Demystifying Cold and Frozen Storage - DHPSNYdhpsny.org/sites/default/files/pdfs/DHPSNY Cold...
Transcript of Demystifying Cold and Frozen Storage - DHPSNYdhpsny.org/sites/default/files/pdfs/DHPSNY Cold...
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Demystifying Cold and Frozen StorageBarbara Lemmen
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A decrease of 10° doubles the lifespan of organic objects
Benefits
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Benefits
Gains years of useful life for original objects
Provides low temperature and low humidity
Buys time to plan and raise money for preservation
Often costs less then digitization
Decreases use and browsing
Best preservation method for unstable materials
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Temperature Ranges
Room Temperature 70°F / 20°C
Cool 54°F / 12°C
Cold 40°F / 4°C
Frozen 32°F / 0°C
Sub-Zero < 0°F / -20°C
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Concerns
Ice crystals forming
Thermal shock
Dimensional changes
Mechanical damage
Risk for condensation
Limited access
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Concerns
Ice crystals forming
Thermal shock
Dimensional changes
Mechanical damage
Risk for condensation
Limited access
Research shows that these are not an issue
and/or
can be addressed with proper procedures
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Costs
• Initial purchase and installation of equipment
• Vapor-proof packaging materials + labor costs
• Storage furniture
• Energy
• Security
• Maintenance
Courtesy of the NPS
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5 Stages
1. Identify and Prioritize Items
2. Prepare the Collection
3. Select Equipment or Facilities
4. Access the Collection
5. Monitor and Maintain the System
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Prioritization
Material
Condition-- Acceptable loss -- Rate of deterioration
Value-- Research-- Cultural-- Future earnings potential-- Obsolescence factor for AV
Access
Budget
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Do you have?
Earlier Film Base Photographic Materials
Color Photographic Materials
Inkjet Prints
Poor Quality Paper and Books
Audiovisual Media
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Film: Black-and-White and Color
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Film
ISO Medium-term Storage Conditions =
ISO Extended-term Storage Conditions =https://filmcare.org/storage_categories
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Photographic Prints: Traditional and Digital
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Courtesy IPI
Photographic Prints
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Audio Visual Media: Magnetic Tape
Courtesy of Wikipedia
ISO 18933:2012Polyester and acetate base
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Audio Visual Media: Optical Disc Media
http://www.yourdictionary.com/optical-disc
ISO 18925:2013
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Paper
NISO Standard TR01-1995 Paper Records: 35-65°F (2 - 18°C) and 30-50%
Brittle wood-pulp paper – approximately 1850-1950
Courtesy of Middlebury College
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Exceptions for Frozen Storage
CDs and DVDs
Collodion negatives
Instant prints, e.g. Polaroids
Additive color processes
Cased photographic images
Bound volumes?
Courtesy Library of Congress
Courtesy swiss-miss.com
Kuriositas.com
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5 Stages
1. Identify and Prioritize Items
2. Prepare the Collection
3. Select Equipment or Facilities
4. Access the Collection
5. Monitor and Maintain the System
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Organization and intellectual control
Critical for retrieval
Process all materials
Create an inventory, labels, vault / freezer maps
Reformat/digitize
Courtesy of Henry Wilhelm
Copyright 2018, CCAHA, all rights reserved.
Organization and intellectual control
Critical for retrieval
Process all materials
Create an inventory, labels, vault / freezer maps
Reformat/digitize
Place high priority itemsinto cold storage
ASAP and digitize
when accessed
Courtesy of Henry Wilhelm
Copyright 2018, CCAHA, all rights reserved.
Rehousing
Replace enclosures and boxes
only if unsound, weak, or brittle
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Relative Humidity (RH)
As the temperature drops, RH increases –- water must be removed to maintain a low RH
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Relative Humidity (RH)
If a cold object is brought into a warm room, it crosses the dew point (100% RH) and condensation occurs
Copyright 2018, CCAHA, all rights reserved.
