Injection moulding 

The equipment described below is used in R&D studies, but SINTEF can also fabricate prototypes and demos for the industry.

Injection moulding machine

SINTEF has a Battenfeld EM 50/120 injection moulding machine which is well suited for the components in this project. Being a servo-electric machine, it has high process repeatability. It is also fitted with several specialities relevant for fabricating micro- and nano-featured components:

• “Variotherm” processing – software for controlling the variation of mould temperature through the cycle (for improved replication)
• Vacuum pump for evacuation of the mould cavity prior to injection (for improved replication)
• Injection-compression moulding (as used when fabricating DVDs)
• Laminar flow box for a clean environment around the mould
• A programming system with a large number of programmable digital and analogue input/output, giving freedom in implementing special processes
• Special equipment for pre-drying small batches of polymers, and keeping these free from contaminations

Moulds and inserts

A mould is also needed in order to injection mould a micro-featured component. SINTEF has two moulds for such applications. One mould is custom-built for fast variotherm processing and evacuation of the cavity. In both moulds, various mould inserts can be mounted. So far we have used Ni inserts (shims) for diffractive optical elements, and brass inserts for lab-on-a-chip components.

Polymers

SINTEF has experience in injection moulding of micro-featured components using polymers such as PC, PMMA and COC.

Characterisation of polymer materials 

SINTEF has equipment for measuring relevant properties of polymer materials, e.g. shear viscosity vs. temperature and shear rate, and the glass transition temperature. 

Characterisation of components

SINTEF has several instruments for characterising micro-featured components and their topography. Atomic force microscopy (AFM), scanning electron microscopy (SEM) and white-light interferometry and optical microscopy is used in this project.  

SINTEF's variotherm mould.

SINTEF's injection moulding machine.

Part of a mould for injection moulding. A Ni shim is mounted at the centre of the cavity (the exposed shim area is 17 mm x 17 mm).