CLOTH / FABRICS | Revchem Composites

15NT350HT3K_TDS.pdf

by | Sep 27, 2025

NT-350HT Modified Epoxy Prepreg

Description
The NT-350HT Enduredge Max represents the next generation highly
toughened prepreg resin technology. This novel prepreg product offers
outstanding surface finish and laminate quality using vacuum bag only
processing. Unlimited out-time (no refrigerated storage) with zero change in
process parameters over time. NT-350HT allows the parts builder to efficiently
build large out-of-autoclave structures with near zero voids without
complicated debulking processes or elaborate cure cycles. While NT-350HT
was designed for OOA processing, it is perfectly suitable for in-autoclave
processes as well. NT-350HT is suitable for aerospace secondary and primary
structures, space and satellite structures and Radomes.

Product Features
Excellent Mechanical Properties full mechanicals without post-cure
No Freezer Storage; >12 months out-time at ambient storage conditions (70-80 F)
Excellent Mechanical Properties with Vacuum Bag Only processing
Unique engineered air release channels allow excellent OOA processing
Very thick laminates can be produced without any debulk steps
No changes in laminate processing conditions or rheology over time
Optimized for high quality surface finish

Neat Resin Properties
Density 1.17 g/cc
Dielectric Properties: Dk = 2.78 ; Df = 0.013
Moisture Absorption per ASTM D-5229: Post 2.2%, Standard 2.8%

DRY Tg ONSET F ( C) LOSS MODULUS F ( C) TAN DELTA F ( C)
Post 275 F (135 C) 293 F (145 C) 332 F (167 C)
Standard 207 F(97 C) 244 F (118 C) 305 F (152 C)

WET Tg ONSET F ( C) LOSS MODULUS F ( C) TAN DELTA F ( C)
Post 210 F (99 C) 235 F (113 C) 316 F (158 C)
Standard 201 F(94 C) 226 F (108 C) 293 F (145 C)

Prepreg Properties
DRY Tg ONSET F ( C) LOSS MODULUS F ( C) TAN DELTA F ( C)
Post 297 F (147 C) 322 F (161 C) 336 F (169 C)
Standard 244 F (118 C) 268 F (131 C) 302 F (150 C)

Method: ASTM D7028

ALL DATA VACUUM BAG ONLY

Prepreg Electrical Properties on Fiberglass
PROPERTY (0 ) 7781 6781
Dielectric Constant at 10 GHz (dry) 4.10 4.00
Loss Tangent at 10 GHz (dry) 0.012 0.012
Dielectric Constant at 10 GHz (24 hr water boil) 4.19 4.8
Loss Tangent at 10 GHz (24 hr water boil) 0.016 0.094

Prepreg Mechanical Properties on Fiberglass
PROPERTY (0 ) METHOD 7781
Flexural Strength ASTM D7264 103 ksi (711 MPa)
Flexural Modulus ASTM D7264 2.9 Msi (18.5 GPa)
Short Beam Shear ASTM D2344 9.2 ksi (63.6 MPa)
Tensile Strength ASTM D3039 60.4 ksi (416 MPa)
Tensile Modulus ASTM D3039 3.9 Msi (26.9 GPa)
All properties normalized to 60% fiber volume except ILSS (fiber volume 40-50%)

Prepreg Mechanical Properties on Carbon
PROPERTY (0 ) METHOD CARBON FIBER
Tensile Strength ASTM D3039 121 ksi (836 MPa)
Tensile Modulus ASTM D3039 9.52 Msi (65.4 GPa)
Poisson s Ratio ASTM D3039 0.05
Compressive Strength ASTM D6641 93.7 ksi (648 MPa)
Compressive Modulus ASTM D6641 9.71 Msi( 66.7 GPa)
Flexural Strength ASTM D7264 138 ksi (952 MPa)
Flexural Modulus ASTM D7264 8.8 Msi (56.1 GPa)
Short Beam Shear ASTM D2344 9.1 ksi (62.4 MPa)
Open Hole Compression ASTM D6484 42 ksi*
Data normalized to 60% fiber volume
* OHC 3K 2×2 twill AS4D 0/45 all others on 3K Grafil TR30S 2×2 twill

