Precision cleaning is a vital process across industries like aerospace, defense, and semiconductor manufacturing. Components must meet exacting contamination standards for systems to operate properly. Precision cleaning uses specialized techniques to remove particles, films, or residues down to micrometer sizes.
However, simply precision cleaning hardware is not sufficient - preserving post-cleanliness is equally critical. Even microscopic contamination introduced during storage and handling can lead to system issues or failures. Appropriate packaging is essential to safeguard cleaned components and prevent recontamination before final integration and use.
This article will explore key best practices for packaging precision cleaned components.
Table of Contents
Key Take-Aways:
- Proper packaging preserves cleanliness and prevents recontamination of critically cleaned surfaces during storage and transport.
- Packaging protects delicate precision components from physical damage through cushioning, immobilization, and impact resistance.
- Impermeable inner layers paired with durable outer layers exclude environmental contaminants over extended durations.
- Purging interiors with inert gases before hermetic sealing maintains clean, dry conditions optimized for surface sensitivity.
- Tamper-proofing methods and cleaning certifications ensure hardware retains "as-cleaned" state and compliance from processing through integration.
- Supplementary shipping protection shields inner packaging and contents from vibration, shock, compression and other hazards during delivery to final use point.
- For contamination-sensitive applications, partnering with skilled precision cleaning partners like Precision Fabricating & Cleaning leverages validated expertise as an extension of internal quality teams.
Why Proper Packaging is Important
Just as precision cleaning removes surface impurities, packaging removes environmental impurities. Both processes work hand-in-hand to deliver hardware free of deleterious materials to exacting customer needs and specifications.
Proper packaging extends the value of precision cleaning by securing cleanliness from the cleanroom until when parts are ultimately installed. It ensures the time, resources, and investments made into contamination control are not wasted prior to use.
Once components meet cleanliness specifications, keeping surfaces free of recontamination is imperative. Even fingerprints on a supposedly clean part can potentially ruin all previous cleaning efforts.
Proper Packaging serves three vital functions:
Preventing Recontamination
The primary goal is safeguarding critically cleaned surfaces from exposure to particulate, films, humidity, or other contaminants during storage and transport. Inner packaging layers provide an impermeable barrier sealed from the outside environment. Purging with dry inert gas excludes moisture and airborne impurities. Strict controls prevent re-soiling cleaned hardware.
Protecting Delicate Parts
Precision cleaned parts often contain highly sensitive instruments or easily damaged elements. Whether components, valves, or calibrated gauges, inappropriate handling can lead to chips, cracks, dents or other irreversible physical damage. Proper packaging cushions components, restricts movement, and shields parts from shocks/vibrations. It preserves mechanical integrity between cleaning and integration.
Guarding Package Integrity
Tamper-proof seals and other indicators verify packaging stays intact as intended. Breaches could allow contaminant ingress even if exterior layers seem unaffected. Signs of unapproved opening also prevent use of potentially corrupted parts. Visible monitoring and tamper evidence ensures components remain in pristine post-cleanliness state.
Proper Packaging Operations
Ideally, proper packaging takes place in the same tightly controlled cleanroom environment where verification occurs. This ensures parts do not risk exposure while being transferred to a separate packaging area. Stringent air/surface particle counts, humidity/temperature levels, and use of cleanroom garments and protocols preserve integrity.
However, it is sometimes impractical or infeasible to package all components in the same advanced cleanrooms used in earlier stages. In these situations, the separate packaging facilities must uphold standards preventing recontamination. Although cleanliness levels may slightly differ from precision cleaning rooms themselves, they ensure no backsliding of previously achieved contamination removal. Environmentally controlled areas for proper packaging must have:
- HEPA-filtered air supply and high air exchange rates
- Strict procedures for parts transfer under clean conditions
- Low-particle workstations and constant cleaning protocols
- Staff properly gowned per cleanroom discipline
- Sufficient contamination control for hardware being packaged
When unavoidable to package components elsewhere, separate facilities must never compromise established cleanliness. Robust preventative measures exclude reintroducing problematic films, residues or microscopic debris back onto cleaned hardware surfaces.
