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Technical Manual
® Way Beyond Ordinar y ®
technical manual
R-Cast technical manual
®
Introduction
R-Cast® acrylic is monolithically cast polymethyl methacrylate (PMMA) acrylic manufactured
to strict internationally accepted structural standards. R-Cast® acrylic rod, tube, and sheet
are lightweight thermoplastics provided primarily in clear finishes, but also available in an
array of colors, both translucent or opaque. All R-Cast® acrylic is hard, rigid, and glassy at
room temperature. It is noted for being highly transparent, easy to maintain, and resistant
to weathering. The monolithic cast technology developed by Reynolds Polymer Technology,
Inc. (RPT) provides the world's thickest acrylic panels especially suited for the needs of
today’s modern aquariums, zoological parks, resorts, pools, and theme parks.
The technical information contained in this manual is compiled from nearly 30 years of
experience in engineering, casting, and fabricating of acrylic and is provided as a courtesy
to the reader. Reynolds Polymer Technology, Inc. assumes no responsibility or liability for the
accuracy of the information provided or results obtained from its use. The information being
given is accepted at the user's risk.
This double-arched aquarium sits at the entryway to the Scheels store in Sparks, Nevada. Two of these
11,000 gallon (42,000 liter) freestanding aquariums span the two main entrances to the store. Each
aquarium is nearly 43 feet long x 7 feet wide x 11 feet tall (13m x 2.1m x 3.5m) and was possible due to
the in-depth engineering and fabrication expertise from RPT.
-photo by Vance Fox
Reynolds Polymer Technology, Inc.• 607 Hollingsworth Street • Grand Junction, CO 81505 • 800.433.9293 • 970.241.4700
RPT Asia, Limited • 109/15 Moo 4 Eastern Seaboard Industrial Estate • Soi ESIE 6B • Pluakdaeng Rayong 21140 Thailand
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General
Manufacturing
R-Cast® acrylic rod, tube, and sheet is monolithically cast from polymethyl methacrylate
resin. The acrylic used for fabrication must satisfy two general requirements:
1. The casting process used in production shall be capable of producing material with the
minimum physical properties shown in ASME PVHO-1 Table 2-3.2. The manufacturer of
the material shall maintain on file certifications showing that the physical properties of
typical material meet or exceed these values.
2. Each acrylic casting must be free of inclusions which either significantly decrease its
structural performance or mar its optical appearance.
Annealing
R-Cast® acrylic is heat treated for superior clarity and strength. Annealing the acrylic
“finishes” the polymerization of the curing process and increases resistance to crazing
caused by either stress or chemical attack. Induced stresses caused by machining or
bonding are eliminated by annealing. The annealing process requires a carefully controlled
heat application and cool down.
Annealing is performed in large, specially designed process ovens in the factory and when
necessary, in custom built portable ovens on the jobsite.
Forming
Being a thermoplastic, R-Cast® acrylic sheet can be heated and formed to provide anything
from gently curving walls to 360° encircling tunnels. Proper heating and cooling techniques
will provide a memory-free formed acrylic sheet. There can be multiple radii in one sheet
and the inside radius can be as tight as three times the thickness of the sheet.
Bonding
When a design requires a sheet larger than a single casting, the larger sheet can be
fabricated by chemically bonding two or more sheets together. The sheets are bonded using
a proprietary methyl methacrylate adhesive developed by Reynolds Polymer Technology,
Inc. to render a bond joint of superior strength and clarity. The bonding process is usually
completed in the factory. When the need arises, panels can be bonded on the jobsite with
the same high quality results as are achieved in the factory.
Weathering Characteristics
All R-Cast® acrylic manufactured by Reynolds Polymer Technology, Inc., unless specifically
requested by the customer, is Ultra Violet (UV) stabilized to prevent degradation and
yellowing that would normally occur with acrylic. The UV stabilizer is an ingredient in the
casting formula rather than a surface coating. This ensures the acrylic is fully protected
through the entire thickness and the UV protection cannot be removed.
