions per slip:
  • Length: 115 mm
  • Width: 25.0 ± 0.3 mm
  • Thickness: 3.15 ± 0.15 mm
• Joint overlap: 25.0 ± 0.3 mm

Preparation & Adhesive Application:

• Adhesive applied uniformly on one smooth face.
• Veneer slips joined without rubbing immediately or as per manufacturer's instructions.
• Test pieces clamped immediately after assembly.

Clamping Details:

• Clamp applies about 50 kg pressure (finger tight on the clamp shown in Fig.4).
• Clamp includes 20 mm thick rubber for uniform pressure.
• Wooden jig (Fig. 5) with 10 mm Ø locating pegs and 6 mm eccentricity ensures proper alignment.

Summary Table:

flowchart LR
    A[Veneer Slip 1] -->|Apply adhesive| B[Overlap Joint 25 mm]
    C[Veneer Slip 2] --> B
    B --> D[Clamp with 50 kg pressure]
    D --> E[Use Wooden Jig with 10 mm pegs]

This ensures consistent test piece quality for adhesive testing as per IS 851.

IS 851: Preparation of Test Pieces for Gap Joints (Appendix C)

Key Specifications:

• Test Slip Size: 150 mm length.
• Adhesive Application: Middle third of one slip coated with adhesive.
• Inserts: Size 62.0 mm × 25.0 mm × 1.30 ± 0.13 mm thick placed as per Fig. 1.
• Gap: Formed by inserts; filled with excess adhesive.
• Second Slip: Also coated on middle third and placed over the first; excess adhesive squeezed out by clamping.
• Conditioning: As per Appendix D before testing.
• Minimum Average Failing Load: ≥ 205 kg for six test pieces.

Preparation Steps Summary:

• Cut two 150 mm slips.
• Coat one slip's middle third with adhesive.
• Place inserts to create a gap.
• Fill gap with adhesive.
• Coat second slip's middle third.
• Assemble and clamp to squeeze out excess adhesive.
• Cure and condition as specified.

Important Dimensions Table:

flowchart LR
    A[Prepare 150 mm slips] --> B[Coat middle third of Slip 1 with adhesive]
    B --> C[Place inserts (62×25×1.3 mm) on Slip 1]
    C --> D[Fill gap with excess adhesive]
    D --> E[Coat middle third of Slip 2 with adhesive]
    E --> F[Place Slip 2 over Slip 1]
    F --> G[Clamp to squeeze out excess adhesive]
    G --> H[Cure and condition as per Appendix D]
    H --> I[Test for failing load ≥ 205 kg]

This ensures standardized, reproducible test pieces for gap joint strength evaluation.

IS 851: Conditioning of Test Pieces (Clause 5.6.1 and related)

Key Specifications:

• Initial Conditioning:

  • Immediately after assembly and clamping, test pieces are placed in a container.
  • Container must be impervious with a close-fitting lid and a small vent hole to accommodate air volume changes.
  • Purpose: Prevent moisture loss during heating.

• Oven Treatment:

  • Container with test pieces is placed in an oven at specified temperature ± 2°C.
  • Duration and exact temperature as per manufacturer's instructions.
  • After heating, cool until safe to handle.

• Post-Oven Conditioning:

  • Remove test pieces from clamps.
  • Store at room temperature (27 ± 2°C) for 16 to 26 hours before testing.

• Water Immersion:

  • Test pieces must be completely immersed in water as per Tables 2 and 3 (refer IS 851 for specific durations and temperatures).

Summary Table (Example):

flowchart TD
    A[Assemble & Clamp Test Pieces] --> B[Place in Impervious Container]
    B --> C[Oven Conditioning at Specified Temp ± 2°C]
    C --> D[Cool Container to Handle]
    D --> E[Remove from Clamps]
    E --> F[Store at 27 ± 2°C for 16-26 hours]
    F --> G[Water Immersion as per Tables 2 & 3]
    G --> H[Testing]

Note: Manufacturer's instructions override default parameters; always confirm temperature/time specifics.

IS 851: Pulling Test Pieces & Computing Results

Key Specifications:

• Testing Machine Accuracy: ±1% in measuring breaking load (Clause 1.1).
• Grip Distance:
  • Gap joints: 65–70 mm
  • Close-contact joints: 115–120 mm (Clause 3.1)
• Loading Rate: Should be consistent to avoid dynamic effects (Clause E-2).

Important Notes on Testing:

• Load transmission is non-axial; bending may affect results.
• Machines vary from flexible (articulated joints) to rigid grips.
• Rigid grips maintain alignment, reducing bending influence (Clause E-0.1).

