Plastic Recycling in the Netherlands

Last week I put my plastic, can and carton recycling wheelie bin out for collection for the last time. The Cities of Utrecht and Amsterdam have decided to let us put our plastic etc in the regular waste, rather than separating it and putting it into its own special bin.

This might sound strange, a backward step, but that is not the case. Over the last 2 years, the Utrecht City Council has conducted a study into plastic waste recycling and discovered something unexpected: they can improve recycling percentages mechanically.

The research found that when the population is asked to separate plastic, cans and cartons from their household waste, the recycling percentage sits at about 26%, but if the process is conducted mechanically on all household waste, this rises to 51%.

I should add at this point that paper, glass and organics will still be collected separately.

There is a huge plastic separation system currently in operation in Rotterdam, take a look at this video. It’s impressive, although it does depart from already home divided materials. And of note to me is that it is transported by boat.

The system uses magnets and infrared cameras to determine and separate the different types of materials, and appears to be so precise that it can be used with regular nondifferentiated waste as described in this video (in Dutch).

I would also like to add that here plastic bottles have a tax that is returnable in the supermarket. 25 cents is added to the price of your water or cola, and you take the bottle back to the supermarket and feed it into a machine (along with your glass). The machine prints you out a receipt and it comes off the shopping bill. As the photo at the top of this post shows, such an approach seems to work. Less bottles are left on the streets, and less are thrown away.

I first came across this idea in Norway more than a decade ago. Collecting bottles that tourists had thrown away in the city centres was a good source of income for the University students.

Self Healing Plastic

One of the problems with plastic is that it is very difficult to repair once damaged. When there is a hole in your plastic bucket you cannot generally mend it. But researchers in Spain have developed the world’s first self healing plastic.

Cutting the self healing plastic

Cutting the self healing plastic

Researchers at the CIDETEC Centre for Electrochemical Technologies in San Sebastian, Spain have developed a plastic that once broken can heal itself. All the user has to do is put the pieces together and leave it at room temperature for a couple of hours, and the material kind of re-molds itself. The repair is said to be 97% perfect within a couple of hours, and perfect 2 days later, and a Youtube video demonstrating the strength of the repair is really quite incredible.

Plastics are made up of polymers, a long chain of molecules that are connected through chemical bonds. Natural polymers are everywhere. In nature, many polymers heal themselves when broken or sliced. Think of your skin when you have a small cut — as the two sides of the cut bind back together, you’re witnessing a self-healing polymer in action.

Synthetic polymers are just as common. Scientists started creating nylon and synthetic rubber to make up for the shortage of silk and rubber during World War II. PVC, polyester and many forms of plastic soon followed.

Putting the pieces together

Putting the pieces together

The Spanish have developed the first human-made self-healing polymer to function without a catalyst, they report in the Sept. 13 issue of the journal Materials Horizon. There are in fact other self healing plastics, but they require a catalyst to start the process (ultra violet light for example). Readers might know about self scratch repair paint, as advertised on TV. This paint is made from prawn shells, a fine example of a natural self healing material that uses the sun as catalyst.

The article states that “The idea behind this is to reconnect the chemical crosslinks which are broken when a material fractures, restoring the integrity of the material. This is expected to provide polymers with enhanced lifetime and resistance to fatigue”.

Testing the repair

Testing the repair

The researchers say this breakthrough will allow them to create stronger sealants, paints, adhesives and more. This could eventually lead to self-repairing pipes, bicycle tires and toys, among a million other possibilities.

Sounds great to me, and the less plastic we throw away the better.

A Miracle Material?

Plastic and its use on mass causes many problems as we all know. It is not biodegradable, made from oil, difficult to recycle and can be found almost everywhere floating in the sea or buried on land. What we need is something to replace it.

Over the last year researchers at the MMC in Paris have been working on a new material. What they have developed is something that might change the future of manufacturing.

See this short article for a more complete description.

Their material is called a vitrimer, it is organic, strong, lightweight and looks to bridge the gap between thermoplastics and thermoset products.

Will vitrimer replace plastic?

Could this be the future of manufacturing?

What this actually means to you and me is a material that is solid but workable across a wide temperature range, so doesn’t melt like plastic, break like glass, can be shaped after production (unlike plastic or other polymers) and easily recycled.

The material can be sculptured without the need for extreme heat, so can be liquefied and moulded and then bent once finished. This makes it an incredibly versatile substance for use in electronics, car manufacturing and many different fields of engineering.

Advantages include the possibility of not using moulds for large structures that produce shapes that cannot be adjusted. If necessary the form required can be made in-situ and manipulated to fit, something that is not possible with steel for example.

The constitution of the materials determines its rigidity, so you can make it like thick rubber with flexibility at room temperature or much more rigid, but it is not brittle and so will not snap.

Given the many problems associated with plastics and the weight issues of using steel, this material looks to offer the promise of a more versatile, easily recyclable, reusable and less polluting alternative, and certain sectors of the scientific community are calling it a wonder material.

One to watch I would say.