Specific Process Knowledge/Back-end processing/Polymer Injection Molder

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Polymer injection molding

The Polymer Injection Molder is no more an open access tool has been moved to DTU Construct

Injection molding machine in the basement under the cleanroom

The injection molder at DTU Nanolab is an Engel Victory Tech 80/45 which is a hydraulic machine with single motor. The machine is also equipped with a robot which can pick up finished samples and place them on a conveyor belt. See the table below for key capabilities of this machine. The user manual, user APV, technical information and contact information can be found in LabManager:

Polymer injection molding Info on LabManager (Click 'Documents' tab to go to documents).

Equipment performance

The polymer injection molding machine at DTU Nanolab is a hydraulic system with the following capabilities:

Parameter		Value
General	Tools	Flat disc, Disc with Luer connectors, Microscope slide
	Clamping force	Up to 450 kN
Processing temperatures	Mold temperature	~15°C to 140°C
	Heating cylinder	Absolute max: 350°C
Molding parameters	Injection speed	Up to 53 cm3/s
	Injection pressure	Up to 2200 bar
	Process types	Constant or variable mold temperature

Polymers

At DTU Nanolab the following polymers are used routinely:

• Topas 5013L-10
  
• Topas 8007S-04
  
• PP
  
• PMMA
  

Topas polymers are supplied by Nanolab. All other polymers are purchased by the users themselves. All polymers (and each individual grade of each polymer) must be approved for use at DTU Nanolab. If you would like to use a new polymer or a new grade of a certain polymer, please fill out the application form which can be found in LabManager by going to the 'Documents' tab of the 'Info' page for the Polymer Injection Molding machine. You can also click this direct link: New_polymer_application.dotx.

When the polymer has been approved you will receive labels which must be used to label your polymer. All polymers left in the injection molding room must be marked with this official DTU Nanolab label. Polymers not labelled appropriately may be thrown out at any time.

The easiest way to get an overview of polymers and processes used on the polymer injection molding machine is to go to LabManager and consult the Process Log for the injection molding machine. If you would like use a non-Nanolab polymer for a test, please contact the owner of the polymer and ask if you can have a sample. A complete list of all polymers in use at DTU Nanolab and who owns them can be found in LabManager on the Info page for the polymer injection molding machine on the 'Documents' tab. You can also click this direct link: Approved_polymers_list.pdf.

Process parameters and optimization

There are no standard injection molding processes because it varies significantly how users prefer to optimize their process and how they prioritize parameters such as polymer type, replication fidelity, dimensional accuracy, optical properties, residual stress and cycle time. However, browsing through the Process Log it's usually not a problem to find a program made for the polymer and tool at hand which can be used as a starting point.

The injection moulding cycle consists of the steps outlined below. Click on each step to get a description of the most important process parameters for each step:

1. Mold heating setup
   
2. Closing mold
   
3. Injection
   
4. Switch-over type
   
5. After (holding) pressure
   
6. Cooling
   
7. Dosing (plastizising)
   
8. Demolding
   
9. Ejection
   
10. Robot sample pickup
    
11. Nozzle settings
12. Process overview

Advanced process parameter optimization and features

This LabAdviser page is just a quick overview of the most important parameters and features. For a full description of parameters and machine features, please refer to the full operating manual from Engel. It can be found in LabManager under Equipment Info -> Polymer Injection Molding -> Documents -> Technical Documents -> EN-VC_Standard_dtu or by clicking this direct link: EN-VC_Standard_dtu.pdf. Please note that this manual refers to a slightly larger machine and some features that are not all available on DTU Nanolab's machine, but all general guidelines and descriptions of the user interface are valid.