Getting Started
The following steps outline the process developed by Liquid Lens to achieve the best results with our polyurethane resin. While applying resin to labels may seem complex initially, we’ve trained many users to quickly master the art of doming.
Health & Safety
When working with our polyurethane resin and hardener, it is crucial to follow safety protocols to prevent health hazards and ensure a safe working environment.
- Always wear appropriate personal protective equipment (PPE) such as gloves, safety glasses, and protective clothing to avoid skin and eye contact.
- Ensure good ventilation or use suitable respiratory protection to avoid inhaling vapors, as inhalation can cause respiratory irritation and other health issues.
- In case of skin contact, immediately wash with soap and water.
- For eye contact, rinse thoroughly with water and seek medical attention.
- Avoid ingesting the products; if ingestion occurs, do not induce vomiting and seek medical advice immediately.
- Always handle and store these chemicals in well-ventilated areas away from sources of ignition and incompatible materials.
Environment
Create an optimal environment for doming:
- Ensure the room is clean, warm, and dry.
- Maintain a dust and fibre free environment to prevent defects during curing.
- Set the temperature between 22-25°C for proper resin flow and dome formation.
- Keep humidity below 35% relative humidity to avoid CO2 bubbles. Use a dehumidifier if necessary.
- Where the correct PPE and dust and fibre free clothing.
Level Surface
Ensure the work surface is flat and level:
- Place an alloy work tray on a level work surface to keep the printed labels stable during resin application.
- Resin flow is gravity-assisted, and surface tension at the label edges prevents overflow.
- The viscosity of the resin helps stop it from spilling over the edges as long as it is not applied too thickly.
- An unlevel surface can cause uneven resin distribution and potential overflow, compromising the quality of the doming process.
Label Setup
Prepare the labels properly to ensure a smooth doming process:
- Carefully weed the sheet by removing the waste layer, leaving only the printed labels on the backing film.
- Lay the sheet on your work surface. Magnetic work surfaces can be useful for securing the sheet.
- Ensure each label is flat before applying the resin.
- Inspect the labels for any dust, debris, or moisture droplets, as these can adversely affect the curing process.
Mixers
Follow these steps to correctly apply your mixer to the resin cartridge:
- Stand the cartridge upright before removing the cap.
- 50ml and 75ml cartridges:
- Twist the cap 90 degrees and remove it.
- Attach the mixer to the cartridge and twist it 90 degrees to lock it in place.
- 200ml and 400ml cartridges:
- Unscrew the collar cap and remove the inner green nose cap. Keep the collar cap for reattachment.
- Attach the mixer by aligning and interlocking the keyway slots and grooves with the cartridge.
- Reapply the collar cap over the mixer and screw it firmly to secure and seal the mixer to the cartridge.
Cartridge caps are re-usable and you can reseal your cartridges after use.
Applicator Gun
Set up the applicator gun properly to begin the resin application process:
- 50ml and 75ml applicators:
- Unlock the cartridge top retaining clip.
- Insert the provided plunger rod and slide back to start position.
- Insert the cartridge by slotting it into position and locking the top retaining clip.
- Squeeze the trigger gently of the applicator gun to engage the plunger rod into the cartridge against the inner piston caps.
- 200ml and 400ml applicators:
- Pull back the plunger rod on the applicator gun.
- Insert the cartridge by slotting it into position.
- Squeeze the trigger gently of the applicator gun to engage the plunger rod into the cartridge against the inner piston caps.
Purge Resin
Ensure the resin is properly mixed and free of air bubbles before application:
- Discharge the first 5ml of resin to ensure proper mixing and to remove any air bubbles.
- Once the resin and catalyst start mixing inside the mixer, the reaction begins, and it is recommended to purge the resin if it sits in the mixer for more than 5 minutes.
- If the resin is left longer than 5 minutes, it may start to harden and will not flow as well, affecting the quality of the application.
- If you have allowed the resin to cure inside the mixer, you may be able to recover the cartridge by replacing the mixer and re-purging it.
Dispensing
Apply the resin carefully to ensure even coverage and avoid overspills:
- Apply resin slowly and uniformly. Use less resin than you think is needed, allowing the resin to naturally flow to the edges.
- Typically, cover about two-thirds of the printed surface area.
- Wait a few minutes after the initial application to allow the resin to settle before adding more resin or making any repairs, such as removing air bubbles or correcting overspills.
Repair
Address any imperfections promptly to ensure a flawless finish:
- Wait approximately 3 minutes after application to inspect and correct any air bubbles.
- To release trapped air bubbles, quickly “flash” the surface with a flame torch.
- Avoid excessive heat to prevent damage to the resin.
- Use the repair tool to promptly clear any dust or debris that may have settled on the resin during doming.
Please be aware that resin can burn very easily. When using a naked torch flame, apply it for only milliseconds, just enough to warm the air inside the bubbles and rise them to the surface.
Curing
Properly curing the resin is essential to achieve the best results:
- Cover the finished sheet with a propagator to protect the domes from dust during curing. Alternatively, you can use one of our work surfaces to cover the sheet.
- Domes are usually touch-dry within 4-6 hours in ideal conditions, allowing you to handle the labels.
- Full curing takes approximately 24 hours, ensuring the resin has completely hardened and reached its maximum durability.
- To reduce curing time, use a Liquid Lens Quality Control Unit (2-4 hours) or a curing oven (about 90 minutes).
- Larger domes cure faster due to more material available for the reaction.
For additional support, please email support@liquid-lens.com.