+86 17727725162 jqj014950@topstarltd.com

Home / How does an all electric injection molding machine address Short-Shot Defects in Medical bottle Caps？

How does an all electric injection molding machine address Short-Shot Defects in Medical bottle Caps？

2025/05/09 By Topstar

Short-Shot Defects in Medical bottle Caps

When using an electric injection molding machine to produce pharmaceutical bottle caps, a common quality problem is insufficient injection, where the molten polymer fails to fill the entire mold cavity, resulting in incomplete bottle caps, which affects the seal integrity and sterility. Inconsistent melt pressure, temperature fluctuations, or insufficient injection speed can cause insufficient injection. These defects are not allowed in medical applications because regulatory agencies like the FDA have strict dimensional tolerances and sealing requirements for medical products. To address this defect and the strict requirements of medical manufacturing, Topstar provides centrally controlled, precision-moulded medical grade injection molding machines to eliminate insufficient injection and ensure reliable, high-volume production of consistent medical bottle caps.

Stable control system of an electric injection molding machine

At the heart of Topstar’s all electric injection molding machines is a highly stable, self-developed control system that coordinates every stage of the molding cycle. Unlike traditional hydraulic injection molding machines, the electric platform provides precise timing and repeatable motion curves with millisecond accuracy. At the same time, proprietary control algorithms continuously monitor injection speed, screw position, and barrel temperature, automatically correcting deviations that may cause material shortages. Maintaining injection speed within ±0.5% and mould temperature within ±0.3°C prevents viscosity peaks and ensures smooth flow of molten resin into every detail of the cap mold. In addition, the control system provides real-time communication, compatibility, and data acquisition awareness to ensure compliance with production regulations for Class I and Class II medical parts, thereby enhancing traceability and quality assurance.

All Electric Injection Molding Machine 2

Low-damping injection seat for accurate metering

Achieving accurate shot volume To avoid underfilling, Topstar’s all electric injection molding machines use low-damping injection seats and electroplated screws. This configuration minimizes mechanical backlash and energy loss during the metering and injection stages. The low-damping seat ensures that the axial force applied to the screw is directly converted into positive plasticization and melt accumulation, keeping the weight difference of each shot within ±0.1%. For medical caps, which often require injection volumes of less than 5 grams for small-diameter caps, this metering accuracy ensures that each cap receives the exact required injection volume. In addition, this stability allows manufacturers to use a variety of medical-grade resins, including polypropylene and polyethylene, without constant recalibration or compromising part integrity.

Low-damping injection seat

Discrete intelligent drive of all electric injection molding machine for stable pressure control

Filling complex bottle cap cavities under high shear conditions requires continuous stability of injection pressure. Discrete intelligent drive technology is integrated in medical-grade all electric injection molding machines, a servo drive architecture that decouples the control loop of each actuator. This enables the injection unit to maintain constant pressure for real-time adjustment, even if the load or material rheology changes suddenly. When injecting the narrow threads and undercut parts of medical bottle caps at high speed, the drive can adjust within microseconds to maintain peak pressure and ensure complete cavity filling. In addition, the intelligent drive system supports advanced diagnostic functions to help technicians monitor energy consumption, torque feedback, and injection curve stability, all of which can achieve a zero-defect manufacturing environment in the medical industry.

Precision molding of complex bottle cap geometries

Medical bottle caps often have tamper-proof bands, flip-top hinges, and internal sealing ribs, requiring precise mold filling. The all-electric injection molding machine provided by Topstar has high repeatability and position accuracy of up to ±0.01 mm, which can accurately replicate complex features. Each cap design recipe stores variable injection speed profiles to control the melt front speed and prevent premature freezing of thin-walled parts. The injection molding machine responds quickly and achieves full injection acceleration within 20 milliseconds, ensuring it fills complex cap molds before the polymer cools. In addition, this precision helps reduce material waste and shorten cycle times, thereby supporting the sustainability and cost-effectiveness of large-scale medical production lines. At the same time, electric injection molding machines can save at least 50% of electricity and up to 60% compared to hydraulic presses, with better energy-saving effects.

Centralized control of medical production lines

Large-scale production of medical caps requires close integration of medical injection molding machines with molding, conveying, inspection, and packaging. The Topstar all electric injection molding machine has a centralized control platform that can communicate seamlessly with auxiliary equipment such as dehumidification dryers, mold temperature controllers, and downstream automatic cap sorting machines. The central control system uses a single communication protocol to coordinate pre-drying cycles, injection plans, and online leak testing. If the system detects a lack of material in the cap, it automatically pauses the production line and adjusts the molding parameters in real time. In addition, the centralized interface enables the quality assurance team to generate real-time reports, conduct statistical process control, and track all production batches, fully complying with ISO 13485 and GMP requirements.

injection molding machines 95-12

Bringing medical caps without production defects

With a stable control system, low-damping injection seat, discrete intelligent drive, centralized production management, and precision molding capabilities, Topstar’s all electric injection molding machine solves the problem of missing material defects in manufacturing medical bottle caps. It becomes a precise and stable medical injection molding machine. Precise and stable motion control, real-time monitoring, and seamless integration with a wider production system ensure the consistency of bottle cap quality.

Prev: Relationship between mold material thickness and mold temperature controller settings

Next: Not Next

TRENDING POSTS

HOT TOPIC

Get A Quick Quote