Unlike most materials, R-Cast® acrylic is resistant to the corrosive effects of saltwater and
chlorine environments. Long term exposure to these harsh conditions will not degrade the
physical properties of the acrylic.
Reynolds Polymer Technology, Inc.• 607 Hollingsworth Street • Grand Junction, CO 81505 • 800.433.9293 • 970.241.4700
RPT Asia, Limited • 109/15 Moo 4 Eastern Seaboard Industrial Estate • Soi ESIE 6B • Pluakdaeng Rayong 21140 Thailand
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Optical Quality
R-Cast® acrylic is generally colorless and clear with minimum haze. (>92% total transmission
with a 2 inch [51 mm] cubed sample per ASTM D-1003). Colored acrylic can be
provided upon request. Colors come in translucent or opaque. Opaque black acrylic is
often used for a high-tech, seamless transition when fabricating all-acrylic tanks.
The refractive index of clear acrylic is 1.49. Air has a refractive index of 1.00 and that
of water is 1.37. Using Snell's law, it is possible to calculate the exact angle of refraction
when viewing through acrylic. At the most severe angle the worst case refraction is
approximately 45 degrees.
Acrylic Design Criteria
Design Stress Levels
Acrylic sheets used for water retaining applications are designed to a membrane tensile
stress level of 800 psi (56 kg/cm2). This design parameter gives a safety factor of 11.2
based on the ASME PVHO-1-1997 minimum standard of 9000 psi (633 kg/cm2) tensile
strength. The safety factor is 13.5 based on the 10,800 psi (759 kg/cm2) average tensile
strength of R-Cast® acrylic.
The 800 psi (56 kg/cm2) design stress level was determined referencing United States
Naval Ocean Systems Center Technical Report 1303, June 1989, “Crazing and
Degradation of Flexural Strength in Acrylic Plates as a Function of Time.” The report
demonstrates that acrylic shows no signs of crazing after ten years when the stress level was
less than 810 psi (57 kg/cm2).
Crazing
Crazing is a deformation mode observed in acrylic when the acrylic is stressed. The stress
can be generated mechanically from poor fabrication and/or poor sanding and polishing
techniques, from incorrect design parameters, or from improper heating and cooling.
Crazing can also appear due to chemical attack from solvents, i.e., acetone, methanol,
MEK, etc. Heat will accelerate the appearance of crazing. Crazing sources do compound
one another, therefore a stressed panel will craze immediately if a solvent is introduced.
To the eye, crazing appears to be similar to hairline cracks. Although crazing may
subsequently break down into crack-like defects under prolonged stress, they must not be
considered damaged because the defects contain polymer materials. This polymer material
connects the polymer above and below the craze which contributes significantly to further
deformation resistance.
These oriented micro fibrils appear continuous when observed under a microscope.
Although crazing of products in service should always be considered undesirable, its
occurrence is not catastrophic since the micro structure of crazes is such that significant
forces may still be carried. This is supported by the observation that under compression,
or upon annealing, crazes tend to retract and disappear. Crazing can be removed by
Reynolds Polymer Technology, Inc.• 607 Hollingsworth Street • Grand Junction, CO 81505 • 800.433.9293 • 970.241.4700
RPT Asia, Limited • 109/15 Moo 4 Eastern Seaboard Industrial Estate • Soi ESIE 6B • Pluakdaeng Rayong 21140 Thailand
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sanding. Once the crazes are removed, the crazing cycle starts again, i.e., if a panel starts
to craze after 15 years, and the crazing is removed, crazing will not occur again until 15
years later.
Bonded Panels
Acrylic rods, tubes and sheets that have been bonded together using RPT's proprietary
bonding adhesive and methods, have a tensile strength over 9000 psi at the bond. The
bond strengths meet the ASME PVHO minimum standards for non-bonded structures, thus,
the long term design stress at a bond is limited to 800 psi (56 kg/cm2). The design safety
factor for bonded acrylic material is 11.2 based on the ASME PVHO-1-2003 minimum
standard of 9000 psi (633 kg/cm2) tensile strength. Due to the superior strength of the
bonding methods used, a bonded panel does not need to be any thicker than a sheet
without bonds.
