Surface Treated Magnesium Hydroxide
Specialty Halogen-Free Fire Retardant for Polyolefin Injection Molding Applications
(MDH) is a product with a proprietary polymeric surface treatment designed
to impart outstanding fire retardance and smoke suppression in polyolefin
injection molding applications while maintaining or improving processing
and mechanical property performance.
It is ideal for applications including fire retardant (FR) garbage bins,
containers, plastic pallets and industrial electrical boxes used in regulated
areas such as hospitals, schools, warehouses and office buildings. Another
specialty application for Vertex 60 SV is automotive plastic parts.
What is Important for Fire Retardant Polyolefin Injection Molding Applications?
•Ease of processing
– Low viscosity at high shear rates
– Fast molding speeds
•Heat stability when processing at >230˚C
•Excellent balance of mechanical properties of the finished part
•Fire retardance: Low rate of heat release and low-smoke generation
•Environmentally friendly ingredients
Meeting Stringent Fire Retardance Requirements
In the past, fire retardant additives containing halogens like bromine and chlorine have been used to impart
fire retardance in many injection molded polyolefin parts. With recent concerns about halogens, customers are
looking for alternative ways to achieve fire retardance and to meet new regulatory requirements for reduced
smoke generation. These smoke requirements are difficult to achieve with halogens, because compounds with
halogenated additives generate dark smoke upon burning.
While these recent regulatory and market changes have narrowed the fire retardant additive choices,
Huber Engineered Materials has introduced a new magnesium hydroxide product specifically designed
to work well in polyolefin injection molding applications – Vertex® 60 SV surface treated magnesium
hydroxide.
Formulating with Vertex® 60 SV Magnesium Hydroxide
Vertex 60 SV surface treated MDH offers the formulator a number of benefits in polyolefin injection molding
applications where stringent fire retardance and smoke suppression requirements are necessary.
Processing Parameters – Twin-Screw Extruder
Note the significant improvement below in process parameters of Huber’s Vertex 60 SV surface treated
magnesium hydroxide compared to untreated and fatty acid treated magnesium hydroxide products.
Vertex® 60 SV MDH
Surface Treatment
Proprietary
Melt Pressure (psi) 60
Extruder Torque (%) 10
Vertex® 60 MDH
None
100
15
Vertex® 60 HST MDH
Stearic Acid
75
12
65% High-Density Polyethylene (HDPE) + 35% MDH (210˚C Process Temperature)
Vertex 60 SV surface treated MDH offers significant processing benefits vs. untreated and fatty acid treated MDH.
Note the 40% reduction in extruder melt pressure and 32% reduction in extruder torque vs. untreated MDH.
Pa.s)
M a g n e s i u m
H y d r o x i d e
VERTEX 60 SV
®
Vertex® 60 SV surface treated magnesium hydroxide
45
40
35
Viscosity @ 6,900 1/s
Viscosity @ 10,000 1/s
Extruder Torque (%) 10
Vertex® 60 MDH
None ® 60 MDH
Vertex
100
None
15
100
45
40
15
Vertex® 60 HST MDH
Stearic® Acid
Vertex
60 HST MDH
75
Stearic
Acid
12
75
12
Shear Viscosity (Pa.s)
Vertex® 60 SV MDH
®
Surface Treatment Vertex
Proprietary
60 SV MDH
Melt Pressure
(psi) Proprietary
60
Surface
Treatment
Extruder
Torque
(%) 60
10
Melt
Pressure
(psi)
Extruder Torque (%) 10
15
35
30
25 ® 60 HST MDH
60 MDH
Vertex
20
Stearic Acid
15
75 10
12 5
0
Viscosity @ 6,900 1/s
Vertex® 60 SV MDH
Viscosity @ 6,900 1/s
Viscosity @ 10,000 1/s
Formulating with Vertex® 60 SV Magnesium Hydroxide (MDH)
Vertex® 60 SV MDH
Surface
Treatment
Proprietary
Capillary
Rheology
Melt Pressure (psi) 60
Extruder Torque (%) 10
Vertex®
None
100
15
Shear
Viscosity
(Pa.s)
Shear
Viscosity
(Pa.s)
45
40
45
35
40
30
35
25
30
20
25
15
20
4510
15
40 5
10
35 0
5
12
Vertex® 60 HST MDH
Viscosity @ 10,000 1/s
Viscosity @ 6,900 1/s
Viscosity @ 10,000 1/s
Shear Viscosity (Pa.s)
Vertex® 60 SV MDH
Surface Treatment
Proprietary
Tensile Stress @ Yield (psi) 3,140
30
Vertex® 60 SV MDH
Vertex® 60 HST MDH
25 0
Flexural
Stress @ Yield (psi) 2,510
®
®
VertexPolyethylene
60 SV MDH
60 HST
MDH
20 High-Density
65%
(HPDE)Vertex
+ 35% MDH
(210°C
Process Temperature)
1%
Modulus
(psi) improved
149,005
Injection
molded polyolefin parts require very high shear rates to adequately fill
theSecant
mold cavity.
The significantly
rheology
15
Viscosity @ 6,900 1/s
Viscosity @ 10,000 1/s
Vertex® 60 MDH
None
3,029
2,477
133,282
V
S
2
2
1
performance
of Vertex® 60 SV surface treated MDH makes it the clear choice when searching for a halogen-free fire retardant for
10
injection
molded parts such as pallets, containers, trays and bins.
