Understanding resin parameters: viscosity, solids content and amine equivalent weight
Translating the underlying data on the test list into a formulation decision that understands the effects of temperature, test methods and batch control on viscosity, solidity, colour and equivalent calculations.
What does it reflect?
Stickyness affects transport, dispersion, mixing, construction resistance, but it is highly dependent on temperature and cutting conditions. Data must be read with confirmation of tested temperature, rotor, rate and method, and cannot be directly compared under different conditions. Resin after low-temperature storage should be fully warmed and evenly mixed and tested.
The formulation viscosity does not equal resin viscosity. pigment fillings, tentacles, wet-dispersible agents and trace moisture can all change the system flow, so selection depends on both the raw material and the performance of the finished product during the static, cut-off and recovery phases.
Solid with actual membrane
Solids content is used to estimate volatilisation, volume contraction and theoretical membrane efficiency. High entropy contributes to the reduction of VOC and multi-channel construction, but low construction viscosity by means of high boiling point solvents or reaction dilution still needs to be judged against specific composition, regulations and final performance.
The temperature and time of the baking at the time of detection of the strong content will affect the results, and the reaction-type system may continue to react during testing. Procurement and quality agreements should be harmonized to avoid seemingly contradictory data from the same material due to different methods.
Amine value and amine equivalent weight
Amine equivalent weight is used to calculate the theoretical ratio of active-hydrogen components to isocyanate components. Use supplier-confirmed data and the hardener NCO content for equivalent calculations, rather than applying a fixed volume or weight ratio to different materials.
pigments, assistants and diluents change the total weight of the A group, but do not necessarily provide live hydrogen. The ratio shall be calculated by distinguishing between reactive and non-reactive components, and then by means of the small calibration target NCO index.
Color, density and appearance
Transparent or light topcoat is more sensitive to changes in color and storage. The material examination not only records the initial colour, but also observes high temperature storage, light and colour development after mixing with hardener. Density relates to volume conversion, filling control and construction theory.
Appearance checks should include transparency, suspensions, crystals, layers and unusual odor. When abnormalities are detected, the batch is quarantined and the storage temperature, packaging seals and preservation periods are checked, and the use of solvents should not continue solely through filtering or exchange.
Create material and trend control
It is recommended that batch trend maps be created for key resin to record at least viscosity, solidity, amine equivalent weight, colour, density and retention. The fact that a single batch is within the specification does not mean that the process is stable, and continuous drift to the upper and lower limits is also a matter of concern.
Quality confirmation should also include target formulation speed checks, such as gel time, touch-dry and hardness under fixed formulations. This allows for earlier detection of the effects of changes in feedstock on production and construction.