Deflection
Initial deflection for acrylic windows with unsupported edges, i.e., open top tanks, will
be limited to 1/400 of the length of the unsupported edge to achieve proper aesthetics.
Deflection can be limited further, but would be an additional aesthetic request by the
designer/architect, not to be considered in any way a structural requirement for safety.
Short Term Loading
When designing for impact, live, or seismic loading conditions, the general design stress
level is 3000 psi (180 kg/cm2). Impact, live, and seismic are short term and infrequent
loading conditions. The 3000 psi (180 kg/cm2) is a safety factor of 3.0 based on the
PVHO minimum tensile stress level of 9000 psi (633 kg/cm2). The safety factor is 3.6
based on the R-Cast® average tensile strength of 10,800 psi (759 kg/cm2).
Acceptance of Material
Dimensional Tolerances
In order to maximize structural strength, provide acceptable optical performance, and
minimize difficulties during installation, the R-Cast® acrylic panels shall meet the following
dimensional tolerances:
•
•
•
•
The actual thickness of each window measured at any location on the window to
be within a tolerance of T +0.5 inch / - 0.00 inch (+12.7 mm), where "T" is the
minimum engineered thickness of the window.
Each viewing surface on a flat plane shall have a flatness tolerance of 0.002 x L,
where "L" is the length of the window.
The length and width of each plane window is fabricated within 0.25 inches (6.4
mm) of specified nominal dimensions.
The sharp corners on the edges of all windows have a chamfer to prevent chipping
during shipping and installation. The width of the 45 degree chamfer does not
exceed 0.13 inches (3.2 mm) for every inch of thickness or 0.50 inches (13 mm)
maximum. Unsupported edges that are visible will have a radiused edge and are
polished as opposed to having a chamfered edge. The size of the radius follows
the same guidelines as the chamfer.
Reynolds Polymer Technology, Inc.• 607 Hollingsworth Street • Grand Junction, CO 81505 • 800.433.9293 • 970.241.4700
RPT Asia, Limited • 109/15 Moo 4 Eastern Seaboard Industrial Estate • Soi ESIE 6B • Pluakdaeng Rayong 21140 Thailand
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Optical Performance Requirements
PVHO
The optical performance demanded of R-Cast® acrylic windows is similar to that of picture
windows. To achieve this performance, the surfaces are polished smooth, without obvious
surface irregularities in the form of waviness, ridges, pits, dimples, bumps, scratches or
scuffs. Minor distortions on the wet side of a window are not visible as they are corrected
by the interface with the water. This is due to the similar refractive indices of water and
acrylic.
"PVHO" is the acronym for Pressure Vessel for Human Occupancy. A majority of PVHOs
include submarines, diving bells, medical hyperbaric chambers, and decompression
chambers. The ASME PVHO manual sets the design standards for any pressurized chamber
built that will be occupied by people. Section 2 of that manual references viewport design.
Per Article 3 of said manual, acrylic is the only acceptable material for use as a window
in a Pressure Vessel for Human Occupancy. Laminated sheets are explicitly deemed not
acceptable.
PVHO is referenced in RPT's acrylic design specifications. It is the most commonly accepted
published standard for acrylic. There is credibility in that the manual is published by the
American Society of Mechanical Engineers, a non-biased entity. The ASME PVHO manual
is accepted by the US military (Navy, Coast Guard, and Air Force), marine surveying
companies (DNV, Lloyd's Registry, ABS), and most importantly, insurance companies both
domestic and international.
Designed for deep sea exploration, the Johnson
SeaLink submersibles are certified for operation
down to a depth of 3,000 feet (915m).
