Repurposing Rotomoulded Wastes
Summary
This is a project that involves concept sketching of 3 solutions to rotational moulded wastes with focus on designing for the circular economy. It involves a thorough proposal for the effective use of a select waste, plans for longevity and end of life management for each solution. My final concept is a workstation made from pre-consumed slimline LLDPE tanks.
Individual project
Year: 2022
Scope: 14 weeks
Category: Designing for the Circular Economy
Skills Used:
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Sketching
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Photoshop, Illustrator
Design Brief
To design a solution that reduces the environmental impacts that plastic waste derived from rotational moulding processes produce. The solution must showcase effectiveness within a circular economy model and demonstrate that addressing this model provides environmental and human-centred value
The information and details included in each of these 3 maps are completely different and each have its own purpose as indicated by their names. As such, mobility-aid users feel that some information are difficult to locate, and it can be taxing having to plan travel routes with disconnected, static information.
Rotational moulding is a manufacturing process used to produce sturdy, often large, plastic products, which often makes them difficult to reuse and recycle.
In Australia, rigid polyethylene such as LLDPE and HDPE is the dominant plastic used in rotational moulded products. They are used mainly in the production of liquid-holding tanks, playground equipment and wall barriers. Since these products must be able to withstand unpredictable weather and climate, they must be produced with thick, even walls without any inconsistencies in the material structure. This means that there are tons of rejects and scraps from the manufacturing process, contributing to a large percentage of “unnoticed” pre-consumer waste.
The Problem
3 Concept Proposals
Concept 1: Shelter with Height Adjustable Roof
Origin: Round LLDPE water tank
The shelter uses large, round water tank as the basis of its shape. A platform made of reclaimed timber is used to raise the shelter off the ground and is attached with several aluminium aligners to hold the walls of the tank in place. In the center of the tank, a metal pole with a raising mechanism allows users to adjust the roof height. Temperature and lighting within are adjusted via this roof adjustment mechanism, which encourages use of natural sources and promotes enjoyment of the outdoor atmosphere.
A tank with radius 2m and height 2m can cosily shelter up to 4 people. Through use of a readily available structure, it is a good replacement to traditional timber or steel-constructed shelters. LLDPE water tanks are resistant against moisture and graffiti which are qualities beneficial for outdoor use.
It is a rental product for public parks and offices, which increases the intensity of product usage. Due do the natural durability and resistance of LLDPE and timber, the shelter has a long service life of up to 25 years. By accessing the QR code on the product, the renter can get a free deinstallation and transportation of the shelter for the required maintenance. The simplicity of the construction ensures that all parts can be easily repaired or replaced without having to scrap the entire structure. The shelter can be easily transported to be used in other locations after careful dismantling and can serve various purposes from indoor to outdoor use, with minimal refurbishing.
If used outdoors, the shelter will show signs of damage after a few years due to stress and weather exposure. By accessing the QR code on the product, the plastic components of the shelter can be sent back to the manufacturer for repair so that it can used once again. If damage is extensive, a replacement pre-consumed waste tank will be sent. The wooden platform, metal pole and other hardware can be easily recycled when damaged or dismantled and reused for shelters in another location.
Concept 2: Partition Frame
Origin: Scraps and cut pieces from pre-manufacturing waste
Partition frames made of either HDPE or polypropylene wastes (not both together as these two polymers cannot be mixed), both of which are highly durable and sturdy materials. HDPE produces a flexible frame, while PP produces a stiff frame and customers can decide which material they prefer when ordering. The cut offs are to be placed in a heat press mould along with other tiny pieces of plastic to form the rectangular shape of the frames. The melted mixed plastics may create uneven and rough surfaces which are not good to look at, however through machine sanding and careful polish, a smooth surface can be achieved.Foam padding or patterned boards can be inserted into the frame’s central channel. Multiple frames can be joined together to create longer partitions.
Partition frames are typically made of steel or timber. In using HDPE or PP, the strength and lifespan of the frame are increased as there are no risks of rot, rust staining and termite infestation. The frame will also not break as easily as a timber frame since it is a single form without any separation. Multiple frames joined together can cater to consumers’ various purposes, from office to decorative household to outdoor garden partition. When repairs are needed, the rental company provides free service as the hot press mould that initially produced the frame can be reused to bond more plastic cut offs to the frame.
When the frame is broken or shows signs or cracking, it will be sent back to the manufacturer for a check-up. The frame can be fixed by once again moulding with waste plastic, however if the material is beyond salvageable, the entire frame will need to be cut and recycled back into pellet form. Similar with the workstation, these pellets can then be mixed with new materials to manufacture other products.
Concept 3: Slimline Workstation
Origin: Slimline water tank
As its name implies, the basic structure of this workstation comes from the slimline water tank. Using the three-columned tank with 2m height, the product is a sheltered workspace with two seats and a table. Specific cuts on the side columns produce two hollowed-out spaces where cylindrical foam seats can be inserted. The center column is cut in half to house a tabletop. The tabletop and seat components are refurbished old products or rejects provided from existing companies. The slimline shape of the tank allows the workstation to be able to fit in narrow spaces but still provide a cosy and somewhat private area for up to two people to work on.
The seating and tabletop in the slimline workstation are components that can be easily removed should they or the main structure needs maintenance. As a furniture used indoors, its service life can be as long as 40 years, with the removable components potentially deteriorating first. However, LLDPE’s high impact and puncture resistance are beneficial towards protecting these components from wear and tear. By accessing the QR code on the product, the renter can request a replacement or repair for any of damaged components free of charge. Other components such as lamps, footrest and bag hangers can be added at the renter’s request, to maximise functionality and meet their needs for the duration of rent.
Once the LLDPE shows signs of weakening, the workstation will be sent back to the manufacturer where the material will be processed into pellet form. LLDPE is a highly recyclable material, and its mechanical properties can be increased by mixing with new polyethylene or other natural fibres (i.e., timber, quartz flour) to become a composite material. The new forms can then be reused in other applications. These apply as well to the furniture components.
