2378SL
2378SL is a differential double-coated adhesive construction featuring a 3.0–3.1 mil silicone PSA on one face and a 1.9–2.1 mil acrylic PSA on the opposite face, supported by a 0.5 mil polyester (PET) film carrier. The construction uses a 2 mil polyester film liner on the silicone side and a 4.7 mil clay-coated semi-bleached paper liner on the acrylic side. Adhesion is asymmetric by design: the silicone side delivers up to 74 oz/in peel and the acrylic side delivers up to 244 oz/in peel (stainless steel, 3-day RT, 180°, 2 mil aluminum foil laminate). Service temperature spans −40°F to 302°F, and both adhesives are suitable for outdoor use.
Key Properties
- Peel Adhesion, Acrylic Side, SS, 3 Days @ 160°F, 180°, 2 MIL Polyester: 219 oz/in (ASTM D3330)
- Peel Adhesion, Acrylic Side, SS, 3 Days RT, 180°, 2 MIL Aluminum Foil: 244 oz/in (ASTM D3330)
- Peel Adhesion, Silicone Side, SS, 3 Days RT, 180°, 2 MIL Aluminum Foil: 74 oz/in (ASTM D3330)
- Tack, Acrylic Adhesive (2 MIL Aluminum Foil): 1,120 gm (ASTM D2979)
- Service Temperature: −40°F to 302°F
- Adhesive Thickness: 3.0–3.1 mils silicone / 1.9–2.1 mils acrylic / 0.5 mil PET carrier
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- Specifications
- Applications
- General Info
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Physical Properties
| Property | Value | Test Method |
| Adhesive Type | Silicone & Acrylic | — |
| Adhesive System | Permanent Adhesive | — |
| Adhesive Side | Double Sided Adhesive | — |
| Color | Clear | — |
| Adhesive Backing / Carrier | Polyester Film | — |
| Liner | Polyester film & clay-coated paper | — |
| Adhesive Thickness, Silicone Side | 3.0–3.1 mils ±0.2 | ASTM D3652 (Modified for Use with Non-Tape Product) |
| Adhesive Thickness, Acrylic Side | 1.9–2.1 mils ±0.1 | ASTM D3652 (Modified for Use with Non-Tape Product) |
| Liner Thickness, Film | 2 mils ±10 | ASTM D3652 (Modified for Use with Non-Tape Product) |
| Liner Thickness, Paper | 4.7 mils ±10 | ASTM D3652 (Modified for Use with Non-Tape Product) |
| Carrier Thickness, Film | 0.5 mils ±10 | ASTM D3652 (Modified for Use with Non-Tape Product) |
Adhesion Properties — Silicone Side, 180° Peel Angle
| Property | Value | Test Method |
| Adhesion to Stainless Steel, 15 Minutes (2 MIL Clear Polyester) | 58 oz/in | ASTM D3330 (Modified for Dwell Time) |
| Adhesion to Stainless Steel, 3 Days @ 160°F (2 MIL Clear Polyester) | 58 oz/in | ASTM D3330 (Modified for Dwell Time) |
| Adhesion to Stainless Steel, 3 Days RT (2 MIL Clear Polyester) | 52 oz/in | ASTM D3330 (Modified for Dwell Time) |
| Adhesion to Acrylic, 3 Days RT (2 MIL Clear Polyester) | 51 oz/in | ASTM D3330 (Modified for Dwell Time) |
| Adhesion to Glass, 3 Days RT (2 MIL Clear Polyester) | 53 oz/in | ASTM D3330 (Modified for Dwell Time) |
| Adhesion to Polypropylene, 3 Days RT (2 MIL Clear Polyester) | 39 oz/in | ASTM D3330 (Modified for Dwell Time) |
| Adhesion to Stainless Steel, 3 Days RT (2 MIL Aluminum Foil) | 74 oz/in | ASTM D3330 (Modified for Dwell Time) |
Adhesion Properties — Silicone Side, 90° Peel Angle
| Property | Value | Test Method |
| Adhesion to Stainless Steel, 3 Days RT (2 MIL Clear Polyester) | 52 oz/in | ASTM D3330 (Modified for Dwell Time) |
| Adhesion to Stainless Steel, 15 Minutes (2 MIL Aluminum Foil) | 45 oz/in | ASTM D3330 (Modified for Dwell Time) |
| Adhesion to Stainless Steel, 3 Days @ 160°F (2 MIL Aluminum Foil) | 63 oz/in | ASTM D3330 (Modified for Dwell Time) |
| Adhesion to Stainless Steel, 3 Days RT (2 MIL Aluminum Foil) | 44 oz/in | ASTM D3330 (Modified for Dwell Time) |
| Adhesion to Acrylic, 3 Days RT (2 MIL Aluminum Foil) | 49 oz/in | ASTM D3330 (Modified for Dwell Time) |
| Adhesion to Glass, 3 Days RT (2 MIL Aluminum Foil) | 49 oz/in | ASTM D3330 (Modified for Dwell Time) |
