Corrective & Preventive Action (CAPA) System

Berkshire is committed to the constant adherence to and improvement of the following methods and principles of process control:

  • Vertical Integration of the Raw Material Supply with Berkshire Processes
  • Dedicated Processing Equipment
  • Process Management Plans
  • Raw Material Specifications
  • Supplier Testing Coupled with Incoming Inspection
  • Change Control Management
  • Change Validation
  • Closed-Loop Corrective Action in Excursion Management

Process Capability

Process capability refers to the repeatability and consistency of a manufacturing process relative to the customer requirements, especially in terms of specification limits of a product parameter. This measure is used to objectively quantify the degree to which a process is or is not meeting its requirements.

Berkshire ensures delivery of the highest quality and most consistent products through constant focus and improvement in the following method and principle of process control:

Process capability measurements and analysis with goals of Cpk>1.33 for all critical parameters

Statistical Process Control (SPC)

To determine whether a process is operating within appropriate limits, Berkshire Corporation employs Statistical Process Control (SPC). Using statistical techniques, we monitor the quality of our processes and products to ensure the delivery of the highest-quality and most consistent products possible.

Our statistically developed control limits provide critical parameters for real-time analysis, monitoring, and alarm with regard to critical process inputs. An in-house metrology enables the measurement and testing of our critical process parameters and product characteristics. Statistical analysis then enables trend review and continuous improvement validation.

Wiper Test Methods

Berkshire tests wiper properties identified by contamination control professionals as most critical. The test methods we employ are vital to product development and quality assurance. All test methods are based on the Institute of Environmental Sciences and Technology (IEST) standard, IEST-RP-CC004.3: Evaluating Wiping Materials Used in Cleanrooms and Other Controlled Environments.

The following are brief descriptions of Berkshire’s Wiper Tests:

Cleanliness

Fibers

A wiper is “washed” in water using a biaxial shaker for five minutes. The fibers released into the water are filtered onto a membrane and counted microscopically. The results are expressed as fibers ≥ 100µm per square centimeter of wiper. [IEST-RP.CC004.3, Section 6.2.2.2]

Particle Generation / Biaxial Shake Test / Orbital Shake Test

A wiper is “washed” in water using a biaxial/orbital shaker for five minutes. A liquid-borne particle counter then tallies the particles released into the water. By dividing the total number of particles released by the area of the wiper, the results are expressed as particles ≥ 0.5µm per square centimeter of wiper. [IEST-RP.CC004.3, Section 6.1.3 / IEST-RP-CC004.3, Section 6.14]

Airborne Particle / Helmke Drum Test

Under controlled conditions, ten wipers are tumbled in a rotating drum to release particles from the wiper fabric. An airborne particle counter counts released particles and results are expressed as the number of particles per wiper per cubic foot of air sampled. [IEST-RP-CC003.4 Section B2.5]

Sorbency

Capacity

A sample of wiper material is saturated with as much fluid as it can hold. After one minute, the material is weighed, and results are expressed in milliliters of fluid per square meter. [IEST-RP.CC004.3, Section 8.1 (Modified)]

Efficiency

This calculation indicates how well a material absorbs, relative to others. Results, expressed in milliliters of liquid per gram of material, assisting in comparing one raw material with another. [IEST-RP. CC004.3. Section 8.1 (Modified)]

Rate

This test is a measurement of the time it takes a wiper to absorb half the total liquid it can hold. Results are expressed in seconds. [IEST-RP. CC004.3. Section 8.2 (Modified)]

Purity

Non-Volatile Residue

Berkshire generates non-volatile residue data using both deionized water and 2-Propanol. Results are expressed in grams of extractables per square meter of wiper, which is a useful guide to relative purity of wipers. [IEST-RP.CC004.3, Section 7.1.2]

Metallic Ions

Ions are extracted in deionized water and quantitatively analyzed by Ion Chromatography. Results are stated in parts per million (ppm). [IEST-RP.CC004.3, Section 7.2.2]

Bond Test Methods

Berkshire tests bond paper properties identified by contamination control professionals as most critical. The test methods we employ are vital to product development and quality assurance. All test methods are based on Recommended Practices and Standards from the Institute of Environmental Sciences and Technology (IEST), the International Organisation for Standardisation (ISO) and the Technical Association of the Pulp and Paper Industry (TAPPI).

The following are brief descriptions of Berkshire’s Bond Paper Tests:

Weight And Thickness

Basis Weight

A sample of bond paper, of known size, is weighed and results expressed as grams per square meter (g/m2). [TAPPI T-410]

Caliper

The thickness of a single sheet of bond paper is measured using a digital micrometer. Results for thickness are expressed in microns (µm). [TAPPI T-411]

Cleanliness

Fibers

A sample of bond paper is “sluiced” in a tray of water for one minute. The fibers released into the water are filtered onto a membrane and counted microscopically. The results are expressed as fibers ≥ 100µm per square centimeter of bond paper. [IEST-RP.CC020.2]

Particle Generation

A sample of bond paper is “sluiced” in a tray of water for one minute. A liquid-borne particle counter tallies the particles released into the water. By dividing the total number of particles released by the area of the bond paper sample, the results are expressed as particles ≥ 0.5µm per square centimeter of bond paper. [IEST-RP.CC020.2]

Purity

Non-Volatile Residue

Berkshire generates non-volatile residue data using both deionized water and 2-Propanol. Results are expressed in grams of extractables per square meter of bond paper. [IEST-RP.CC020.2]

Metallic Ions

Ions are extracted in deionized water and quantitatively analyzed by Ion Chromatography. Results are stated in parts per million (ppm). [IEST-RP.CC020.2]

Strength

Tear

The force required to tear bond paper is tested across the width and length of the sample. Results are expressed in millinewtons (mN). [ISO 1974:2012]

Burst

The pressure required to burst bond paper is tested with results expressed in kilopascals (kPa). [ISO 2758:2014]