5
0
Vertex® 60 SV MDH
Vertex® 60 HST MDH
900
®
®
Huber Magnesium Hydroxide
Mechanical
Property
Comparison
Vertex
60 SV MDH
Vertex
60 MDH
Vertex® 60 HST MDH
Vertex
®
Vertex
Surface Treatment
Proprietary
None 60 MDH
Stearic® acid
Vertex
60 SV MDH
Vertex
Vertex
60 HST MDH
Vertex
600
Tensile Stress
@ Yield (psi) Proprietary
3,140
3,029 500
2,600 acid
Surface
Treatment
None
Stearic
FlexuralStress
Stress@
@Yield
Yield (psi)
(psi) 3,140
2,510
2,477 400
2,343
Tensile
3,029
2,600
300
®
®
®
Vertex
60 SV MDH
Vertex 2,477
60 MDH
Vertex 60
HST MDH
1% Secant
Modulus
(psi)
149,005
133,282
128,427
Flexural
Stress
@ Yield
(psi)
2,510
2,343
200
100
Surface
Treatment
None 133,282
Stearic acid
1% Secant
Modulus (psi) Proprietary
149,005
128,427
kW/m2
800
®
700
®
60 SV MDH
®
60 MDH
60 HST MDH
®
0
Tensile Stress @ Yield (psi) 3,140
3,029
2,600
0
50
100
150
200
250
300
65% High-Density Polyethylene (HPDE) + 35% MDH (210°C Process Temperature)
Flexural Stress @ Yield (psi) 2,510
2,477
2,343
Time
(Seconds)
The improved toughness of the Vertex 60 SV surface treated MDH compound makes it ideal for applications
900
1%
Secant
Modulus
(psi) and 149,005
133,282
128,427
with
high impact
strength
high flexural modulus requirements.
Vertex® 60 SV MDH
Vertex® 60 MDH
Vertex®® 60 SV MDH
Vertex 60 HST MDH
Vertex® 60 MDH
kW/m2
2
2
kW/m
kW/m
Rate of Heat Release (50 kW/m2)
300
200
0
100
0
1/s 1/s
1/s
6
5
4
3
2
4
3
150
300
350
400
450
0
50
100
150Time
200(Seconds)
250
300
350
400
450 1
100
150
Time (Seconds)
200
250
300
2
0
350
400
450
0
50
100
150
200
250
300
350
400
450
Time (Seconds)
Vertex9® 60 SV surface treated MDH shows superior fire retardant
performance
vs. untreated and fatty acid treated MDH. The
peak heat
8
Vertex® 60 SV MDH
release97 for Vertex 60 SV is ~30% lower vs. the other materials tested.
Note
Vertex® 60 MDH
8
the 9ability
of Vertex 60 SV to reduce and control the heat release
rate
Vertex®® 60
SVas
MDH
Vertex® 60 HST MDH
6
the 8fire7 progresses (60-200 seconds).
Vertex 60 MDH
®
7
Vertex® 60 MDH
Vertex® 60 HST MDH
5
100
Time (Seconds)
5
6
4
5
3
4
2
3
1
2
0
1
Vertex® 60 SV MDH
6
50
50
250
7
0
0
200
450
8
Vertex® 60 SV MDH
Vertex® 60 MDH
Vertex® 60 HST MDH
400
Rate of Smoke Generation (50 kW/m2)
Vertex® 60 HST MDH
1/s
800
900
700
800
600
700
500
600
900
400
500
800
300
700
400
200
600
300
100
500
200
400 0
100
350
Vertex 60 SV MDH
Vertex® 60 HST MDH
Vertex® 60 MDH
Vertex® 60 HST MDH
Vertex 60 SV surface treated MDH also significantly reduces the
amount of smoke produced as the material burns. This is a
desired effect as it allows for longer escape times in settings such
as warehouse fires containing plastic pallets or storage bins.
Typical Physical Properties
Specific Gravity (g/cm3)
Color
Refractive Index
Mohs Hardness
325 Mesh Residue, %
2.3
Wh
1.5
2.5
0.3
1/
5
4
3
2
H y d r o x i d e
M a g n e s i u m
®
VERTEX 60 SV
1
0
0
50
100
150
200
250
300
350
400
450
Time (Seconds)
Vertex® 60 SV Surface Treated Magnesium Hydroxide (MDH)
Typical Physical Properties
Specific Gravity (g/cm3)
Color
Refractive Index
Mohs Hardness
325 Mesh Residue, %
Median Particle Size by Laser Light Scattering (µ, LLS-Microns)
Specific Surface Area (BET, m2/g)
Decomposition Temperature
Free Moisture @105˚C, %
2.36
White
1.58
2.5
0.3
3.0
12
330˚C
0.25
Chemical Composition
Magnesium Hydroxide Mg(OH)2, %
Calcium, %
Chloride, %
Iron, %
Loss on Ignition (1200˚C), %
≥99 (Untreated Base)
≤0.6
≤0.3
≤0.08
31 (Untreated Base)
About Huber Engineered Materials
Huber is your fire retardant and smoke suppressant expert with over 30 years of experience offering product
use guidance and a dedicated technical team for strong customer service focus and support. Contact us today
for more information about Vertex 60 SV surface treated magnesium hydroxide and to order a sample.
THERE ARE NO IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Refer to Huber’s Standard Conditions of Sale for the only
express warranties applicable to the Huber products. Products incorporating Huber products are not warranted by Huber. In no event is Huber liable for consequential damages.
Vertex® is used, applied for, or registered as a trademark of J.M. Huber Corporation for magnesium hydroxide in various countries around the world.
©2015 J.M. Huber Corporation
MDH/Vertex60SV/PolyolefinInjectionMolding/Dec2015