Green Tire Adhesion & Difficult Demolding? Internal Spray + Bladder Release Agent Combination Reduces Cost and Improves

Green tires often sit stacked for hours or even longer between building and curing; during curing, they must press tightly against the curing bladder inside a 140–180°C mold. These two stages are precisely where hidden losses in tire plant yield and bladder life occur.

According to on-site observations by the technical team at Qingdao Fukai Rubber & Plastic New Materials Co., Ltd. at an all-steel tire customer's production line in East China, when green tires are stacked in multiple layers without effective interlayer separation, the inner liner can adhere to the inner liner, or green tires can partially stick to each other during pickup—ranging from surface scuffing to full-layer scrapping. In the curing stage, if the bladder surface lacks a stable protective film, mold opening frequently results in green tire sticking to the bladder, bladder tearing, and trapped air in the tire interior—damaging both the green tire and shortening bladder life.

These problems have three direct consequences: first, increased green tire rework rates; second, faster curing bladder replacement frequency and reduced production per bladder; third, prolonged mold-opening time due to difficult demolding. On a production line with annual output of millions of tires, the cumulative material and downtime losses are considerable.

This article focuses on three things—"green tire storage separation + curing bladder protection + compound internal lubrication for demolding"—and presents a combination solution with real product parameters, selection tables, operating procedures, and FAQ answers for process and procurement colleagues to directly evaluate.

Green tire internal spray is a separation/release liquid sprayed on the inner surface of the green tire (inner liner side). Its core task is to form a stable, uniform, slidable interface between the curing bladder and the green tire inner surface, allowing the cured tire to release smoothly from the bladder while preventing inner liner layers from adhering during storage.

Qingdao Fihonor's SIP-9296GF Green Tire Internal Spray is an "inorganic filler-containing tire internal release agent" containing reactive silicone polymers. It is a gray-black suspension liquid; after spraying, the color facilitates visual observation and spray volume control. It offers good air-venting properties, effectively prevents bladder-to-inner-liner adhesion, and produces a glossy, smooth tire interior after curing.

The curing bladder is a core tooling component in tire curing, repeatedly expanding and contracting at high temperatures (120–230°C). Bladder release agent is a protective film coated on the bladder surface, providing high-temperature lubrication, multiple-release performance, and wear resistance—protecting the bladder and extending its service life.

SBC-08 Bladder Release Agent is a water-based semi-permanent bladder release agent designed specifically for bladder operating temperatures of 120–230°C. Above 120°C, it forms a protective film with good adhesion on the bladder surface.

Internal release agent is an internal additive added directly to the compound during mixing. It acts on the "rubber–metal" interface, reducing compound viscosity, improving flowability, reducing adhesion between compound and mixer rotors, mill rolls, and curing molds, and mitigating mold fouling.

FNM-926 Internal Release Agent consists of calcium fatty acid salts and amide ester waxes. It is compatible with natural rubber and virtually all synthetic rubbers, particularly suitable for EPDM and butyl (IIR) compounds. It does not affect vulcanization performance and is a low-toxicity formula suitable for rubber products in contact with food.

Internal release agents (e.g., FNM-926) work inside the compound, dispersing uniformly during mixing, improving overall compound flowability, roll sticking, and mold fouling. Spray-type external release agents (e.g., bladder release agents, mold release agents) act on tooling surfaces. The two mechanisms are complementary: one handles "compound not sticking to metal, easy ejection," the other handles "tooling surface not sticking to tire, easy demolding."

Green tire adhesion, bladder sticking, and compound mold sticking appear to occur at different stations, but the underlying contradiction is the same: rubber naturally tends to "stick" to contact surfaces when heated and pressurized. The built green tire sticks to adjacent green tires, sticks to the bladder during curing, and sticks to metal during mixing. Solving only one issue leaves the other two continuously producing defects. Deploying internal spray, bladder release agent, and internal release agent by station is equivalent to setting up three separation and lubrication interfaces simultaneously along the "green tire–bladder–mold–compound" chain—more robust than single-point fixes.

Viewed on a tire production line, the three products' roles cover the entire process from building to curing: SIP-9296GF guards the green tire storage and curing internal interface, SBC-08 guards the curing bladder surface, and FNM-926 guards the compound interior. Below are real parameters listed by stage for process and procurement colleagues to evaluate.

In terms of applicable tire types: all-steel tires, with thick carcasses and long cure times, have higher requirements for bladder protection and inner liner separation; semi-steel passenger tires, with fast pace and long shifts, prioritize semi-permanent durability and easy touch-up of the release agent; OTR and large-size tires are sensitive to demolding resistance, where internal release agent addition noticeably alleviates mold sticking. The three products can be combined according to different tire type pain points—no one-size-fits-all approach needed.

The three products below correspond to "storage separation, bladder protection, compound lubrication"—usable individually or combined based on line conditions.

