Extenders for Use in Synthetic Resin Adhesives (Urea-formaldehyde) for Plywood- Code of Practice

IS 1508: Scope - Key Formulas and Specifications

• Scope: Specifies criteria for conformity of moisture, ash, and fat content in materials, ensuring compliance with test results rounded per IS 2-1960.

Key Formulas (Clause 3.4.3)

• Mean (X):
  [ X = \frac{\sum \text{Test Results}}{\text{Number of Tests}} ]

• Range (R):
  [ R = \text{Maximum Test Result} - \text{Minimum Test Result} ]

• Corrected Mean:
  [ \text{Corrected Mean} = X + 0.6 \times R ]

Criterion for Conformity (Table 2)

Notes:

• Test results are recorded as per IS 1508 and rounded off according to IS 2-1960.
• Appendix B (Clause 4.2) provides detailed procedures for moisture content determination.

flowchart TD
    A[Test Results] --> B[Calculate Mean (X)]
    A --> C[Find Range (R)]
    B --> D[Calculate Corrected Mean = X + 0.6R]
    C --> D
    D --> E{Check Criterion}
    E -->|Meets| F[Conforms to Standard]
    E -->|Fails| G[Does Not Conform]

This ensures material quality compliance per IS 1508.

IS 1508 - Definitions and Key Formulas

Key Formulas for Test Results (Clause 3.4.3)

• Mean (X):
  [ X = \frac{\sum \text{Test Results}}{\text{Number of Tests}} ]

• Range (R):
  [ R = \text{Maximum Test Result} - \text{Minimum Test Result} ]

• Corrected Mean:
  [ \text{Corrected Mean} = X + 0.6R ]

Criterion for Conformity (Table 2)

Notes

• Final test values should be rounded per IS 2-1960.
• Defects in vegetable-based starch extenders include impurities (sand, clay), coarse granules, and deteriorated flour affecting ash content and odour (Appendix G).

flowchart LR
    A[Test Results] --> B[Calculate Mean (X)]
    A --> C[Calculate Range (R)]
    B --> D[Calculate Corrected Mean = X + 0.6R]
    D --> E{Check Criterion}
    E -->|Meets| F[Conforms]
    E -->|Fails| G[Non-Conformance]

This summary provides essential definitions and conformity criteria for moisture, ash, and fat content testing per IS 1508.

IS 1508: Sampling and Test Specimen Preparation

Key Specifications from Clause 3.2:

• Individual Test Specimen (3.2.1):

  • Take 3 scoop-fulls from each selected bag:
    • 1 from top
    • 1 from middle
    • 1 from bottom
  • Collect about 2 kg or more of powder.
  • Mix thoroughly.
  • Store in a moisture-proof container.

• Composite Specimen (3.2.2):

  • Take equal quantities from each bag selected.
  • Mix thoroughly to form a composite.
  • Store in a moisture-proof container.

Additional Notes:

• Results must be rounded off as per IS 2-1960, matching the significant figures of the specified values.

Summary Table:

flowchart LR
    A[Select Bags] --> B[Individual Specimen]
    B --> C[3 scoops from top, middle, bottom]
    C --> D[Mix ~2 kg powder]
    D --> E[Store in moisture-proof container]

    A --> F[Composite Specimen]
    F --> G[Equal quantity from each bag]
    G --> H[Mix thoroughly]
    H --> I[Store in moisture-proof container]

This ensures representative, moisture-protected samples for reliable testing.

IS 1508 - Requirements: Key Formulas & Specifications

1. Mean and Range Calculations (Clause 3.4.3)

• Mean (X):
  [ X = \frac{\sum \text{Test Results}}{\text{Number of Tests}} ]
• Range (R):
  [ R = \text{Maximum test value} - \text{Minimum test value} ]

2. Criterion for Conformity (Table 2)

3. Compliance Check (Clause 3.4.3.1)

• The lot conforms if the corrected mean ≤ specified limit.

