A. Face Stock
- Composition Options:
The Procurement Request will clearly identify which of the
following face-stock materials is to be used for the particular
application intended by the purchaser.
- Polyester: White opaque film, 1-2 mil thick.
The polyester must be biaxially oriented, non-recycled film
with no plasticizers added.
- Polypropylene: Clear, colorless, or white
opaque film, 1-2 mil thick, biaxial orientation preferred.
- Paper:
- pH: 8.0 - 9.5, (TAPPI T 509 om-88), cold extraction,
slurried pulp
- Alkaline Reserve: between 2 and 5% calculated
as calcium carbonate (ASTM D4988)
- Lignin: Kappa number of 5 or less (TAPPI T236
cm-85)
- Bleeding: If colored, the color must show no
bleeding when soaked in distilled water for 48 hours while
held under suitable weight in contact with white bond paper.
- Sizing: only neutral or alkaline sizing should
be used.
- Degree of Whiteness:
White pigmented label face-stocks must have a minimum brightness
of 82% as measured by directional reflectance at 457 nm (TAPPI
T452 cm-92).
- Brightness Retention:
Accelerated Aging: The
color of the face-stock must not change more than 10 points of
brightness as measured
by directional reflectance at 457 nm when exposed for 28 days
at 90°C and 50% RH. The brightness will be measured according
to TAPPI T452 cm-92.
Photo Degradation: The color of the face-stock
must not change more than 10 points of brightness as measured
by directional reflectance at 457 nm when exposed 24 hours
to a Xenon arc lamp in an Atlas Weatherometer under the following
conditions: Irradiance Level: 1.0 watts/m2 at 420
nm. Inner filter: Borosilicate glass. Outer filter: clear soda
lime glass. Black panel temperature: 50°C. Wet bulb depression:
8.5°C. The brightness will be measured according to TAPPI
T452 cm-92.
- Color Bleed (non-white face-stocks only):
Colored labels must show no bleeding when soaked in distilled
water for 48 hours while held under suitable weight in contact
with white bond paper.
B. Adhesive
- Composition:
The pressure-sensitive adhesive layer must possess high permanence
characteristics such that labels, once applied, remain attached
permanently and can be removed only with difficulty. The adhesive
must be clearly identifiable as an acrylic polymer or copolymer
by its infra-red spectrum.
- Bond Strength:
The adhesive must demonstrate sufficient initial bond strength
for the label to support a test weight of 200g for 10 minutes.
- Test Method:
This procedure is a 90-degree peel test, modified from
ASTM D2860M-90. The bonding strength of the adhesive to two different
substrates is assessed. Test Panels used in this test are LC
Standard Test Panels B-1 and B-2. The materials used for these
LC Standard Test Panels have been selected to represent the
range of board types commonly found in boxes used in housing
library materials in any large collection.**
A set of three
labels, size 1" x 2 1/2 , is applied to each
of the two Test Panels over a Mylar window that permits only
a one inch square area of the adhesive side of the label to
be in contact with the substrate, as illustrated in ASTM D2860M-90,
procedure B. The labels are set in place by applying firm pressure
with the edge of a 3M plastic applicator, model no. P.A.-1,
to the labels in four downward strokes. The test samples are
then allowed to cure for 7 days in an environmental chamber
conditioned to 73°F and 50% RH.
At the end of this dwell
time a 200 gram weight is suspended from the free end of the
label and timed for 10 minutes. At
the end of this test period, labels must not have peeled away
from the substrate by more than 10 millimeters. Failure of
this test with any of the two test panels will disqualify the
stock and no further testing need be performed.
**For collections with boxes using only one type of board
or a special type of board, all testing will be done using
that type of board only. Special board will be described
on the purchase order.
- Bond Strength after Accelerated Aging:
The adhesive, once set after the initial 7-day dwell time,
must remain permanently affixed to both the face-stock and
the substrate with no loss of adhesive strength for the life
of the object to which it is applied, under conditions of normal
use.
Test Method: This procedure is a 90-degree
peel test, modified from ASTM D2860M-90.
