FAQ's

Twin Packs

Robnor developed the twin pack, which is a unique packaging system for supplying resin systems:

· No weighing or mixing equipment is required
· Packs are virtually free of air
· Minimum operator skill required
· Accurate resin / hardener ratio
· Castings can be made direct from the pack - no need for pouring vessels
· Operator contact with resin and hardener minimised
· Reduced waste
· No cleaning up or cleaning materials required
· No capital expenditure on machinery
· A twin pack offers great flexibility - easy to use practically anywhere

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Twin Pack Mix Instructions

1.Observe the Health & Safety instructions on the pack label and any printed special mixing instructions, which may, in part, contradict the following. Wear a pair of suitable gloves.

2. Remove the outer wrapper by cutting with scissors taking care not to puncture the inner Twin-pack. This outer wrapper may be made of transparent film or, particularly in the case of polyurethane's, of aluminium. Aluminium outers are provided to protect resins which are moisture sensitive; therefore it is important to inspect them before opening. IF THERE ARE ANY HOLES OR TEARS IN THE ALUMINIUM DO NOT USE THE PACK. Aluminium bags may contain some small moisture absorbing desiccant sachets which should be discarded.

3. Remove the Twin-pack, unfold, and remove the rubber end-caps from the center clip if fitted.

4. Grip the pack on each side of the centre clip and pull gently in a stretching motion. This will cause the clip and rail to spring off, leaving the resin and hardener together in the sachet, free to mix.

5. Start mixing the two components by persistent hand kneading of the sachet until the contents are almost uniformly blended. Then place the pack on a smooth level surface and using the previously removed pack separator as a scraper, push the resin and hardener from the sides and corners of the pack into the middle. Now knead the contents together again by hand.

6. Repeat the operation in Step 5; this is particularly important with high viscosity or heavily filled systems or in cases where there is only a small proportion of hardener to be mixed with the resin (wide ratio).

7. Mixing time will depend upon the viscosity of the system and size of the pack. Two or three minutes would be an average; however operator experience can reduce the time. Materials with a short usable life (pot-life) will need to be mixed as quickly as possible. The rule, however, must be "if in doubt - mix again" as insufficient mixing will result in soft spots of uncured material in the final product.

8. Place the sachet on a smooth surface and, using the clip, scrape the mixture well away from the tapered corner of the pack. Now cut off the tapered corner, making a hole just large enough to permit the required rate of flow. Dispense the mixed system by squeezing the sachet from the bottom, releasing the pressure and up-ending the sachet to stop the flow.

9. Discard the empty pack into a suitable container where any remaining material can be allowed to cure within the pack and become inert.

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Part Numbering System

Prefix Product Colour Size
RX 700K / BK / 500

PX = Epoxy Resin Mixed System, twin pack, kit etc
RX = Epoxy Resin
HX = Epoxy Hardener
EL = Urethane Resin Mixed System, twin pack, kit etc.
RL = Urethane Resin
HL = Urethane Hardener
   Colours (2 letter code):
      NC = No added colour
      BK = Black
      BL = Blue
MP = Miscellaneous Product

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Cleaning

All equipment contaminated with mixed material should be cleaned before the material has hardened. Robnor Resins TS130 is an appropriate non-flammable cleaning agent, although other solvents may be found suitable eg. Robnor TS106. TS130 will also remove cured material provided it is allowed to soak for a number of hours.

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Disposal

Provided the resin and hardener have been properly mixed, as per instructions, the resultants material will be chemically inert and therefore able to be land filled; subject to local government regulations.

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Combustion

Polyurethanes generally ignite at approx. 415°C. Decomposition is by depolymerisation, liberating the polyol and isocyanate.

Pyrolysis decomposition products will consist of: carbon, carbon dioxide, carbon monoxide, hydrogen cyanide, nitriles and water.

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