The R-Cast® acrylic pilot sphere allows for
greater field of vision for the occupants and is
well suited to this application because of it's
thermal capabilities, strength, and precision
manufacturing.
Reynolds Polymer Technology, Inc.• 607 Hollingsworth Street • Grand Junction, CO 81505 • 800.433.9293 • 970.241.4700
RPT Asia, Limited • 109/15 Moo 4 Eastern Seaboard Industrial Estate • Soi ESIE 6B • Pluakdaeng Rayong 21140 Thailand
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R-Cast® Physical Properties
Property
ASTM Method
US
Customary
Units
Average
Value
Metric
Units
Average
Value
ASTM-D792
ASTM-D638
ASTM-D638
ASTM-D638
ASTM-D790
ASTM-D695
ASTM-D732
ASTM-D256
ASTM-D256
ASTM-D256
ASTM-D785
ASTM-D2583
-psi
psi
%
psi
psi
psi
ft-lbs/inch
lbf*in/in
lbf*in/in
---
1.19
10,800
450,000
4.0
16,000
17,500
10,000
0.414
2.1
107
M-103
49
-Kg/cm²
Kg/cm²
-Kg/cm²
Kg/cm²
Kg/cm²
J/m
kgf*cm/cm
kgf*cm/cm
---
-759
31 x 10³
-1,125
1,230
703
22.1
0.4
20
---
ASTM-D621
ASTM-D702
%
%
0.85
2
---
---
Residual Monomer, per ASME PVHO-1 method,
Paragraph 2.2.5
Methyl Methacrylate
Ethyl Acrylate
%
%
1.6
1.6
---
---
OPTICAL
Clarity, Visually Rated (clear acrylic)
Light Transmittance (0.1” nominal thickness)
UV Light Transmission (290nm - 330 nm)
Haze
Refractive Index @ 77°F
ASTM-D702
ASTM-D1003
ASTM-D308
ASTM-D1003
ASTM-D542
-%
%
%
--
Must be readable
92
5
<1
1.49
-----
-----
°F
300-315
°C
149-157
°F
°F
°F
BTU/(hr)ft2 (°F/in)
in/min
°F
cal/lb °F
%
226
239
150
1.3
1.0
910
428
10
°C
°C
°C
w/m °K
mm/min
°C
cal/g °C
108
115
66
0.19
25
490
0.35
MECHANICAL
Specific Gravity
Tensile Strength
Tensile Modulus
Tensile Elongation
Flexural Strength
Compression Strength
Shear Strength
IZOD Impact Strength, notched @ 1/8”
Impact Strength, Notched (Charpy Method)
Impact Strength, Unnotched (Charpy Method)
Rockwell Hardness (M Scale)
Barcol Hardness
Deformation Under Load
@ 4,000 psi @ 73°F
Residual Shrinkage (int. strain)
THERMAL
Forming Temperature
Heat Deflection Temperature (under load 264
psi; 18.6 kg/cm2)
Vicat Softening Point
Maximum Service Temperature
Coefficient of Thermal Conductivity (k-factor)
Flammability (0.13 inch [3mm] thick)
Self-Ignition Temperature
Specific Heat @ 77 °F (25 °C)
Smoke Density Rating
ASTM-D648
ASTM-D1525
Cenco-Fitch
ASTM-D635
ASTM-D1929
ASTM-D2843
Reynolds Polymer Technology, Inc.• 607 Hollingsworth Street • Grand Junction, CO 81505 • 800.433.9293 • 970.241.4700
RPT Asia, Limited • 109/15 Moo 4 Eastern Seaboard Industrial Estate • Soi ESIE 6B • Pluakdaeng Rayong 21140 Thailand
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THERMAL, CONT.
