ENGEL Introduces Infrared Robot Unit for Mass Production of Lightweight Thermoplastic Composites

The infrared radiation heats and forms three different thicknesses of organic flakes for the aesthetic surface during overmolding.

ENGEL’s production unit uses infrared radiation to heat and form three different thicknesses of organic plates and forms a high quality visible surface during the same injection molding process.

ENGEL Austria, the manufacturer of injection molding machines and provider of system solutions, has announced that it will introduce infrared curing technology as its manufacturing unit at the K 2019 trade fair (Düsseldorf, Germany, October 16-23). Part of the preform has overmolded overmolded with a thermoplastic composite.

ENGEL will use the organomelt process to produce demonstration parts to reflect the latest innovations in the door module. ENGEL’s production cells are considered to be the world’s first to use infrared radiation to heat and form three organic sheets of varying thickness, as well as the same high-quality visible surface forming process for injection molding. The system will be equipped with three ENGEL easix articulated robots running simultaneously.

“In the automotive industry, the importance of thermoplastic composites is increasing,” said Dr. Norbert Müller, Director of the ENGEL Lightweight Composites Technology Center.

There are two main reasons for this. First, a consistent thermoplastic process can effectively integrate the molding and functionalization of fiber reinforced prepregs, thereby reducing unit cost. Second, recycling strategies can be more easily formulated using only thermoplastic polymers.

“Returning the composite material component to the material loop at the end of its useful life is one of the priorities for the continued development of the electric vehicle industry,” Müller noted. “Even in aircraft manufacturing, thermoplastic solutions are now becoming more frequent.”

ENGEL’s answer to sustainable transportation needs is the organism. In an organometallic process, a fiber reinforced prepreg having a thermoplastic matrix such as an organic sheet and tape is heated, inserted into a mold, formed there and overmolded directly with a thermoplastic. This process has been used for mass production, and ENGEL organomelt is used for fully automatic production of front-end carriers and other items.

As the process evolves, ENGEL is working with customers and partners to design the production aspects of composite components with targeted load distribution.

“In the future, several different prepregs will be combined for each part to tailor the lightweight structural features to the shape of the relevant part and the different stresses in the various areas inside the part,” explains Müller. “The production units at the K show will clearly show great potential.”

The molding process was developed in cooperation with automotive supplier Brose (Coburg, Germany). According to ENGEL, the production unit is currently the only system in the world capable of simultaneously processing three differently shaped organic plates with a thickness between 0.6 mm and 2.5 mm in a fully automated process, including an integrated IR oven. Since the organic plate is selected on the basis of the load distribution, it is possible to handle the different stresses of the various constituent regions – this is the result that Brose helps to ensure through various simulation processes. For example, the presentation component made at K show is harder in its sash area than on the inside of the door.

Since the organic plates are selected in a targeted manner based on the load distribution, different stresses in the respective component regions can be handled.

Ultra-compact infrared oven integration

One challenge in processing organic sheets is the heating of the prepreg. The time it takes to heat and cool depends on their thickness. It is important to rapidly heat the material without damaging the material because of the rapid and direct transition to the mold that heats the prepreg. ENGEL’s organometallic production unit is based on the dual 3660/800 injection molding machine and therefore includes two integrated IR furnaces. The vertical infrared oven is located directly above the clamping device and is used to heat the organic plate to a thickness of only 0.6 mm. In this way, the thin organic plate quickly reaches the mold, ensuring that it has not cooled and is impossible to form. A standard horizontal IR oven on the base above the moving platen will be used for two thicker organic plates (1 mm and 2.5 mm). This arrangement shortens the distance between the oven and the mold and saves space because the oven does not require a separate floor space. Both infrared ovens are developed and manufactured in-house by ENGEL. These and the three easix robots are fully integrated with the IMM’s CC300 control unit for centralized control via the machine’s display.

All three organic plates are heated simultaneously. Then two of the three easix robots can be used to process the organic board. They are adjacent to each other above the clamping unit. When the first robot is responsible for handling two thicker organic plates, the second robot is responsible for handling the thinnest plates. During the entire heating process, it maintains the organic plate in front of the vertical radiation field to place it in the mold after the set heating time has elapsed. The third robot is located next to the clamping unit. The job is to remove the molded part while moving one of the three organic sheets into the mold for the injection molding process.

The organic sheet obtained from Chinese raw material producer Blonde (Shanghai, China) is made of glass fiber and is made of polypropylene. When the mold built by Georg Kaufmann Formenbau (Remetschwil, Switzerland) is closed, an organic board is formed. Immediately thereafter, they were overmolded with glass fiber reinforced polypropylene in the same mold. The shape of the rib is located on the back side of the part, while the texture of the leather appearance is formed on the visible side.

“When directly overmolding organic sheets, we get an excellent grained leather look that was previously impossible with organic sheets,” says Müller. “In this regard, we are laying the groundwork for the future production of large structural thermoplastic door structures using organometallic processes.”

Automation plays a key role

ENGEL’s production solutions developed at its Lightweight Composites Technology Center are known for their high efficiency and cost effectiveness – both of which are essential requirements for high volume production applications.

“Engel’s extensive expertise in automation has played an important role,” said Walter Aumayr, vice president of Engel Automation and Composite Systems.

Thanks to the simultaneous operation of the three ENGEL easix articulated robots, the organometallic units on the ENGEL booth will provide the most advanced integrated composite machining examples and are the most complex production units ever exhibited by ENGEL. Trade show.

“The more process stages we integrate, the more individual systems we have in a production unit, and the more complex the process,” Aumayr said. “As a system solution provider, therefore, Engel ensures consistent operational logic and joint data management throughout the unit, making it easier to use articulated robots. Workers in the shop can easily operate easix robots.”

A special aspect of the ENGEL system is that the IR oven is also fully integrated into the CC300 control unit, ensuring uniform operation logic throughout the process. In addition, since the molding machine, robots and peripherals all access the same database in the ENGEL system solution, the risk of error is reduced and the efficiency is improved. No additional hardware is required, and the easix articulated robot can synchronize its motion with the motion in the mold, such as the core or ejector movement.

“So we can reduce cycle time and capital expenditures, especially when it comes to large-scale systems,” Aumayr said.