Pin Holes

1.0 PURPOSE

1.1 To establish a standard method for detecting and counting pinholes in aluminium foil used for Pharma & Food packaging.

2.0 SCOPE

2.1 This procedure applies to all incoming aluminium foil (e.g. blister foil, strip foil).

3.0 REFERENCE(S) & ATTACHMENTS

3.1 References

3.1.1 In-house

3.2 Attachments

3.2.1 Nil

4.0 RESPONSIBILITY

4.1 Quality Control Analyst:

4.1.1 Responsible for performing the test and recording data.

4.2 Supervisor / Manager:

4.2.1 Responsible for reviewing and approving the test results.

4.3 QA Head / Plant Head:

4.3.1 To approve the new or revised STM, and to ensure the implementation of the defined system.

5.0 DISTRIBUTION

5.1 Quality Assurance

5.2 Quality Control

6.0 DEFINITION(S) & ABBREVIATION(S)

6.1 Definitions

6.1.1 Pinhole Light Box: An enclosed box equipped with a light source delivering an illumination of at least 1000 lux at the inspection surface.

6.1.2 Magnifying Glass: With 5x to 10x magnification power.

6.1.3 Darkened Room: A room with minimal ambient light to optimize visibility.

6.2 Abbreviations

6.2.1 Nil

7.0 PROCEDURE

7.1 Sampling

7.1.1 Cut three representative samples from the foil roll.

7.1.2 Sample Templates: Prepared frames of specified dimensions (e.g. 100 mm, 200 mm, 250 mm).

7.1.3 Avoid using the outermost layers of the roll.

7.1.4 Ensure each sample matches the size of the test frame template.

7.1.5 Keep samples flat and free of artificial wrinkles or creases.

7.2 Testing Environment

7.2.1 Turn off the main overhead lights in the testing room.

7.2.2 Ensure the room is sufficiently dark.

7.2.3 Turn on the pinhole light box.

7.3 Examination

7.3.1 Place the test specimen flat over the viewing window of the light box.

7.3.2 Ensure no light escapes from the edges around the sample.

7.3.3 Look directly down onto the sample surface from a distance of approximately 30 cm.

7.3.4 Count every pinpoint of light that penetrates through the foil.

7.3.5 Use a magnifying glass to verify doubtful or microscopic points.

7.3.6 Mark each detected pinhole with the fine marker pen.

7.3.7 Repeat the process for the remaining two samples.

7.4 Calculations

7.4.1 Record the total number of pinholes found in each tested sample area.

7.4.2 Calculate the average number of pinholes per square meter using the formula below:

7.4.3 Pinholes/m² = Total number of pinholes counted / Total area of tested samples (in m²)

7.5 Acceptance Criteria

7.5.1 Thickness < 20 microns: No pinholes allowed in the tested area.

7.5.2 Thickness ≥ 20 microns: Must meet specification limits (typically less than 10 to 20 pinholes per square meter).

7.5.3 Pinhole Size: No individual pinhole must exceed the maximum allowable diameter specified in the raw material specification.

7.6 Documentation

7.6.1 Record the Batch Number, Date of Testing, and Analyst Name.

7.6.2 Log the total pinhole count and calculated value per square meter in the raw material analytical report.

8.0 REVISION HISTORY

+----------------+----------------+----------------+----------------+----------------+----------------+ | Revision No. | 00 | Effective | | CC No. | | | | | Date | | | | +----------------+----------------+----------------+----------------+----------------+----------------+ | Details of revision: New SOP | +-----------------------------------------------------------------------------------------------------+