Sunshine 22A Gel Time Tester
| Origin | USA |
|---|---|
| Manufacturer Type | Authorized Distributor |
| Origin Category | Imported |
| Model | 22A |
| Pricing | Upon Request |
Overview
The Sunshine 22A Gel Time Tester is a precision-engineered benchtop instrument designed for the quantitative determination of gel point—the critical time at which thermosetting resins and reactive polymer systems undergo irreversible transition from liquid to viscoelastic solid under controlled isothermal conditions. Based on the principle of torsional resistance measurement, the system monitors torque transmitted through a rotating glass stirrer (1 rpm) immersed in the sample; the abrupt increase in rotational resistance—indicative of network formation and loss of fluidity—triggers automatic detection of the gel point. This method aligns with ASTM D3056–85, a standardized test protocol widely adopted in polymer R&D, quality assurance, and production process validation. The instrument delivers high reproducibility (< ±1% relative standard deviation), enabling reliable shelf-life prediction via Arrhenius-type analysis (gel time vs. 1/T plots) and supporting formulation optimization across epoxy, phenolic, unsaturated polyester, melamine-formaldehyde, and other crosslinking systems.
Key Features
- Automated gel point detection with audible and visual alarm activation upon torque threshold crossing
- Digital temperature controller with ±0.2 °C stability over range up to 315 °C, ensuring precise isothermal immersion bath control
- Integrated synchronous motor drive delivering consistent 1 rpm rotation for stirrer shaft—critical for minimizing shear-induced artifacts
- Self-terminating test cycle: automatic shutdown upon gel point identification prevents over-curing and data contamination
- Front-panel temperature setpoint interface with real-time digital display and thermal safety cutoff
- Modular hardware configuration including stainless steel support stand, borosilicate glass test tubes, calibrated glass stirrers, silicone rubber stoppers, and PTFE-coated heating elements
Sample Compatibility & Compliance
The 22A accommodates a broad spectrum of thermoset precursors—including monomers, oligomers, resin blends, casting compounds, and food-grade gelling agents—within standard 15–20 mL test volumes. Its mechanical detection approach eliminates reliance on optical or rheological assumptions, making it especially suitable for opaque, filled, or highly scattering systems where laser-based or oscillatory methods may fail. The instrument complies with ASTM D3056–85 for gel time measurement and supports traceable calibration practices required under ISO/IEC 17025-accredited laboratories. When paired with optional Digi-Sense temperature controller (P/N 8900005, K-type thermocouple, 0–850 °C, ±1 °C accuracy), full thermal validation per ASTM E2877 or IEC 60584 is achievable.
Software & Data Management
While the base 22A operates as a standalone analog-digital hybrid unit without embedded software, its design facilitates integration into GLP/GMP-compliant environments. All operational parameters—including set temperature, start time, and recorded gel time—are manually logged or transcribed into LIMS or ELN platforms. The system supports audit-ready documentation: automatic timestamped alarms, physical test records (tube labeling, operator ID), and manual calibration logs for torque sensitivity and thermal uniformity. For regulated users, the absence of proprietary firmware ensures compatibility with 21 CFR Part 11-compliant electronic signature workflows when paired with validated third-party data capture tools.
Applications
- Formulation development of epoxy, polyurethane, and acrylic resins for aerospace composites and electrical encapsulants
- Shelf-life estimation of reactive adhesives and potting compounds using accelerated aging protocols
- In-process QC during batch manufacturing of thermoset molding compounds and laminating resins
- Academic research on crosslinking kinetics, vitrification behavior, and network formation mechanisms
- Food science applications involving thermo-reversible gels (e.g., gelatin, agarose, pectin) under controlled thermal histories
- Regulatory submission support for FDA, REACH, and RoHS compliance dossiers requiring documented gelation profiles
FAQ
What standards does the Sunshine 22A comply with?
It conforms to ASTM D3056–85 for gel time determination and supports alignment with ISO 2137 (penetration testing context), ASTM E2877 (temperature uniformity), and GLP documentation requirements.
Can the 22A be used for non-polymer systems such as food gels or pharmaceutical hydrogels?
Yes—the torsional resistance method is material-agnostic and effective for any system exhibiting a measurable viscosity inflection at gelation, including biopolymer and colloidal gels.
Is the temperature controller included with the base 22A unit?
No—the digital temperature controller is an optional accessory (P/N 8900005); the standard 22A includes only the immersion heater assembly and analog thermostat.
How is calibration verified for gel time accuracy?
Calibration involves periodic verification of stirrer rotation rate (1 rpm ±0.1 rpm), thermal bath uniformity (±0.2 °C across tube zone), and timing circuit drift (<0.5 s/h), typically performed quarterly per internal SOPs.
Does the instrument support multi-point temperature profiling for Arrhenius analysis?
Yes—users can conduct sequential tests at two or more isothermal setpoints and export raw gel time data for linear regression of ln(tgel) vs. 1/T to derive activation energy.
