Low Pressure Molding: A Comprehensive Alternative to Potting
What is Macromelt® good for? An even better question to ask might be what is it GREAT for? This MUST be asked at the beginning of a project, as there are many advantages to using Low Pressure Molding with Macromelt® materials, and there are some projects better suited for a different process and type of material. The Macromelt® Data chart below will give you an idea whether LPM is right for your application. Feel free to contact us with any questions.
Macromelt® Molding Material Data
Material
OM 633 / OM 638
OM 641 / OM 646
OM 652 / OM 657
OM 673 / OM 678
MM 6208 / MM 6208S
Color
amber/black
amber/black
amber/black
amber/black
amber/black
Physical
Specific gravity, S.G.
0.98
0.98
0.98
0.98
0.98
Working temperature, °C
-40 to +125
-40 to +125
-40 to +100
-40 to +140
-40 to +130
Elongation @ rupture, %
400
800
400
500
600
Hardness @ 25°C, shore A
90
92
77
88
78
Hardness @ 125°C, shore A
65
63
N/A
64
N/A
Softening point, ball & ring, °C
175
175
155
185
155
Glass transition temperature, °C
-36
-35
-45
-50
-42
Molding temperature, °C
200 to 240
210 to 240
180 to 230
210 to 240
190 to 230
Viscosity @ 210° C, mPas
3700
7000
4100
3400
3600
Electrical
Dielectric constant @ 1kHz
4.5 / 4.7
5.1 / 5.5
6.2 / 6.3
4.9 / 4.9
6.1 / 6.3
Volume resistivity, Ohm cm
1.7E15 / 2.4E13
6.3E12 / 1.7E12
1.0E12 / 7.2E11
1.90E12 / 1.90E12
1.9E11 / 1.6E11
Dielectric strength, kV / mm
24 / 19
25 / 22
14 / 15
20 / 20
23 / 23
Ratings
FDA category, adhesives
175.105 (0M633)
175.105 (0M641)
175.105 (0M652)
175.105 (0M673)
175.105 (0M6208)
Flammability rating
V-0
V-0
V-0
V-0
V-0
Characteristics of Macromelt® Materials worth noting
1. Each grade of material is available in the amber base version and in black.
2. Some custom colors are available – contact us.
3. The softer materials generally offer the best adhesive properties. However, Cavist Manufacturing will perform adhesion tests on actual application substrates in order to recommend a specific molding compound.
4. These molding compounds shrink approximately 1.5% after molding.
5. Moisture and solvent resistance requirements will be key factors in selecting a specific grade of material. Most Macromelt materials do not have good resistance to polar solvents in combination with mechanical stress.