Approved Proper Packaging Materials
Precision cleaned components have strict cleanliness specifications, measured in particles per square centimeter or residual films in angstroms. Packaging in direct contact with hardware must match these stringent levels so as not to undo previous contamination removal efforts.
Typical approved materials include:
- Inner Layers: The innermost barrier contacting cleaned parts is typically an impermeable fluorohalocarbon film like Aclar or a polyamide film such as Nylon. For hardware exposed to oxygen systems, fluoropolymers are mandated while polyamides suffice for other applications. These non-shedding layers prevent particulate or gaseous recontamination of underlying surfaces.
- Outer Layers: Though not touching precision cleaned articles directly, outer layers also prevent ingress of contaminants over time. Polyethylene films are flexible, durable and help exclude moisture and vapors. Aluminized films also act as vapor barriers while resisting pinholes and micro-cracks. Outer layers mainly protect inner layers from damage, tears or other packaging failures.
- Cleanliness Standards: All packaging must meet or exceed the verified post-cleaning cleanliness of stored hardware itself. This includes scintillation counts for residual surface films as well as particulate densities. Certification procedures for proper packaging materials ensure pristine condition is maintained.
Purging and Sealing
Simply using approved packaging materials touches cleaned components is insufficient - how they are sealed is equally important. Proper purging and sealing:
- Interior Purging: Before sealing, the package interior is purged with clean, dry gaseous nitrogen. Removing residual ambient air inside excludes moisture and potential airborne contaminants. Nitrogen is an inert gas that will not react with surfaces. Humidity is also greatly reduced.
- Hermetic Sealing: Once purged, the package is completely sealed through methods like heat sealing or adhesive bonding. The seal ensures no outside air, particles, or moisture can enter over extended storage periods. Tight proper packaging also restricts movement that could release particles through abrasion. Approved techniques produce an impermeable barrier.
- Vacuum Packaging: Some high sensitivity applications may also draw vacuum within sealed packaging for an added measure against trace contamination. The lack of gases minimize particle retention and surface reactions. However, vacuums also increase chances of seal breach through handling wear or perforations.
Together, inert gas purging and high-integrity seals provide robust environmental isolation until components are ready for integration. They maintain cleanliness by preventing influx of contaminants. Proper sealing techniques suited for the specific materials are vital for storage life. Heat sealing ensures leak-tight, long-lasting seals against infiltration.
Specialized Proper Packaging Techniques
While fundamentals of interior purge bags and durable outer layers are consistent, proper packaging methods must accommodate different precision cleaned components and surfaces:
Pressure Sensitive Tapes
Tapes like vinyl or polyester with acrylic adhesives conform to specifications ensuring cleanliness and ease of removal after long durations. Taping avoids stretching which can fail package seals. An outer end tab simplifies removal without contaminating underlying layers.
Heat Sealing
Primary closure for bags relies on thermoplastic fusion under controlled temperature, pressure and dwell time profiles. This enables strong, leak-tight seals resisting moisture, gases and damage over extended durations. Improper heat sealing risks channels for contamination.
Proper Packaging Protecting Small Parts
Items such as o-rings and fasteners use individual inner bags heat welded shut after nitrogen purge to retain inert conditions without damage. Outers bags then group sealed bags for efficiency.
Shielding Tubes and Flanges: End caps, blank flanges, formed films and tapes reliably protect exposed tubing ends and flange openings during storage. All direct media surfaces have irremovable inner barriers and durable, snug-fitting outer protection.
Protecting Filter Elements
Filter elements are packaged in conformal inner bags per media requirements, expelling excess air before heat sealing. Outer layers of polyethylene and dimple wrap cushion the assembly, labeled as “Fragile” for care in handling. The snug fit and layering protects delicate filter membranes from pleat collapse or other damage during transports.
