Multifunctional thermoforming enables cost-effective production of complex plastic components
Abstract
By combining the molding and joining process it is now possible to produce geometrically complex molded parts with large surfaces and integrated functional elements in a highly cost-efficient manner. This also enables more flexible production (changing patterns and colors).
Background
Thermoforming is a method used for shaping thermoplastic materials. To this end the material is heated or formed by means of air pressure or vacuum. This manufacturing process allows for low-cost series production and has so far been particularly suitable for large, but less complex components such as housing shells or panels.
A method developed at the University of Stuttgart enables functional elements to be integrated during the forming process. It is thus possible to create geometrically complex parts at low cost.
Problem
Parts that integrate multiple functions are often manufactured using injection molding, which is a inflexible tool-based production methods. Thermoformed parts can be added later, but this requires additional steps and tooling which results in higher production costs.
Solution
By adapting the molding tool, it is possible to integrate functional elements into the thermoforming process. Here, the integration of functional elements can be executed simultaneously with the thermoforming process of the fiber reinforced component. Moreover, this production process is more energy-efficient because the thermal energy required for thermoforming can also be used for welding the functional elements or activating an adhesive. If no adhesive is used, the molded part is joined by welding it to the contact surface (e.g. by laser welding). The integration of optical conductors into the mold also allows forming and joining steps to be sequenced flexibly.
By combining the molding and joining process it is thus possible to significantly improve production in terms of flexibility. In this way, functional elements can be reliably and cost-effectively joined to components during the thermoforming process in series production at high cycle rates. Another benefit: higher process flexibility compared to injection molding. For example, by changing the semi-finished products, components with different patterns or colors can be produced in series.
![Diagram of the procedure in three steps: 1. Insertion of semi-finished product and functional element(s) into the thermoforming mold (left), 2. Forming and joining (center) and 3. Demolding of the finished component with functional element (right) [Fig.: University of Stuttgart].](/fileadmin/user_upload/img/Technologieangebote/14_024_Verfahrensschritte_en.jpg "Diagram of the procedure in three steps: 1. Insertion of semi-finished product and functional element(s) into the thermoforming mold (left), 2. Forming and joining (center) and 3. Demolding of the finished component with functional element (right) [Fig.: University of Stuttgart].")
Diagram of the procedure in three steps: 1. Insertion of semi-finished product and functional element(s) into the thermoforming mold (left), 2. Forming and joining (center) and 3. Demolding of the finished component with functional element (right) [Fig.: University of Stuttgart].
Advantages
- Molded parts with functional elements can be producedat significantly lower costs
- Forming and joining in a single process
- Integral joint of functional element and molded part by bonding or welding
- Complex component geometry can be realized
- More flexible production (changing patterns and colors)
Fields of application
Series production of plastic components with functional elements