A set of three labels is applied to each of the two Test Panels
in the same manner as described under Item 2 above. The labels
are then subjected to accelerated aging at 80°C and 50%
RH for 28 days. At the end of the aging period the test samples
are placed in an environmental chamber conditioned to 73°F
and 50% RH for 24 hours.
At the end of the conditioning period
a 90° peel test
is performed as in Item 2 above with the exception that a 400
gram weight is used.
At the end of this test period, labels
must not have peeled away from the substrate by more than 10
millimeters.
C. Other Label Properties
- Curling/Lifting/Ooze:
The labels must not show any sign of curling, lifting, buckling,
or puckering, nor any evidence of the adhesive oozing beyond
the label edges.
Test Method: A set of three
labels, size 1 1/4" x 1 1/4", is applied to each of the LC
Standard Test Panels, so that the entire adhesive side of the
label is in
contact with the substrate. The labels are set in place by
applying firm pressure with the edge of a 3M plastic applicator,
model no. P.A.-1, to the labels in four downward strokes.
The
labels are then subjected to accelerated aging at 80°C
and 50% RH for 28 days. At the end of the aging period, the
labels are examined visually.
- Print Fastness:
The label stock must be able to accept and retain a clean,
legible image from a laser printer.
The label stock will be
printed with a test pattern consisting of a sample phrase or barcode
centered on each label using
a printer selected by the Library. The printer model to be
used in this test will be noted on the purchase order. Inability
to print the stock on the selected printer, obtain a clear,
crisp and complete image, or read the bar-code with a scanner
will constitute a failure. Any failure of the label stock during
the printing process will disqualify the stock and no further
testing will be performed.
Test Method: A strip
of 3M Tape #230 is applied over the printed test pattern on
the label by rubbing
down the tape using three fingers in six firm strokes. The
tape is then peeled back at a 180° angle. Legible characters
visible on the test tape, and/or degradation of the printed
image on the face-stock, constitute a failure. (This method
is described in Archival Copies of Thermofax, Verifax and
Other Unstable Records, Technical Information Paper No.
5, Washington, D.C., National Archives and Records Administration,
1990).
- Abrasion Resistance of Printed Image:
The printed image on the label must be able to resist moderate
abrasive forces with minimal smudging of the ink.
Test Method: This
procedure follows ASTM D5264-92. Printed labels are attached
to a piece of LC Standard
Test Paper P-1 which has been cut to fit the base of the Sutherland
Rub Tester. The test specimen is placed on the rubber pad on
the base of the Sutherland Rub Tester, as described in ASTM
D-5264-92, printed side facing the receptor block. The test
specimen is then rubbed for 20 strokes using the A-1 Standard
Receptor, Imperial Lapping Film with aluminum oxide 9-µm
particles. The extent of smudging is evaluated by selecting
an area of the greatest density of smudged ink, 3-5 mm away
from a printed character, and measuring its optical density
using a reflectance densitometer. The density of the smudged
area is compared to the density of a clean, unprinted, area
of the label stock.
Density changes above 0.06 constitute a
failure.
- Effect on Photographic Material:
If specified on the purchase order for use with collections
of photographic materials, the labels must pass
the Photographic Activity Test. Both the face stock and
adhesive side of the label will be tested. Test to be
conducted and results reported as described in ANSI IT9.16-1994,
or latest revision. This test can be performed by the Image
Permanence Institute (c/o Rochester Institute of Technology,
Frank E. Gannett Memorial Building, P.O. Box 9887, Rochester,
NY 14623-0887. Tel.: 716-475-5199, FAX: 716-475-7230) or
other pre-approved laboratory.
- Suitability for Cold Storage:
The labels must
be able to pass all of the tested properties listed above after
being exposed to conditions of 0°C for
24 hours, followed by 24 hours at 73°F and 50% RH.
A. Problem-free Print Feeding
The label sheet must lie flat without any curling and permit problem-free
self-feeding from a stacking paper tray.
