Flexible Production with Rotary Cap Compression Moulding Machines

Rotary cap compression moulding machines are designed to produce various plastic caps with consistent quality and efficiency. This configuration supports different levels of automation and speed, offers an alternative to injection moulding, and accommodates a variety of cap geometries through changeable mould cores and compression screws.

Advantages and applicable scenarios of fully automatic, high-speed and semi-automatic models

Fully automatic units integrate feeding, heating, compression, and unloading into one continuous workflow. They often include robotic arms or pneumatic systems to transfer preheated preforms into the mould and to remove finished caps. Typical applications include beverage and pharmaceutical closures, where thousands of caps are required every hour.

High‑speed variants emphasise cycle‑time reduction while preserving product quality. These models are suited for operations aiming to boost throughput on existing factory floors. Examples include lines that need to switch rapidly between different cap sizes while maintaining a consistent hourly output.

Semi‑automatic machines require some operator assistance, such as manual loading of preforms or basic part removal. They tend to have simplified control panels and fewer auxiliary systems, resulting in lower capital investment and simpler maintenance. They also provide flexibility when frequent mould changes are needed for small volume runs.

The essential difference between compression moulding and injection moulding

Compression moulding places a measured amount of plastic material directly into an open, heated mould cavity. The mould then closes under pressure, shaping the material against the cavity walls.

Compression moulding typically operates at lower injection pressures, relying more on mould temperature maintenance to ensure complete flow. Injection moulding uses high-pressure injection to fill intricate features quickly.

Compression moulding can reduce material waste because only the exact amount of plastic needed is introduced into the mould cavity. Injection moulding often generates more sprue and runner scrap, although runner‑less hot‑runner systems can mitigate this. For cap production, where repeated simple shapes are made, compression moulding provides a leaner operation.

Compression machines have fewer moving parts and simpler screw and barrel assemblies compared to injection presses. This can lower maintenance requirements and reduce downtime. Injection machines, however, can handle a wider range of part complexities and tighter tolerance demands.

Changeable Mould Cores and Compression Screws for Different Cap Types

Different cap styles—such as screw caps, sports‑top closures, and flip‑top lids—require specific cavity geometries. Cores are precision‑machined to maintain tight dimensional tolerances and to integrate features like tamper‑evident bands or sealing beads.

The compression screw (or plunger) applies vertical force to the plastic preform within the cavity. Variations in screw diameter, stroke length, and tip shape correspond to different cap heights and diameters.

Many modern machines include quick‑change fixtures or modular inserts that allow tool replacement in under an hour. This capability reduces downtime during product changeovers, making the equipment agile for multiple product lines.

Rotary cap compression moulding machines offer flexible solutions across a spectrum of production needs. Full‑automatic and high‑speed models deliver continuous, high‑volume output, while semi‑automatic versions serve smaller runs and prototyping. Compression moulding presents an efficient alternative to injection moulding, especially for simple, repetitive cap geometries with lower internal stress and material waste.

Taizhou Chuangzhen Machinery Manufacturing Co., Ltd. is located in Chengjiang Industrial Zone, Huangyan District, Taizhou City, Zhejiang Province. Our main products are plastic bottle cap forming machine, folding machine, cutting machine, etc. The companies adhering to the "customer-oriented, forge ahead" business philosophy to provide our customers with quality service.