Arburg finds a 'pearl' of sustainability as it molds with paper, bioplastics

Germany's Arburg GmbH + Co KG and a Swiss partner developed a way to processes "paper pearls" made of fiber and a bio-based plastic and it's finding its way onto factory floors in the furniture and packaging industries.

The pearls have a fiber content of more than 50 percent that is combined with a plastic material to become not only injection moldable but compostable at the end of its life cycle.

There is no need for any petroleum-based plastics, according to Arburg officials, who began working on the new concept about two years ago keeping manufacturers seeking more sustainable products in mind.

The machine builder partnered with Model Group, a Swiss paper and cardboard packaging manufacturer, to develop pearls that could be reliably processed on standard Allrounders instead of plastic granules.

Early adopters recognized that combing a traditional material like paper with modern injection molding technology could open the door to a wide range of more environmentally friendly products, according to Luca Simon, Arburg's applications manager circular economy.

"You could use a bioplastic based on sugar or corn. It's flexible and the choice depends on the application and whether you want the part rigid or flexible," Simon said.

Since this capability is in the early stage of development, right now paper pearls would be more expensive than other materials.

"But in the future, when we scale it up, the plan is for it to be below normal [pricing of] standard plastics," Simon said. "Recycled paper fibers are very cheap. They are basically free."

At Fakuma 2024, an electric Allrounder 370 A with a clamping force of 600kN will produce positioning tools for furniture connectors called Slot Locks in a two-cavity mold with a cycle time of about 60 seconds.

The components, which are usually made of conventional plastic, are used as assembly aids when putting furniture together.

As paper injection molded parts, the Slot Locks weigh 19.7 grams and can be composted after use.

Following premieres in the U.S and Poland, Arburg's new Allrounder 720 E Golden Electric has come full circle with a debut in Germany.

The press offers electrical precision, process stability and a small installation area with a width of just 1,848 millimeters (72 inches), which Arburg officials say is significantly reduced compared with other machines in its class. This was achieved partly through a new safety door with recessed handles.

Still, thanks to an electric mold height adjustment system, mold installation heights of up to 800 millimeters are possible and the drive components are optimized for a clamping force of 2,800 kN.

The slim design means more machines can fit on the production floor, which results in an increased output per square meter.

The machine has a place in almost every industry from technical injection molding to applications such as dimensionally stable housings for electromobility, thick-walled closures for household goods, precision components for medical technology, and the construction and leisure industries.

At Fakuma 2024, the Allrounder 720 E Golden Electric has a size 800 injection unit to produce polypropylene razor covers in a 24-cavity mold from Hack. The cycle time is about 11.5 seconds for each molded part, which weighs 1.2 grams.

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An Allrounder More 2000 will process thermoplastics (PBT) and liquid silicone rubber (LSR) to create food-safe spatulas from a hard-soft combination that are ready for use. The intelligent assistance functions of the Gestica control system ensure optimum cycle time and energy efficiency. A Yaskawa six-axis robot handles the injection molding process.

The machine is equipped with two electric injection units, sizes 170 and 400. With the smaller vertical injection unit, the handle is made of food-grade PBT from BASF. The pre-molded part rotates from the upper to the lower finishing station in the 1+1-cavity mold from Polarform via a servo-electro index unit with a motor from Arburg's sister company AMKmotion. A horizontal injection unit is used to overmold the soft spatula component made of a non-tempered LSR from Wacker.

The machine comes standard with a highly dynamic electric toggle-type clamping unit, energy-efficient, liquid-cooled servo motors, two electric injection units and a choice of 1,600 or 2,000 kN clamping force.

The two components are injected directly and with no waste. A hot runner system is used for the PBT handle, while overmolding with LSR is done by a servo-electric cold runner with a needle valve from Ewikon.

The downstream cooling station sees the spatulas cooled down in a defined and precise manner. Surface structures are then accurately applied by a Rea laser station and, finally, deposited on a conveyor belt by a Yaskawa six-axis robot. Thanks to the systematic selection of materials and the automated process, the end product is ready for use in a cycle time of around 60 seconds.

When it comes to digitalization, Arburg officials say the key isn't the sheer quantity of data collected, but its quality and relevance to form the basis for successful process optimization.

For example, relevant data can be used to create forecasts for predictive maintenance, generate paperless evaluations and documentation in real time, and access injection molding knowledge with the help of AI-supported apps.

In this way, sequences can be dynamically controlled and optimized in "smart" production, allowing available resources to be used even more efficiently — for example in order planning, quality assurance, mold management and maintenance.

At Fakuma 2024, for example, an LSR dosing unit communicates with the Gestica control system via Euromap 82.3 during the production of multi-component spatulas with an Allrounder More 2000.

Communication takes place via standard Ethernet and standard plug connectors. The devices are automatically recognized and integrated into the control system using plug and play.

For standardized interlinking, all Arburg presses are equipped with an Internet of Things gateway as standard and have basic connectivity.

Two exhibits focused on industrial additive manufacturing feature a Freeformer 750-3X processing plastic granules into functional components in hard-soft combination and a TiQ 2 filament printer demonstrating how equipment and robot grippers are 3D printed.

The Freeformer 750-3X will produce functional components from a wide range of different plastic granulates, including materials with specific approvals and certifications for the medical, electronics, mobility and aerospace markets.

The temperature of the build chamber can be raised to 200° C and the granulate is plasticized at up to 450° C. The component carrier that lends the system its name is 750 square centimeters in size.

Arburg officials point to three discharge units for complex geometries and functional hard-soft combinations. The industrial 3D printer can be used to quickly and flexibly additively manufacture and customize larger functional components or small batches, using the Arburg Plastics Freeforming method.

The TiQ 2 filament printer will demonstrate how equipment and robot grippers are 3D printed. The gripper is specially designed for the careful removal of injection-molded parts.

The entry-level TiQ 2 device is particularly suitable for daily use in an industrial and injection molding environment. It uses the fused filament fabrication (FFF) method to process fiber-reinforced filaments into grippers and operating equipment, for example.

A hybrid Allrounder 570 H64 will produce 64 syringe plungers in one shot designed specifically for reduced material usage in 6 seconds as a demonstration for a high-speed medical application.

Launched in 2023, the Allrounder Hidrive machines, which have hybrid technology, save energy and resources while making production more efficient, reliable and user friendly, according to Arburg officials.

The Hidrive series is suitable for typical mass-produced medical products.

A clean room version of a hybrid Allrounder 570 H "Ultimate" with a clamping force of 2,000 kN is on exhibit with special options including a clean-air module, light gray medical color scheme and a conveyor belt with a tunnel cover.

The exhibit will be equipped with a 64-cavity mold from Ruhla, and will process medical polypropylene from Borealis.