How long can I leave PERMASET Puff Paste on the substrate before activating it with heat?

For example, can I print it and apply the heat to activate the puff 7 days later?

ANSWER:

PERMASET Puff Paste has been specifically designed for screen printing on textiles but it can be used on substrates like paper and wood.

Results will vary depending on the paper weight (thickness and density), fibre (wood or non-wood fibres such as cotton and hemp) and sizing (resistance to water penetration/fibre wetting that might cause paper to warp, cockle or disintegrate when wet). Adhesion and scratch resistance are also likely to be affected.

It is important to test the results bearing in mind the following:

Using PERMASET Puff Paste on paper or wood:

    Paper: PERMASET Puff paste can be screen printed onto paper, but the paper’s thickness and type may affect the puff effect. Thicker, more absorbent papers may hold the Puff Paste better, while thinner papers might warp or wrinkle due to the moisture in the Puff Paste. These effects relate to dimensional stability when wet.

    Wood: Puff paste can also be used on wood. The key is to ensure the wood surface is smooth and properly prepared (e.g. cleaned, sanded and dusted) for best adhesion. The puff effect on wood can create interesting textures. There has been some suggestion that it might not puff as uniformly as it does on fabric due to the rigidity of the wood, but we have not seen any evidence of this variability.

Timing for Activating Puff Paste with Heat:

    Application and Activation Timing: PERMASET Puff Paste is typically activated by heat soon after it is applied, but that’s typically in a production setting where there’s a productivity benefit in completing the whole process in one line. There is no logical nor technical reason why you cannot delay this activation if needed. However, there are some practical considerations. In your case, applying the heat 7 days later should be feasible, provided certain precautions are taken:

        Storage Conditions: The printed substrate should be kept in a clean, dry environment to prevent contamination or damage to the uncured Puff Paste. Avoid areas with excessive dust, humidity, or extreme temperatures, as these factors can affect the Puff Paste’s ability to puff properly when heat is eventually applied.

        Ink Stability: PERMASET Puff Paste should remain stable for several days before activation. There is some suggestion that the printed film might begin to dry out or lose its puffing ability if left for too long, but again, we have seen no evidence of that. If you’re going to be using this delayed process on an ongoing basis, then it would serve you well to conduct some controlled experiments and record the results.

Best Practices:

    Always always ALWAYS test before use on unusual substrates or under unusual conditions.

    Test on various paper types: Before committing to a large project, test PERMASET Puff Paste on a small section of your paper or wood to ensure you achieve the desired effect. It is also worthwhile testing a little up and a little down; that is, slightly longer and shorter and slightly hotter and cooler. This may seem very time consuming, but properly recorded and curated over time, this body of information will become an invaluable resource and will be your own private superpower.

    Temperature and Time: When you do apply heat, use the recommended temperature and duration. PERMASET Puff Paste generally requires a temperature of around 140-150 °C (284-302 °F) for a few seconds for proper activation. Take care that you do not overheat the puff particles or they will explode and collapse, leaving an unattractive plasticky film. Excess heat may also result in the paper being singed or scorched and discolouring or worse, burning.

In summary, PERMASET Puff Paste can be used on paper and wood, and you can wait several days before activating it with heat, provided the printed substrate is stored properly. Testing beforehand will help you achieve the best results.