High-quality surfaces guaranteed: Medical closure caps
16-cavity multi-cavity mold with valve gate and direct gating
Perfect for applications where hygiene is paramount: Thanks to the valve gate system, our 16-cavity mould for the production of medical closures not only offers a high-quality surface. At the same time, direct gating reduces the amount of material required for high-quality, efficient production of medical closures.
Precision injection tool for medical sealing stoppers
Our customer needed a tool to produce high quality stoppers for vials manufactured in a clean room. These stoppers not only have to protect advanced medicines from contamination, but also protect the environment from leakage of the medicines, some of which are radioactive. At the same time, they must not contaminate the drug with residues, even when the caps are pierced with medical needles.
The main challenge with this multi-cavity mould was therefore not the usual mould efficiency requirements. Rather, it was to produce a mould without micron-scale burrs to meet the requirements of a medical product.
Our Hofmann specialists used their many years of experience to design a suitable mould with a valve gate system and direct injection to meet all the requirements.
After all, just like our customers, we are aware that errors in medical projects can harm human lives.
No contamination thanks to the valve gate system
The valve gate system provides a clean and precise injection point on the stopper. This prevents the formation of burrs, plastic residue or threads, making the surface particularly suitable for medical applications. In general, the system contributes to a uniform and flawless surface quality, especially for visible or high-precision components.
In this case, a high quality valve gate system from Günther Heißkanal was installed.
What is a valve gate system?
A valve gate system is based on special hot runner nozzles that prevent excess injection residue at the injection point. As the gate diameter is closed with a steel needle after the plastic melt has been injected, no plastic can escape from the cavity. This ensures a clean injection point without plastic threads or other material residues.
In combination with direct gating, as with this mold, the valve gate system results in lower material consumption as no sprue is produced. For this reason, Hofmann uses specially adapted injection moulds with direct gating technology and precise temperature control.
What is a direct gating?
Direct gating is an injection molding method in which the plastic melt is injected directly into the mould cavity without the need for an additional runner or distribution system.
For optimum direct injection, precise control of the melt flow and accurate positioning of the injection point are crucial in order to minimize the risk of weld lines and air pockets. This is why Hofmann uses specially adapted injection molds with direct gating technology and precise temperature control.
Advantages of a valve gate system including direct injection for the medical sector
- Higher process stability: The controlled opening and closing of the sprue makes injection molding processes more reproducible and less prone to errors.
- Clean sprue areas: The targeted closure of the sprue results in barely visible sprue marks or material burrs on the component.
- Prevents contamination: Since no sprue is required, no material residues can contaminate the molded parts.
- Improved surface quality: Since there are no threads or drops, the surface of the molded part is smoother and of higher quality.
- Prevention of air inclusions: The system supports uniform filling of the cavities, which reduces air inclusions and defects in the component.
- Shorter cycle times: Direct injection without additional runners shortens the cooling time and increases the production speed.
- Reduced material consumption: Without sprue, material consumption is minimized, which saves costs and protects the environment.
Your contact for injection moulding
Christian Richardt
Technical Sales Director - Customer Projects
T: +49 9571 766-9660
sales@hofmann-impulsgeber.de