Coefficient of Thermal Expansion
ASTM-D696
°F
-40
-20
0
20
40
60
80
100
120
140
ELECTRICAL
Dielectric Strength (short time,
1/8 inch thick [3mm])
Dielectric Constant, 60 Hertz
Dielectric Constant, 1,000 Hertz
Dielectric Constant, 1,000,000 Hertz
Dissipation Factor, 60 Hertz
Dissipation Factor, 1,000 Hertz
Dissipation Factor, 1,000,000 Hertz
Volume Resistivity
Surface Resistivity
ASTM-D149
ASTM-D150
ASTM-D150
ASTM-D150
ASTM-D150
ASTM-D150
ASTM-D150
ASTM-D257
ASTM-D257
volts/mil
------ohm-in
ohms
430
------6.3 x 1015
1.9 x 1015
KV/mm
------ohm-cm
17
3.5
3.2
2.7
0.06
0.04
0.02
1.6x 1016
ASTM-D570
ASTM-D570
ASTM-D570
%
%
%
0.2
0.0
0.2
----
----
ASTM-D570
ASTM-D570
ASTM-D570
ASTM-D570
ASTM-D570
ASTM-D570
%
%
%
%
%
%
0.2
0.5
0.6
0.8
1.0
1.1
-------
-------
WATER ABSORPTION
Water Absorption, Equilibrium,
24 hrs @ 73°F
Soluble Matter Lost, 24 hours
Dimensional Change During Immersion (24 hrs)
Weight Gain During Immersion
24 hrs @ 73°F
7 days @ 73°F
14 days @ 73°F
21 days @ 73°F
35 days @ 73°F
48 days @ 73°F
ODOR
TASTE
10-5 (in/in/ °F)
2.9
3.0
3.2
3.4
3.7
4.0
4.3
4.7
5.1
5.4
°C
-40
-29
-18
-7
4
16
27
38
49
60
10-5 (mm/mm/ °C)
5.22
5.40
5.76
6.12
6.66
7.20
7.74
8.46
9.18
9.72
None
None
Reynolds Polymer Technology, Inc.• 607 Hollingsworth Street • Grand Junction, CO 81505 • 800.433.9293 • 970.241.4700
RPT Asia, Limited • 109/15 Moo 4 Eastern Seaboard Industrial Estate • Soi ESIE 6B • Pluakdaeng Rayong 21140 Thailand
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Chemical Resistance
This table applies to clear, R-Cast® acrylic.
This table shold be used only as a general
guide, and, when in doubt, should be
supplemented by tests replicating actual
working conditions.
R = Resistant
R-Cast® acrylic withstands this substance for
long periods and at temperatures up to
120° F (49° C).
LR = Limited Resistance
R-Cast® acrylic only resists the action of
this substance for short periods at room
temperature. The resistance for a particular
application must be determined.
N = Non Resistant
R-Cast® acrylic is not resistant to this
substance. It either swelled, was attacked,
dissolved or was damaged in some manner.
Plastic materials can be attacked by chemicals
in several ways. The methods of fabrication
and/or conditions of exposure of R-Cast®
acrylic as well as the manner in which the
chemicals are applied, can influence final
results even for "R" coded chemicals. Some of
these factors are listed below.
Fabrication - Stress generated while sawing,
sanding, machining, drilling, polishing, and/
or forming.
Exposure - Length of exposure, stresses
induced during the life of the product due to
various loads, changes in temperatures, etc.
Application of Chemicals - By contact,
rubbing, wiping, spraying, etc.
Chemical
Acetic Acid (5%)
Acetic Acid (Glacial)
Acetic Anhydride
Acetone
Acrylic Paints & Lacquers
Ammonia (aqueous solution)
Ammonium chloride (Saturated)
Ammonium Hydroxide (10%)
Ammonium Hydroxide (Conc.)
