Powder Phenolic Resins in
Bonded Abrasives
The Benefits of SG-3378 in Bonded Abrasives

Bonded abrasive manufacturers around the world commonly use powder phenolic resins as part of the primarybonding medium in cutting discs, grinding discs, grinding wheels, snagging wheels and polishing blocks.
Epoxy-modified powder phenolic resin brings some unique features to bonded abrasives, contributed to theintrinsic characteristics of epoxy resin:• Resistance to mechanical stress• Improved toughness• Improved crack resistance• Superior adhesion to glass fiber• Soft grinding action• Improved cutting efficiency• Increased resistance to alkaline grinding fluid• Improved aging/water resistance
SG-3378, epoxy-modified powder phenolic resin,can help to formulate bonded abrasives with highbursting speed and high stock removal rates.

SG-3378 Properties
SG-3378 powder has a medium flow, medium
hexamine level, fine particle size and medium curerate.
GradeFlow

Hexamine

Cure Time 160°C

SG-3378

27-32 mm

8.8-9.2 %20-40 seconds

The resin must be stored away from heat sources
and moisture.

SG-3378 Characteristcs
SG-3378 softens rapidly under the influence ofliquid resin, after which it portrays the tack characterof epoxy resin.

Abrasive Mix Characteristics• Increased mix binding property• Balanced wetness and green strength• Good flow into glass fiber mesh during pressing

Formulatory Guidelines
IG-3378 is ideal for use in, but not limited toSG-3378 is best used in conjunction with

• Cutting discs• Grinding discs• Grinding wheels• Snagging wheels• CR-2632 water-based liquid resol resin• Conventional water-based liquid resol resin• Unmodified powder phenolic resin of short flow
and high hexamine level

In terms of additives, the use of grinding aids (other than cryolite and pyrite) are optional and remain at thediscretion of the formulator. The use of hardening agents has proven very useful.

Typical Formulations
2.5 mm Cutting Disc, 6 mm Grinding Disc

Filler0.50

Hardening agent

0.05

Parts by Weight
Aluminium oxide mixture

100

Curing Schedules

Water-based liquid resol resin

4.90

SG-3378

12.50

Many different oven curing schedules exist, varying
according to the thickness of the discs, resin
systems used and other physical requirements.
In general, cutting discs would employ an ovenschedule of about 28 hours, for example:Cryolite and pyrite

9Filler

0.50

Hardening agent

0.05

6 mm Grinding Disc, 2.5 mm Cutting Disc
Parts by Weight
Aluminium oxide mixture

100CR-2632 water-based liquid resol resin

4.70

SG-3378

13.10

Sodium or potassium cryolite

2.41

Calcium fluoride

2.41

Pyrite

4.48

Red iron oxide

2.99

Packing density promotor

0.16

2.5 mm Cutting Disc, 6 mm Grinding Disc
Parts by Weight

Temperature GradientTimeHolding TimeAmbient to ca. 85°C (185°F)

2 Hours

1 HourTo 100°C (212°F)

2 Hours

2 Hours

To 120°C (248°F)

2 Hours

2 Hours

To 140°C (284°F)

2 Hours

2 Hours

To 185°C (365°F)

4 Hours

7 Hours

Cool Down

2 Hours0 Hours

Grinding discs would employ an oven schedule ofabout 30-38 hours, for example:
Temperature GradientTime

Holding Time

Ambient to ca. 85°C (185°F)

2 Hours

1 HourAluminium oxide mixture100

To 100°C (212°F)

7 Hours0 Hours

Water-based liquid resol resin

5.10

To 120°C (248°F)

3 Hours0 Hours

SG-33786.25

To 140°C (284°F)

5 Hours0 Hours

SG-3145

6.25

To 185°C (365°F)

3 Hours

7 Hours

Cryolite and pyrite

9Cool Down

2 Hours0 Hours

What this means for you
ASK Chemical’s SG-3378 offers unique benefits as the primary bonding medium in cutting discs, grinding discs, grinding wheels, snagging wheels and polishing blocks. If sharp cutting action and fast stock
removal is necessary, SG-3378 will provide added benefit. Please contact your sales representative foradditional information regarding SG-3378.