Knowde Enhanced TDS
Identification & Functionality
- Chemical Family
- Polymer Name
- Composite Materials Functions
- Technologies
Features & Benefits
- Features and Benefits
- Suitable for both mechanical and hand mixing processes
- Exhibits excellent wetting of filler particles to achieve the required filler loadings.
- Finished castings have excellent painting and staining properties.
Applications & Uses
- Applications
- Recommended Applications
Crystic® 921 has been developed specifically for polymer concrete. A lower viscosity, thixotropic version is available, Crystic® 921PALV. This is suitable for pigmented castings filled to a low level, or not at all.
- Formulation Guidelines
Crystic® 921 should be allowed to attain workshop temperature (18oC - 25 oC) before use. Crystic® 921 is formulated for room temperature curing applications. It requires the addition of accelerator and then the correct amount of catalyst - Norox® KP9 catalyst or Norox® MEKP-925H to start the curing reaction. The recommended formulation is given below: Products made with Crystic® 921 are generally filled with different grades of powdered filler (e.g. calcium carbonate), minimum 50% by weight. Higher amounts may be added but this may require the mold to be vibrated. Pigment pastes can be mixed with Crystic® 921 or 921PALV, when a specific color is required.
Table 1: Formulation for room temperature curing of Crystic® 921PALV.
Component Parts by weight Crystic® 921PALV 100 Norox® KP9 1.0-3.0 Pigment paste 1-5 The catalyst must be stirred thoroughly into the resin shortly before use. Curing should not be carried out at temperatures below 15ºC. The resin, mold and workshop should be at, or above, 15ºC before curing is carried out. Scott Bader (Pty) Ltd. will not be liable for problems caused by use at lower temperatures than recommended.
Properties
- Color
- Typical Liquid Resin Properties
- Casting Properties (Unfilled)
- Note
* Curing Schedule. 24 hrs @ 20°C, 3 hrs @ 80°C
† Curing Schedule. 24 hrs @ 20°C, 5 hrs @ 80°C, 3 hrs @ 120°C
| Value | Units | Test Method / Conditions | |
| Acid Value | 20 | mg KOH/g | — |
| Non Volatiles | 62 | % | — |
| Viscosity (at 25°C, using Brookfield RVT, 100rpm) | 290 | cPs | — |
| Stability (in dark at 25°C) | 3 | Months | — |
| Gel Time (at 25°C, with 2% Accelerator R using 1.5% Norox® KP9) | 4 | Minutes | — |
| Value | Units | Test Method / Conditions | |
| Barcol Hardness (Model GYZ 934-1)* | 40 | — | — |
| Deflection Temperature (under load 1.80 MPa) †* | 68 | ºC | — |
| Elongation (at break, 20°C)* | 1.4 | % | — |
| Tensile Strength* | 52 | MPa | — |
| Tensile Modulus* | 3975 | MPa | — |
Packaging & Availability
- Packaging Type
- Packaging
- Crystic® 921 is supplied in 25kg, 225kg and 1125kg intermediate bulk containers
Storage & Handling
- Storage
- Crystic® 921 should be stored in the dark in suitable closed containers. It is recommended that the storage temperature should be less than 20°C where practical but should not exceed 30°C. Ideally containers should be opened only immediately prior to use.
- Pot Life
The temperature and the amount of catalyst control the gel time of the resin formulation. The level of filler has a strong influence on this, as shown in table 1. It is important to base the filler loading on the mass of the resin component, not on the mass of the mix.
Table 2: Geltimes in minutes for Crystic® 921 alone and with 300phr of Kulubrite 10
Accelerator G level Norox KP9 level Kulubrite 10 level 0 300phr 2phr 2phr 6-7 min 30-35 min - Crystic® 921 is formulated for use between 15ºC and 35ºC. It is recommended that workshop temperatures be maintained within this range. At temperatures above 30°C, the gel time even at 1% Norox® KP9 can be so short that there is insufficient working time to fill the mold. Also, this can cause excessive exotherm which may cause moldings to crack. In such cases, do not use less than 1% catalyst as this can cause undercure. Rather use Norox® MEKP-925H .
- At temperatures below 15°C, the curing reaction can be so slow that there is a high probability of undercure of the resin, even with over 3.0% Norox® KP9. Do not use more than 3% catalyst as that will not speed up the geltime appreciably or result in a faster cure; in fact it can further retard the cure. Rather warm up the resin and working area so that it is above 15°C