Going Pro

Plastics Recovery

The Shruder - An Industrial Shredder and Extruder for Single-use Plastics

Plastic Collective

Issue 16, October 2018

Meet the Team: Plastic Collective

mark and louise


Founder of Plastic Collective

BSc (Zool/Anth.), G.C. Env. Ed., GDip. Ed.(Bio./Chem)


COO and Principal Consultant

BSc, M.A.H.A., Dip Proj Mgmt

With knowledge about plastic, a desire to create a plastics circular economy, and by engaging with the right people, Louise Hardman has been able to commercialise her Shruder machine for sustainable plastic recycling solutions.

You may recall our Moonshots article from Issue 13 that spoke of a day where we could perhaps recycle our waste on-site instead of trucking it around the country or the world! This led to one of our readers, Lexi from Coffs Harbour Hacker Space, notifying us about a brilliant Coffs Harbour local, Louise Hardman, who had developed a mobile recycling machine, and commercialised it!

We were eager to reach out to Louise to learn more about her amazing machine, and her Plastic Collective initiative. Louise was more than happy to speak with us.


Louise first studied and worked as a Zoologist for around 20 years, spending time working in wetlands, studying turtles and other sea life.

In the early 90s, Louise found a sick turtle, which sadly passed away just days later. A dissection found that it had died from ingesting over 30 types of plastic. This was the catalyst to her passion to keep plastics out of the oceans, as she went on to complete a Bachelor of Science.

In 2003, while on a holiday in Thailand with her daughter, Louise witnessed a young local girl throwing a bag of rubbish into the river. The girl explained that it was normal practice, and the river would take the rubbish away. This was the catalyst to study environmental education and become a teacher.

A few years ago, a serious knee injury enabled her to turn her attention towards developing solutions to the massive waste plastic problem.


Louise stated that 74% of the plastic in the ocean comes from the Asia-Pacific region. In this region, there are 4,000 inhabited islands across 10 countries. After some research, Louise worked out that these 370 million people were burning, dumping or throwing away over 11 million tonnes of plastic every year!

Louise saw that there was plenty of plastic coming into the islands, but very little recycling. With people on the islands only earning around $5,000 per year income, there were no means or incentives to recycle. Louise recognised that the problem was more around that people didn’t understand the value in plastic, so she set about educating people of its value and how it could be reused.


"I had a burning desire to come up with a solution to stop plastic going into the ocean, so I started browsing the internet for mobile recycling solutions”, Louise said. After about a week scouring the internet for a solution, Louise came across Dave Hakkens in the Netherlands, with his Precious Plastic initiative. Louise contacted Dave and began working with the open-sourced blueprints.

The recycling machine Louise had in mind needed to be portable, able to safely shred plastic and be able to extrude it into filament or cord for reuse.

In 2016, Louise met up with a local engineer to build a shredder/extruder prototype, hence the name Shruder (pronounced Shroo-der). What started as a small $200 investment quickly turned into a 2-year project with close to $100,000 in R&D funds.

Plastics have different chemical compositions and mechanical properties, which Louise researched in depth, having a background in Chemistry. For instance, plastics break down differently, some plastics float while other types of plastic sink in water. If the plastic was going to be processed there was the melting point and many other considerations, such as strength, density, flammability, flexibility, etc to consider.

The machine also needed to be super safe, strong, reliable, easy to transport, and even shippable to other countries.


Most funds to develop the prototype came from Louise’s savings and with help from friends and family. There was also a small grant from the government (Minimum Viable Product Grant).

In late 2016, Louise joined the 6 Degrees Coworking Hub in Coffs Harbour who taught her how to pitch. By mid-2017, Louise was on stage pitching her portable recycling machine to a panel of judges at the StartUp Coffs Coast competition. Not only did she win, but one of the judges, Mark Wolf, had 40 years experience in environmental monitoring and disaster management systems. Mark saw the potential of the Shruder and aligned with Louise’s cause. Mark could also help commercialise the Shruder with the help from engineers in his businesses.


With Louise’s plastics knowledge and passion, and Mark’s know-how and access to specialised engineers, they set about turning Louise’s prototype, named the Shruder-817, into a commercial unit.

In December 2017, Louise demonstrated her prototype for two weeks in Vanuatu at the Pacific Mini Games. This allowed the team to see how the Shruder would function in a real-world environment and what improvements needed to be made to commercialise it.