Aniline
Battery Acid
Benzaldehyde
Benzene
Bituminous Emulsion
Bromine
Butanol
Butyl Acetate
Calcium Chloride (Saturated)
Calcium Hypochlorite
Carbon Tetrachloride
Cement
Chlorine Water
Chloroform
Chromic Acid (40%)
Citric Acid (10%)
Cottonseed Oil (Edible)
Detergent Solution
Diesel Oil
Diethyl Ether
Dimethyl Formamide
Dioctyl Phthalate
Ethyl Acetate
Ethyl Alcohol (50%)
Ethyl Alcohol (95%)
Ethylene Dichloride
Ethylene Glycol
2-Ethylhexyl Sebacate
Formaldehyde (40%)
Formic Acid (2%)
Formic Acid (40%)
Gasoline (Regular, Leaded)
Glycerine
Glycerol
Glycol
Heptane
Hexane
Hot Bitumen
Code
R
N
LR
N
LR
R
R
R
R
N
R
N
N
N
N
LR
N
R
R
N
R
LR
N
N
R
R
R
R
N
N
N
N
LR
N
N
R
R
R
R
LR
LR
R
R
R
R
R
LR
Chemical
Hydrochloric Acid
Hydrofluoric Acid (40%)
Hydrogen Peroxide (3%)
Hydrogen Peroxide (28%)
Isooctane
Isopropyl Alcohol
Kerosene
Lacquer Thinner
Lactic Acid (80%)
Methane
Methyl Alcohol (50%)
Methyl Alcohol (100%)
Methyl Ethyl Ketone (MEK)
Methylene Chloride
Mineral Oil
Mortar
Motor Fuel (benzene-free)
Motor Fuel (with benzene)
Muriatic Acid (20%)
Nitric Acid (10%)
Nitric Acid (40%)
Nitric Acid (Conc.)
Oil Paints (pure)
Olive Oil
Oxygen
Ozone
Phenol Solution (5%)
Phosphoric Acid (10%)
Plaster of Paris
Soap Solution (Ivory)
Sodium Carbonate (2%)
Sodium Carbonate (20%)
Sodium Chloride (10%)
Sodium Hydroxide (1%)
Sodium Hydroxide (10%)
Sodium Hydroxide (60%)
Stearic Acid
Sulfuric Acid (3%)
Sulfuric Acid (30%)
Sulfuric Acid (Conc.)
Thinners (general)
Toluene
Trichloroethylene
Turpentine
Urine
Water (Distilled)
Xylene
Reynolds Polymer Technology, Inc.• 607 Hollingsworth Street • Grand Junction, CO 81505 • 800.433.9293 • 970.241.4700
RPT Asia, Limited • 109/15 Moo 4 Eastern Seaboard Industrial Estate • Soi ESIE 6B • Pluakdaeng Rayong 21140 Thailand
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Code
R
N
R
N
R
LR
R
N
LR
R
LR
N
N
N
R
R
R
N
R
R
LR
N
R
R
R
R
N
R
R
R
R
R
R
R
R
R
R
R
R
N
N
N
N
LR
R
R
N
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Acrylic vs Glass
There are two choices to consider when evaluating glazing needs: glass or acrylic.
Both are popular materials well entrenched within the aquarium and exhibit industries.
While glass was once the primary material and has been in use the longest, advances
in acrylic technology delivered a more versatile product that many professionals now
prefer. Acrylic is recommended for large installations that demand expansive windows,
custom shapes, or the seamless joining of several panels together. For many smaller,
simpler exhibits, glass is preferred for its economical price. At RPT, we provide design
and engineering for both acrylic and glass and manufacture our own proprietary
R-Cast® acrylic featured in aquariums, zoos, pools, and architectural installations
worldwide.
Glass
When public aquariums first gained a foothold in the 1850s, exhibits used glass
to showcase their aquatic animals. For the first time ever, visitors to the increasingly
popular public aquariums had a chance to see marine life all in one location in
ways never before imagined. As time went on, glass technologies evolved to make
the exhibits bigger and safer. Today, when designing exhibits that feature glass, the
windows are required to be constructed of fully tempered, laminated panes. Fully
tempered glass is stronger than annealed glass and has greater impact resistance. If
tempered glass should break, it fractures into tiny pieces, much like safety glass on car
windows. Any glass other than fully tempered will break into large, dangerous shards
upon impact.
