Technical Bulletin
May, 2006
3
Structural Performance Tests of VHB
™
Structural Glazing Tapes
Introduction
3M™ VHB™ Acrylic Foam Bonding Tapes have been used worldwide in a variety of
applications in the construction industry. To further support consideration for structural
glazing applications, performance tests were conduced at an independent accredited 3rd party
test facility (Winwall Technology Pte Ltd - Singapore) to evaluate 3M™ VHB™ Structural
Glazing Tape under stresses and environmental conditions that glass panels would typically
experience in a glazed curtain wall system.
Summary
The glazed panels constructed with 3M™ VHB™ Structural Glazing Tapes provided
excellent performance overall compared to a control panel glazed with a one part structural
silicone. The first test sequence consisted of a PVB laminated glass panel bonded with 3M™
VHB™ Structural Glazing Tape 4972, a double glazed unit (DGU) bonded with 3M™
VHB™ Structural Glazing Tape G23F and a DGU bonded with a one part structural silicone.
No failure was observed with either the 3M™ VHB™ Tape or the structural silicone glazed
panels in any of the tests including ASTM E330 wind load structural tests at ambient, cold
and hot temperatures (-25°C and 70°C) up to 2.9 kPa (60 psf), corresponding to a wind speed
of 250 kph (155 mph). After this, pressures were gradually increased up to 8.4 kPa (175 psf)
at ambient temperature conditions. At this point the laminated glass failed and blew out of
the chamber. However, glass was still attached and bonded to the 3M™ VHB™ Structural
Glazing Tape 4972 around the perimeter of the frame demonstrating the high strength of the
tape. An 8.4 kPa pressure load is equivalent to a wind speed of 426 kph (264 mph).
A second test sequence patterned after the first test sequence was run consisting of two
single pane tempered glass panels. One was bonded with 3M™ VHB™ Structural Glazing
Tape G23F and the other with one part structural silicone. The DGU panel bonded with
3M™ VHB™ Structural Glazing Tape G23F was also subjected to this second test sequence
after surviving the first test sequence. No failure was observed with either the 3M™ VHB™
Tape glazed panels or the structural silicone glazed panel in any of the tests including ASTM
E330 wind load structural tests up to 10 kPa (210 psf), which corresponds to a sustained
wind speed of 290 mph (467 kph).
(1)
Conclusions
In the tests conducted, 3M™ VHB™ Structural Glazing Tape G23F and 4972 fulfilled all
the requirements as specified by ASTM E283, ASTM E331 and ASTM E330 test methods.
Their performance exceeded expectations as shown in tests with more stringent conditions
such as structural loads at -25°C (-13°F) and at 70°C (158°F) with test method ASTM E330.
The conditions set for air infiltration and water leakage were higher than the minimum
standards outlined in ASTM E283 and ASTM E331. Furthermore, the destructive structural
load performance for the laminated glass frame was exceeded by > 250% (failure due to
glass breakage, and > 300% for structures with tempered glass and DGU glass.
Overall, in the tests conducted, there were no observable differences between 3M™ VHB™
Structural Glazing Tapes and structural silicone in terms of performance; all fulfilled and
exceeded their basic objectives.
pg_0002
pg_0003
Panels
The glazing panels submitted for the construction tests were built at a leading manufacturer
of architectural curtain wall panel systems using designs, assembly procedures, and factory
conditions typical of the construction industry. The panels measured 1m by 2m and were
made of laminated glass, double glazed unit glass (DGU) and single pane tempered glass.
Similar units with a common one part structural silicone sealant used in the industry were
also fabricated with the exception of the laminated glass construction.
