Tearing through plastic
UNIVERSITY OF CAMBRIDGE
LICENSING OPPORTUNITY
A Cambridge group has developed a new way to make polymer films with precisely determined microscopic holes - for fluid transport, DNA analysis, or even "tear here" marks in plastic packaging.
The invention
Microcapillary film extrusions
Polymer films with holes running through them. The invention is the process used to make the materials. The patented process puts tailor-made holes into melt-processed polymers. For example, one possible material is linear low-density polyethylene, used to make plastic bags.
An extruder melts polymer pellets and sends the molten material through an extrusion die. The polymer then flows over gas injectors, and as it flows the molten material sucks in air through pipes. The flow of air into the polymer forms microcapillaries that run through the film.
Manipulating the processing conditions can produce capillaries of a range of sizes and shapes. The process can also handle other meltable materials.
The inventors
The invention was the work of Professor Malcolm Mackley and Bart Hallmark at the University of Cambridge. Professor Mackley heads the Polymer Fluids group in the Department of Chemical Engineering.
Applications
This invention could have any number of uses. The holes through the film can be between 5 to 500 micrometres in diameter. The micro-capillaries can carry liquids or gases at pressures of up to ~50 bar.
A microcapillary can also be used to make film tear reliably along a predetermined path.
The researchers have identified a range of broad application areas:
- Medical: fluid transport; porous matrix applications
- Chemical and biochemical analysis: fluid transport; liquid encapsulation; micro-reactor applications; chromatography columns; capillary electrophoresis (DNA analysis)
- Heat exchange
- Optics
- Tear guiding in packaging
The IPR
The first patent (number GB2408961) was published recently. Another patent, to protect the tearing application, is in the works.
The offer
The IPR is in the hands of Cambridge Enterprise, the university's technology transfer business. They are looking for companies interested in licensing this invention for different applications or materials. There is already a deal with Bioprogress to develop this technology for soluble films.
