Effects of Drying Methods - PowerPoint PPT Presentation

Loading...

PPT – Effects of Drying Methods PowerPoint presentation | free to download - id: 66d0a-ZDc1Z



Loading


The Adobe Flash plugin is needed to view this content

Get the plugin now

View by Category
About This Presentation
Title:

Effects of Drying Methods

Description:

Effects of Drying Methods – PowerPoint PPT presentation

Number of Views:31
Avg rating:3.0/5.0
Slides: 61
Provided by: nar31
Learn more at: http://www.archives.gov
Category:

less

Write a Comment
User Comments (0)
Transcript and Presenter's Notes

Title: Effects of Drying Methods


1
Comparison of Drying Methods Hilary A. Kaplan
and Kathleen A. Ludwig United States National
Archives and Records Administration
IFLA Pre-Conference 2003
2
SWELLING DISTORTION
3
METAL FASTENER CORROSION
PARCHMENTS STICKING TOGETHER
WHAT WATER DOES TO PAPER AND
PARCHMENT
4
BLEEDING MEDIA DYES
WHAT WATER DOES TO PAPER AND
PARCHMENT
5
MOLD
DISCOLORATION FROM DEGRADATION BY-PRODUCTS
6
  • Comparisons and Observations
  • In-house
  • Air drying
  • Dehumidification drying
  • Off-site by vendor
  • Dehumidification drying
  • Vacuum Freeze-drying
  • Patented Vacuum Freeze-drying

7
PATENTED VACUUM FREEZE-DRY PROCESS
AIR-DRYING
VACUUM THERMAL DRYING
Book Before Book After
VACUUM FREEZE-DRYING
DEHUMIDIFICATION DRYING
8
Diverse media and formats often contained in one
box
9
Expendables
Boxes packed in the same order with similar
records
10
All boxes were immersed in 5 cm of water for 24
hours
Half of the boxes also received water from
above
11
Records Drained for 2 Hours Before Freezing
Records Wrapped Prior to Freezing
12
PACKING FOR FREEZING
LINING INTERIOR OR EXTERIOR WITH PLASTIC
INTERLEAVING BETWEEN VOLUMES
13
  • Variables
  • All compared records were not identical in
    structure and media
  • Differential wetting may have occurred at the
    outset
  • Handling and environmental conditions may have
    varied greatly

14
Thawing Prior to Air Drying
4 days at -20 C
15
AIR DRYING
16
Air Drying on Blotters
Interleaving with Polyester
Non-Woven Fabric
17
Plastic Must be Removed for Effective Air
Circulation
Note that
Encapsulation May Not Prevent Moisture Intrusion
18
Air Drying Conditions for a 2 Day Period Average
Temperature 21-22 º C
19
Trucks Holding Frozen Records
for Dehumidification
Dehumidification-Drying Chamber
20
Closer view of Supported Books
Items on Dehumidification-Drying Rack
21
Dehumidification-drying After Thawing
Curl After 48 Hours of
Dehumidification-drying
22
After dehumidification-drying, records no longer
fit in their 2 original boxes.
23
Dehumidification-drying IN-SITU
(Items never removed from their box)
24
Delmhorst P-2000 moisture meter
with 30.5 cm probe

Moisture content was measured daily and recorded
25
T and RH of the On-Site Dehumidification Drying
Chamber
for the 13 day period 2/22/02-3/7/02 Average
Temperature 21-37 º C
26
Mold grew during dehumidification- drying
in-situ. The wet samples were eliminated from
further comparison.
27
Some records were returned without labeling
information
28
Original order altered
29
Original labels were returned in new boxes
30
On-site Dehumidification
Vendor Dehumidification
Air dry
Control Vacuum Freeze-dry
Patented Vacuum Freeze-dry

