GB/T 15331-2020 PDF in English
GB/T 15331-2020 (GB/T15331-2020, GBT 15331-2020, GBT15331-2020)
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| GB/T 15331-2020 | English | 165 |
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Test method for water vapor transmission rate of pressure-sensitive tapes
| Valid |
| GB/T 15331-1994 | English | 159 |
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Test method for water vapor transmission of pressure-sensitive tapes
| Obsolete |
Standards related to (historical): GB/T 15331-2020
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GB/T 15331-2020: PDF in English (GBT 15331-2020) GB/T 15331-2020
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 83.180
G 38
Replacing GB/T 15331-1994
Test method for water vapor transmission rate of
pressure-sensitive tapes
ISSUED ON: NOVEMBER 19, 2020
IMPLEMENTED ON: OCTOBER 01, 2021
Issued by: State Administration for Market Regulation;
Standardization Administration of the People's Republic of
China.
Table of Contents
Foreword ... 3
1 Scope ... 5
2 Normative references ... 5
3 Terms and definitions ... 5
4 Classification ... 6
5 Method One: Test of vertical water vapor transmission rate (WVTRvertical) ... 6
6 Method Two - Test of section water vapor transmission rate (WVTRcross-section)
... 11
7 Test report ... 15
Foreword
This Standard was drafted in accordance with the rules given in GB/T 1.1-2009.
This Standard replaces GB/T 15331-1994 “Test method for water vapor
transmission of pressure-sensitive tapes”. Compared with GB/T 15331-1994,
the main technical differences in this Standard are as follows:
- modified application scope of the standard (see Clause 1 of this Edition,
Clause 1 of Edition 1994);
- added normative references (see Clause 2 of this Edition);
- modified terms and definitions (see 3.1, 3.2 of this Edition, Clause 2 of
Edition 1994);
- added that the test method is divided into test method for vertical water
vapor transmission rate (see Clause 5 of this Edition) and test method for
section water vapor transmission rate (see Clause 6 of this Edition);
- modified principle (see 5.1, 6.1 of this Edition, Clause 3 of Edition 1994);
- modified test box in instruments and equipment (see 5.2.1 of this Edition,
Clause 4 of Edition 1994);
- added test cover (see 5.2.2, 6.2.2 of this Edition);
- added electronic balance requirements in instruments and equipment,
division is 0.0001g (see 5.2.5 of this Edition);
- added solvents required to use and requirements in instruments and
equipment (see 5.2.7, 6.2.7 of this Edition);
- added weights required to use and requirements in instruments and
equipment (see 5.2.8, 6.2.8 of this Edition);
- added edge sealing material in instruments and equipment (see 5.2.9 of
this Edition);
- added sampling requirements (see 5.3 of this Edition);
- added requirements for standard test environment (see 5.4 of this Edition);
- deleted weighing conditions (see Clause 6 of Edition 1994);
- added preparation of test piece (see 5.6 of this Edition, Clause 5 of Edition
1994);
Test method for water vapor transmission rate of
pressure-sensitive tapes
1 Scope
This Standard specifies test principle, instruments and equipment, preparation
of test piece, test steps and result calculation for water vapor transmission rate
of pressure-sensitive tapes.
This Standard includes test methods for vertical water vapor transmission rate
and section water vapor transmission rate. The test method for vertical water
vapor transmission rate is applicable to single-sided or double-sided pressure-
sensitive tape. The test method for section water vapor transmission rate is
applicable to double-sided pressure-sensitive tape.
2 Normative references
The following referenced documents are indispensable for the application of
this document. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any
amendments) applies.
GB/T 4851-2014, Measurement of static shear adhesion for adhesive types
GB/T 22396, Terminology relating to pressure sensitive adhesive products
3 Terms and definitions
For the purposes of this document, the terms and definitions defined in GB/T
22396 as well as the followings apply.
3.1 vertical water vapor transmission rate; WVTRvertical
under certain conditions, the mass per unit area of water vapor passing through
the tape perpendicular to the direction of the adhesive surface per unit time
NOTE: Usually it is expressed in grams per square meter day [g/(m2·d)].
3.2 section water vapor transmission rate; WVTRcross-section
under certain conditions, the mass per unit length of water vapor permeating
the tape in the sectional direction per unit time
NOTE: Usually it is expressed in grams per square meter day [g/(m2·d)].
