ELASTOSIL® P 7671 A/B and MinghuiLink RTV-4020 are both very soft addition-cure silicones for flexible and skin-contact applications. P 7671 emphasizes very low viscosity and specialized prosthetic applications, while RTV-4020 offers a similar soft hardness range with higher published tensile strength, tear strength and elongation for lifecasting and flexible reproductions.
Addition-Cure Silicone
Life Casting Silicone
ELASTOSIL® P 7671 A/B and RTV-4020 are both very soft silicones, but they favor different priorities. P 7671 emphasizes very low viscosity and specialized prosthetic applications, while RTV-4020 offers similar softness with higher published tensile strength, tear strength and elongation for lifecasting and flexible reproductions.
ELASTOSIL® P 7671 A/B and RTV-4020 are both very-soft addition-cure silicones, with P 7671 at approximately Shore OO 18 and RTV-4020 at Shore OO 20. Both provide high flexibility for soft molds and easy demolding.
Both use a 1:1 mix ratio, with similar published working times of approximately 40 minutes for P 7671 and 30–40 minutes for RTV-4020. P 7671 has the lower and more balanced component viscosity at approximately 1,800 mPa·s for both components, compared with 2,200 and 1,800 mPa·s for RTV-4020.
Mechanical performance favors RTV-4020. It publishes 1.0±0.5 MPa tensile strength, 4±0.5 N/mm tear strength and 560±50% elongation, compared with approximately 0.5 MPa, 1.5–2 N/mm and 400% for P 7671.
Application positioning is the main distinction. WACKER positions P 7671 for orthotics, prosthetics and skin-contact flexible applications, while RTV-4020 is more directly positioned for lifecasting and flexible reproductions. Overall, P 7671 emphasizes low viscosity and specialized prosthetic applications, whereas RTV-4020 offers stronger published mechanical performance for soft mold-making applications.
| Technical Parameter | WACKER ELASTOSIL® P 7671 A/B | MinghuiLink RTV-4020 |
|---|---|---|
| Silicone Type | Addition-cure RTV-2 | Platinum-cure silicone |
| Mix Ratio | 1:1 by weight | 1:1 by weight or volume |
| Shore Hardness | Approx. Shore OO 18 | Shore OO 20 |
| Viscosity | 1,800 mPa·s (Part A) | 2,200±200 mPa·s (Part A) |
| Working / Pot Life | 40 min @ 23°C | 30–40 min |
| Demold / Cure Time | Rapid room-temperature cure; conditions depend on part size and thickness | 4–5 h cure |
| Tensile Strength | 0.5 MPa | 1.0±0.5 MPa |
| Tear Strength | 1.5–2 N/mm | 4±0.5 N/mm |
| Elongation | 400% | 560±50% |
| Shrinkage | Not publicly listed | ≤0.2% |
| Typical Applications | Orthotics, prosthetics and skin-contact flexible applications | Lifecasting, prosthetics and flexible reproductions |
| Technical Data Sources | ELASTOSIL® P 7671 A/B | RTV-4020 |
| Key Factor | WACKER ELASTOSIL® P 7671 A/B | MinghuiLink RTV-4020 | What It Means |
|---|---|---|---|
| Hardness | Approx. Shore OO 18 | Shore OO 20 | P 7671 is slightly softer. |
| Working Time | 40 min | 30–40 min | Both provide a similar processing window. |
| Component Viscosity | 1,800 / 1,800 mPa·s | 2,200 / 1,800 mPa·s | P 7671 publishes lower and more balanced component viscosity. |
| Tensile Strength | 0.5 MPa | 1.0±0.5 MPa | RTV-4020 publishes the higher tensile value. |
| Tear Strength | 1.5–2 N/mm | 4±0.5 N/mm | RTV-4020 publishes substantially higher tear strength. |
| Elongation | 400% | 560±50% | RTV-4020 publishes higher elongation. |
| Application Positioning | Orthotics, prosthetics and skin-contact applications | Lifecasting, prosthetics and flexible reproductions | P 7671 has stronger orthotic positioning; RTV-4020 is more directly focused on lifecasting. |
| Cure Information | Rapid room-temperature cure; fixed time not publicly listed | 4–5 h cure | RTV-4020 provides the clearer published cure-time specification. |
| Application | ELASTOSIL® P 7671 A/B | RTV-4020 |
|---|---|---|
| Lifecasting | Suitable | Strong candidate |
| Delicate Reproductions | Strong candidate | Strong candidate |
| Easy Demolding | Strong candidate | Strong candidate |
| Prosthetic Applications | Strong candidate | Strong candidate |
| Orthotics | Strong candidate | Suitable |
| Skin-Contact Applications | Strong candidate | Suitable with application-specific validation |
| Thin / Repeatedly Handled Parts | Suitable with design consideration | Strong candidate |
| Soft Flexible Components | Strong candidate | Strong candidate |
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Competitor specifications are based on publicly available manufacturer documentation, with links to the original sources where available. Missing values are shown as “Not publicly listed” and are not estimated or inferred. Specifications may change, so always check the latest manufacturer documentation and conduct application-specific testing before production use. Product names and trademarks belong to their respective owners. This comparison is provided for technical and informational purposes only and is not endorsed by the brands mentioned.