The commercialised unit, Shruder MKII, is a dual purpose, compact, industrial shredder and extruder, purpose-built for recycling of used plastics. It shreds single-use plastic items, which can then either be on-sold to plastic recyclers or extruded into filament or cord to be made into new products. Interestingly, the first MKII machine was sold to Coca-Cola.


The Shruder-MKII:

A dual-purpose, compact, industrial shredder and extruder, purpose built for shredding single-use plastics for on-sale to recyclers or extruding into cord, filament or small moulded items. Capable of shredding 5kg of plastic/hour (1.4 tonne per month!) and extruding up to 120m/hour (20km per month).


On top of the shredder box is a hopper to load the clean plastic. Sharp knives and blades spin at high speed at the bottom of the hopper to shred the plastic into tiny pieces. The blades are specially shaped and shimmed for a high tolerance to ensure an effective and efficient shred. The blades are made from nitrogen hardened steel because stainless steel was not hard enough.

A powerful 1.5kW 3-phase motor drives the blades, and a single to 3-phase inverter is used to allow it to be powered from 240V 10A mains power. The inverter also helps boost the power in case the power fluctuates, which can be common in small islands. Louise explained that the source plastic material doesn't need to be clean before shredding, and that there are two different classes of plastic:

CLEAN PLASTIC: Such as general household waste. Just a simple rinse is necessary and any labels removed.

DISCARDED PLASTIC: Depending on where the plastic has been discarded will depend on how well it shreds and extrudes. Plastic such as HDPE or PP that floats in the ocean would have started breaking down. This plastic needs to be commingled with clean plastic.

It is important that the plastic is completely dry, and the shredded plastic is kept in air sealed containers when not being extruded.

When it comes to maintaining the Shredder, Mark explained the Shredder box is linked to the gearbox using a flexible coupling. This makes it easy for someone who lacks the mechanical expertise to maintain the unit on-site without the need for special tools for re-alignment.


The extruder is an option that integrates into the Shredder in order for it to transform the plastic shreds into a plastic that can be reused.

The extruder works by placing the shredded plastic shards into the hopper. A large screw then pushes the plastic through a barrel into a hydraulic tube that is heated between 130°C - 270°C using heater bands. This melts the plastic, which in turn comes out of a nozzle for injecting into silicone moulds or winding onto a spool for later use. To avoid the moving parts being clogged by solidifying plastic, an electric clutch is used to only move the plastic through when the ideal temperature is met.

Plastics including HDPE and PP work well, however, Louise has found that PET is too messy to process. The structure of PET changes as it breaks down, which means it can crystallise in the extruding process. It can, however, be commingled with other plastics. Different temperature and flow rates can be set depending on the source material viscosity and whether it is going to be injected into a mould or wound onto a spool.


Louise claims that the extruded filament can be just as good as a new material bought in a store, and obviously much cheaper compared to rolls that are about $30 to $40. The 3D printer will need to be of a high standard though to handle any lumps that may appear in the extruded filament.

Louise has seen people 3D print or mould tiles, garden stakes, furniture and even hand planes for surfing. A book that will be supplied with the Shruder includes instructions to make 28 products, such as the hand plane from bottle caps.

To improve efficiency and throughput of the extruder, Mark mentioned there are plans to install vibrators on the extruder hopper which will shake the plastic shreds better into the extruder.


We spoke to Mark at length about the electronics in the Shruder. It became evident very quickly that Mark was very proud of the machine and spoke highly of the engineering team’s achievement.

Mark explained that at the heart of the Shruder is a Programmable Logic Controller (PLC), an industrial grade microcontroller that monitors and controls the motor, etc. Another crucial component is a Variable Speed Drive (VSD) that controls the speed and torque of the internal motor. The VSD also ensures the filament extrudes at the correct rate and automatically reverses the motors if they come under load to avoid any blockages. The control panel is logically laid out for ease of use.

The Shruder-MKII is engineered for performance and safety. The electrical system has been carefully engineered to operate safely in humid and salt water environments. A PLC monitors and controls the Variable Speed Drive that controls the speed and torque of the internal motor.


The Shruder includes Wi-Fi technology built-in, which has a few different benefits. Firstly, it enables the machine to be monitored from another room using an App, without the need to be at the machine constantly. If you are using the shredder you would need to be by the machine constantly feeding plastic in, but you would only need to attend to the Extruder every 20 minutes or so to refill the hopper with shredded plastic.

Secondly, the machine can be connected to a secure Cloud App, which enables the support team in Australia to securely monitor the machine’s condition. The support team can provide advice remotely and advise when maintenance is required.