Relative Humidity (RH)
If a cold object is brought into a warm room, it crosses the dew point (100% RH) and condensation occurs
https://i.pinimg.com/originals/cf/7b/00/cf7b00d574e923171f65ea644e19d5e2.jpg
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Vapor-proof Packaging
Creates a microclimate around the photographs, to control RH
Side benefits Prevents condensation during retrieval Protects from leaks or mechanical failure in storage Protects during handling while frozen
Cons Upfront cost Labor intensive Ongoing cost and time for repackaging after use Prevents browsing
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Vapor-proof Packaging Components
1. Photographs in box
2. Moisture Buffer- minimal trapped air- filler materials
3. RH indicator cards
4. Two vapor barrier bags
Copyright 2018, CCAHA, all rights reserved.
Vapor-proof Packaging Components
1. Photographs in box
2. Moisture Buffer- minimal trapped air- filler materials
3. RH indicator cards
4. Two vapor barrier bags
Copyright 2018, CCAHA, all rights reserved.
Vapor-proof Packaging Components
1. Photographs in box
2. Moisture Buffer- minimal trapped air- filler materials
3. RH indicator cards
4. Two vapor barrier bags
Copyright 2018, CCAHA, all rights reserved.
Vapor-proof Packaging Components
1. Photographs in box
2. Moisture Buffer- minimal trapped air- filler materials
3. RH indicator cards
4. Two vapor barrier bags
Copyright 2018, CCAHA, all rights reserved.
Vapor-proof Packaging Components
1. Photographs in box
2. Moisture Buffer- minimal trapped air- filler materials
3. RH indicator cards
4. Two vapor barrier bags
Copyright 2018, CCAHA, all rights reserved.
NPS Design with Static Shield Inner Bag
1. 2.
3. 4.Courtesy of NPS
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National Park Service Cold Storage Website
http://www.cr.nps.gov/museum/coldstorage/html/intro1_1.html
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Critical Moisture Indicator (CMI) Design
Two heavyweight polypropylene Ziplock bags Desiccated matboard sheets = moisture trap Create 2 microclimates
“Image Archive Freezer Kit”
$25
Home-made CMI Lower cost - purchase components separately Increased flexibility in size and shape of package
Courtesy of Metal Edge Inc.
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5 Stages
1. Identify and Prioritize Items
2. Prepare the Collection
3. Select Equipment or Facilities
4. Access the Collection
5. Monitor and Maintain the System
Copyright 2018, CCAHA, all rights reserved.
5 Stages
1. Identify and Prioritize Items
2. Prepare the Collection
3. Select Equipment or Facilities Leased Commercial Storage Space
Free-standing Unit
Walk-in Vault or Storage Room
with Humidity control – “Active”
without Humidity control – “Passive”
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Leased Commercial Space
Permanent or temporary solution
Expensive over time
Reduced access
Look for vendor with a good track record and securityNo climate controlled storage available for nitrate
Courtesy of Iron Mountain
Sub-zero vault of the Corbis Bettmen at Iron Mountains/National Underground Storage Vital Records Facility - Courtesy of Henry Wilhelm
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Free-Standing Refrigerator or Frost-free Freezer
Pros Typically 35°F (2°C) or 0°F (-18C) Fast and easy to buy and maintain Can operate in collection area Models hold 20 to 72 CF Multiple units can be used Cost-effective for < 150 cubic ft
Cons compared to vault Sealed packages control RH Shelf space limited and less flexible
Courtesy of NPS
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Features to look for
Commercial or Scientific Large capacity Lock from the outside Alarm (will be supplemented) Temperature read out Adjustable, sturdy wire shelves Low heat generation Quiet operation
Images courtesy of NPS
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Free-standing Refrigerator
Color negatives and slides at theMonmouth County Archives
Courtesy of Gary Saretzky
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Loading the Refrigerator or Freezer
Labels and humidity indicator cardsfacing out
Maximize available space
Distribute the weight evenly
Adjust or remove shelves/drawersas needed
Do not block the cold air vent inside
Be sure that the temperature hasstabilized and the unit acclimatedfor 24 hours
Courtesy of Sarah S. Wagner
Copyright 2018, CCAHA, all rights reserved.
