Method for determination of formaldehyde content in particle board by extraction method called perforator method

IS 13745: Scope - Key Specifications & Formulas

Scope Summary:

• Applicable for determining formaldehyde content in particle boards.
• Extraction apparatus and procedure specified for standardized testing.
• Conditions for sampling, conditioning, and testing are defined.

Extraction Apparatus (Clause 5.3)

Perforator Value Formula (Clause 7.2)

[ \text{Perforator value} = \frac{3.0 \times (V_0 - V_1) \times (100 + M)}{m} \quad \text{mg formaldehyde/100 g dry board} ]

Where:

• (V_0) = volume (ml) of 0.01 mol/L thiosulphate for blank
• (V_1) = volume (ml) for test
• (M) = moisture content (%)
• (m) = mass (g) of test pieces before extraction

Note:

• 1 ml of 0.01 mol/L thiosulphate ≈ 0.15 mg formaldehyde
• Round results to next integer

Test Report Must Include (Clause 7.2)

• Board origin, type, thickness (mm), bulk density (kg/m³)
• Moisture content (%) at

IS 13745: Normative References - Key Details

Perforator Value Formula (Clause 7.2)

The formaldehyde content (Perforator value) in mg/100 g dry board is calculated as:

[ \text{Perforator value} = \frac{3.0 (V_0 - V_1) (100 + M)}{m} \quad \text{mg/100 g} ]

Where:

• (V_0) = volume (ml) of 0.010 mol/L thiosulphate for blank test
• (V_1) = volume (ml) of 0.010 mol/L thiosulphate for test
• (M) = moisture content (%) of particle board
• (m) = mass (g) of test pieces before extraction

Note: 1 ml of 0.01 mol/L thiosulphate ≈ 0.15 mg formaldehyde.

Test Report Must Include (Clause 7.2)

• Origin, type, thickness (mm), bulk density (kg/m³)
• Sampling & testing dates, moisture content (%)
• Perforator value (mg formaldehyde/100 g dry board)
• Board condition details (e.g., location, surface finish)
• Disclaimer on formaldehyde emission variability

Extraction Apparatus (Clause 5.3)

Key components for formaldehyde extraction:

• Spiral condenser (~400 mm length)
• Conical adaptors (various sizes)
• Filter insert (porosity P 160, 100-160 µm)
• Perforator attachment (1000 ml with cock)
• Round-bottom flask (1000 ml)
• Double bulbed tube (~380 mm length)
• Absorption bulb (250 ml conical flask)

flowchart LR
    A[Sample Preparation] --> B[Extraction Apparatus]
    B --> C[Formaldehyde Extraction]
    C --> D[Titration with Thiosulphate]
    D --> E[Calculate Perforator Value]
    E --> F[Report Generation]

This ensures standardized measurement of formaldehyde content in particle boards as per IS 13745.

IS 13745: Sampling & Preparation of Test Pieces

Key Specifications

• Test Piece Size:

  • 25 mm × 25 mm × board thickness (Clause 3.1.2)

• Number of Test Pieces:

  • 18 pieces for moisture content (Clause 3.1.2)
  • Additional pieces (~500 g) for formaldehyde extraction

• Conditioning:

  • Boards: 43 days
  • Test pieces: 6 days
  • Environment: 27 ± 2°C, 65 ± 5% RH (Clause 3.3)
  • For production control: test pieces stored hermetically at ambient temp, test within 24 hrs (Clause 3.2)

• Moisture Content Determination:

  • Use 5 to 6 test pieces (25 mm × 25 mm) (Clause 6.2)

Sampling & Preparation Summary

Notes

• Use analytical grade reagents and distilled/demineralized water for analysis (Clause 3.3).
• Conditioning significantly affects moisture and formaldehyde results.

flowchart TD
    A[Board Sampling] --> B{Purpose?}
    B -->|Production Control| C[Cut immediately]
    C --> D[Store hermetically at ambient temp]
    D --> E[Test within 24 hrs]
    B -->|Other Purposes| F[Condition boards 43 days]
    F --> G[Cut test pieces]
    G --> H[Condition test pieces 6 days at 27±2°C, 65±5% RH]
    H --> I[Test as agreed]

This ensures repeatable and reliable formaldehyde and moisture testing per IS 13745.

