Oerlikon HRSflow: Pinless hot-runner technology for additional materials and injection moulding applications

Oerlikon HRSflow has expanded the range of applications for its pinless hot-runner technology, "Stargate HRS". Previously used primarily in packaging applications involving polypropylene (PP) and recycled polypropylene (r-PP), the system is now also suitable for processing polymethyl methacrylate (PMMA), acrylonitrile butadiene styrene (ABS), polystyrene (PS), high-density and low-density polyethylene (HDPE and LDPE), as well as filled polymers, according to the manufacturer. The system covers shot weights ranging from 40 grams to 2.5 kilograms.

Shorter cycle times and reduced material consumption
The hot-runner system uses a mechanically actuated central shut-off mechanism to control melt flow into the mould cavity. Unlike conventional valve-gate hot-runner systems, the design operates without valve pins. According to the company, the nozzle design improves cooling performance, potentially reducing cycle times by up to 20 percent, depending on the application and processing conditions.

Advert

The hot-runner nozzles are designed to provide uniform melt flow at a constant flow velocity. By minimising melt stagnation zones, the system is intended to facilitate faster colour changes and reduce the amount of scrap generated during these operations.

Tests conducted at Oerlikon HRSflow's research and testing laboratory also identified the potential to reduce part weight by up to 17 percent. In combination with optimised mould design, processing technology and machine settings, uniform cavity filling allows thinner wall sections and thus lower material consumption.

Another design difference compared with conventional valve-gate hot-runner systems is the elimination of the actuators typically positioned axially above the valve pins. This allows the overall mould height to be reduced. Depending on the mould design, smaller hot-runner nozzle diameters and closer cavity spacing are also possible.

Practical trial with a 1.5-litre bucket made from recycled PP
During a demonstration in early September 2026 at the company's facility in San Polo di Piave, Italy, Oerlikon HRSflow demonstrated the use of its pinless hot-runner technology in the production of a thin-walled 1.5-litre bucket made from r-PP. The demonstration used a two-cavity mould developed by Serbia-based Inmold Group, incorporating the "Stargate HRS" hot-runner system.

With a reported shot weight of 41 grams, a cycle time of 4.7 seconds was achieved. No take-out plate was required. According to the company, no melt stringing occurred, and the moulded parts met the specified quality requirements.

In addition to Oerlikon HRSflow, the project involved injection moulding machine manufacturer Engel, plastics distributor Guztec Polymers and Inmold Group. The achieved processing results were based on the coordinated optimisation of the injection moulding machine, mould design and hot-runner system.

Fakuma 2026
Friedrichshafen, Germany
12–16 October 2026
Hall A1, Stand 1211

More information:
www.oerlikon.com/hrsflow, www.hrsflow.com, www.engelglobal.com, guztecpolymers.com, inmold-ltd.com

Oerlikon HRSflow, San Polo di Piave, Italy

back to news list