4. Rounding Off (IS 2-1960)

• Final test values should be rounded to the same decimal places as specified values.

flowchart TD
    A[Test Results] --> B[Calculate Mean (X)]
    A --> C[Calculate Range (R)]
    B & C --> D[Calculate Corrected Mean: X + 0.6R]
    D --> E{Corrected Mean ≤ Specified Limit?}
    E -- Yes --> F[Conforming Lot]
    E -- No --> G[Non-Conforming Lot]

This ensures statistical consistency and quality control in testing moisture, ash, and fat contents per IS 1508.

IS 1508: Common Defects in Vegetable Based Starchy Extenders (Clause 5 & Appendix G)

Key Points on Common Defects (Appendix G):

• Inferior Materials: Use of deteriorated flours, mill sweepings is limited. These increase ash content and cause discoloration and bad odor.
• Impurities: Tapioca powder may contain sand/clay; excessive amounts increase ash content and affect quality.
• Granule Size: Coarse granules swell slowly and produce uneven viscosity. Fine powder is preferred for smooth, uniform solutions.

Specifications:

Acidity Limit (Clause 4.6):

• Max titrable acidity: 12 ml of 0.1 N NaOH per 1 g of moisture, ash, and fat-free material.

Summary Diagram: Defect Impact on Extender Quality

flowchart LR
    A[Raw Material] --> B{Quality}
    B -->|Good| C[Fine Powder]
    B -->|Inferior| D[Deteriorated Flour / Mill Sweepings]
    B -->|Impurities| E[Sand / Clay]
    C --> F[Uniform Viscosity]
    D --> G[High Ash, Bad Odor]
    E --> G
    G --> H[Lower Quality Extender]

Use fine, clean, good-quality flour/starch to ensure extender quality per IS 1508.

IS 1508: Marking and Packaging Key Points

Marking (Clause 7.1)

Each package must clearly show:

• Name of the material
• Manufacturer’s name or trademark
• Net weight of contents
• Year and month of manufacture

Packaging

• Packaging should protect the material from contamination and damage.
• Use appropriate materials (e.g., wooden cases, fiberboards) as per the nature of the product.
• Follow IS standards related to packaging materials (e.g., IS 4834 for veneered wood boards).

Quality Assurance (Clause 3.4.3)

• Calculate Mean (X) and Range (R) of test results (moisture, ash, fat).
• Use Corrected Mean = X + 0.6R to check conformity.

ISI Mark (Clause 7.1.1)

• Use ISI mark only under license.
• Indicates compliance with IS 1508 and continuous quality control.

flowchart TD
    A[Packaging] --> B[Marking]
    B --> C[Material Name]
    B --> D[Manufacturer Name]
    B --> E[Net Weight]
    B --> F[Date of Manufacture]
    A --> G[Protection from Damage]
    A --> H[Use IS Standard Packaging]

This ensures traceability, quality, and safe transport of materials per IS 1508.

IS 1508: Determination of Fineness of Granules

Key Specifications (Clause 4.1)

• Powder must completely pass through IS Sieve 100 (aperture size: 150 microns).
• At least 80% by weight must pass through IS Sieve 80 (aperture size: 180 microns).

Testing Procedure (Appendix A)

1. Dry the powder to constant weight.
2. Weigh the sample before sieving.
3. Sieve the sample through IS Sieve 80 and IS Sieve 100 separately.
4. Weigh the residue retained on each sieve.

Calculation Formula

[ \text{Percentage passing} = \frac{\text{Weight of powder passing through sieve}}{\text{Total weight of sample}} \times 100 ]

Summary Table

flowchart TD
    A[Weigh dried powder sample] --> B[Sieve through IS Sieve 80]
    B --> C[Weigh residue retained on Sieve 80]
    B --> D[Collect powder passing Sieve 80]
    D --> E[Sieve through IS Sieve 100]
    E --> F[Weigh residue retained on Sieve 100]
    E --> G[Collect powder passing Sieve 100]
    C & F --> H[Calculate % passing for each sieve]

This ensures granules meet fineness requirements for quality control per IS 1508.