Laminated layers of tempered glass are required so that in the event of a broken
or compromised layer, there are back-up, or redundant, layers to keep the exhibit
enclosed for a short time until it can be replaced. If the exhibit is a water retaining
exhibit, the window is designed in such a way that should one layer fail, the
remaining layers will carry the hydrostatic load until the exhibit can be safely drained
and the window replaced. If the glass is not laminated, any failure would be nearly
instantaneous and considered catastrophic, similar to a water balloon hitting pavement.
Any non-laminated glass windows should never be used for water retaining exhibits.
Early aquariums, such as this one from 1905,
featured smaller, glass aquatic displays with simple
flat panels. Today, glass remains suitable for smaller
exhibits that don’t require forming or invisible seams.
- Belle Isle Aquarium in Detroit, Mich. courtesy of Detroit Publishing
Company.
While glass has greater scratch resistance than acrylic, it is not scratch proof. In
instances where acrylic will get heavily scratched, glass will likely scratch, too. The
difference between the two, even though it takes more force to scratch glass, is that
when glass scratches it is difficult – if not impossible – to repair the scratches. The only
solution at that point is to fully replace the glass. This can become cost prohibitive with
exhibits that people regularly touch or interact with. Likewise, when there is a crack or
other flaw appearing in the glass, it cannot be repaired. The only solution when that
happens is full replacement of the panel before a catastrophic event occurs.
Reynolds Polymer Technology, Inc.• 607 Hollingsworth Street • Grand Junction, CO 81505 • 800.433.9293 • 970.241.4700
RPT Asia, Limited • 109/15 Moo 4 Eastern Seaboard Industrial Estate • Soi ESIE 6B • Pluakdaeng Rayong 21140 Thailand
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As far as optical qualities go, glass provides an increasing amount of distortion as
the thickness increases. In general, the thicker the glass, the more discoloration that
appears and contributes to the visible distortion.
Acrylic
Acrylic provides greater versatility in what windows
can look like and how visitors interact with the
exhibit. This first-ever, double-radiused, monolithic
window would have been impossible if designed
with glass.
- California Academy of Sciences, San Francisco, Cali., photo by
EPKvision.com
Since the 1970s, acrylic aquariums proved to be a lighter, more versatile alternative
to glass. As time and technology progressed, acrylic became the material of choice
for those looking for their aquarium designs to stand out from the rest. Unlike glass
that must laminate thinner sheets together, R-Cast® acrylic can be cast to the required
thickness for the project in a single pour. This results in a material that has greater
optical clarity and adaptability. Because acrylic is 17 times stronger than glass – and
four times stronger than concrete – and weighs half as much as glass, acrylic has
significantly more versatility in how and where it can be used. Acrylic can be formed
into nearly any shape and the configurations are nearly endless when used with our
proprietary, invisible seam bonding process to glue panels together. Whether it’s a
tunnel along the floor of an aquarium exhibit, an underwater room in the middle of a
dolphin tank, or a huge view panel to view whale sharks, acrylic offers the capability
to go beyond the ordinary.
Acrylic, being a plastic, is much more forgiving than glass. Glass is unpredictable in
there is always a breakage possibility due to flaws in the material. When designing
with glass, engineers can only lower the breakage possibility, they can never eliminate
it. Acrylic, however, is predictable in its performance. Since it’s known exactly when
acrylic will break, it’s easier to engineer and design the material well beyond that
breakage point, called a safety factor. Barring catastrophic outside factors, being able
to design and test material built to a safety factor over 10 eliminates the risk of failure.
Should a flaw appear, acrylic won’t shatter, unlike glass. When acrylic is damaged, it
can hold – even if it’s a water retaining application – until it is fixed, which is perhaps
the most important safety point. Whether it’s a scratch or something more serious, the
panel can usually be restored to like-new condition without affecting its performance.