4 Classification
According to the different directions of water vapor passing through the
pressure-sensitive tape, the test method for water vapor transmission rate of
pressure-sensitive tape is divided into test method for vertical water vapor
transmission rate (WVTRvertical) and test method for section water vapor
transmission rate (WVTRcross-section).
5 Method One: Test of vertical water vapor
transmission rate (WVTRvertical)
5.1 Principle
The pressure-sensitive tape is pasted on the test box with desiccant. Cover with
a ring test cover to form a test piece.
The test piece is exposed to an environment with controlled temperature and
humidity. Weigh the mass of the test piece at regular intervals. When the weight
gain of the test piece reaches equilibrium, use the mass increase per unit time
and unit area of the tape to express the vertical water vapor transmission rate.
5.2 Instruments and equipment and material
5.2.1 Test box: made of non-moisture-absorbing material; its water vapor
transmission rate is zero (aluminum or stainless steel is recommended). The
test box has flat, smooth and rigid edges. The size is shown as Figure 1.
Sampling is carried out in accordance with the provisions of 5.4.3 and 5.4.4 in
GB/T 4851-2014.
5.4 Standard test environment
The standard environment temperature is (23±1)°C. The relative humidity is
(50±5)%.
5.5 Number of test pieces
Each sample at least makes 3 test pieces.
5.6 Preparation of test piece
5.6.1 Use solvent to wipe clean the bonding surface of the test box edge and
the ring test cover. Place in the standard test environment for at least 10min.
5.6.2 Fill the test box with anhydrous calcium chloride to about 10mm away
from the opening. Ensure that calcium chloride does not contact the tape in
subsequent operations.
5.6.3 Glue the specimen to the edge of the test box. No bubbles or wrinkles
allowed. Trim the tape protruding from the edge of the test box. Then align the
ring test cover with the outer edge of the test box and glue it. It is recommended
to directly cut the tape specimen into a disc with the same diameter as the outer
edge of the test box before bonding.
For single-sided tape, when bonding as above, it needs to borrow other double-
sided tapes. Conduct auxiliary bonding of ring test cover and adhesive tape
without adhesive surface. It is recommended to cut the auxiliary double-sided
tape directly into the same shape as the ring test cover. Note that the auxiliary
double-sided tape is allowed to cover the water permeability test area of the
specimen. It is recommended to use PET double-sided tape for auxiliary
bonding.
5.6.4 Use impermeable sealing material to seal the outer circumference of the
test piece.
5.6.5 The total weight of the test piece and the total weight during the test shall
not exceed 80% of the range of the electronic balance used.
5.6.6 Put a 1000g weight on the test piece horizontally for 10min. Note that the
weight is not allowed to contact the tape adhesive surface.
5.7 Test steps
5.7.1 Put all test pieces into an oven at (49±1)°C and heat for 30min.
Δi - The mass change of the test piece of the ith test T time interval, in grams
(g);
Δi+1 - The mass change of the test piece after the i+1th test T time, in grams (g);
Relative change rate of Δi - The change rate of the weight of the test piece in
the i+1th time interval, %.
When the relative change rate of at least 3 adjacent Δi does not exceed 10%,
the test is completed.
Take the arithmetic mean of the 3 adjacent Δi as the final result, recorded as
Δaverage.
5.9 Result calculation
According to formula (3), calculate the vertical water vapor transmission rate
(WVTRvertical) of each specimen, to the nearest of 0.01g/(m2·d).
Where,
WVTRvertical - The vertical water vapor transmission rate, in grams per square
meter day [g/(m2·d)];
Δaverage - The arithmetic average value obtained when the relative change rate
of three adjacent Δi does not exceed 10%, in grams (g);
24 - 1 day is 24 hours;
T - The test time of the test piece in the test environment, in hours (h);
0.002462 - The test area of specimen, in square meters (m2).
6 Method Two - Test of section water vapor
transmission rate (WVTRcross-section)
6.1 Principle
The pressure-sensitive tape is pasted on the edge of the test box with desiccant.
Cover a cover plate of same area to form a test piece.
The test piece is exposed to a controlled environment. Weigh the mass of the
WVTRvertical
Δaverage
......
Source: Above contents are excerpted from the PDF -- translated/reviewed by: www.chinesestandard.net / Wayne Zheng et al.
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