Computation of Results:

• Measure breaking load (P) accurately.
• Compute joint strength as:

[ \text{Strength} = \frac{P}{A} ]

Where:

• (P) = breaking load (N)
• (A) = effective cross-sectional area of the joint (mm²)

Preparation of Test Pieces (Appendix F):

• Use test slips for close-contact joints.
• Follow dimensions and preparation methods as per Appendix F to ensure consistency.

flowchart LR
    A[Prepare Test Piece] --> B[Set Grip Distance]
    B --> C[Apply Load in Testing Machine]
    C --> D[Measure Breaking Load (P)]
    D --> E[Calculate Joint Strength = P / A]

This ensures standardized, reliable assessment of joint strength per IS 851.

IS 851: Preparation of Test Pieces for Close-Contact Joints (Clause 5.6.2, Appendix F)

Key Specifications:

• Test slips size: 150 mm length.
• Adhesive application: Coat the middle third of one slip's length.
• Inserts: 62.0 × 25.0 × 1.30 ± 0.13 mm (thickness) placed as per Fig. 1.
• Adhesive gap: Fill the gap between slips with excess adhesive.
• Clamping: Assemble slips, squeeze out excess adhesive, and clamp tightly.
• Conditioning: As per Appendix D (standard room conditions unless specified).
• Testing: Pull test as per Appendix E.

Failing Load Criteria:

Summary of Preparation Steps:

1. Cut two 150 mm slips.
2. Apply adhesive on middle third of one slip.
3. Insert metal inserts (62 × 25 × 1.3 mm).
4. Fill gap with adhesive.
5. Apply adhesive on second slip's middle third.
6. Join slips, clamp, and remove excess adhesive.
7. Condition as per Appendix D.
8. Test as per Appendix E.

flowchart LR
    A[Cut 150 mm slips] --> B[Apply adhesive on middle third of slip 1]
    B --> C[Place inserts (62x25x1.3 mm)]
    C --> D[Fill gap with adhesive]
    D --> E[Apply adhesive on slip 2 middle third]
    E --> F[Join slips and clamp tightly]
    F --> G[Condition (Appendix D)]
    G --> H[Pull test (Appendix E)]

This ensures consistent test pieces for reliable failing load determination of close-contact joints.

IS 851: Water Resistance Test Key Specifications

1. Test Types (Clause 3.1)

2. Gap Joints Water Resistance (Clause 5.5.1, Table 2)

3. Close-Contact Joints Water Resistance (Clause 5.5.2, Table 3)

4. Test Procedure Summary

• Prepare 6 test pieces as per Appendices C (Gap joints) or F (Close-contact joints).
• Condition samples as per Appendix D.
• Immerse in water at specified temperature/time (Appendix G).
• Pull test as per Appendix E.
• Average failing load must meet or exceed values in Tables 2 & 3.

This ensures joint durability under water exposure relevant to the type of plywood or panel tested.

flowchart LR
    A[Prepare 6 Test Pieces] --> B[Condition

IS 851: Resistance to Micro-Organisms (Mycological Test) - Key Points

Test Reference:

• Clause 5.6, Appendix H (Clauses 5.6.1 & 5.6.2)

Test Setup (Clause H-1.1):

• Use a rectangular dish (enameled iron, glass, or porcelain) filled with ~25 mm depth of moistened sawdust of non-durable timber (e.g., semul).
• Sawdust is moistened with aqueous solution containing 12 g cane sugar/litre.
• Moisture content: enough to wet sawdust but not squeeze out water (approx. 3x weight of dry sawdust).
• Specimens are pressed so their upper surface is flush with sawdust surface.

Test Requirements (from Table 5.3.1 excerpt):

• Tests performed only if purchaser requires.
• Applies to adhesive types: BWP, BWR, WWR (Clause 5.6.1 & 5.6.2).

Summary:

• Mycological test simulates fungal attack by incubating specimens on sugar-moistened sawdust.
• Minimum strength after test:
  • Gap joint: 180 kg
  • Close contact joint: 200 kg
• Ensures adhesive durability against microbial degradation.

flowchart LR
    A[Prepare sawdust with sugar solution] --> B[Fill dish with 25 mm sawdust]
    B --> C[Press test specimen flush with sawdust surface]
    C --> D[Incubate for specified period]
    D --> E[Measure failing load of joint]
    E --> F{Load >= Specified Min?}
    F -->|Yes| G[Pass]
    F -->|No| H[Fail]

This test ensures the adhesive's resistance to fungal degradation as per IS 851 standards.