(3)
Technical Bulletin
Structural Performance Tests of 3M
™
VHB
™
Structural Glazing Tapes
Glass Panel:
1. Single Pane 8mm Tempered
2. Double Glazed Unit (6mm/10mm/6mm)
3. Laminated Glass (4mm/PVB/4mm)
pg_0004
(4)
Technical Bulletin
Structural Performance Tests of 3M
™
VHB
™
Structural Glazing Tapes
Panels
8mm Tempered Glass Panel with:
Structural Silicone Sealant
3M™ VHB™ Structural Glazing Tape G23F
STRUCTURAL SEALANT
8MM THK CLEAR TEMPERED GLASS
3M™ VHB™ TAPE G23F
8MM THK CLEAR TEMPERED GLASS
SPACER TAPE
Weather
Sealant
3M™ VHB™
Tape G23F
pg_0005
(5)
Technical Bulletin
Structural Performance Tests of 3M
™
VHB
™
Structural Glazing Tapes
Panels
Double Glazed Unit with:
Structural Silicone Sealant
3M™ VHB™ Structural Glazing Tape G23F
WEATHER SEALANT
22MM THK CLEAR TEMPERED DOUBLE GLAZING
WEATHER SEALANT
STRUCTURAL SEALANT
SPACER TAPE
22MM THK CLEAR TEMPERED
DOUBLE GLAZING
Weather
Sealant
3M™ VHB™
Tape G23F
3M™ VHB™ TAPE G23F
pg_0006
(6)
Technical Bulletin
Structural Performance Tests of 3M
™
VHB
™
Structural Glazing Tapes
3M™ VHB™ Structural
Glazing Tapes
3M™ VHB™ Structural Glazing Tapes G23F and 4972 have been selected for curtain
wall glazing applications due to their acrylic foam tape performance properties which
are suitable for bonding glass to metal frame assemblies. The performance of 3M™
VHB™ Structural Glazing Tapes has also been proven with over 15 years of
successful curtain wall applications for glass panels around the world.
Product Number Adhesive/Foam Type Thickness Tape Color Liner Type
G23F
Acrylic /Conformable 2.3mm (0.090") Grey
Red film liner
4972
Acrylic /Conformable 2.0mm (0.080") Grey
Green film liner
A most common proven structural silicone sealant from a well known manufacturer
was used in this study to compare the performance of 3M™ VHB™ Structural
Glazing Tapes in similarly designed curtain wall panels.
Product
Description
Type
Structural Sealant
One part, neutral cure
Architectural grade
The same weather sealant was used in all the designs. It is also a one part, neutral cure
silicone material.
Panels
Laminated Glass with
3M™ VHB™ Structural Glazing Tape 4972
WEATHER SEALANT
3M™ VHB™ TAPE 4972
8.76MM THK CLEAR LAMINATED GLASS
3M™ VHB™
Tape 4972
pg_0007
(7)
Technical Bulletin
Structural Performance Tests of 3M
™
VHB
™
Structural Glazing Tapes
Testing
2 sets of panels were subjected to the following test sequences to evaluate their
performance. The first set of panels consisted of laminated glass (with 3M™ VHB™
Tape 4972) and double glazed units (one with 3M™ VHB™ Tape G23F and one with
one part structural silicone sealant). The second set of panels consisted of 8mm
tempered glass. One constructed with one part structural silicone sealant and one with
3M™ VHB™ Tape G23F. Also included in this second set of panels was the DGU
constructed with 3M™ VHB™ Tape G23F from the first set of tests. Summaries of the
test methods, observations, and official results are provided on the following pages.
While curtain wall systems can incorporate many different designs and materials, the
testing of these “typical" panels demonstrate the high performance level of 3M™
VHB™ Tapes in these demanding applications.
Laminated
Glass with
3M™ VHB™
Structural
Glazing
Tape 4972
DGU with
Structural
Silicone
DGU with
3M™ VHB™
Structural
Glazing
Tape G23F
Single Pane
Tempered
8mm with
3M™ VHB™
Structural
Glazing
Tape G23F
Single Pane
Tempered
8mm with
Structural
Silicone
DGU with
3M™ VHB™
Structural
Glazing
Tape G23F
(from previous
tests)
First set of panels
Second set of panels
pg_0008
(8)
Technical Bulletin
Structural Performance Tests of 3M
™
VHB
™
Structural Glazing Tapes
Test Sequence
The test sequences (shown in the flow chart below) consisted of measuring the air
leakage, water penetration, thermal cycling, air infiltration, water leakage and wind
load structural performance at ambient conditions, -25°C (13°F) and elevated
temperatures at 70°C (158°F). The air infiltration was done again to confirm the integrity
of seal/adhesion properties of both 3M™ VHB™ Tapes and the one part structural
silicone sealant. At the end of the test sequence, the uniform static pressure was then
increased to more than 200% of the designed wind load in both directions (± pressure).
