Injection molding is scalable, which means it can cater to a variety of production volumes, from small-scale prototypes to mass production. This scalability offers manufacturers the flexibility to meet different market demands.

Don’t forget that you can find out more, and apply to join Precious Plastic as a volunteer, by paying a visit to their site at next.preciousplastic.com.

Injection moulding is one of the most commonly used methods to mass-produce plastic products. It is very similar to extrusion moulding, with the main difference being the way the molten plastic is distributed into the mould. The industrial process typically involves melting granulated plastic inside the barrel of an injection machine, which is then pushed into a temperature-controlled split mould at high pressure by an internal reciprocating screw. This process is the most common modern method of manufacturing plastic parts, and can be used to make everything from small kitchen items and bathroom appliances to outdoor cabinets, sheds, and large playground items for children.

Similar to the Shredder, the total bill of materials cost for the machine sits at around £200, depending on your location. “We used a 100 rpm 12 V DC motor, digital speed controller, and 12 V DC power supply designed for high wattage LED installations,” explains Simon Clark, who travelled to Haiti in 2016 to help his cousin Sarah set up a community-based Precious Plastic workshop. “For the body of the extruder, we started with a stainless pipe, cut out the hopper hole, and welded on plates for the hopper to attach to,” he says. “The extruder build was completed on the second last day of the trip.”

Injection molded parts can undergo a variety of post-processing operations, such as assembly, machining, laser marking, pad printing or surface finishing, to meet the exact requirements of the medical device.

In comparison, Dave’s Injection machine is designed to produce small batches of very precise, detailed objects, such as phone cases or desktop toys. First, flake feedstock is fed into the barrel and then heated for 15–20 minutes. Once the plastic in the barrel reaches a molten state, pressure is applied using a steel plunger, operated by a hand-powered lever.

The output size of the flakes can be changed by altering the size of the sieve placed within the machine to act as a filter. “Different sizes of flakes will give a different pattern; smaller flakes melt easier, but take longer to shred,” explains Dave.

Making new plastic has become even less expensive than recycling, unbelievably, due in no small part to a global excess supply of oil. Without a market for these recycled materials, even putting waste plastic into your recycling bin doesn’t necessarily mean that it will be recycled, as it often ends up in a landfill anyway. This caught the attention of Dutch designer Dave Hakkens, who, for his graduation project at Design Academy Eindhoven, decided to do something about it.

We have been serving the medical industry for nearly 40 years, specializing in handling complex, multi-part programs and medical device molding for a variety of customers. Our direct contact with doctors and other medical professionals gives us insight into their needs and helps define and assist with final product solutions.

Many medical devices must be in direct contact with the human body. Injection molding allows manufacturers to choose biocompatible materials, ensuring patient safety. These materials can be sterilized without affecting their properties, making them suitable for a wide range of medical applications.

One of the most significant advantages of injection molding is its design flexibility. Engineers can create complex, customized components with minimal tooling changes. This adaptability is essential in a field where the demand for innovative and unique medical devices is ever-expanding.

Optional upgrades include insulating the barrel using ceramic wool, and a perforated steel sheet to reduce heat transfer with the surrounding air, improving the energy efficiency of the entire system. “To create an efficient process, it is advisable to run the machine for a few hours once it is started. Don’t start and stop the machine too often as the process will be very inefficient,” says Dave.

Injection molding offers unmatched precision and consistency in the production of medical device components. The process allows for intricate designs and tight tolerances, ensuring that each part is identical to the next. This uniformity is crucial in the medical field, where reliability and precision are paramount.

Although the Precious Plastic Shredder machine is capable of producing flake feedstock directly from unprocessed plastic waste without the need for a separate granulator, Dave suggests breaking up bigger plastic objects into smaller chunks with hand tools as a precautionary measure, to prevent the machine from jamming.

The latest documentation suggests using a wood auger to transport flake feedstock down the barrel, but commercial extrusion machines use purpose-built reciprocating screws. Theoretically, the mechanical energy generated by these screws rotating inside of the barrel reduces the amount of electrical energy consumed by the band heaters to melt the plastic, resulting in a more energy-efficient system. However, the added friction requires a more powerful (and likely more expensive) motor, which is why the use of an industrial extrusion screw is mentioned as an optional upgrade, rather than a base design.

