Injection Molding is the most common method for manufacturing plastic parts, particularly for complex shapes. Injection Molding can also be utilized to manufacture “hybrid thermoplastic composite” components by integrating continuous fiber-reinforced inserts. This process is often referred to as Composite Overmolding. TAFNEX™ UD Tape can be used as local reinforcement at critical locations, reducing overall wall thickness and thereby material consumption. Additionally, it is possible to manufacture high-performance composite components by using TAFNEX™ Structural Sheets or Sandwich Panels as reinforcing inserts. These sheets or panels are formed into shape beforehand or within within the mold, while functionalization is added through the injected polypropylene (PP) material, e.g., TAFNEX™ Compound. Due to high investment costs, injection molding is primarily used for large-volume productions.
Incorporating reinforcing inserts allows for a reduction in both the material usage and the overall weight of an injection-molded component.
Apart from sprue removal, injection-molded components generally require little to no additional post-processing.
Composite Overmolding enables the production of complex, high-performance components with integrated functional elements. This technology allows multiple individual parts to be consolidated into a single component, significantly reducing assembly efforts.
Composite Overmolding can achieve cycle times comparable to regular Injection Molding by parallelizing additional steps. The cycle time usually varies from one to two minutes, depending on the component's size.
A complete Composite Overmolding production line can be automated with robots and conveyor belts, managing operations from handling the reinforcing insert before injection to post-processing tasks including sprue removal.
The process varies depending on the type of TAFNEX™ insert used and whether the insert needs to be formed. While the process for using TAFNEX™ UD Tape closely resembles regular Injection Molding, using a sheet or tailored blank insert requires additional peripheral machinery to form the insert within the mold. Learn more below.
This overmolding process can be employed if the insert is flexible enough to be formed without being heated above its melting point, or if the insert does not need to be formed at all. TAFNEX™ UD Tape is sufficiently flexible for up to two or three layers, depending on the forming radius/curvature.
1. Positioning the insert in the open mold
2. Closing the mold
3. Injection/overmolding
4. Opening the mold
5. Demolding
This overmolding process is used when the insert needs to be heated above its melting point to be formed into the desired shape. This applies to all TAFNEX™ Sheets and tailored blanks with more than two or three layers, depending on the forming radius/curvature.
1. Heating the insert above its melting point
2. Positioning the insert in the open mold
3. Closing the mold + forming
4. Consolidation + injection/overmolding
5. Opening the mold
6. Demolding
TAFNEX™ Tubes can be functionalized using the previously mentioned Composite Overmolding technologies with standard Injection Molding machinery. However, there is also the option to utilize a novel technology: Robotized Injection Molding. This mobile Injection Molding machinery from ANYBRID GmbH allows for the functionalization of TAFNEX™ Tubes immediately after the Tape Winding process. Based on the specific application, either a robotic arm or a gantry system is employed. Further exploration of this technology for industrial use is currently underway as part of the WI-IN research project.
For this injection-molded front trunk (frunk), several strips of slit tape are used as local reinforcements. These tape strips are locally heated and pre-formed during their transport into the machine. This demonstrator has been developed within the T3-Hub research project at Aachen Center for Integrative Lightweight Production (AZL) at RWTH Aachen University in cooperation with BBP Kunststoffwerk and Porsche Engineering.
A thin TAFNEX™ Structural Sheet is overmolded with a PP-GF compound to create a drone frame with built-in functionality that simplifies the overall assembly effort.
Through Injection Molding of a TAFNEX™ Compound, it's possible to mass-produce drone blades while incorporating special features such as leading edge serrations to reduce noise.
Overmolding a thick TAFNEX™ Structural Sheet with a PP-GF compound results in a front bumper beam that features built-in functionality, thereby streamlining the overall assembly effort.
This injection-molded "VISION Rear lamp" demonstrator from ARRK VS incorporates a TAFNEX™ Design Sheet with semi-transparent chips (Luminous Carbon). This integration allows for back illumination, enhancing its visual appeal with a graceful glow.