IS 13745 Key Specifications & Formulas for Reagents and Materials

Extraction Apparatus (Clause 5.3)

• Components: Spiral condenser (400 mm), conical adaptors (various sizes), filter insert (porosity P160, 100-160 µm, diameter 60 mm), perforator attachment (1000 ml, 4 mm bore), round-bottom flask (1000 ml), double bulbed tube (380 mm length, 50 mm bulb diameter), absorption bulb (250 ml conical flask).
• All dimensions in mm as per Fig.1.

Reagents (Clauses 4.2, 4.4)

Titration Procedure (Clause 5.4)

1. Mix 100 ml formaldehyde solution + 50 ml iodine + 20 ml NaOH.
2. Keep in dark for 15 min.
3. Add 10 ml H2SO4 → brown color (excess iodine).
4. Back titrate excess iodine with sodium thiosulphate using starch indicator.

Important Notes

• Avoid oxidizable impurities (ethyl alcohol, acetone).
• Standardize iodine and thiosulphate solutions regularly.

Formula for Formaldehyde Content (from titration)

[ \text{Formaldehyde (mg)} = (V_{\text{I2}} - V_{\text{Na2S2O3}}) \times N \times 30 ]

Where:

• (V_{\text{I2}}) = volume of iodine solution (ml)
• (V_{\text{Na2S2O3}}) = volume of thiosulphate used (

IS 13745: Extraction Apparatus Specifications (Clause 5.3)

The apparatus for formaldehyde determination consists of these key parts:

Key Operational Points (Clause 6):

• Use 100 g test pieces + 600 ml toluene in round-bottom flask.
• Fill perforator attachment with 1000 ml distilled water, leaving 10–20 mm space above siphon outlet.
• Absorption bulb filled with ~100 ml distilled water.
• Maintain reflux rate: 50–70 drops/min.
• Extraction duration: 2 hours from first bubbling (bubbling onset between 20–30 min).
• Thermal insulation on perforator sidearm to ensure toluene circulation.

Diagram: Apparatus Flow (Simplified)

flowchart LR
    A[Round-bottom Flask (1000 ml)] --> B[Perforator Attachment (1000 ml)]
    B --> C[Spiral Condenser]
    C --> D[Double Bulbed Tube]
    D --> E[Absorption Bulb (250 ml)]

This setup ensures proper reflux, extraction, and absorption for formaldehyde content analysis.

IS 13745: Execution of Tests - Key Specifications & Apparatus

Conditioning of Boards & Test Pieces (Clause 3.3)

• Boards conditioned for 43 days at 27 ± 2°C and 65 ± 5% RH.
• Test pieces conditioned for 6 days at same conditions.
• Use analytical grade reagents and distilled/demineralized water for analysis.
• For boards already installed or special cases, sampling and conditioning methods must be mutually agreed and documented.

Extraction Apparatus (Clause 5.3 & Fig.1)

• Spiral condenser (~400 mm length; cone 45/40, socket 29/32)
• Conical adaptors (45/40 to 71/51 and 29/32 to 45/40)
• Filter insert: Porosity P160 (100-160 µm), 60 mm diameter
• Perforator attachment: 1000 ml with 4 mm bore cock
• Round-bottom flask: 1000 ml, socket 40/50
• Double bulbed tube: ~380 mm length, bulbs ~50 mm diameter
• Absorption bulb: Conical flask 250 ml
• Two 25 ml measuring cylinders (Clause 5.9)

Notes on Testing

• Test results depend on board condition at testing time.
• Sampling, preparation, and conditioning affect results and must be reported.

Summary Diagram of Extraction Apparatus (simplified):

graph LR
A[Round-bottom Flask 1000 ml] --> B[Perforator Attachment with Cock]
B --> C[Filter Insert (P160)]
C --> D[Spiral Condenser]
D --> E[Double Bulbed Tube]
E --> F[Absorption Bulb (250 ml)]

This setup ensures accurate formaldehyde content determination in particle boards per IS 13745.

IS 13745: Calculation and Expression of Results (Clause 6.5.2 & related)

Key Points:

• Number of Determinations (6.1):

  • Tests must be done in duplicate.
  • Duplicate values may differ by max 5 mg/100 g or 10% of the larger value.
  • If exceeded, perform a third determination.
  • For routine control, a single test may suffice.