IS 1508: Determination of Moisture Content

Key Formula (Appendix B, Clause 4.2)

[ \text{Moisture content (%)} = \frac{\text{Loss in weight}}{\text{Oven-dry weight of sample}} \times 100 ]

• Loss in weight = Weight before drying - Weight after drying
• Dry sample in an oven at 105 ± 5°C until constant weight.

Moisture Content Specification (Clause 4.2)

• Moisture content shall not exceed 14% by weight.

Criterion for Conformity (Clause 3.4.3, Table 2)

Summary:

• Calculate moisture % by weight loss on oven-dried sample.
• Ensure moisture ≤ 14% for compliance.
• Use mean and range of multiple tests to find corrected mean for conformity check.

flowchart TD
    A[Sample Weighing] --> B[Dry in Oven at 105°C]
    B --> C[Weigh Dry Sample]
    C --> D[Calculate Weight Loss]
    D --> E[Compute Moisture Content %]
    E --> F{Moisture ≤ 14%?}
    F -- Yes --> G[Pass]
    F -- No --> H[Fail]

Determination of Ash Content as per IS 1508

Procedure (Appendix C, Clause 1.1)

• Take ~5 g of the sample in a weighed crucible.
• Dry in air-oven at 100–105°C until constant weight (oven-dry sample).
• Incinerate on a clay-pipe triangle with a low Bunsen flame.
• Gradually increase flame to full capacity until carbon-free ash remains.
• Heat crucible + ash for 20 min at 750°C (muffle furnace or blowpipe).
• Cool in desiccator and weigh the ash.

Formula (Clause C-2.1)

[ \text{Ash content (% by weight)} = \frac{b}{a} \times 100 ]

Where:

• ( a ) = weight of oven-dry sample (g)
• ( b ) = weight of ash (g)

Specification (Clause 4.3)

• Ash content ≤ 4% of oven-dry weight.

Summary Table

flowchart TD
    A[Sample ~5g] --> B[Oven dry at 100-105°C]
    B --> C[Incinerate at low flame]
    C --> D[Increase flame to full]
    D --> E[Heat at 750°C for 20 min]
    E --> F[Cool & weigh ash]
    F --> G[Calculate % Ash = (ash weight / oven dry weight)*100]

This method ensures accurate ash determination per IS 1508.

IS 1508: Determination of Fat Content (Appendix D, Clause 4.4)

Key Formula for Fat Content (% by weight)

[ \text{Fat %} = 100 \times \frac{W_2 - W_3}{W_1} ]

• W1 = Weight of oven-dry sample (g)
• W2 = Weight of flask + fat (g)
• W3 = Weight of flask after light petroleum extraction (g)

Extraction Procedure (Clause 3.2 Summary)

• Cool sample tube to 27 ± 2°C.
• Add 10 ml alcohol, mix thoroughly.
• Add 25 ml ether, seal with water-wetted cork (pre-extracted with ether).
• Shake vigorously for 30 s.
• Wash cork and tube neck with 25 ml light petroleum, mix again.
• Allow layers to separate (≥30 min) or centrifuge at 1000 rpm for 30 s.
• Remove ether layer into a dry 200 ml flask, wash tube with ether 2x (10 ml each).
• Repeat extraction 3 more times.
• Use water-wetted cork (no rubber stoppers).