| Adhesion to Polypropylene, 3 Days RT (2 MIL Aluminum Foil) | 31 oz/in | ASTM D3330 (Modified for Dwell Time) |
Adhesion Properties — Acrylic Side, 180° Peel Angle
| Property | Value | Test Method |
| Adhesion to Stainless Steel, 15 Minutes (2 MIL Clear Polyester) | 64 oz/in | ASTM D3330 (Modified for Dwell Time) |
| Adhesion to Stainless Steel, 3 Days @ 160°F (2 MIL Clear Polyester) | 219 oz/in | ASTM D3330 (Modified for Dwell Time) |
| Adhesion to Stainless Steel, 3 Days RT (2 MIL Clear Polyester) | 174 oz/in | ASTM D3330 (Modified for Dwell Time) |
| Adhesion to Acrylic, 3 Days RT (2 MIL Clear Polyester) | 188 oz/in | ASTM D3330 (Modified for Dwell Time) |
| Adhesion to Glass, 3 Days RT (2 MIL Clear Polyester) | 214 oz/in | ASTM D3330 (Modified for Dwell Time) |
| Adhesion to Polypropylene, 3 Days RT (2 MIL Clear Polyester) | 15 oz/in | ASTM D3330 (Modified for Dwell Time) |
| Adhesion to Stainless Steel, 3 Days RT (2 MIL Aluminum Foil) | 244 oz/in | ASTM D3330 (Modified for Dwell Time) |
Adhesion Properties — Acrylic Side, 90° Peel Angle
| Property | Value | Test Method |
| Adhesion to Stainless Steel, 3 Days RT (2 MIL Clear Polyester) | 58 oz/in | ASTM D3330 (Modified for Dwell Time) |
| Adhesion to Stainless Steel, 15 Minutes (2 MIL Aluminum Foil) | 55 oz/in | ASTM D3330 (Modified for Dwell Time) |
| Adhesion to Stainless Steel, 3 Days @ 160°F (2 MIL Aluminum Foil) | 183 oz/in | ASTM D3330 (Modified for Dwell Time) |
| Adhesion to Stainless Steel, 3 Days RT (2 MIL Aluminum Foil) | 115 oz/in | ASTM D3330 (Modified for Dwell Time) |
| Adhesion to Acrylic, 3 Days RT (2 MIL Aluminum Foil) | 96 oz/in | ASTM D3330 (Modified for Dwell Time) |
| Adhesion to Glass, 3 Days RT (2 MIL Aluminum Foil) | 104 oz/in | ASTM D3330 (Modified for Dwell Time) |
| Adhesion to Polypropylene, 3 Days RT (2 MIL Aluminum Foil) | 26 oz/in | ASTM D3330 (Modified for Dwell Time) |
Mechanical Properties
| Property | Value | Test Method |
| Expected Shear Adhesion, Silicone Adhesive, Laminated to 2 MIL Clear Polyester, 1 Hour Dwell (1 SQ IN, 4 LB Load) | 5 hours | ASTM D3654 — Method A |
| Expected Shear Adhesion, Silicone Adhesive, Laminated to 2 MIL Aluminum Foil, 1 Hour Dwell (1 SQ IN, 4 LB Load) | 5 hours | ASTM D3654 — Method A |
| Expected Shear Adhesion, Acrylic Adhesive, Laminated to 2 MIL Clear Polyester, 1 Hour Dwell (1 SQ IN, 4 LB Load) | 25 hours | ASTM D3654 — Method A |
| Expected Shear Adhesion, Acrylic Adhesive, Laminated to 2 MIL Aluminum Foil, 1 Hour Dwell (1 SQ IN, 4 LB Load) | 20 hours | ASTM D3654 — Method A |
| Tack, Silicone Adhesive, Laminated to 2 MIL Clear Polyester | 780 gm | ASTM D2979 |
| Tack, Silicone Adhesive, Laminated to 2 MIL Aluminum Foil | 780 gm | ASTM D2979 |
| Tack, Acrylic Adhesive, Laminated to 2 MIL Clear Polyester | 1,020 gm | ASTM D2979 |
| Tack, Acrylic Adhesive, Laminated to 2 MIL Aluminum Foil | 1,120 gm | ASTM D2979 |
Thermal Properties
| Property | Value | Test Method |
| Service Temperature | −40°F to 302°F | — |
| Minimum Application Temperature | 50°F | — |
Shelf Life / Storage
| Property | Value | Test Method |
| Shelf Life | One year stored at 70°F and 50% RH | — |
| Expected Exterior Life | Depends on substrates; both adhesives are suitable for outdoor use | — |
- Bonding of silicone foam, silicone rubber, and LSR substrates to metal, glass, or rigid plastic components
- High-strength dissimilar-material lamination where the acrylic side handles aggressive bonding to polar substrates
- Outdoor applications where both adhesives are rated suitable for exterior service
- High-temperature bonding operating up to 302°F where heat-aged peel performance is critical
- Precision die-cut adhesive components requiring independent dual-liner converting
Common industries: Silicone rubber converting, medical device converting, electronics assembly, industrial manufacturing, outdoor specialty lamination.
