Injection of 2-Part Resins into Silicone Molds

Standard Operating Procedure (SOP)
Title: Injection of 2-Part Resins into Silicone Molds
Effective Date: In review
Review Date: [Insert Date]
Prepared by: [Your Name/Position]

1. Purpose
This SOP outlines the procedure for injecting 2-part resins into silicone molds to ensure consistency, quality, and safety in the manufacturing process.

2. Scope
This procedure applies to all personnel involved in the injection process of 2-part resins into silicone molds.

3. Materials and Equipment

• 2-part resin in dual chamber injection tubes
• New mixing tips
• Silicone molds
• Isopropyl alcohol (IPA) for cleaning
• Personal protective equipment (PPE): gloves, goggles, lab coat
• Flow hood with UV light

4. Procedure

4.1 Cleaning and Preparing the Flow Hood

1. Start by cleaning all surfaces inside the flow hood with isopropyl alcohol (IPA).
   • Dampen a cloth with IPA and wipe down the work surface, side walls, and any equipment that will be used during the injection process.
2. After cleaning, activate the flow hood and allow it to run for 30 minutes with the UV light switched on.
   • This helps to ensure a sterile working environment before proceeding with resin injection.

4.2 Preparation of Silicone Molds

1. Ensure all silicone molds are clean and free of contaminants.
2. Clean the silicone molds thoroughly using isopropyl alcohol (IPA).
   • Dampen a cloth with IPA and wipe down all surfaces of the molds.
   • Pay special attention to sprue holes and any detailed areas.
3. Allow the molds to dry completely before proceeding with the injection process.

4.3 Setting Up Resins for Injection

1. Take the dual chamber injection tube and secure it in the dispensing gun.
2. Attach a new mixing tip to the dispensing gun. Always use a new tip for each injection.
3. Hold the injection tube with the mixing tip facing upwards.

4.4 Expelling Air from the Injection Tube

1. Gently depress the trigger of the dispensing gun to express any air trapped in the chamber.
2. Ensure that the tip is directed upward to prevent resin leakage or spillage.

4.5 Injecting the Resin into Molds

1. Place the prepared silicone mold in the housing unit to ensure stability during injection.
2. Locate the sprue hole on the mold where the resin will be injected.
3. Slowly inject the resin through the sprue hole until excess resin begins to flow out of the opposite sprue hole.
4. Monitor the injection process to ensure an even fill and avoid air bubbles.

4.6 Curing the Resin

1. Once the molds are filled set them aside in the flow hood.
2. Allow the molds to cure for a minimum of 12 hours and according to manufacturer instructions.

5. Safety Considerations

• Always wear appropriate PPE during the entire process.
• Ensure adequate ventilation when working with resins and IPA.
• Follow all safety data sheets (SDS) for the materials used.

6. Documentation

• Document the batch number, date, and any observations made during the injection process. This information should be recorded in the production log.

7. References

• Manufacturer's instructions for the specific resin used.
• Safety Data Sheets (SDS) for the materials involved.

8. Revision History

• [Insert revision history]