„Bolt-on injection unit“ from Langzauner and ENGEL

Langzauner presses can be simply supplemented with an bolt-on injection unit from ENGEL. Thermoplastic fibre composite preforms – for example thermoplastic organosheets– are formed and functionalised in a single integrated step, whereby the press itself acts as clamping unit, similar to an injection moulding machine.


Back-injection of semi-finished products

The bolt-on injection unit from Engel and Langzauner enables to subsequently back-inject already thermoformed organosheets (or semi-finished products) with thermoplastic injection moulding material. This back-injection process is mainly used to locally functionalise organosheets such as ribs for local reinforcements, or to cover the complete surface of the part.

The bolt-on-injection unit from ENGEL allows thermoplastic solutions with functionalization through injection moulding while using fiber composite semi-finished products (organosheets). In one single integrated step, thermoplastic fibre-reinforced plastic products – such as organosheets and UD tapes – can be formed and functionalised. For example, reinforcing ribs or assembly elements are moulded immediately in the same mould after thermoforming using a thermoplastic from the same matrix material group as the thermoplastic sheet.

This not only enables a highly efficient and fully automated production process, but also contributes to the circular economy. The consistent thermoplastic mono-material approach facilitates subsequent recycling of the parts.

Simple integration in the existing press process

Our innovative bolt-on injection unit is positioned next to the press. The bolt-on unit will be connected to the mould (or hot runner, deflector plate) and the injection process will be start.  Data recording and process control are centrally performed by the press control system.

The bolt-on injection unit – features

The fully integrated bolt-on-injection unit from Engel is capable to cope with both standard and high performance plastics (including ABS, PC, ABs/PC, PEEK, PA, etc.) which can be processed at temperatures higher than 450°C. The consistent use of thermoplastic materials enables a high degree of process integration to ensure totally worry-free functionalisation of the parts. This, in turn, reduces the time taken, the raw material input and the energy requirements. Depending on individual requirements of our customers, Langzauner and Engel are customizing and fully integrating the bolt-on injection units.

A recent project was successfully implemented at the Technology Center Thermoplastic Composites of the Leibniz-Institut für Verbundwerkstoffe GmbH (IVW), whereby an injection unit from Engel with a screw diameter of 70 mm was selected.

Typical process sequence – at a glance

  1. Loading of a preheated reinforced semi-finished product (organosheet, GMT, LFT etc.) by hand or using an automated Langzauner transfer frame
  2. Closure of the press
  3. Connecting the injection unit to the mould (simultaneously to the closure of the press)
  4. Injection of thermoplastic material
  5. Dwell time for cooling (composite compound)
  6. Disconnection of the injection unit
  7. Opening of the press
  8. Removal of the component

Integration of the ENGEL bolt-on injection unit

The development and integration of the bolt-on injection unit was successfully performed in the course of the 2600 tonne short-stroke press of the Technology Center Thermoplastic Composites (TTC) of the Leibniz-Institut für Verbundwerkstoffe GmbH (IVW). The requirements to integrate the injection unit were pretty challenging, since maximum flexibility and precision were aimed, while at the same time  space in the building was a limiting factor. Langzauner decided to integrate an injection unit from ENGEL, one of the leading manufacturers of injection moulding equipment.

  • The injection unit can be independently operated through the ENGEL CC300 control system and has also been integrated entirely in the press control system.
  • Thus, all injection parameters can be easily adjusted while real-time process monitoring is possible.

Experts collaboration for top results

“ Langzauner and ENGEL were able to demonstrate the perfect symbiosis of innovative injection moulding technology and special press machine construction, for flexible integration into individual production processes. Together we can guarantee absolute top performance! The know-how and experience of the two companies resulted in an excellent solution that is now ready for the market.” Matthias Mayr of ENGEL