MR. JO JR-3000 — the practical, shop-ready unmodified epoxy resin
MR. JO JR-3000 — the practical, shop-ready unmodified epoxy resin
JR-3000 is an unmodified, multipurpose BPA epoxy resin with EEW 185–195 (typical 188) and viscosity 10,000–15,000 mPa·s (typical 11,800 mPa·s). It is engineered to behave like familiar industry baselines (YD128 / GY250 / KER828 / B11) while solving common shop problems: unpredictable cure, messy inventory, and process mismatch between casting, laminating and potting operations.
Below is a focused, practical guide for engineers, formulators and production leads who need a dependable resin that’s easy to use, easy to stock, and easy to tune.
Problem statements we solve
- Inconsistent resin baseline across jobs. Formulations drift when a resin’s EEW or viscosity varies or is unfamiliar. JR-3000 sits in a common EEW band, so resin/hardener pairing and stoichiometry behave predictably.
- Pack size inefficiencies. Too-large drums mean waste; tiny tubs mean frequent reorders. JR-3000 is available in 10 / 20 / 30 kg packs and barrels — practical for both prototype and production runs.
- Process mismatch: one shop needs wetting + degas for casting; another needs pumpable viscosity for laminates. JR-3000’s mid-range viscosity hits that “sweet spot” — pumpable yet stable for many processes.
- Formulation uncertainty: JR-3000 accepts common fillers, pigments and reactive diluents with predictable behavior, reducing trial time for modifications.
Why the specs matter (quick technical notes)
- EEW (~188): gives a reliable reactive-equivalent baseline for hardener selection and stoichiometry; it’s a common commercial standard that simplifies hardener matching.
Viscosity (~11.8 Pa·s): medium-high — low enough to wet fibers and degas effectively, high enough to reduce excessive flow in thin laminates. If you need more body or less viscosity, adjust with compatible reactive diluents or choose a higher-viscosity JR grade.
🧑🔧 Ideal For:
- Residential and commercial waterproofing
- Concrete walls, slabs, terraces, parapets, sunken areas
- Basements, tanks, balconies, fiber cement sheets
- Sites where field quality control is difficult
Applicators who prefer ready-to-mix solutions without dilution steps
Typical applications
- Laminates and hand-layup composites (good wetting & resin flow)
- Potting and encapsulation for electrical components (adequate viscosity for intrusion)
- General casting and small-to-medium decorative pours (when degassing is available)
- Adhesive base for formulated structural adhesives after filler or thickener addition
Job-ready workflow (production / lab version)
- Assess the application: decide whether the job prioritizes wetting & degas (casting/laminate) or edge-hold (adhesive). JR-3000 suits both with minor formulation choices.
- Choose hardener: select amine/anhydride/modified amine per desired pot life, Tg and yellowing tolerance. Hardener selection controls cure speed and final thermal performance.
- Material conditioning: bring resin and hardener to stable ambient temperature (20–25 °C) before mixing. Temperature affects viscosity and pot life.
- Measure & mix: weigh components accurately. Mix Part A + Part B per your hardener’s guidance; scrape vessel sides and bottom. For larger volumes, use mechanical low-speed mixers to avoid entraining air.
- Degas (if needed): for clarity-critical casts, degas mixed batches under vacuum or use small batches and a slow pour technique.
- Place / pour / laminate: pour from one side to displace air under plates; for laminates, wet out fibers fully and use rollers or vacuum bagging where applicable.
- Cure & post-cure: follow hardener TDS for initial and post-cure cycles to reach design Tg and mechanical properties.
- Document: log batch numbers, ambient conditions and mix weights for traceability and troubleshooting.
Formulation & handling tips
- Viscosity tuning: use reactive diluents to lower viscosity for deep casts; use thickening agents (fumed silica) or choose JR-3003/3125 for high-body needs.
- Pigments & fillers: coated fillers reduce spotty discoloration. Pre-disperse pigments in a small resin portion before full mixing for uniform color.
- Batch control: avoid very large mixed masses — heat build-up accelerates cure and increases risk of yellowing or micro-voids.
- Degassing: JR-3000’s lower-mid viscosity makes it responsive to vacuum degassing — good for optical casting and void-free potting.
Common pitfalls & troubleshooting
- Tacky/under cured parts: verify correct hardener choice, accurate mix ratio and thorough mixing. Low temperature can inhibit cure.
- Core haze or internal bubbles: reduce batch size, degas, or pour in stages; seal porous inclusions to avoid outgassing.
- Too rapid gel / overheating: mixed mass too large or ambient too warm — reduce batch size and control component temperatures.
- Poor adhesion: substrate contamination or inadequate surface profile — abrade, clean, and prime as needed.
Inventory & shelf-life practicalities
- Pack sizes available: 10 / 20 / 30 kg and barrels — choose small packs for R&D and short runs, barrels for continuous production.
- Shelf life: JR-3000 shows stable shelf performance in company packaging when stored cool and dry. Rotate stock (FIFO) and avoid long open containers.
Safety & compliance (brief)
Use appropriate PPE (nitrile gloves, goggles), local exhaust ventilation and follow MSDS guidance for handling and disposal. Avoid skin contact and inhalation of vapors; dispose of waste per local regulations.
Choose JR-3000 when you need a reliable, industry-standard unmodified epoxy resin that balances pumpability, wetting and degas performance. It’s the pragmatic baseline for labs and production lines that require predictable formulation behavior, convenient pack sizes and straightforward tuning via hardener or reactive diluent.
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