Order in Folder Altered
31
Distortion in Identical Groups of
Paper Records Dried Differently
Vacuum Freeze-Dry
Air Dry
Control Patented Vacuum
Dehumidification Freeze-Dry Vendor On
Site
32
Vacuum Freeze-Dry
Patented Freeze-Dry
Control
Air Dry
Bound Records
33
Control
Air Dry
Patented Vacuum Freeze-Dry
Vacuum Freeze-Dry
Ability to Open Flat
34
Vacuum Freeze-Dry
Patented Vacuum Freeze-Dry.
Vendor Dehumidi -fication
On-Site Dehumidi-fication
Air Dry
Control
Fastened Bound Records
35
Patented Vacuum Freeze-Dry
Vacuum Freeze-Dry
On-Site Dehumidification
Vendor Dehumidification
Air Dry
Control
Pamphlet Bindings
36
Changes occurred to Vinyl Cover in the Patented
Vacuum Freeze-Dry Process
37
Vendor Dehumidification
Control
MAY LEAVE IN PLACE
Vacuum Freeze-Dry
On-Site Dehumidification
Patented Vacuum Freeze-dry .
Air Dry
SHRINK-WRAP FILM
38
Interleaving Required to Prevent Adhesion of
Coated Paper During Air and Dehumidification-Dryin
g
On-Site Dehumidification
Air Dry
39
Patented Vacuum Freeze-Dry .
Vacuum Freeze-Dry
No interleaving required for coated
paper in Vacuum Freeze-drying processes
40
Vendor Dehumidification
On-site Dehumidification
Air dry
Control Vacuum Freeze-dry
Patented VFD
Rolled Records
41
CONTROL PATENTED VACUUM FREEZE-DRY
BEFORE
AFTER
42
PATENTED VACUUM FREEZE-DRY VACUUM FREEZE-DRY
AIR DRY
Delamination of cellulose nitrate coating
43
On-site Dehumidification
Control
Air Dry
Patented Vacuum Freeze-Dry .
Vendor Dehumidification
Vacuum Freeze-Dry
POLYESTER L-SLEEVES
44
Only Vacuum Freeze-Drying Processes Were
Successful in Drying Encapsulated Items
45
Air Drying
Dehumidification Drying
Drying Ineffective When Items Left in Sleeves
46
Metal Fasteners Corroded Before Records Dried
47
LESSONS LEARNED
  • Contact vendors BEFORE an event strikes.
  • Gain an understanding of the .PARTICULAR
    PROCESSES AVAILABLE.
  • Check references. EVALUATE CAREFULLY.
  • Specify EXACT TREATMENT. Make.sure
    terminology is clear.

48
LESSONS LEARNED (2)
  • Obtain a LISTING OF FEES for services.
  • MINIMUM CHARGE
  • ADDITIONAL FEES
  • COSTS FOR RETURN SHIPPING
  • One US record storage box gt 1 cubic foot One
    US storage box billed as 1.2 cubic feet

49
LESSONS LEARNED (3)
  • Intellectual control and original order MAY
    NOT BE PRESERVED
    unless specified.
  • Indicate how groupings of records are to be
    re-associated if fastener, folder, or adhesive
    attachment cannot be retained with records.

50
LESSONS LEARNED (4)
  • Specify desired label information and...
    replacement box quality.
  • Shipping may contribute to records
    .distortion and length of exposure to moisture
  • DESPITE ALL EFFORTS, RECORDS MAY BE LOST

51
Real Life Disaster Events
ASSEMBLING AND LABELING NEW BOXES
HUMAN CHAIN
PROPER STACKING ONTO PALLETS
LOADING OF FREEZER TRUCK
52
Air Drying Advantages
  • Small quantities of wet or damp materials
  • Remain in repository
  • Item by item inspection
  • Best results for plastic coated materials

53
Air Drying Disadvantages
  • Labor intensive
  • layout and reassemble records
  • plastic enclosures must be removed
  • Large areas of surface space required
  • Cockling without restraint during drying results
    in increased volume of dried materials
  • Coated papers block without interleaving
  • Extensive handling may increase.damage

54
Air Drying Disadvantages
  • Costs for supplies and equipment
  • absorbent materials
  • energy to operate dehumidifiers and fans
  • Costs for staff time
  • Staff not carrying out regular work routine
  • Workspace occupied by drying activities
  • Chance for disruption of original order
  • Possibility of mold

55
Dehumidification Drying Advantages
  • Suitable for large quantities of damp materials
  • Can be carried out on-site or at vendors
    facility
  • Allows for access for the materials during the
    drying process

Dehumidification Drying Disadvantages
  • Results in greatest distortion
  • Corrosion of metal fasteners

56
Vacuum Freeze-Drying Advantages
  • Large quantities of wet materials.
  • Least distortion
  • Minimizes corrosion of metal fasteners
  • Soluble media will not move
  • Coated papers do not require interleaving
  • Plastic films do not require removal.
  • Less chance for disruption of original order.

57
Vacuum Freeze-Drying Disadvantages
  • No access
  • Must be frozen prior to drying
  • Small quantities expensive
  • Bubbling of cellulose nitrate coated
    architectural linen drawings

58
DORIS HAMBURG, DIRECTOR PRESERVATION PROGRAMS
MARY LYNN RITZENTHALER, CHIEF DOCUMENT
CONSERVATION LABORATORY
CATHERINE NICHOLSON, SUPERVISORY
CONSEVATOR DOCUMENT CONSERVATION LABORATORY
STAFF FROM THE
WASHINGTON NATIONAL RECORDS CENTER
DOCUMENT CONSERVATION LABORATORY RESEARCH AND
TESTING
ACKNOWLEDGEMENTS
59
(No Transcript)
60
(No Transcript)
About PowerShow.com