Criterion for Conformity (Table 2, Clause 3.4.3)

Notes:

• Use distilled water, rectified spirit, ether, and HCl as per specifications.
• Ensure thorough mixing for complete fat extraction.
• Calculate mean and range from multiple tests for accuracy.

flowchart TD
    A[Oven-dry Sample (W1)] --> B[Extraction with Alcohol + Ether]
    B --> C[Separation of Fat Layer]
    C --> D[Evaporation of Ether]
    D --> E[Weigh Flask + Fat (W2)]
    E --> F[Extraction with Light Petroleum]
    F --> G[Weigh Flask after Extraction (W3)]
    G --> H[Calculate Fat % = 100*(W2

IS 1508: Determination of Nitrogen Content (Clause 4.5, Appendix E)

Key Formula (Clause E-3.1):

Calculate nitrogen % on moisture, fat, and ash-free basis as:

[ \text{Nitrogen %} = \frac{N \times 10,000}{W \times (100 - M - A - F)} ]

Where:

• N = Weight of nitrogen (g) from titration (Clause E-2.7)
• W = Weight of sample (g) (Clause E-2.1)
• M = Moisture content (%)
• A = Ash content (%)
• F = Fat content (%)

Determining Nitrogen Weight (Clause E-2.7):

[ N = (V_{\text{sample}} - V_{\text{blank}}) \times 0.0028 \text{ g} ]

• (V_{\text{sample}}) = Volume (ml) of 0.2 N H₂SO₄ used for sample
• (V_{\text{blank}}) = Volume (ml) of 0.2 N H₂SO₄ used for blank
• 1 ml of 0.2 N H₂SO₄ corresponds to 0.0028 g nitrogen

Summary:

• Nitrogen content is standardized on a dry, fat-free, ash-free basis.
• Use titration volumes to find nitrogen weight.
• Adjust for moisture, fat, and ash to get accurate nitrogen %.

flowchart TD
    A[Sample Weight (W)] --> B[Determine M, A, F (%)];
    B --> C[Calculate N from titration];
    C --> D[Apply formula: N% = (N*10000)/(W*(100-M-A-F))];
    D --> E[Final Nitrogen Content %];

This ensures consistent nitrogen determination as per IS 1508.

IS 1508: Determination of Acidity (Appendix F, Clause 4.6)

Key Formula for Acidity Calculation (Clause F-2.1):

[ \text{Acidity} = \frac{10,000 \times (500 N_1 - 50 V N_2)}{W (100 - M - A - F)} ]

Where:

• (N_1) = Normality of standard NaOH solution
• (V) = Volume (ml) of standard H₂SO₄ used to neutralize 50 ml supernatant
• (N_2) = Normality of standard H₂SO₄
• (W) = Weight (g) of sample
• (M) = Moisture % by weight
• (A) = Ash % by weight
• (F) = Fat % by weight

Notes:

• Acidity is expressed as ml of 0.1 N NaOH per 100 g of moisture-, fat-, and ash-free sample.
• The test involves titrating the sample supernatant with standard alkali and acid solutions.
• Moisture, fat, and ash percentages are deducted to get the dry basis for acidity.
• Blank test titration volume must be deducted from sample titration volume for accuracy (Clause 2.7).

Quick Reference:

This formula standardizes acidity on a moisture-, fat-, and ash-free basis for consistent quality control.

IS 1508: Common Defects in Vegetable Based Starchy Extenders (Appendix G)

Key Points from Appendix G (Clause 5.1):

• Material Quality:

  • Use only good quality flours/starches; avoid deteriorated flours or mill sweepings.
  • Inferior materials increase ash content and cause discoloration.
  • Deteriorated flour may impart bad odor or mouldy appearance.

• Impurities:

  • Tapioca powder may contain sand and clay impurities.
  • High impurities increase ash content and affect visual quality.

• Particle Size:

  • Coarse granules swell slowly and give uneven texture.
  • Powder must be finely ground for uniform viscosity and smoothness.

Additional Specifications:

Summary Table: Defects & Indicators

flowchart TD
    A[Raw Material] --> B{Quality Check}
    B -->|Good Quality| C[Fine Grinding]
    B -->|Deteriorated/Impurities| D[Reject or Limit Usage]
    C --> E[Uniform Powder]
    E --> F[Extender Product]
    D --> G[High Ash, Bad Odor, Poor Texture]

Note: Always perform ash content and sensory tests to ensure compliance with IS 1508 standards.