Side-Gated Contact Lens Packaging for Faster Mold Cooling
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Solution Overview
Problem
The cycle-time associated with injection molding of contact lens packages limits the production throughput of blister packs, necessitating a reduction in the time required to cool plastic in the mold.
Innovation Solution
The use of side gating in injection molding for contact lens packaging, which includes features like draft and wipe surfaces, facilitates faster cooling and reduces cycle time by positioning the nozzle away from the thermal mass, allowing for more efficient polymer distribution and separation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If top surface gating is used in injection molding, then polymer distribution is achieved, but cooling time increases and production throughput is limited
Solution Approach 1:
The patent transitions from top surface gating (horizontal dimension) to side gating (vertical dimension perpendicular to the mold opening direction). This dimensional change allows the nozzle to be positioned away from the thermal mass of the contact lens package, enabling faster cooling and reducing cycle time from 6.0 seconds to 4.0-4.5 seconds while maintaining proper polymer distribution through the modified gate geometry with draft and wipe surfaces
2Loss of time
If side gating is used to reduce cooling time, then cycle time decreases, but manufacturing complexity increases due to additional surface requirements
Solution Approach 1:
The patent applies local quality by creating specific surface features (draft surface and wipe surface) only at the gate region rather than throughout the entire mold. The draft surface provides oblique geometry for easy part release, while the wipe surface perpendicular to the mold opening direction ensures clean separation of the gate from the contact lens package. These localized surface treatments achieve the desired cycle time reduction without requiring complex modifications to the overall mold structure
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach significantly reduces the overall cycle time from 6.0 seconds to 4.0-4.5 seconds, enhancing production throughput and maintaining package quality while reducing costs.
Implementation Method 1
injection molding of plastic is used to fabricate the package
Implementation Method 2
the time required to cool plastic in the injection mold
Data Source
AI summary
Packages, systems, and methods of the present disclosure are generally directed to the use of side gating in injection molding to form packaging for contact lenses. As compared to gating along a top surface of a contact lens package, the use of a side gate in injection molding to form a package for contact lenses may significantly reduce the time required to cool plastic in the injection mold, thus offering potential to reduce the overall cycle time for the injection molding process and increase fabrication throughput of the package.