Dow SILASTIC 8257 Silicone Foam

Features Of Dow SILASTIC 8257 Silicone Foam

1. Ultra-low compression set for long-term sealing integrity under continuous thermal and mechanical stress.

2. Excellent resistance to extreme temperatures (–65 °C to +200 °C short-term, –55 °C to +180 °C continuous).

3. Low outgassing and minimal volatile organic compound (VOC) emission—validated per ASTM E595 for space-grade applications.

4. Flame-retardant formulation meeting UL 94 HF-1 and FMVSS 302 automotive interior flammability requirements.

5. Consistent, closed-cell foam structure with uniform density (~0.35 g/cm³) and high compressibility (>70% recovery after 24h at 25% deflection).

Typical Applications Of Dow SILASTIC 8257 Silicone Foam

1. Aerospace cabin seals and environmental barrier gaskets requiring low smoke/toxicity performance.

2. Electric vehicle (EV) battery module edge seals and thermal interface gap fillers.

3. Medical device enclosures and diagnostic equipment housings needing ISO 10993-compliant biocompatibility support.

4. High-reliability LED lighting fixtures exposed to thermal cycling and outdoor UV/humidity.

5. Semiconductor manufacturing tooling seals where particle generation and chemical inertness are critical.

Specifications Of Dow SILASTIC 8257 Silicone Foam

Compatible Systems Of Dow SILASTIC 8257 Silicone Foam

Dow SILASTIC 8257 Silicone Foam – Frequently Asked Questions (FAQ)

Q1: What is the CAS Registry Number for Dow SILASTIC 8257 Silicone Foam?

A: As a proprietary cured elastomeric foam material, Dow SILASTIC 8257 does not have a single CAS number; its base polymer components include CAS 68083-19-2 (polydimethylsiloxane, PDMS) and CAS 107-46-0 (dimethylsilanediol), but final product composition is protected under trade secret provisions.

Q2: Is post-cure required after fabrication, and how does it affect extraction behavior?

A: Yes — a 2-hour post-cure at 200 °C is recommended to fully stabilize the platinum catalyst system and minimize low-molecular-weight siloxane (LMWS) extractables; validated per USP <87> and <88>, this step reduces volatile residue by >90% versus uncured foam.

Q3: How does Dow SILASTIC 8257 compare to SILASTIC 8250 in terms of compression set and service temperature?

A: SILASTIC 8257 offers superior compression set resistance (≤15% vs. ≤25% for 8250 at 150 °C) and extended upper-temperature capability (+180 °C continuous vs. +150 °C for 8250), due to optimized crosslink density and reinforced filler dispersion.

Q4: Does this material comply with EU Medical Device Regulation (MDR) Annex I essential requirements?

A: While Dow SILASTIC 8257 itself is not a finished medical device, it meets ISO 10993-5 (cytotoxicity), -10 (irritation/sensitization), and -12 (sample preparation) test criteria; full MDR compliance requires validation by the device manufacturer within the final assembly and sterilization context.

Q5: Can Dow SILASTIC 8257 be used in direct contact with potable water systems?

A: Not without system-level certification — while the base chemistry shows low extractables in NSF/ANSI 61 simulated water testing (≤10 µg/L total organics), formal approval requires third-party verification of the final gasket geometry, installation method, and exposure duration per local regulatory authority requirements.