Prepreg Mechanical Properties in Uni-Directional Fibers
Hexcel IM-7 fiber NT-350 resin system autoclave cured
Normalized to 57% fiber content (except SBS)
PROPERTY METHOD RESULT
Tensile Strength ASTM D3039 355 ksi (2451 MPa)
Tensile Modulus ASTM D3039 21.9 Msi (150.4 GPa)
Compressive Strength ASTM D6641 208.9 ksi (1440 MPa)
Compressive Modulus ASTM D6641 20.4 Msi (140.6 GPa)
Flexural Strength ASTM D7264 170.9 ksi (1178.3 MPa)
Flexural Modulus ASTM D7264 19.9 Msi (137.1 GPa)
Short Beam Shear ASTM D2344 12.4 ksi (85.0 GPa)

Layup option for minimal configuration

Layup option for improve bag side. Use this when bag side has to be
taken into consideration.
Poor results unless vacuum is applied throughout full cure process
including while in oven.
ToolSurface
NEXX Layup (up to 25 plies).
Peelply
Solid Teflon film + holesin pattern no closerthan10cm
apart
SealantTape(allaround)
Breather(the thinnerthe better)
Rubbersealant(allaround)
VacuumBag
ReleaseAgent(Marbocote45Eco type)1
2
3
4
5
6
7
8
ToolSurface
NEXX Layup (up to 25 plies).
Teflon film + smallholes(pattern no lessthan10x10cm)
SealantTape(allaround)
Breather(the thinnerthe better)
Rubbersealant(allaround)
VacuumBag
ReleaseAgent(Marbocote45Eco type)1
2
3
4
5
6
7

Layup process for improved bag side

1
2 3
4
5
6
7
8

Proper cure process will show a small leak through the tack hole on the
Teflon film (4) creating a drop on the breather.

TOOL SIDE BAG SIDE

Poor results unless vacuum is applied throughout full cure process
including while in oven.

NT-350HT Baseline Oven Cure

EPOXY PREPREG, ADHESIVE, AND RESIN GUIDELINES AND HANDLING
PROCEDURES
The following guidelines are provided to our customers to assure that best
practices are used to attain the best results from NEXX Technology s epoxy
products. Keep in mind that these procedures represent best practices for all
composite prepreg and adhesive materials.

FREEZER STORAGE
Freezer storage is not required. It will not damage the product but is
completely unnecessary. The product is designed to be kept on the shop floor
at temperatures below 100 F (37 C) for over a year with no changes in
properties, rheology or processing conditions.

MOISTURE ABSORPTION AND SENSITIVITY
While very resistant to moisture absorption after cure, epoxies can be adversely
affected by moisture uptake prior to cure. Other materials may experience
moisture buildup when they are removed from frozen storage. Fortunately, the
Enduredge prepreg does not require freezer storage. It will always be ready for
immediate use

HANDLING MATERIALS
When handling any prepreg materials, always wear clean, powder-free latex
gloves. This assures that no hand oils are transferred to the prepreg and/or
composite during processing. The presence of oils in the part could lead to
problems in both mechanical and electrical performance of the part. This also
guards against dermatitis that may occur with some users.

USE OF HONEYCOMB AND FOAM CORE MATERIALS
When using nonmetallic honeycomb and foam core materials for sandwich
structures, the materials should always be dried in an oven prior to lay-up to
drive off any moisture that may be in the core. The core should be cooled in the
presence of a desiccant to avoid moisture uptake. Following drying, it is always
best to use the material as soon as possible. Recommended core dry
time/temp: 121 C (250 F) for 3-4 hours.

CONTACT INFORMATION
North America & Asia Pacific
NAsales@nexx-technologies.com
(718) 877-6217
Europe, Middle East & Africa
EUsales@nexx-technologies.com
(718) 877-6217

Nexx-Technologies
c/o Mitsubishi Gas Chemical America, Inc.
655 Third Avenue
19
th
Floor
New York, NY 10017
(212) 687-2810
www.enduredge.com
www.mgc-a.com

The information presented herein is believed to be accurate and reliable but is presented without
guarantee of responsibility on the part of Mitsubishi Gas Chemical Company. It is the responsibility
of the users to comply with all applicable laws and regulations and to provide for a safe
workplace. The users should consider any health or safety hazard, or information contained herein
only as a guide, and should take those precautions which are necessary or prudent to instruct
employees and develop work practice procedures in order to promote a safe work environment.
Further, nothing contained herein shall be taken as an inducement or recommendation to
manufacture or use any of the herein materials or processes in violation of existing or future
patents. Mitsubishi Gas Chemical is not affiliated with any other Mitsubishi Group Company.

15NT350HT12K_TDS.pdf