2378SL is a differential double-coated adhesive construction engineered for bonding silicone-family substrates to conventional polar substrates in a single laminating step. The construction is built on a clear polyester (PET) film carrier with a 3.0–3.1 mil permanent PSA silicone adhesive on one side, protected by a clear ultra-smooth polyester film release liner, and a 1.9–2.1 mil permanent PSA acrylic adhesive on the opposite side, protected by a one-side clay-coated semi-bleached mando paper release liner.
The dual-liner system allows independent processing of each adhesive face during converting and assembly.
The TDS publishes one of the most comprehensive adhesion data sets in the H-O catalog, with peel measurements across stainless steel, acrylic, glass, and polypropylene at multiple peel angles (180° and 90°), dwell times (15 minutes / 3 days RT / 3 days at 160°F), and laminate films (2 mil polyester and 2 mil aluminum foil).
The acrylic side delivers very high peel performance — up to 244 oz/in on stainless steel under aluminum foil laminate — while the silicone side maintains the consistent moderate peel typical of silicone PSA chemistry (45–74 oz/in on stainless steel across test conditions).
Notably, the acrylic side actually increases peel adhesion at 160°F dwell (219 oz/in vs. 174 oz/in at RT for polyester laminate), indicating positive heat-aging characteristics. Polypropylene peel is 39 oz/in on the silicone side and 15 oz/in on the acrylic side, confirming the silicone face’s stronger LSE compatibility. Shear hold is 5 hours on the silicone side and 20–25 hours on the acrylic side. Tack is 780 gm (silicone) and 1,020–1,120 gm (acrylic).
Both adhesives are suitable for outdoor use; minimum application temperature is 50°F.
What differentiates 2378SL from SA1911?
Both are differential silicone/acrylic double-coated tapes, but 2378SL has a substantially more aggressive acrylic side — peel adhesion of up to 244 oz/in on stainless steel versus 70 oz/in for SA1911. The silicone-side performance is comparable (52–74 vs. 72 oz/in).
2378SL also publishes extensive multi-substrate, multi-angle, multi-laminate adhesion data with explicit outdoor-use suitability for both adhesives, while SA1911 publishes more concise data with explicit tensile/elongation values. Selection depends on whether the acrylic-side bonding strength or carrier mechanical specification matters more.
Why is peel adhesion important when selecting this tape?
For 2378SL, the acrylic side's heat-aged peel adhesion (219 oz/in at 3 days/160°F vs. 174 oz/in at RT for polyester laminate) is particularly notable — many adhesives lose strength after thermal aging, but 2378SL's acrylic side actually gains. This suggests post-cure cross-linking behavior that supports use in thermally cycled or elevated-temperature service environments.
What is the service temperature range for 2378SL?
2378SL has a service temperature range of −40°F to 302°F, with a minimum application temperature of 50°F.
Is 2378SL suitable for outdoor or UV-exposed applications?
Yes. The TDS explicitly states both adhesives are suitable for outdoor use, although expected exterior life depends on the substrates being bonded. No specific regulatory compliance standards are listed on the TDS for this material.
How should 2378SL be specified?
Specify grade (2378SL), orientation (silicone side to silicone substrate / acrylic side to polar substrate), adhesive thicknesses (3.0–3.1 mils silicone / 1.9–2.1 mils acrylic), carrier (0.5 mil PET), liners (2 mil polyester film on silicone side / 4.7 mil clay-coated paper on acrylic side), compliance requirements, dimensional tolerances, and finished format.