Panel Set Up
Temperature
Cycling
Water
Penetration
Air
Infiltration
E 283
E 331
Water
Penetration
Air
Infiltration
E 283
E 331
-25°C, 70°C
Structural
Tests (32°C)
E330
Air
Infiltration
>200% Wind Load
Additional tests; not
required by most
country codes
To check integrity of chamber
and panels before start of tests
To check sealing property of
3M™ VHB™ Tape G23F
and one part structural sealant
after temperature cycle
To check sealing property of
weather sealant with 3M™
VHB™ Tape G23F
and structural sealant after
subjecting to temp. cycle
and wind load pressure at
different conditions
Thermal Aging
A set of three panels, with two panels assembled using 3M™ VHB™ Structural Glazing
Tapes, were given 20 thermal cycles from -25°C to 70°C (-13°F to 158°F) with the
temperature extremes held for a minimum of 15 minutes. The cycles subjected the 3M™
VHB™ Tapes to thermal aging and stresses due to thermal expansion and contraction of
the bonded parts. The 3M™ VHB™ Structural Glazing Tapes retained complete contact
throughout the thermal cycles, with no loss of adhesion.
pg_0009
(9)
Technical Bulletin
Structural Performance Tests of 3M
™
VHB
™
Structural Glazing Tapes
Air Leakage
The air infiltration test was conducted in accordance with ASTM E283 “Standard Test
Method for Determining Rate of Air Leakage Through Exterior Windows, Curtain Walls,
and Doors under Specified Pressure Differences across the Specimen" with a static
pressure of 0.3 kPa (6.24 psf), corresponding to an 80 kph (50 mph) wind load. This test
was repeated again at the end of the structural wind load test at elevated temperature.
There was no measurable air leakage through the 3M™ VHB™ Tapes and the one part
structural silicone sealant bonding the frames around the perimeter of the panels.
Air Leakage
The air infiltration test was conducted in accordance with ASTM E283 “Standard Test
Method for Determining Rate of Air Leakage Through Exterior Windows, Curtain Walls,
and Doors under Specified Pressure Differences across the Specimen" with a static
pressure of 0.3 kPa (6.24 psf), corresponding to an 80 kph (50 mph) wind load. There was
no measurable air leakage for both sets of glass panels demonstrating that 3M™ VHB™
Structural Glazing Tape can withstand the severe test conditions (thermal aging and
structural load at extreme temperature settings).
Water Penetration
The water penetration test was performed in accordance with ASTM E331 “Standard Test
Method for Water Penetration of Exterior Windows, Skylights, Doors, and Curtain Walls
by Uniform Static Air Pressure Difference" with a high pressure water spray under a
static pressure of 0.72 kPa (15 psf) for 15 minutes. The panels assembled with 3M™
VHB™ Tapes G23F and 4972 had no water leakage through the tape. Performance was
comparable to that of the one part structural silicone sealant.
Wind Load Structural
At ambient 32°C (90°F),
-25°C (13°F) and 70°C (158°F)
The wind load structural test was performed in accordance with ASTM E330 “Standard
Test Method for Structural Performance of Exterior Windows, Curtain Walls, and Doors
by Uniform Static Air Pressure Difference". The panels were subjected to both positive
wind loads (inward acting force) and negative wind loads (outward acting force – the
most severe direction for frame attachment). The panels were first subjected to loads of
0.5, 1.0, 1.9 and 2.9 kPa (10, 20, 40 and 60 psf) in each direction with the peak pressure
held for 1 minute. The 2.9 kPa (60 psf) level represents the basic design pressure for a
typical high-rise building or a sustained wind speed of 250 kph (155 mph). The glass
panels were visually inspected after the loads. All glass panels showed no sign of any
visual defects. The heating and cooling chamber was then set up in front of the glass
panels simulating the external side of the curtain wall. Temperature was lowered to -25°C
(-13°F). Then the panels were subject to loads of 0.5, 1.0, 1.9 and 2.9 kPa (10, 20, 40,
and 60 psf) in each direction and held for 1 minute at each pressure load. Then
temperature was increased to 70°C (158°F) and similar sequences of wind load pressure
cycling were conducted. After the structural wind load tests at these temperature settings,
the heating/cooling chamber was removed. The panels were inspected visually for any
sign of delamination or defects. All glass panels showed no sign of any visual defects.
It was noted that there was visible moisture condensation on the spacer tape of the 8 mm
tempered glass glazed unit constructed with the one part structural silicone sealant after
the structural wind load tests at various temperature settings.
