Addition Silicone for Non-Yellowing Pads

INTRODUCTION
Transparent silicone breast pads, push-up inserts and post-mastectomy breast prostheses sit against the skin for hours daily and must remain crystal clear, skin-soft and color-stable for years. A prosthetic form typically contains 200 to 600 grams of gel enclosed in a thin silicone film. The decisive material choice is addition-cure versus condensation-cure silicone: condensation-cure systems release alcohol or other small-molecule by-products during cure and rely on tin catalysts, whose residues can catalyze gradual yellowing, while addition-cure platinum systems crosslink hydrosilylation with zero by-products and no tin, giving a clean, color-stable gel network. Hong Ye HY-9409 is a two-component platinum addition-cure transparent gel with penetration 150 plus or minus 30, viscosity 2200 plus or minus 400 mPa.s, FDA 21 CFR 177.2600 and LFGB food-contact reports, and a water-white cured appearance engineered to resist yellowing under normal wear and washing. This article compares the two chemistries for this visually and medically demanding application.


PRODUCT REQUIREMENTS
Breast pad and prosthesis gel requires: water-white transparency with long-term anti-yellowing; skin-safe non-toxic chemistry with FDA/LFGB and ISO 10993 support available; zero cure by-products and no tin catalyst; realistic soft-tissue feel with stable penetration; cohesion inside thin film membranes; and tolerance of repeated washing with soap and water. In breast-pad detail, the gel must keep water-white transparency for years, with little yellow-index change after heat aging and sweat contact. Dispensed within 20-40 minutes of mixing and cured to penetration 150+/-30 in 4-6 hours, its feel approaches real soft tissue with natural weight and deformation. It is compatible with films, adhesives and fabric edges, and does not migrate or leak inside membranes. It tolerates repeated soap-and-water washing and light cosmetics contact without picking up dust; FDA/LFGB and ISO 10993 support is available, with batch COA supplied.

CORRESPONDING PRODUCT MODEL PARAMETERS
Recommended model: HY-9409 - Transparent low-tack grade for intimate apparel, personal-care and body-contact products requiring clarity and skin-safe materials

GRADE SELECTION GUIDE
The HY-94 series offers three standard jelly gel grades for liquid-channel sealing, soft electronic potting and body-contact gel products. Their color, cone penetration, tack and typical applications are described below so users can choose the grade that matches sealing force, shape retention and processing needs.
HY-9400 is a blue grade with cone penetration 200 (0.1mm) and high tack. It is mainly used in HEPA/ULPA filter gel channels and biosafety cabinet seals, and in other applications that require strong adhesion and repeatable re-sealability.
HY-9405 is a blue grade with cone penetration 170 (0.1mm) and medium tack. It is recommended for electronic potting and sensor encapsulation, and for applications that balance softness with dimensional stability.
HY-9409 is a transparent grade with cone penetration 150 (0.1mm) and low tack. It fits transparent gel pads, intimate apparel and prosthetic devices, and other applications that require visual clarity or easy repositioning.

FREQUENTLY ASKED QUESTIONS
Q: Why does condensation-cure gel turn yellow?
A: Tin catalyst residues and cure by-products can promote oxidation and discoloration over time; addition-cure HY-9409 has neither tin nor by-products, so it stays water-white far longer.
Q: Is the gel safe against breast skin for daily wear?
A: Yes. It carries FDA 21 CFR 177.2600 and LFGB reports, is non-toxic and odorless, and ISO 10993 biocompatibility testing can be arranged for medical prosthetic lines.
Q: Does washing affect the gel?
A: No. The gel is enclosed in a silicone film; normal soap-and-water washing does not affect the cured network, which is rated for continuous service from -60 to 200C.

QUALITY ASSURANCE & CERTIFICATION
Every batch of Hong Ye HY-94 series jelly gel is produced under ISO 9001 certified quality management in a dedicated silicone workshop, with incoming raw-material inspection, in-process mixing control and finished-product testing on every batch. Before release each lot is checked for viscosity, mix ratio, cure time, penetration, color and tack, and a Certificate of Analysis (COA) listing the actual measured values ships with every order. Standard grades carry RoHS 2.0 and REACH SVHC test reports; skin-contact and baby-care grades can be supplied with FDA 21 CFR 177.2600 and LFGB Section 30/31 reports and, on request, ISO 10993 biocompatibility testing; flame-retardant grades meet UL94 V-0. Food-contact, medical and export orders are supported by the corresponding compliance files for customer qualification. Hong Ye has manufactured and supplied jelly gel to contractors, filter builders and equipment makers in over 60 countries since 2005, with monthly capacity above 500 tons, batch traceability and multi-language documentation. Application engineers provide grade selection, sample evaluation, on-site or video pouring guidance and after-sales follow-up, and technical data sheets (TDS), safety data sheets (SDS) and test reports are available before order to support tender and audit processes.


CONCLUSION
The market for tank sealant jelly gel in this application area continues to expand as cleanroom construction, electronic encapsulation, automotive electrification, energy storage and consumer product manufacturing drive demand for reliable two-component addition-cure silicones. Hong Ye supports this growth with ISO 9001 certified production, 500-plus ton monthly capacity, complete compliance documentation and responsive application engineering. Buyers evaluating suppliers are advised to look beyond unit price and compare batch-to-batch consistency, documentation completeness, delivery stability and technical service responsiveness, because the cost of a sealing or potting failure - rework, downtime, certification delay or product recall - far exceeds the incremental cost of a quality gel. Choosing the correct grade for the channel, operating temperature and service environment, following the 1:1 mixing and pouring procedure and validating with a small trial batch all help secure a durable seal. Hong Ye welcomes sample requests and application enquiries; our engineers will recommend the HY-9400, HY-9405 or HY-9409 grade that matches the sealing or potting requirement and support qualification from first sample through volume production.