• Composition: Suspension of inorganic fillers and polymer compounds (MSDS shows approximately ~76% water, ~5% reactive polymers, ~10% silica, ~2% surfactant, ~6% filler, ~1% carbon black).
• Appearance: Gray-black suspension liquid.
• pH (1:10 deionized water): 7.0–10.0; MSDS pH approximately 8.5.
• Active content: 18.0–25.0% (4h/105°C determination; MSDS approximately 21%).
• Form/Viscosity: Medium viscosity, readily miscible with water.
• Usage: No dilution required; spray onto green tire inner surface using atomizing or airless spray equipment; essentially no settling, slight agitation recommended; must be completely dried before curing after spraying.
• Safety: Non-hazardous; flash point reaches 100°C (no flash point data); store sealed, protect from freezing, high temperature, and sunlight; shelf life at least six months.
• Packaging: 25 kg / plastic drum, 50 kg / plastic drum.
• Synergy Recommendation: Best release results when used with Fihonor SBC series bladder coatings.

• Type: Water-based semi-permanent bladder release agent.
• Operating Temperature: Designed for bladder operating temperatures of 120–230°C; forms film on bladder surface above 120°C.
• Core Characteristics: High-temperature lubrication, multiple release, wear resistance; semi-permanent, single coating lasts over 4 hours; non-polluting, easy release; CFC-free, harmless to humans.
• Physical/Chemical Indexes: Milky white liquid; non-volatile content 10.0–15.0%; pH 3.0–8.0; shelf life 6 months.
• Usage: Can use as-is; brush, dip, or spray; for new bladders, pre-coating recommended before first use—close mold and preheat for 20+ minutes, apply another coating before formal curing, and allow bladder to contract–expand 2–3 times for full coverage and accelerated water evaporation.
• Packaging: 25 kg / drum, 50 kg / drum.
• Storage: Below 30°C in cool, dry place; protect from freezing, high temperature, and sunlight; shelf life six months.

• Composition: Mixture of calcium fatty acid salts and amide ester waxes.
• Appearance: Brown granules (technical brief) / light yellow flakes or granules (English TDS).
• Melting Range: 97–107°C (technical brief); English TDS melting point 80–105°C.
• Ash Content: 4.5–5.5% (technical brief) / ≤7.0% (English TDS).
• Vulcanization Discoloration: None.
• Function: Reduces compound viscosity, improves flow, enhances rubber–metal interface lubrication, improves extrusion dimensional stability and die swell stability; reduces mold contamination, improves filler dispersion, enhances processing safety.
• Safety: Non-hazardous; low toxicity, suitable for food-contact rubber products; does not affect vulcanization performance.
• Packaging: 20 kg / paper-plastic bag, 1 ton / pallet.
• Storage: Cool, dry place; shelf life at least 2 years.

Below is an executable operating procedure, starting with verbs, ready to be incorporated directly into work instructions.

1. Inspect — Check that the green tire inner surface is clean and free of standing water; confirm spray equipment (atomizing/airless) pressure is normal.
2. Stir — Slightly agitate SIP-9296GF as-is; no dilution required.
3. Spray — Uniformly spray internal spray onto the green tire inner surface; gray-black color facilitates visual confirmation of uniform coverage and no misses.
4. Dry — Allow green tire to completely dry after spraying before storage or curing.
5. Stack — Stack dried green tires according to specified layer count; interlayer separation protection is now in place.

1. Pre-coat — Before/after first installation of new bladder, apply one coat of SBC-08 as-is by brush, dip, or spray.
2. Preheat — Close mold and preheat for 20+ minutes to allow release agent to form film on bladder surface.
3. Re-coat — Apply another coating before formal curing after pre-coating; allow bladder to contract–expand 2–3 times for full coverage and water evaporation.
4. Touch-up — Touch up as needed based on curing conditions; apply one coat each time, allow bladder to contract–expand 2–3 times before loading mold for curing.
5. Inspect — Check bladder surface for missed areas; release film should be uniform and appropriately thick.

1. Weigh — Weigh FNM-926 per Table 3 dosage (e.g., EPDM at 1–3 phr).
2. Charge — Add together with other materials during mixing; initial mixing stage addition recommended to optimize release.
3. Mix — Mix normally until uniformly dispersed; note improvement in compound roll sticking.

1. Observe — Check if green tire sticks to bladder after mold opening, if trapped air or scuffing exists in tire interior.
2. Check — Verify bladder surface release film integrity, absence of missed areas or localized wear.
3. Touch up — Immediately touch up missed areas with SBC-08; perform contraction–expansion venting.
4. Verify — Check if internal spray is completely dry; incomplete drying directly causes sticking and trapped air.
5. Adjust — If compound still sticks to mold, increase FNM-926 dosage by 0.5–1 phr per Table 3 for verification.
6. Record — Record cumulative cure cycles per bladder and demolding defect counts to evaluate life changes.