If you want to speed up your rate of production, an optional upgrade is to move the compression area to the underside of the machine so the oven can be used to heat up another mould while the first is being compressed and another cooled. This way, the machine can run continuously.

Injection molding allows medical design engineers the freedom to design complex or intricate parts, a vast selection of suitable materials and the consistency to produce both low and high volumes of devices.

The high initial tooling costs can be a barrier to entry for some manufacturers. However, once the molds are in place, injection molding is incredibly cost-effective for large production runs. The ability to produce a large number of parts in a short time reduces unit costs significantly, making it an ideal choice for mass production.

Cameron is a technology and communications specialist, passionate about the use of open-source hardware for social innovation

he Extrusion machine is used to process flake feedstock into a continuous plastic thread which, in turn, can be used to make new raw materials, such as granulated plastic and 3D printer filament, or even spun around moulds to form unique products. “Technically, if you have enough plastic and a well-streamlined process, you could be recycling 24/7,” explains Dave.

Process validation is the best way to ensure the production of safe parts, to reduce rejection rates, to prevent part failures in the field and to ensure the part meets with application, specification and regulatory obligations.

In many cases, our medical device customers look to process validation to ensure quality parts.  After all, patients lives depend on PTI to deliver high quality parts each and every time.

With streamlined production processes, injection molding can significantly reduce time-to-market for medical devices. This is crucial in a rapidly evolving industry where innovations can make a significant impact on patient care and outcomes.

PTI Engineered Plastics provides medical device manufacturers with full-service advanced product development delivered in a compressed timeframe. With superior design for manufacturability, tooling, and molding capabilities, PTI turns product visions into reality and gets your product to market first.

ompression moulding is one of the original processing methods for manufacturing plastic parts, and was widely used in the bakery industry before plastic materials even existed. Today, compression moulding is commonly used to manufacture car parts and household appliances. Polymer feedstock is directly placed into a heated mould cavity, and pressure (usually ranging from 800 to 2000 psi) is applied by a hydraulically driven press, until the material has conformed to the shape of the mould. Throughout this process, heat and pressure are maintained until the polymer feedstock has been cured. While most commercial applications use only thermoset polymers, Dave’s machine is designed to use recyclable thermoplastics, including HDPE.

At around £120 (depending on your location), the total bill of materials cost for the Injection machine is around 40% less than the Shredder or Extrusion machine. This is mostly thanks to the system’s manual operation, which does not require a motor. It is worth noting, however, that this does not include the cost of fabricating or purchasing a mould.

So far, Koun estimates that around 22 000 kilograms of waste material has been recycled into new products. “Even though they’re still far from fully covering their expenses with sales, we believe they’re on the right path to make the project financially sustainable in the near future.”

Overall, the process is very straightforward and easy to understand, which makes it great for educational and demonstration purposes. Flake feedstock is inserted into the hopper and then pushed along a narrow steel barrel by an extrusion screw, which moves the material towards band heaters, positioned uniformly along the length of the barrel. Once the flake feedstock reaches 130 to 170°C, the molten plastic is pushed through an extrusion nozzle to form a single continuous thread.

“What makes Koun special is their ability to merge Precious Plastic with traditional Moroccan crafts, by combining plastic with metal, wood, and textiles in unique ways,” says Dave.

On 26 May 2018, the FAMAE Foundation awarded 300 000 euros to the Precious Plastic project, to further develop their machines. The plan for Precious Plastic Version 4, as Dave describes it, includes the development of semi-industrial systems that are capable of recycling plastic in much larger quantities than is currently achievable with the existing open-source machines. Dave also plans to welcome 45 volunteers from around the world to work on the project from his new warehouse in the centre of Eindhoven. Let’s take a look at the machines.

“Besides being more productive and efficient, this upgrade makes the machine easier to build as you don’t need to install the compression mechanism inside the oven,” reveals Dave.

Some of the most common materials used in medical devices are: Polypropylene, ABS, Polyurethane, Polyvinylchloride, Polycarbonate, Polystyrene, Polysulfone, Acetal and Polyethylene.

When you finish working with the shredder, make sure to store away the shredded plastic or the next person using the shredder won’t know what plastic type is in the bucket. Now you’re ready to start producing new products!