B. Non-contamination of Printer by Adhesive Residue
The labels must not transfer adhesive to the platens or any other
parts of a laser printer under extended, but normal use. There
must not be any adhesive deposits on the platens or other accessible
parts of the printer that can be seen visibly or felt by stickiness
to the touch.
C. Odorlessness
The label stock must not emit odors deemed objectionable or hazardous
to the work environment by the Library of Congress according to
TAPPI T483.
D. Liner
The release liner under all label configurations must allow for
easy and complete peeling of the face-stock without shearing of
the adhesive layer.
E. Workmanship
All label edges will be cut square and clean, and sizes accurate
to specification.
F. Shelf-Life
The adhesive must have a one year usable shelf-life such that
the initial adhesion strength will be the same for labels applied
up to one year after the original delivery date under ambient storage
conditions. The labels must also maintain their capacity to be
printed upon.
G. Dimensions
Dimensions will be specified on the purchase order.
H. Packaging
The items must be packed in standard commercial containers which
are constructed to ensure that they are received in perfect condition
- dry, undamaged and without kinks or creases. The outside of each
container must be identified by type, size and number of items
within, manufacturing run or batch number and Purchase Order number
or Contract number.
A. Testing
- Responsibility:
The supplier is responsible for meeting all the requirements
specified herein. The Library of Congress has the right to
perform any of the tests set forth in the specification where
such tests are deemed necessary to ensure that supplies conform
to prescribed requirements.
- Sampling:
To sample for testing, shipments will be sampled according
to MIL-STD-105E at inspection level S-2 with an acceptable
quality level of 2.5 percent defective from each lot offered.
Copies of MIL-STD-105E are available from Naval Publications
and Forms Center; Standardization Document Order Department,
Building 4, Section D; 700 Robbins Avenue; Philadelphia, Pennsylvania
19111-5094.
- Materials:
The following materials are required to perform the tests
in this specification:
- LC Standard Test Panel B-1
- LC Standard Test Panel B-2
- LC Standard Test Paper P-1
- Polyester (Mylar D)
- 3M Tape #230
- 3M Imperial Lapping Film, aluminum oxide 9-µm particles
- Carey Lea Silver Test Film
- Elite Photographic Paper
- Whatman No. 1 filter paper
- Methods:
Tests will be conducted in accordance with specified test
methods of the American National Standards Institute (ANSI),
the American Society for Testing and Materials (ASTM), and
the Technical Association of the Pulp and Paper Industry (TAPPI)
and/or as described. Publications describing these tests may
be ordered directly from the technical associations:
- ANSI, 1430 Broadway, New York, NY 10018
- ASTM, 100 Barr Harbor Drive, W. Conshohocken, PA 19428-2959
- TAPPI, One Dunwoody Park, Atlanta, GA 30348
- Tests:
Requirements
|
Test Method |
pH (paper face-stock) |
8.0 - 9.5 |
TAPPI T509 om-88 |
Alkaline Reserve (paper) |
2 - 5% |
ASTM D4988 |
Lignin (paper) |
Kappa < 5 |
TAPPI T236 cm-85 |
Brightness, initial |
> 82% |
TAPPI T452 om-92 |
Brightness, after aging |
< 10 pts. change |
TAPPI T452 om-92 |
Photo Degradation |
< 10 pts. change |
TAPPI T 452 om-92 |
Color Bleed (color stock) |
none |
24 hours-distilled water under weighted paper |
Adhesive ID |
acrylic |
infra-red spectrum |
Bond Strength |
200g, < 10 mm peel |
ASTM D2860M-90 (modified) |
Bond Strength - Aged |
400g, < 10 mm peel |
ASTM D2860M-90 (modified), after aging |
Curling/Lifting/Ooze |
none |
visual, after aging |
Print Fastness |
no legible characters on tape |
NARA Technical Information Paper No. 5 |
Print Abrasion |
< 0.06 pts. density change |
ASTM D5264-92 |
PAT |
pass |
ANSI IT9.16-1994 |
FAILURE TO MEET ANY OF THE SPECIFICATIONS WILL BE CAUSE
FOR REJECTION.
Library of Congress
Library of Congress
Help Desk (
August 1
October 12, 2005
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