University of the Arts London
Materials Evaluation Spreadsheet.pdf (218.41 kB)

DAC Materials Research for Cell Furniture Project

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posted on 2024-04-30, 13:24 authored by Lorraine Gamman, Adam Thorpe

When specifying materials for in-cell items, there are many aspects to consider like safety, sustainability and how the materials could impact wellbeing. This is a challenging task, considering the demands and constraints placed on the prison environment. When working with this complexity it becomes apparent how each part of the system is intricately connected. In the process of choosing materials we are not only looking at the experience of the end user in-cell, but the whole life cycle of the product: from the experiences of the prison industries staff and prisoners working with the materials used in manufacture, to the distribution, assembly, use, repair, disposal and recycling of these prison products.

Materials currently used by for HMP cell furniture​

One of the drivers for this project was to solve problems surrounding the current materials. The metal furniture is austere, uncomfortable and has issues around weaponisation and ligature. The Whitewood (or MDF) furniture is inexpensive but comes at a high cost as it is destroyed and replaced at an unsustainable rate, without the possibility of recycling due to the chemical adhesives used to make MDF material.

New Materials​

DAC aimed to propose new materials and strategies for environmentally and socially sustainable prisons, considering the whole lifecycle of all the furniture proposals. To do this DAC used varied research methods and what was particularly successful, were visits and discussions with the users of the furniture (the prisoners and prison staff), the sector leads of the prison industries, who amongst other things, oversee the production and distribution of prison products, and potential suppliers of materials. In addition to a summary of findings and proposals for different materials, all technical information can be found in the materials evaluation spreadsheet.

Below is a breakdown of the evaluation points we used when assessing materials:

  • Fire safety
  • Potential for weaponization
  • Haptics and comfort
  • Sustainability
  • Lifespan and durability
  • Storage / transport (material and end product)
  • Cost of raw material
  • Manufacturing process and workability
  • Potential for prisoner employment and qualifications

​Research Overview

Summary of the materials research, insights and proposals​

The functional style and materials currently used in UK prisons can be described as ‘hard architecture’ (Matter, 2017) which is understandable when thinking of the challenging circumstances. However, living in this environment can wear down the inhabitants, being surrounded by materials that are tough, ‘resistant to human impact’ and devoid of comfort. Our research into use, misuse and abuse of the furniture found that there were many different motives for the damage of furniture, but that commonly, feelings of frustration, cries for attention and raging anger were taken out on the furniture, in some cases to the level of ‘flatpacking’ (the total destruction and ‘posting’ of furniture through the cell door’s window panel).

Matter architecture practice produced a report called Wellbeing in Prison Design: A guide (2017) in which they describe ‘hard architecture’ and its effects:

‘The entire environment should not be designed to be indestructible as this tends to encourage destructive activities. Providing elements that require a small degree of care in use, particularly in individual spaces can help foster better connections between people and their environments.’ (Matter, 182)​

To go further, Mike Ashby makes the point in Materials Experience (2014) that, ‘People do not throw away [or destroy?] things for which they have an emotional attachment. (Ashby, 2014). The design of the new furniture aims to have better functionality as well as responding to prisoners’ desires, working to increase the chance of such an emotional attachment. However, how can material changes help to encourage this? Matter put forward that ‘use of soft materials reduces the negative effects of ‘hard architecture’ (Matter, 182), referencing Viktor Papanek’s (1995) work that curves and soft forms can induce a feeling of calm. We have explored materials that can bring any sense of comfort and calm to the cell, as well as more destructible elements that are designed with destruction in mind, a method of ‘target softening’.

‘Target softening’ evolved from Ronald V Clarke’s Situational Crime Preventions’ (1995) whose concept of ‘target hardening’ increases the physical resistance of an object to attack (Clarke, 1995). Target softening is defined by Adam Thorpe as the ‘preventing [of] theft or damage from forceful attack... by literally deflecting and/or absorbing the force of the attach rather than resisting it’ (Thorpe, 2008). In terms of materials and our context of cell furniture design, this also chimes with Matter’s move away from ‘indestructible’ design, we know that prisoners will get frustrated in their cells and destruction can elevate these feelings. Instead of making things ultra-robust, could we add softness that can withstand aggression without breaking or be easily recycled and replaced – for instance, cardboard?

Pathways to Sustainability


There are some simple steps that HMPPS's waste management industry can take to improve recycling. At the moment there are only two or three plastics granulators over the entire estate. In order for HMP to utilise their own materials streams and repurpose their recycled plastics, they would need to have plastics recycling centres at more prisons and supporting infrastructure to make the collection of plastic from all prisons feasible. HMP's current plastics supplier, Plastribution, offers sustainable options like replacing recycled plastic granules with the current virgin PP, however, this would require re-testing plastic product like the existing chair. Also, these options would not have an effect on increasing recycling or developing HMP's recycling system itself, so we advise spending more attention on waste management and recycling in the immediate time frame rather than altering the material.

Immediate & Near Future Implementations

Our proposal to use circular, recycled plastic from Bright Green, is currently in the testing phase. Bright Green plans to work with three local prisons to collect PP and PE plastic waste that they will pay for and recycle. Part of this recycled plastic will go towards creating material for injection moulding, which is being engineered by Bright Green's innovation lab to match HMPPS/PSPI's requirements. This proposed circular model and trail goes towards providing jobs for prisoners in a number of ways. Immediately the extra sorting of material, separating PP and PE will mean that more men are occupied in the prison-based Material Recycling Facilities (MRFs). Longer term, Bright Green would like to open a sorting workshop to sort additional external material.

Waste management and recycling is a promising industry for the prisoners to get involved with because it is an increasing growing sector in the UK and will expand as more legislation around plastics and recycling is implemented. Through this industry, the prisoners could have the potential to learn forklift driving, QC testing and training for Wamitab to level 4.

Design Futures​

There is a large body of research exploring long term innovate solutions for plastics. An example of these next generation materials are Poly(diketoenamine)s (PDK’s), which have been developed by Dr. Brett Helms’ lab in Berkley, California. PDK's are a group of plastics designed for simple and low energy recycling without loosing any properties of virgin plastic. Helms points out that, ‘recycled plastics are low-value commodities due to the residual impurities and the degradation of polymer properties with each cycle of re-use.' (Christensen et al., 2019). This is interesting for prisons because the fire retardant (FR) standards mean that plastic will always be down-cycled as the FR properties cannot be proven on the second cycle. We spoke to Dr. Brett Helms about this research and found out that the process uses hydrochloric or sulfuric acid, meaning that they would not be able to carry out this process in the prisons. For safety reasons it would have to be done externally, but using this plastic could kick start closed loop production systems in the UK. If PSPI were to use this plastic, there would be a large amount being produced, recycled and re-manufactured. Within the prison service we have the opportunity to utilise the high level of material usage by building a circular system that incorporates external industries. This would support HMPPS's and the UK’s journey towards closed loop manufacturing.


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