ELASTOSIL® RT 620 A/B and MinghuiLink RTV-4115 are soft addition-cure silicones with similar processing times but different strengths. RT 620 is specifically designed for pad-printing applications and offers 900% elongation, while RTV-4115 is better suited to soft mold making with a simple 1:1 mix ratio and substantially higher published tear strength.
Addition-Cure Silicone
Platinum-Cure Silicone
ELASTOSIL® RT 620 A/B and RTV-4115 are both soft silicones, but their primary strengths are different. RT 620 is the better fit for pad printing and repeated deformation, while RTV-4115 is better aligned with soft mold making, simpler 1:1 processing and higher tear resistance.
ELASTOSIL® RT 620 A/B and RTV-4115 are both soft addition-cure silicones, at 17 Shore A and 15±1 Shore A respectively. The small hardness difference is less important than their different application focus and mechanical properties.
RT 620 uses a 10:1 mix ratio with approximately 35 minutes of pot life, while RTV-4115 uses a simpler 1:1 system with approximately 30–40 minutes working time. RTV-4115 is therefore easier to proportion manually, while the published processing windows are broadly similar.
RTV-4115 has lower published Part A viscosity at approximately 4,000 mPa·s, while RT 620 publishes 7,000 mPa·s Part A, 1,200 mPa·s Part B and 6,000 mPa·s mixed viscosity. Because the manufacturers report different measurement points, the values should be compared with care.
Mechanical performance shows a clear trade-off. Both publish similar tensile strength, but RT 620 offers much higher elongation at 900%, while RTV-4115 publishes substantially higher tear strength at 26±0.5 N/mm. RT 620 therefore favors repeated deformation, while RTV-4115 offers greater resistance to tearing during mold handling and demolding.
WACKER specifically positions RT 620 for printing pads, emphasizing flow, self-deaeration and rapid demolding. RTV-4115 is more broadly positioned for soft mold making and flexible reproductions. The main choice is therefore between specialized pad-printing performance and general-purpose soft mold durability.
| Technical Parameter | WACKER ELASTOSIL® RT 620 A/B | MinghuiLink RTV-4115 |
|---|---|---|
| Silicone Type | Addition-cure RTV-2 | Platinum-cure silicone |
| Color | Translucent | Translucent |
| Mix Ratio | 10:1 by weight | 1:1 by weight or volume |
| Shore Hardness | 17 Shore A | 15±1 Shore A |
| Viscosity | 7,000 mPa·s (Part A) | 4,000±200 mPa·s (Part A) |
| Working / Pot Life | 35 min | 30–40 min |
| Demold / Cure Time | 4 h tack-free | 4–5 h cure |
| Tensile Strength | 5.0 MPa | 5.0±0.5 MPa |
| Tear Strength | ≥12 N/mm | 26±0.5 N/mm |
| Elongation | 900% | 450±50% |
| Shrinkage | ≤0.1% | ≤0.1% |
| Typical Applications | Printing pads and pad-printing applications | Soft molds, flexible reproductions and delicate mold applications |
| Technical Data Sources | ELASTOSIL® RT 620 A/B | RTV-4115 |
| Key Factor | WACKER ELASTOSIL® RT 620 A/B | MinghuiLink RTV-4115 | What It Means |
|---|---|---|---|
| Hardness | 17 Shore A | 15±1 Shore A | Both are soft; RTV-4115 is slightly softer. |
| Mix Ratio | 10:1 | 1:1 | RTV-4115 is simpler for manual batching. |
| Working Time | 35 min | 30–40 min | The published processing windows are broadly similar. |
| Component Viscosity | 7,000 / 1,200 mPa·s | 4,000 / 2,800 mPa·s | RTV-4115 has lower Part A viscosity, while RT 620 has lower Part B viscosity. |
| Tear Strength | ≥12 N/mm | 26±0.5 N/mm | RTV-4115 has the higher published tear-strength value. |
| Elongation | 900% | 450±50% | RT 620 offers substantially greater stretch capability. |
| Application Focus | Pad printing and printing pads | Soft molds and flexible reproductions | The products serve different primary applications. |
| Turnaround | 4 h tack-free | 4–5 h cure | The published cure windows are broadly similar, but the endpoints differ. |
| Application | ELASTOSIL® RT 620 A/B | RTV-4115 |
|---|---|---|
| Pad Printing | Strong candidate | Not specifically positioned |
| Soft Mold Making | Suitable | Strong candidate |
| Flexible Reproductions | Suitable | Strong candidate |
| Repeated Deformation | Strong candidate | Suitable |
| Easy Demolding | Strong candidate | Strong candidate |
| Delicate Detail Molds | Strong candidate | Strong candidate |
| Manual Small-Batch Mixing | Suitable with accurate weighing | Strong candidate |
| 3D-Printed Masters | Suitable with compatibility testing | Suitable with compatibility testing |
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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.