Vacuum Casting is a copying technique used for the production of small series of functional plastic parts. Using two-component polyurethanes and silicone molds, Vacuum Casting is known for its fast production of high-quality prototypes or end-use products.

Technical Specifications

Standard lead time Up to 10 copies within 10 working days
Standard accuracy ±0.3% (with lower limit on ±0.3 mm on dimensions smaller than 100 mm)
Minimum wall thickness To ensure that the mold is filled properly, a wall thickness of at least 0.75 mm is necessary. For best results, we recommend a wall thickness of at least 1.5 mm
Maximum part dimensions The size of the mold is limited by the dimensions of the vacuum chamber (1900 x 900 x 750 mm) and by the volume of the product (maximum volume: 10 liters)
Typical quantities Up to 25 copies per mold (depending on the mold’s complexity and the casting materials)
Surface structure High-quality surface finish comparable to injection molding

Datasheet

Rubber-like polyurethanes

  Units RPU4 RPU5 RPU6 RPU10 RPU11 RPU12 RPU13
Density g/cm³ 1.02 1.08 1.09 1.02 – 1.07 1.14 – 1.15 1.05 – 1.1 1.04 – 1.09
Hardness at 23°C Shore A 63 79 85 35 51 95 70
Tensile Strength MPa 3 12 17 1.5 – 3.5 3 9.5 – 11.5 6.5 –   8.5
Tear Strength KPa 24 67 83 n/a 18 n/a 20 – 25
Elongation at Break % 1000 620 810 900 – 1100 1200 200 – 300 400 – 500
Color   Light amber Black Black Translucent Beige Translucent Off-white
Colorability in Mass -/+/++/+++ + - - ++ + ++ ++
Max Operating Temperature °C 80 80 80 70 70 70 70

Actual values may vary with build condition

 

ABS-like polyurethanes

  Units HMPU1 HMPU3 HMPU3P HMPU4 HMPU5 HMPU6
Density g/cm³ 1.14 1.17 1.16 1.2 1.2 1.2
Hardness at 25°C Shore D 80 80 80 85 81 82
Hardness at 60°C Shore D >65 (120°C) 70 (130°C) 70 (130°C) n/a n/a n/a
Tensile Strength MPa 60 54 54 70 60 70
Tensile Modulus MPa n/a 1650 1650 n/a 2800 n/a
Bending Strength MPa 80 87 87 110 105 105
Bending Modulus MPa 2300 1600 1600 2500 2100 2500
Elongation at Break % 11 11 11 9 7.5 15
Impact Strength kJ/m² >60 Charpy 56 Charpy 56 Charpy 50 71 70 Charpy
Glass Transition Temperature °C >120 n/a n/a 100 95 105
Heat Deflection Temperature °C n/a 120 120 n/a n/a 92
Max Casting Thickness mm 5 – 10 5 – 10 5 – 10 5 5 5
Color   Black Black Beige Opalescent Off-white White
Colorability in Mass -/+/++/+++ - - + + ++ ++
Special Purpose   High thermal resistance High thermal resistance High thermal resistance Thermoplastic-like parts High impact resistance High thermal and impact resistance
Thermoplastic similarity   ABS ABS ABS Polycarbonate, ABS ABS Polystyrene-filled ABS
  Units HMPU7 HMPU10 HMPU11 HMPU13 HMPU14 HMPU15HQ
Density g/cm³ 1.11 1.2 – 1.25 1.19 1.04 – 1.08 1.17 – 1.23 1.06
Hardness at 25°C Shore D 77 85 80 85 85 – 90 86
Hardness at 60°C Shore D 68 (80°C) 80 (80°C) 65 (150°C) n/a n/a n/a
Tensile Strength MPa 40 85 61 66 80 – 85 68
Tensile Modulus MPa n/a n/a 1800 2400 n/a 2600
Bending Strength MPa 51 150 80 110 105 – 115 100
Bending Modulus MPa 1310 4500 1850 2400 2250 – 2750 2100
Elongation at Break % 25 3 13 7.5 6 – 8 6
Impact Strength kJ/m² n/a 30 Charpy 41 Charpy 48 Charpy n/a 42 Charpy
Glass Transition Temperature °C 108 95 220 95 n/a 100
Heat Deflection Temperature °C 90 92 190 – 195 85 65 – 75 85
Max Casting Thickness mm n/a 5 5 10 15 100
Color   White Off-white Light amber Transparent Straw Transparent
Colorability in Mass -/+/++/+++ ++ + + +++ + +++
Special Purpose   Food-safe under certain conditions n/a High thermal resistance UV-stable Flame-retardant UL 94 V-0 UV resistance, high transparency
Thermoplastic similarity   ABS Polyoxymethylene / POM PA6.6 / PPS / PEEK PC / PMMA n/a PC / PMMA

Actual values may vary with build condition

 

PE/PP-like polyurethanes

  Units LMPU1e LMPU2 LMPU3 LMPU4 LMPU5 LMPU6 LMPU7 LMPU8
Density g/cm³ 1.08 1.22 1.13 – 1.17 1.08 1.21 1.21 1.21 1.21
Hardness at 23°C Shore D 64 – 67 70 76 70 80 80 80 80
Hardness at 80°C Shore D n/a 64 68 n/a n/a n/a n/a n/a
Tensile Strength MPa 27 27 40 25 47 n/a n/a 26
Tensile Modulus MPa 530 942 n/a 530 1225 n/a n/a 750
Bending Strength MPa 28 42 80 30 60 48 64 27
Bending Modulus MPa 450 1050 1200 500 1310 1010 1320 645
Elongation at Break % 120 50 25 100 43 n/a n/a 62
Tear Strength kN/m 94 n/a n/a n/a n/a n/a n/a n/a
Impact Strength kJ/m² Unbreakable 15 Izod > 50 Charpy n/a 14 Izod 15 Izod 13 Izod 11 Izod
Glass Transition Temperature °C 100 78 90 90 – 100 127 – 195 105 – 132 125 – 195 70 – 90
Heat Deflection Temperature °C n/a 65 n/a 55 105 – 175 90 – 110 115 – 180 45 – 60
Color   Beige / Dark Beige White / Beige Translucent Beige Translucent Translucent Translucent Translucent
Colorability in Mass -/+/++/+++ + ++ +++ + +++ +++ +++ +++
Thermoplastic similarity   PE PP PE 30% GF PE / PEHD PP GF PP PP GF PEHD

Actual values may vary with build condition

 

How Does Vacuum Casting Work?

Vacuum Casting begins by producing a master model, typically using Stereolithography or Laser Sintering, with a high-quality surface finish. Then a silicone mold is produced by casting silicone around the master copy, partially under vacuum to avoid air bubbles. After curing, the silicone mold is cut according to pre-defined parting planes and the master is removed, leaving a cavity to make copies.