Overall, the Compression machine is simple to understand and very powerful, when properly mastered. It can be operated by a single person and can be used to easily create beautiful products, provided you have the right mould and materials. The bill of materials cost is comparable to the Injection machine (around £120, depending on your location).

The complete kit consists of four main machines constructed from sheet metal and scrap parts: a shredder for creating waste plastic flake, an extrusion machine for processing the plastic flake into 3D printer filament and granulated plastic, an injection moulding machine for the production of very precise objects, and finally a compression oven for making large and durable objects. Dave’s website, preciousplastic.com, acts as the central hub from which his community of over 100 000 participants organise and educate themselves. The page for each machine includes all the details you need to build one yourself. There’s also information on how to use the recycled plastic to make everything from building materials and household items, to phone cases and even cheap and cheerful jewellery.

Once divided by type and colour, the waste plastic is passed through a slow-moving shredder to produce chips of various irregular sizes. The resulting chips are washed thoroughly to remove contaminants, such as chemical residue, food and labels, and then passed through a second machine called a granulator. The granulator runs at a higher speed than the shredder, and is designed to produce flake feedstock of a specific size for recycling into new products. According to Dave, the going rate for cleaned flake feedstock is eight to ten times higher than unshredded plastic, and 10 kg of clear PET flake typically sells for around £70 on the community Bazar.

Dave’s Compression machine uses an electric kitchen oven to heat flake feedstock for 30 to 40 minutes, before a car jack applies pressure to the molten material by pushing the mould against the ceiling of the oven. After a couple of minutes of applying pressure, the car jack can be released and the mould can be removed for cooling in air or water. Once the mould has cooled, it can be safely opened, enabling you to inspect your new product. If mixing different-coloured plastic flake, the Compression machine gives a mottled, flake-like look to plastic. This process is generally slower than extruding or injecting, but it allows for more ambitious products to be created. “This machine can also be used to create new raw materials, like big sheets of plastic,” says Dave.

Precious Plastic is a global community of makers working towards a solution to plastic pollution. Hundreds of people from around the world have built these open-source machines to recycle waste plastic into unique products and building materials.

At PTI, we collaborate with you to achieve the best possible design for manufacturability.  In fact, we have a FREE guide to help you with this.

Having served the medical industry for nearly 40 years, we understand medical device manufacturing.   Plastic Injection Molding remains one of the best manufacturing methods for achieving precision and cost-efficiency as well as maintaining patient safety.

The bill of materials cost for the Shredder machine sits at around £200, depending on your location, which is remarkably good when compared to prefabricated models of a similar specification. Commercial shredders typically start at around £2000 if you’re willing to have one shipped directly from China, and cost significantly more if purchased from Europe or the United States.

Process Validation as defined by the FDA is “The collection and evaluation of data, from the process design stage throughout production, which establishes scientific evidence that a process is capable of consistently delivering quality products.”

At PTI, we have over 16,000 square feet of ISO Class 8 cleanroom space that we utilize in our injection molding process to ensure as little contamination as possible.  We adhere to strict protocols that meet the demands the medical industry requiring ISO 14644 Cleanroom specifications, including bioburden and electrostatic discharge (ESD).

According to a report by the Ellen MacArthur Foundation, just five per cent of the 311 million tons of plastic produced every year is effectively recycled. Around 40 per cent of this plastic ends up in landfills, and over 30 per cent goes on to pollute the planet’s delicate ecosystems, including the world’s oceans.

Careful selection of materials is extremely important within the medical industry. Materials must meet FDA and other regulatory standards, ensuring patient safety, biocompatibility, sterilizability and durability.  As Injection molding allows for a vast selection of both thermoplastic and thermoset materials to choose from, there is certain to be a material suitable for just about any application.

While exploring the documentation, you may notice that although detailed CAD drawings are provided for the cutting blade design, only a loose framework is suggested for the machine’s overall construction. There is a good reason for this. The Shredder’s loose design can be adapted for any motor with a power of +/- 2 kW and output speed of +/- 70 rpm, which means the size and shape of the motor selected may vary wildly from one build to the next.