Summarizing the real parameters above into "comparable improvement logic" for management reporting:

• Separation interface temperature matching: SBC-08 operating window 120–230°C covers the vast majority of tire curing temperatures; film forms above 120°C, semi-permanent for over 4 hours—meaning multiple cure cycles can be supported within a single shift.
• Internal spray active content 18–25%: Stable suspension system, gray-black for easy observation, controllable spray volume; combined with "dry completely before curing," significantly reduces trapped air in tire interior.
• FNM-926 ash content only 4.5–5.5%, melting range 97–107°C: Low ash is friendly to sensitive areas such as inner liner airtight layer; does not affect vulcanization performance, no discoloration after cure.
• Full series non-hazardous: SIP-9296GF, SBC-08, and FNM-926 are all transported and stored as non-hazardous materials, reducing warehousing and logistics compliance burden.

Taking an all-steel tire curing line as an example: if the current average production per bladder is N cycles due to sticking and scuffing, introducing SBC-08 with stable film formation is expected to increase production cycles per bladder as surface wear and scuffing decrease; combined with SIP-9296GF resolving inner liner interlayer adhesion, green tire rework rate correspondingly decreases; FNM-926 added at 2 phr to relevant compounds improves mixer roll sticking and mold fouling. Specific improvement magnitudes depend on line conditions, bladder material, and formula—small-batch verification before scale-up is recommended.

From an industry perspective, tire plants face increasing cost-reduction pressure, with equipment utilization and yield as two main themes. Bladders and molds, as high-value tooling, directly affect per-tire manufacturing cost; green tire rework not only consumes materials but also occupies building and curing capacity. Using mature additives to reduce these hidden losses is a process improvement direction with clear ROI—no major formula changes required.

For export customers, all three products are non-hazardous with complete SDS, bringing logistics and compliance convenience—simpler ocean freight declaration, suitable for stable supply to Southeast Asia, Middle East, Europe, and other destinations. This is also why many overseas tire plants prefer to include separation and release agents in their one-stop procurement lists.

A1: Taking SIP-9296GF as an example, it is a water-based suspension with 18–25% active content. When sprayed per specification and fully dried before curing, it will not leave residue in the tire interior affecting cure. The key is "spray uniformly, dry thoroughly"—excess or incomplete drying is what causes trapped air and sticking. Follow work instructions for uniform single-layer spray volume.

A2: SBC-08 is a semi-permanent release agent; a single coating maintains over 4 hours above 120°C. Actual touch-up frequency depends on cure cycle and bladder condition—typically once per shift as needed. After each application, allow bladder to contract–expand 2–3 times and confirm surface dryness to balance release and bladder life.

A3: No. FNM-926 technical data explicitly states it does not affect vulcanization performance and causes no discoloration after cure. It improves compound flowability and rubber–metal interface lubrication, reduces mold fouling—it is a processing aid with essentially no interference with the crosslinking system. Use at recommended phr with confidence.

A4: They act at different locations—usable individually or combined. SIP-9296GF handles green tire inner surface and inner liner interlayer separation; SBC-08 handles curing bladder surface protection. Combined, they simultaneously solve "storage adhesion" and "curing bladder sticking/demolding damage." If only a single pain point exists on-site, introduce one first as targeted treatment.

A5: All three are non-hazardous but require cool, dry, sealed storage—avoid freezing, high temperature, and direct sunlight. SIP-9296GF and SBC-08 have approximately 6-month shelf life; FNM-926 up to 2 years. Manage by batch/lot number with FIFO to prevent quality degradation from prolonged storage.

A6: Reference data: EPDM 2–5 phr (technical brief 1–3 phr), IIR/BIIR/CIIR 1–3 phr (technical brief 2–5 phr). Different sources show slight range variations; refer to incoming TDS and combine with your plant's compound roll sticking and release conditions—start from mid-range for small-scale trials, then fine-tune.

A7: All three products are managed as non-hazardous with complete MSDS/SDS, facilitating ocean freight and export compliance declaration. SIP-9296GF and SBC-08 are produced by Qingdao Fihonor Chemical Technology Co., Ltd.; Chinese and English technical documents available. Before export, verify SDS version and labels per destination country requirements.

A8: Monitor four indicators: first, green tire pickup adhesion rate and inner liner scuffing rate; second, mold-opening demolding resistance and bladder surface condition; third, post-cure tire interior flatness and trapped air points; fourth, compound roll sticking frequency and mold fouling cycle. Compare these four before and after to determine if the combination solution is effective.

The solution described in this article addresses two pain points—"green tire adhesion + curing demolding damage"—presenting a combination approach with SIP-9296GF internal spray, SBC-08 bladder release agent, and FNM-926 internal release agent. All three products are from mature brands such as Qingdao Fihonor; parameters are from their published TDS and MSDS—not arbitrarily set.

Qingdao Fukai Rubber & Plastic New Materials Co., Ltd. is the sales and supply entity for the above additives, providing additive selection, samples, bulk supply, and on-site technical support to tire and rubber product manufacturers domestically and internationally. Contact: Amy, WECAT  +86 17685723962. We communicate technically with the premise of "helping customers solve problems"—no empty rhetoric, only