Cellulose Nitrate Film
“National Fire Protection Association (NFPA) 40”
Addresses flammability of nitrate movie and sheet filmduring storage and handling
‘Extended storage’ cabinet required for 25 to 50 lbs-- can be a flammable materials storage freezer (FMSF)
Note: Maximum 50 lbs film per freezer
Freezer can not be in thesame space as collections
FMSF gives out much more heat than FSFFF
Courtesy LabRepCo
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Walk-in Vault vs. “Freezer Bank”
150 Cubic Feet is the tipping point
Vault Larger capacity is generally more E efficient than multiple, small
units You can avoid packaging
Multiple Units Noise and Weight factors Costs can escalate > 10 units Energy draw for many units
may be higher, requiring added wiring May need external cooling for heat load
Courtesy of Sarah S. Wagner
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Walk-in Vault
Freezer typically 0 - 5°F (-18 – 2°C) Refrigerator typically 35 - 40°F (2 – 5°C)
Pros Can have RH control at 35%, or not Cost-effective for collections > 150 cubic Ft. or anticipated to grow
More flexible and efficient use of space Custom and standard sizes Can reuse existing and/or flexible shelving systems
Cons Construction and maintenance complex Cost high, especially with RH control Requires dedicated space Packaging/bagging for warming or vestibule may be needed
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Walk-in Vault
Courtesy of Henry Wilhelm
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Vault with Humidity Control
RH controlled for entire space
30 to 40% RH common
No packaging necessary Retain objects in original format, housing, framing Browsing and item level retrieval improves access No problems with faulty packaging No preconditioning – objects will adjust to vault RH
Air filtration for volatile organics common
Courtesy of the National Park Service
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Freezer within Cold Vault with Humidity Control
The Museum of Modern Artfreezer 30-35F/35%
refrigerator 50F/40%surrounding room conditions 70F/50%
Courtesy of the Henry Wilhelm
Courtesy of Amber Kehoe
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Vault/Room without Humidity ControlAKA Simple Freezer Vault
No RH control Less expensive Less common
Gasketted-sealed cabinetsRH controlled with microclimate created within the cabinet
Courtesy of Henry Wilhelm
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5 Stages
1. Identify and Prioritize Items
2. Prepare the Collection
3. Select Equipment or Facilities
4. Access the Collection
5. Monitor and Maintain the System
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Accessing the Collection
Retrieval
“Time out of storage”
Staging/Acclimatization
Reconditioning/RepackagingCourtesy of Henry Wilhelm
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Time Out of Storage
IPI “Storage Guide for Acetate Film”
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Staging or Acclimatization
Bring cold/frozen material to room T and RH and reach thermal equilibrium
To prevent condensation and uneven drying
Time required depends on multiple factors
Can be accomplished in several ways....
* 24 hours is standard
Courtesy of the National Park Service
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Warming Procedure
1. If unpackaged, place object/box into sealed plastic bag and squeeze out excess air
2. If transporting outside the building, place into an insulated container
3. Move to a room temperature location
4. When it no longer feels cool, wipe off excess moisturewith a cloth and open bag
Courtesy of the NPS
Copyright 2018, CCAHA, all rights reserved.
5 Stages
1. Identify and Prioritize Items
2. Prepare the Collection
3. Select Equipment or Facilities
4. Access the Collection
5. Monitor and Maintain the System
Copyright 2018, CCAHA, all rights reserved.
“An Ice Scientist’s Worst Nightmare”
https://www.nytimes.com/2017/04/11/climate/ice-cores-melted-freezer-alberta-canada.html?mcubz=1
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Monitor the System
Malfunctions may lead to
Loss of RH control
Heat build up
Water
Combat with:
Redundant systems
Alarms
Periodic Inspections
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Alarms
REF/FREEZER Temperature alarm
wireless or wired into system
VAULT Fail-safe automatic shut down systems and alarm
if T or RH exceeds upper or lower limits
Standing water detector for condensation
Courtesy of Henry Wilhelm
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Periodic Visual Inspections
RH cardsCheck when unit first stabilizes, then every 3 monthsOuter card < 60% and inner bag < 50%
Check monitoring devices
Check freezers for frost build up
Check air vents are not blocked
Maintenance
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Important Paperwork
Keep on the exterior of equipment
Map of contents
Inspection Log
All procedures
Equipment manuals
Emergency numbers
Courtesy of Sarah S. Wagner
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Summary
Preservation Requires Freezing StorageEarlier Film Base Photographic MaterialsColor Photographic MaterialsInkjet Prints
Preservation Requires Cold StoragePoor Quality Paper and BooksAudiovisual Media
QUESTIONS?