Sell your recycled products If working with steel moulds, the molten thread emerging from the nozzle is repeatedly wrapped around the mould until the desired effect is achieved and the new product is formed. Dave says that an important point to keep in mind when using this technique is always to design moulds with convex walls, as this makes it much easier to release the plastic product from the mould without damaging it. Mastering this process generally requires a bit of patience and practice, but anyone should be able to make unique and interesting objects after a few attempts.

Dave began developing a series of low-tech machines to move plastic recycling from expensive, large, industrial-scale factories, and into the hands of enthusiastic makers looking for new, more environmentally friendly materials to work with. The resulting set of open-source, easy-to-build machines enables almost anyone, anywhere, to contribute to plastic recycling, while opening up new opportunities for economic development and job creation. Since launching the Precious Plastic project in 2013, over 200 plastic recycling workspaces have been set up, and new ones are opening up around the world every week.

Mold Design is a crucial step in the injection molding process.  Once you’ve finalized your part in CAD software for fit and function, it must then be transformed into a design for molding to ensure the capture of all the specified details.  In some cases, certain features of the part design may not be manufacturable via the injection molding process.

Injection molding produces parts with a high level of structural integrity, ensuring they can withstand the rigors of their intended application. These parts are less prone to defects and offer superior performance over their lifecycle.

Injection molding for medical devices represents the perfect synergy of precision engineering and advanced manufacturing technology. Its benefits, from precision and consistency to cost-efficiency and regulatory compliance, make it a top choice for design engineers and medical device manufacturers. The process empowers engineers to innovate, create intricate components, and bring lifesaving devices to market faster than ever before. The future of medical device manufacturing is being molded with precision, and injection molding is at the forefront of this revolution.

Koun collects raw material from local schools, businesses, and the streets of Casablanca’s Medina itself, which is then cleaned and processed before being sent to one of three workshops to make furniture, clothing, or stationery.

Finally, the site’s global online marketplace, known as the ‘Bazar’, helps community members to generate income through their plastic recycling activities, by selling recycled products and machine parts. One example is Koun (which in Arabic translates as ‘either’), a social enterprise based in Morocco which employs young people to collect and transform plastic waste into products, which are sold through the online Bazar and their bricks-and-mortar store in Casablanca.

Once the plunger has forced the molten plastic into the mould, the mould can be carefully removed and cooled before opening. “The process in itself is tightly connected with moulds and mould-making. If you have a precise mould, you can create beautiful products in a matter of minutes and start a little local production,” says Dave. However, unlike the Extrusion machine, which uses a reciprocating screw to mix the flake feedstock in the barrel, the Injection machine cannot homogeneously blend different coloured plastics. “The output colour is often unpredictable when mixing colours in the barrel, allowing for surprising patterns that can add to the beauty of your products,” Dave explains. Complex moulds can be made using a CNC mill or aluminium foundry and a bit of welding.

The industrial process to reclaim waste plastic typically starts with manually dividing the collected material by type and colour. The most common waste plastic laying around your home is probably PET (polyethylene terephthalate) used for drinks bottles, and HDPE (high-density polyethylene) used to produce household detergent and shampoo bottles.

Meeting stringent regulatory requirements is a non-negotiable in the medical device industry. Injection molding excels in this regard. The ability to use FDA-approved materials and consistently produce parts that meet these standards ensures compliance from the outset.

Precious Plastic isn’t going to solve the problem of waste plastic by itself, but, as Dave said above, “Precious Plastic is, above all, a cultural tool to change the way society perceives plastic”, and it’s well on its way to achieving this goal. It’s enabling makers not only to take plastic out of the waste system, but show just how beautiful waste products can become when they’re treated with care and an artist’s eye.

We have some important news to share about HackSpace: Issue 81 was the last issue of HackSpace as a standalone magazine, and HackSpace has become part of The MagPi, the official Raspberry Pi magazine. Starting with issue 145, We’ll be adding pages to The MagPi to make room for the stories and tutorials you’ve come to expect from HackSpace.

The injection molding process generates minimal material waste compared to other manufacturing methods. This not only contributes to cost savings but also aligns with the increasing focus on sustainable and environmentally friendly manufacturing practices.

Furthermore, we have over 5,000 square feet of controlled environment space.  This segregated area is temperature controlled and pressurized, and can accommodate part decorating, assembly and packaging needs.