So, when deciding what material to use in your exhibit, consider the finished size, the
location of the installation, and if it will be a unique shape or monolithic panel with
visible or seamless joints. Whether you decide on glass or our R-Cast® custom cast
acrylic, RPT can provide the design and engineering expertise you need.
Reynolds Polymer Technology, Inc.• 607 Hollingsworth Street • Grand Junction, CO 81505 • 800.433.9293 • 970.241.4700
RPT Asia, Limited • 109/15 Moo 4 Eastern Seaboard Industrial Estate • Soi ESIE 6B • Pluakdaeng Rayong 21140 Thailand
reynoldspolymer.com
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technical manual
R-Cast technical manual
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R-Cast® Acrylic vs Glass
R-CAST ACRYLIC
TEMPERED LAMINATED GLASS
FABRICATION
Very Easy
Not possible once tempered
SCRATCH RESISTANCE
Softer than glass
Very Resistant
REPAIRABILITY
Easily repairable
Difficult
CLARITY
Very Clear
Extremely Clear
COLOR
Nearly color free at any
thickness
Standard glass has green
tint that's very prominent with
thick panels.
Low iron glass has very little
color, but still significantly
more color than acrylic.
FORMABILITY
Easy
Difficult, especially with
laminate
SIZE AVAILABILITY
Unlimited with bonding
Limited
SHAPE AVAILABILITY
Any shape with custom
order
Flat panels recommended
BRITTLENESS
Slightly Brittle
Very Brittle
WEIGHT
1/2 that of glass
Twice that of acrylic
CATASTROPHIC FAILURE
Very Slight
Slight
SPONTANEOUS FAILURE
Impossible
Possible
EASE
OF INSTALLATION
SAFETY
BURNING CHARACTERISTICS Class III per IBC
Class I per IBC
SMOKE GENERATION
High
None
IMPACT RESISTANCE
Great
Good
SAFETY FACTOR
IN
DESIGN 11.2
Reynolds Polymer Technology, Inc.• 607 Hollingsworth Street • Grand Junction, CO 81505 • 800.433.9293 • 970.241.4700
RPT Asia, Limited • 109/15 Moo 4 Eastern Seaboard Industrial Estate • Soi ESIE 6B • Pluakdaeng Rayong 21140 Thailand
reynoldspolymer.com
© 2014. R-Cast and “Way Beyond Ordinary” are registered trademarks of Reynolds Polymer Technology, Inc. All rights reserved. RPT-14-001
12
2.0
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®
technical manual
R-Cast technical manual
®
Finite Element Analysis
RPT's Engineering department uses a state of the art finite element analysis software
package for stress analysis. Essentially, the finite element method is a computer-aided
mathematical technique for obtaining numerical solutions to physical systems which
are subjected to external loads. Using the finite element method, the RPT engineering
staff models the required panel, tank or other desired shape with the proper geometry,
constraints, and loading conditions. The results are analyzed and the glazing thickness
optimized based on the project design criteria.
A finite element analysis calculation packet is provided upon request. The packet
typically includes the following items:
•
•
•
•
•
Physical properties specifications;
One copy of the glazing design criteria;
One copy of the finite element analysis element description section;
Glazing shop drawings and installation details, if required;
Graphical representation of the finite element analysis model loading
conditions and stress plots;
• Numerical listing of model loading conditions and results.
Reynolds Polymer Technology, Inc.• 607 Hollingsworth Street • Grand Junction, CO 81505 • 800.433.9293 • 970.241.4700
RPT Asia, Limited • 109/15 Moo 4 Eastern Seaboard Industrial Estate • Soi ESIE 6B • Pluakdaeng Rayong 21140 Thailand
reynoldspolymer.com
© 2014. R-Cast and “Way Beyond Ordinary” are registered trademarks of Reynolds Polymer Technology, Inc. All rights reserved. RPT-14-001
13
Way Beyond Ordinar y
®