Since 2017, ERMO’s patented Electric In-Mold Closing (E-IMC) lets manufacturers mold and close flip-top caps in a single cycle inside the tool. By generating a programmable curved trajectory driving translation and rotation axes simultaneously E-IMC replaces the external closing station, reducing floor space and total cost per part while improving repeatability on complex, non-symmetrical caps.
Unlike conventional IMC systems, ERMO’s E-IMC delivers custom programmable closing curves by simultaneously and independently controlling multiple electric actuators. This ensures a highly precise and repeatable mold cap closing process that’s fully integrated into the plastic injection molding workflow.
Challenge: integrated mold cap closing for dual-flap flip-top caps
A leading global brand required a flip-top cap for a large spice jar with two hinged flaps a non-symmetrical design where the larger flap had to close before the smaller. The client needed this complex cap to be moulded and closed in a single plastic injection molding cycle, reducing handling, cycle time, and equipment needs.
Key specifications:
- Material: PP
- Cavities: 4
- Part weight: 7.95 g
- Functional requirement: Sequential flap closing with a non-linear, curved trajectory
Traditionally, such requirements involve both a mold and an external mechanical cap closer, which increases footprint, handling time, and cost. The challenge was to eliminate external processes and fully integrate mold cap closing into the plastic injection molding process.
Solution: programmable mold cap closing inside the plastic injection molding tool
ERMO responded with its standard E-IMCmechatronic module and controller, seamlessly integrated into the injection mold. Only the motion curve was customized to match the complex geometry and force profile of the dual-flap cap. The hardware remained standard.
By executing mold cap closing directly inside the mold immediately after cooling and before part ejection ERMO eliminated the need for post-moulding closing stations. This resulted in a highly efficient, compact, and cost-effective solution within a standard plastic injection molding cycle.
Results: measurable gains in plastic injection molding efficiency
- By integrating mold cap closing into the plastic injection molding cycle, ERMO’s E-IMC delivers quantifiable benefits:
- Single-step operation: Mould and close the cap in one machine, eliminating secondary closing stations and reducing floor space
- Lower total cost per part: Fewer machines, fewer operators, less maintenance, and fewer rejects due to programmable motion control
- Process flexibility: Fine-tune mold cap closing curves on-the-fly to accommodate material variability, colour changes, or recycled content
- Cycle time efficiency: Adds just ~1 second for cap closing, but eliminates downstream handling resulting in faster overall production
- Improved uptime and serviceability: Remote diagnostics and fast configuration changes simplify maintenance, ramp-ups, and product changeovers
Why ERMO’s E-IMC is unique in mold cap closing for plastic injection molding
Unlike traditional IMC systems that perform rigid, fixed-motion sequences (translation, then rotation), ERMO’s E-IMC generates true curved motion trajectories, driven by multiple electric axes in parallel.
This allows for:
- Precise, sequential flap closing ideal for non-symmetrical flip-top caps
- Programmable motion curves tailored to the cap’s geometry and hinge force
- Full integration within plastic injection molding, with no external closing equipment
This flexibility makes E-IMC the only solution on the market capable of handling advanced mold cap closing requirements inside high-volume, high-speed plastic injection molding environments.
How it works: intelligent mold cap closing in the plastic injection molding cycle molding
- Custom curved trajectory: Larger flap closes first, then smaller flap following a smooth, programmable in-mold motion path
- Real-time tuning: Adjust motion curves at the HMI to maintain quality across different resin or colour lots (including PCR and regrind PP) without hardware changes
- Remote support: ERMO can connect remotely to update, fine-tune, or validate mold cap closing parameters
- Reusability: One E-IMC controller cabinet can support multiple molds by simply uploading the correct motion profile
- Scalability: Proven on 4-cavity molds, scalable up to 24–36 cavities while maintaining the same in-mold cap closing principle
Why choose ERMO: experts in mold cap closing for plastic injection molding
- Adaptive, programmable motion: Only ERMO offers full control over curved closing trajectories directly in-mold, perfectly suited for complex flip-top caps
- Injection moulding expertise: Over 45 years of experience in high-precision mold design (multi-cavity, thin-wall, multi-material)
- Sustainable technology: All electric in-mold cap closing systems (E-IMC, E-IMA, E-IML) reduce energy consumption and mechanical wear in high-output plastic injection molding
ERMO’s E-IMC is not just a mold cap closing system: it’s a competitive advantage for manufacturers seeking to streamline their plastic injection molding processes, reduce costs, and deliver consistent, high-quality flip-top closures.