Protecting Gauges
Shock-sensitive devices like gauges or transducers cannot undergo vacuum packaging, but have ports wrapped under specifications then bagged in protective layers without air removal. The exclusion of vacuums prevents possible interior damage. These instruments require extra precautions against drops or vibration compared to more robust components. Careful handling preserves calibration and sensitive internals.
Effective packaging adapts based on factors like part geometries, surface sensitivity, storage length needs and transport modes. Tailored techniques for categories of hardware ensure contamination prevention goals are met.
Certification and Tamper Evidence
Documenting the cleaning and proper packaging of precision components provides assurance of cleanliness levels and proper techniques. This includes:
- Cleaning Certificates: All packaged cleaned hardware has documentation listing part numbers, serial numbers, cleaning specification followed, certification counts/results, and name of responsible processor. These assure end users that rigorous contamination control was performed.
- Tamper-Proofing: Seals, tapes or other tamper indicating mechanisms visually signal if packaging was opened or altered after cleaning processor completion. This prevents improper substitution, re-exposure of surfaces or questioning if handled components retain validated cleanliness levels, especially for subcontractor supply chain scenarios. Applied seals, labels and design elements verify no aspect was disturbed.
- Visible Inspection: Transparent bagging materials, humidity indicator cards, and other inspectable measures affirm preserved conditions from outside packaging. Determining "healthiness" of the systems avoids unnecessary seal breaking. External elements also make tampering patently evident even on high-integrity, double-bagged packaging.
Together, these practices provide traceability for cleaned parts, ensuring no loss of quality from providers to end component integration without clear responsibility. They also maintain trust in the absence of constant custody. Certification policies affirm parts remain in compliant, pristine states through each supply and handling stage.
Supplementary Shipping Protection
While interior packaging preserves cleanliness, outer durable packaging protects those layers from environmental and physical hazards of transport:
- Dimpled Wrap Cushioning: High-density polyethylene pads envelop packaged parts acting as a shock absorbing barrier against impacts, abrasion, and compression during handling. They safely spacing parts in collectors or shipping boxes without direct contact.
- Secured Interior Movement: Interior anchors, braces and partitions further restrict any motion of protected parts. This prevents particle generation from components rubbing together during vibration or shocks. Immobilizing interior goods prevents damage.
- Rigid Exteriors: Cardboard, wood or rigid plastic boxes add further crush/drop protection with high burst strength. Tightly packed interiors avoid shifting. Some systems like flange covers also guard corners from bending or tearing.
- Secured to Pallet: Bagged components are often stretch or shrink wrapped to a pallet to avoid box shifting. This prevents falling over or collisions across a truck bed or cargo hold. Pallets better distribute loads.
While cleaned parts packaging focuses on contamination and moisture, supplementary shipping safeguards fragility and physical survivability over transmission channels. Adequate shipping protection allows packages to endure significant abuse over long distances while shielding interior contents from deterioration. Defence-in-depth ensures cleaned hardware arrives safely.
Conclusion
Proper packaging is a vital final step in preserving the value of precision cleaned hardware. Appropriate materials, sealing techniques, and handling procedures are all tailored to sustain the contamination-free status that extensive cleaning processes achieve.
While fundamentals are consistent across applications, particulars adapt based on the forms and sensitivities of parts and instruments. Proper packaging combines both science in technical specifications and art in implementing those to safeguard investments in cleaning.
Partnering with knowledgeable cleaning houses who possess demonstrated expertise enables companies to meet proper packaging requirements for sensitive components. As industries push the boundaries of miniaturization and performance, contamination control grows ever more paramount. Trusted processors becoming extensions of internal quality teams.
Precision Fabricating & Cleaning is a leading choice for precision cleaning and proper packaging services across defense, space, semiconductor, aviation and other sectors with exacting needs.
Contact PFC today to learn more about how our capabilities can cost-effectively augment your quality programs.