Wind Load Structural
At ambient 32°C (90°F)
The wind load structural test was again performed in accordance with ASTM E330
“Standard Test Method for Structural Performance of Exterior Windows, Curtain Walls,
and Doors by Uniform Static Air Pressure Difference". The panels were then subject to
loads of 4 kPa and held for 10 seconds at ambient temperature conditions. Then pressure
was reversed and increased up to a suction of 4 kPa and held for 10 seconds. For the first
set of panels, this procedure was repeated at 5 kPa (104 psf) and 6 kPa (125 psf) which is
200% of the design pressure load. All the glass panels passed this test successfully.
pg_0010
(10)
Technical Bulletin
Structural Performance Tests of 3M
™
VHB
™
Structural Glazing Tapes
Wind Load Structural
Destructive at ambient,
32°C (90°F)
The wind load structural test was performed in accordance with ASTM E330 “Standard
Test Method for Structural Performance of Exterior Windows, Curtain Walls, and Doors
by Uniform Static Air Pressure Difference". The panels were subjected to an increase
in negative pressure (glass panels were being pushed away from frame) until failure
occurred. It was noted that at -8.4 kPa, the laminated glass construction with 3M™
VHB™ Structural Glazing Tape 4972 failed. After observing the video clip, it appeared
that the laminated glass started breaking from the center of the glass panel due to
deflection beyond the capability of the laminated glass. Even though the majority of glass
blew out, the 3M™ VHB™ Tape 4972 held the glass in place around the perimeter
demonstrating the capability of the tape to act as an effective bonding agent at this
extreme pressure. No delamination or any visual defect was seen on the DGU panels with
either 3M™ VHB™ Tape G23F or one part structural silicone sealant.
The second set of panels constructed with 8 mm tempered glass, (one with 3M™ VHB™
Tape G23F and the other with one part structural silicone sealant) together with the 3M™
VHB™ Tape G23F DGU panel from the first set of tests, were again subjected to similar
wind loads however, the peak pressure recorded was ± 8 kPa and held for 10 seconds.
8 kPa corresponds to a wind speed of 416 kph (258 mph). Pressure was then increased up
to the limit of the blower. In this case, the chamber managed to achieve up to ± 10 kPa
without failure, which corresponds to a wind speed of 467 kph (290 mph). Tempered glass
panels constructed with both one part structural silicone sealant or 3M™ VHB™ Structural
Glazing Tape G23F showed no sign of failure after the 10 kPa pressure load. The DGU
panel constructed with 3M™ VHB™ Tape G23F also withstood the ± 10 kPa load without
failure, even though it has been subjected to 40 cycles of thermal aging and 2x the structural
wind loads at the extreme temperature settings.
All statements, technical infor mation and recommendations contained in this document are based upon
tests or experience that 3M believes are reliable. However, many factors beyond 3M’s control can affect the
use and performance of a 3M product in a particular application, including the conditions under which the
product is used and the time and environmental conditions in which the product is expected to perform.
Since these factors are uniquely within the user’s knowledge and control, it is essential that the user
evaluate the 3M product to determine whether it is fit for a par ticular purpose and suitable for the user’s
method of application.
Product Use
3M warrants for 24 months from the date of manufacture that 3M™ VHB™ Tape will be free of defects in
material and manufacture. 3M MAKES NO OTHER WARRANTIES, EXPRESS OR IMPLIED, INCLUDING
BUT NOT LIMITED TO, ANY IMPLIED WARRANTY OF MERCHANTABILITY OR FITNESS FOR A
PARTICULAR PURPOSE. This limited warranty does not cover damage resulting from the use or inability
to use 3M™ VHB™ Tape due to misuse, workmanship in application, or application or storage not in
accordance with 3M recommended procedures.
Limited Warranty
If the 3M™ VHB™ Tape is proved to be defective within the warranty period stated above. THE EXCLUSIVE
REMEDY, AT 3M’S OPTION, SHALL BE TO REFUND THE PURCHASE PRICE OF OR TO REPAIR OR
REPLACE THE DEFECTIVE 3M™ VHB™ TAPE. 3M shall not otherwise be liable for loss or damages,
whether direct, indirect, special, incidental, or consequential, regardless of the legal theory asserted, including
negligence, warranty, or strict liability.
Limitation of
Remedies and
Liability
This Industrial Adhesives and Tapes Division product was manufactured under a 3M quality system registered to ISO 9001: 2000 standards.
IS O 90 0 1: 20 0 0
Printed in U.S.A.
©3M 2006 70-0709-3991-6 (5/06)
Recycled Paper
40% pre-consumer
10% post-consumer
3
Industrial Business
Industrial Adhesives and Tapes Division
3M Center, Building 21-1W-10, 900 Bush Avenue
St. Paul, MN 55144-1000
800-362-3550 • 877-369-2923 (fax)
www.3M.com/industrial

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