• Calculation of Result:

  • Average the two acceptable duplicate values.
  • If a third test is done, use the average of the two closest values.

• Expression of Results:

  • Formaldehyde content is expressed as mg per 100 g of the sample.

Extraction Apparatus (Clause 5.3 & Fig.1):

Summary Diagram of Apparatus Flow:

flowchart LR
    A[Round-bottom Flask (6)] --> B[Perforator Attachment (4)]
    B --> C[Filter Insert (3)]
    C --> D[Conical Adaptor (5)]
    D --> E[Double Bulbed Tube (7)]
    E --> F[Spiral Condenser (1)]
    F --> G[Conical Adaptor (2)]
    G

IS 13745: Test Report Key Formulas, Tables & Specifications

1. Perforator Value Calculation (Clause 7.2)

[ \text{Perforator Value (mg/100g dry board)} = \frac{3.0 (V_0 - V_1)(100 + M)}{m} ]

• (V_0) = ml of 0.010 mol/L thiosulphate for blank test
• (V_1) = ml of 0.010 mol/L thiosulphate for test
• (M) = Moisture content (%) of board
• (m) = Mass (g) of test piece before extraction

Note:

• 1 ml of 0.01 mol/L thiosulphate ≈ 0.15 mg formaldehyde
• Round results to next integer

2. Test Conditions (Clause 3.3)

• Conditioning of boards: 43 days at 27 ± 2°C, 65 ± 5% RH
• Conditioning of test pieces: 6 days at same conditions
• Use analytical grade reagents and distilled/demineralized water

3. Minimum Test Report Information

• Origin, type, thickness (mm), bulk density (kg/m³)
• Manufacturing, sampling, titration dates
• Moisture content (%) at testing
• Perforator value (mg formaldehyde/100g dry board)
• Description of any deviations from standard
• Include standard disclaimer on formaldehyde emission variability

4. Equipment

• Two 25 ml measuring cylinders (Clause 5.9)

Summary Diagram: Test Report Contents

graph TD
  A[Test Report] --> B[Board Origin]
  A --> C[Board Type & Thickness]
  A --> D[Bulk Density]
  A --> E[Dates: Manufacture, Sampling, Titration]
  A --> F[Moisture Content]
  A --> G[Perforator Value]
  A --> H[Deviations & Remarks]
  A --> I[Standard Disclaimer]

Use this formula and report structure to ensure compliance and clarity in formaldehyde content testing per IS 13745.

IS 13745: Committee Composition & Key Specifications

Committee Composition (Annex A)

• Chairman: Dr. P. M. Ganapathy (Indian Plywood Industries Research and Training Institute)
• Convener: Dr. H. N. Jagadeesh (Indian Plywood Industries Research and Training Institute)
• Members: Representatives from:
  • Forest Departments
  • Plywood Manufacturers' Associations (West Bengal, Assam, South India)
  • Directorate General of Technical Development
  • Ministry of Defence, Railways, Civil Aviation, Public Works
  • National Test House, National Buildings Organization, Forest Research Institute
  • Central Building Research Institute (CSIR)
  • Indian Academy of Wood Science
  • Federation of Indian Plywood and Panel Industry
  • Various plywood manufacturing companies

Key Formulas

• Perforator Value (Formaldehyde content):

[ \text{Perforator value} = \frac{3.0 (V_0 - V_1) (100 + M)}{m} \quad \text{mg/100 g dry board} ]

Where:

• (V_0) = volume (ml) of 0.01 mol/L thiosulphate for blank

• (V_1) = volume (ml) of 0.01 mol/L thiosulphate for test

• (M) = moisture content (%)

• (m) = mass (g) of test pieces before extraction

• Moisture Content:

[ M = \frac{M_1 - M_0}{M_0} \times 100 ]

Where:

• (M_1) = mass before drying (g)
• (M_0) = mass after drying (g)

Test Report Must Include:

• Board origin, type, thickness (mm), bulk density (kg/m³)
• Dates (manufacture, sampling, titration)
• Moisture content (%)
• Perforator value (mg formaldehyde/100 g dry board)
• Additional relevant details (surface coating, finishing, etc.)

This committee ensures standardization and quality control in particle board formaldehyde testing per IS 13745.