ENGEL Tie-Bar-Less Technology 35th Anniversary: Forging the Path of Innovation and Evolution in the Injection Molding Industry

The inspiration for the development of the tie-bar-less technology stemmed from practical needs: a customer complained to ENGEL that the traditional four tie-bar structure severely interferes with mold installation, and that changing molds would be much more convenient without the obstruction of tie-bars. Based on this, the ENGEL development team began researching whether it was possible to completely eliminate the tie-bars in the clamping unit of injection molding machines. This seemingly simple idea led to a significant breakthrough in mechanical design—previously, regardless of machine size or application scenario, "injection molding machines must be equipped with four tie-bars" was considered an unshakeable engineering principle. The birth of the tie-bar-less clamping unit marks a complete revolution in design philosophy.

ENGEL solved the problem of asymmetric force on C-frame structures through an innovative joint principle: replacing traditional tie rod guidance with a robust frame and utilizing a freely moving bending rod joint between the moving platen and the clamping piston (later patented as the Force Divider system). This Flex-Link flexible connecting element ensures absolute parallelism of the mold parting surfaces, while simultaneously achieving uniform clamping force distribution across all cavities of the platen and the entire mold surface. The new model, born from this innovation, is not only renowned for its technical advantages but also opens up new dimensions in mold design. The first complete production line was launched in 1990, and in 2000, the series was officially named "victory."

From manually lubricated sliding bearings in prototype machines to today's Flex-Link systems with decentralized force application, ENGEL continues to improve the joint system of tie-bar-less machines while expanding the product line and introducing new drive technologies.

All three have the inherent advantages of a tie-bar-less clamping unit: larger mold installation space, quick mold change, user-friendly operation interface, and flexible automation integration. The open template design also enables the application of large and complex molds on machines with lower clamping force, significantly reducing investment costs.

ENGEL's unique position in the tie-bar-less field is not only due to its first-mover advantage in technology but also benefits from continuous iteration and refinement of its patent layout. Its design value is particularly evident in multi-cavity mold scenarios with small projected areas — compared to traditional models, it can reduce energy consumption by up to 30%, while also decreasing equipment size and procurement costs.

The introduction of ecodrive servo-hydraulic drive technology reduces the energy consumption of hydraulic machines to the level of electric machines, making it an ideal solution for high energy efficiency requirements when combined with a tie-bar-less design. Currently, all ENGEL hydraulic and hybrid models are equipped with the ecodrive system as standard.

The key to the enduring vitality of the tie-bar-less technology over 35 years lies in its outstanding adaptability. Whether for cleanroom applications, multi-component processes, or highly automated production units, ENGEL models can meet demands through modular configuration.