SPECS BROS., LLC
  • Home
  • About Us
    • About Us History
    • About Us Clients
    • About Us Client Comments
  • Archival Transfer
    • Archival Transfer Basics
    • Archival Transfer Getting Started
    • Archival Transfer Commercial Services
    • Archival Transfer Consumer Services
  • Disaster Recovery
    • Disaster Recovery Services
    • Disaster Recovery Emergency Response
    • Disaster Recovery Magnetic Tapes Can Survive Flood Exposure
    • Disaster Recovery Institutional Disaster Response For Magnetic Tape Materials
    • Disaster Recovery Images of Flood Damaged Tapes
  • White Papers
    • White Paper: Basic Material Identification of Legacy Tapes In An Archive
    • White Paper: Basic Inspection Techniques To Sample The Condition of Magnetic Tape
    • White Paper: Dangers of Inadequate Restoration
    • White Paper: The Benefits of Tape Cleaning
    • White Paper: Common Signs of ​Problem 3/4" and Beta Videocassettes
  • Preservation
    • Preservation Basics
    • Preservation Tape Endangerment Issues
    • Preservation Minimum Tape Handling Standards
    • Preservation Effects of Moisture On Tape
    • Preservation Effects of Temperature On Tape
    • Preservation Legacy Tape Timeline
    • Preservation Video Tape Proliferation Until 2000
    • Preservation History of Tape Obsolescence
    • Preservation Standards and Recommended Practices in Print
    • Preservation FAQs
  • Contact Us

PRESERVATION
EFFECT OF MOISTURE
ON TAPES

Picture

EFFECTS OF MOISTURE ON TAPES

Exposure to water is the primary environmental factor that causes damage to magnetic tape.
 
Moisture, often absorbed into the tape from humid air, breaks down the long-chain polyester molecules that are the major structural ingredient of the recording and back-coat layers.  The reaction, called binder hydrolysis, produces a residue of low-molecular weight oligomers and carbolic acid.  This residue has adhesive properties that interfere with tape usage.  The hydrolysis reaction can also weaken the tape structure.
 
The amount of moisture a tape is exposed to determines the speed and degree of hydrolytic decay.   Long-term exposure to high relative humidity conditions will tend to increase the amount of “adhesive” oligomer residue.  Extended exposure to low RH can stabilize or even reduce the amount of residue.
 
Humidity has three additional effects on magnetic tape.  It can impact the physical dimension of tape, it can allow for damaging fungal growth and it can compromise a tape’s elasticity.
 
Tape expands and contracts with moisture content.  Even though tape can be thousands of feet long and only a very small fraction of an inch thick, the primary vector of expansion is thickness.  As tape absorbs moisture, the tape gets thicker and tightens the pack.  This can cause stretching.  As tape releases moisture in low RH environments, it gets thinner and loosens the pack.  This can result in tape slippage, folding and cinching.
 
If relative humidity is high enough for an extended time, fungus can grow on and damage tape.  For this reason, tape should never be stored in an environment that exceeds 50% RH.
 
Should tape actually be submerged, even for short periods of time, the elasticity and structural integrity can be compromised.  Extreme care must be taken handling wet tapes as physical stress put on tape when the elasticity is compromised can cause permanent deformation.


© 2006-2016 SPECS BROS., LLC. All rights reserved.
  • Home
  • About Us
    • About Us History
    • About Us Clients
    • About Us Client Comments
  • Archival Transfer
    • Archival Transfer Basics
    • Archival Transfer Getting Started
    • Archival Transfer Commercial Services
    • Archival Transfer Consumer Services
  • Disaster Recovery
    • Disaster Recovery Services
    • Disaster Recovery Emergency Response
    • Disaster Recovery Magnetic Tapes Can Survive Flood Exposure
    • Disaster Recovery Institutional Disaster Response For Magnetic Tape Materials
    • Disaster Recovery Images of Flood Damaged Tapes
  • White Papers
    • White Paper: Basic Material Identification of Legacy Tapes In An Archive
    • White Paper: Basic Inspection Techniques To Sample The Condition of Magnetic Tape
    • White Paper: Dangers of Inadequate Restoration
    • White Paper: The Benefits of Tape Cleaning
    • White Paper: Common Signs of ​Problem 3/4" and Beta Videocassettes
  • Preservation
    • Preservation Basics
    • Preservation Tape Endangerment Issues
    • Preservation Minimum Tape Handling Standards
    • Preservation Effects of Moisture On Tape
    • Preservation Effects of Temperature On Tape
    • Preservation Legacy Tape Timeline
    • Preservation Video Tape Proliferation Until 2000
    • Preservation History of Tape Obsolescence
    • Preservation Standards and Recommended Practices in Print
    • Preservation FAQs
  • Contact Us