Mass production of precision LSR parts has never been so efficient

At the K show 2022, ENGEL joined forces with partner NEXUS Elastomer Systems to advance the production of umbrella valves made of liquid silicone rubber (LSR). The fully automated production cell combines highest output with maximum quality consistency, while also improving cost effectiveness at the same time.

Whether for automotive, medical technology products or packaging, umbrella valves are used for a wide range of applications. These industries share very strict process consistency requirements in injection molding production. Precision molding of the small parts is safety-relevant. This quality feature combined with maximum efficiency and cost-effectiveness is essential for mass production.

The production cell at the ENGEL booth showcased the quality and efficiency potential for the production of umbrella valves with a diameter of 7 mm. The exhibit combined an e-victory injection molding machine and smart digital assistance with NEXUS's innovative mold and plasticizing technology. The production on a 64-cavity mold is fully automated and includes an ENGEL easix articulated robot and an integrated vision control system for 100% quality control.

Consistent quality with smart assistance system

The tie-bar-less servo-hydraulic clamping unit in combination with the electric injection unit make injection molding machines from the ENGEL e-victory series the ideal choice for precision applications with LSR. The electric injection unit ensures high-precision injection. On top of this, the machine design supports low-flash processing of low-viscosity materials without the need of reworking. The moving platen follows the mold precisely while clamping force is being built up, which results in excellent platen parallelism. Patented Force Dividers ensure that the clamping force is distributed evenly over the entire mold mounting platen. Even with large multiple-cavity molds, the cavities at the edge of the platen are kept closed with exactly the same clamping force as those in the mold center.

The highest possible machine movement precision is not enough. Batch fluctuations in the raw material, or changing environmental conditions, for example, due to the weather, increase the need for digitalization. Equipped with the iQ weight control smart assistance system from ENGEL's inject 4.0 portfolio, the injection molding machine continuously analyses the injection profile and readjusts quality-relevant process parameters in the same cycle whenever deviations from the reference cycle occur.

Compact automation

Accessibility and the available space in the mold area of this tie-bar-less injection molding machine are unique. For multiple-cavity molds, often smaller machines can be used than the mold size would normally require. This keeps both investment costs and operating costs low. At the same time, the productivity per unit of area gets increased. Which is a key figure for efficiency in many companies, and especially in cleanroom production.

The ENGEL easix articulated robot ensures optimum space utilization of the automation and also requires very little headroom. It is connected with the injection molding machine and the vision quality control system and the discharge station. The robot adapts if additional process units need to be integrated upstream or downstream of the injection molding process afterwards.

NEXUS designed the 64-cavity mold with a demolding device; this means that the parts can be picked up very easily and quickly by the end-of-arm tool of the easix robot.

For high-precision control of the filling quantity, the cold runners in the mold are equipped with electric needle shut-off systems. NEXUS's Timeshot technology controls the filling quantity by the injection time. Each cavity can be controlled individually, even in very large molds with up to 128 cavities.

More transparency and reliability

NEXUS specifically developed the ServoMix X20 LSR dosing system, which ensures air-free dosing of liquid silicone rubber, to be used on the smallest footprint. It is networked via OPC UA with the injection molding machine and the MES authentig by TIG, a company of the ENGEL Group. This ensures full process data monitoring and complete traceability down to the level of single cavities.

It is the first time that ENGEL is demonstrating networking of the injection molding machine and the LSR dosing unit via OPC UA in line with the Euromap 82.3 standard live at a show. It shows how networking makes production more transparent and reliable and how work processes are accelerated.

The process data of the dosing unit is available during ongoing production in the CC300 controller of the injection molding machine and can be used for even more precise process monitoring and continuous process optimization. The dosing parameters are stored in the mold’s part data record. This means that they are immediately available on the machine control when the mold is set up again.

Get in touch

Are you interested in injection molding, looking for the right equipment or just want to learn more about ENGEL?

Don’t hesitate to reach out to us by filling out the form, giving us a call at +1 (717) 714-3235 or by contacting us by email. For more information, visit engelglobal.com.