For the Shruder to be commercialised, safety and reliability were high on the list to be addressed.

With Mark’s background in instrumentation, telemetry and communications, and engaging with two of his partner companies, Mark had all the right people working on the Shruder to turn from the prototype to a commercialised unit.

The first company had specialist mechanical engineers to work on all the mechanical components. The second company had the electrical engineers with experience with Supervisory Control and Data Acquisition (SCADA) control systems. These specialists also ensured the machine met safety standards.

By using a PLC and VSD drive, the motor’s current could be monitored. If the motor becomes overloaded the clutch will put the motor in reverse to remove any jam.

To be reliable in the field, the Shruder has been built to sustain prolonged use in tropical, humid, harsh, salt-water environments. It has been built durable enough to handle being transported on a ship overseas or on a trailer across long bumpy highways.

Mark explained that a Shruder was recently sent to Double Beach in Queensland, and then onto Airlie beach on Queensland’s Whitsunday Coast. The Shruder successfully endured transport on a trailer across long highways and sand dunes with not even a screw coming loose from a terminal block. The Shruder was tested for any wear on the blades from the marine plastic.

Environmental conditions have been factored into the design. Not only does the machine need to withstand salt-water environments, it needs to be ventilated for humid weather, but at the same time be ant and insect proof!


There is an optional green energy pack available to power the Shruder where mains power is not available. This kit is made up of an inverter/regulator, up to 6 large solar panels and 4 deep-cycle batteries. This will mean the Shruder will become a permanent installation, however, in order to keep the Shruder portable, there is also an option for connecting a 2kW diesel generator. Perhaps in the future shredded plastic could be turned into a fuel to power the generator.

There is also scope to provide a generator that runs on bio-diesel in the future, suited for countries who want to be completely green. Brilliant!


As mentioned earlier, Louise sees education as a key component to developing a circular economy. With some training and educating businesses, the design loop could be closed from recycling plastic and turning it into new products. The Shruder is a great tool to help in the education process.

It is also important to put emphasis around the material science of plastic because each plastic behaves in its own way. UV resistance, strength, and flammability need to be considered before using for particular applications - you don’t want flammable roof tiles!

Louise educates 3 different groups of people when commissioning a Shruder:

COLLECTORS: These people come up with systems to collect and store wasted plastic

TRANSFORMERS: The people who transform the waste into raw materials for creators

CREATORS: The people who consume the raw materials. For example, it could be a company making bio-filters from shredded PP, or Women’s groups weaving baskets from the extruded cord.

With the success of the Shruder and the publicity around it, Louise now finds herself invited and sponsored to attend many events in Australia and around the world. In Australia, interest has mostly been from councils wanting Louise to attend events to demonstrate and educate the public about reducing and recycling waste.


There are currently two commissioned Shruder units going to Bali, one going to Borneo, two in Australia and eight more about to be commissioned soon. Louise also has one on hand for hire at events, such as festivals or beach cleanups.

Louise aims to have 100 Shruders commissioned within 3 years and 100,000 within 10 years. Her goal is for countries to become plastic neutral.

It’s not about getting rid of all plastic, but instead respecting plastic, reducing reliance on plastic, and not having any going into the sea. According to the Plastic Collective's data, the average individual consumption of plastics in Australia is around 100kg of single-use plastic per year, and that Asian countries are around 10 to 30kg per person, per year. She hopes that Australians can reduce their plastic usage to 10kg per person per year. Louise practices what she preaches, by using keep-cups, re-usable shopping bags, bamboo cutlery, re-usable straws, etc. Her annual plastic use is approximately 5 kg, and none of it goes to landfill.


Louise’s advice for any of our readers wanting to turn their idea into a commercialised unit is to work with experts in their field. Trying to learn everything yourself can be costly, time-consuming and overwhelming, so working with people in their chosen field certainly helps.

Mark’s advice to our readers is to make something that is unique, innovative and safe. Be sure it complies with any standards if it is going to be commercialised, and be sure to keep testing and improving the next one as you learn how the device is used in the real world.


The Shruder is available as just a shredder for people who just need to shred the plastic to resell to another party to process. The shredder on its own is also ideal for medium to large size boats to reduce the amount of space required to hold waste.

The Shruder with the integrated Extruder sells for around $28K. Most of the cost is because of the sophisticated, weather resistant and reliable electronics. Be sure to get in touch with Louise if you are interested, and check the Plastic Collective programs on www.plasticcollective.co.