Recycled glass project links students with industry.

David Puxley(*)

This article describes how an annual recycled glass competition involving the University of Central England has helped to strengthen the links between education and industry and increase students' awareness of recycling issues.

In 1995 Birmingham City Council

initiated a Recycled Glass Competition with the University of Central England in Birmingham. This fortuitously coincided with the aims of the Department of Three Dimensional Design to increase student awareness of environmental issues, and actively participate in a 'live' or realistically structured project.

The competition, which was directed towards second year BA (Hons) students specialising in ceramics and glass, required the design and production of a recycled trophy for an award presentation, ideally for organisations which had successfully encouraged or facilitated the recycling of glass containers.

The sponsor of the Trophy Competition, British Glass Recycling Company, which ultimately took over the organisation of the competition, was represented on the judging panel by Colin Clapshoe and initially Wendy McCarron, later to be succeeded by Andrew Parkinson.

The introduction to the project created a somewhat festive spirit, as certain students considered that the most effective way to research the intricacies of recycled glass would be to purchase the bottles, drink the contents and then contemplate the design issues at a later stage.

What became clear from the outset of the competition, however, was the number of misconceptions held about the recycling process, from collection and colour separations to costs and contaminates. In addition, few had appreciated that bottle banks would also accommodate glass jars and that when recycled bottles were repeatedly re-melted, the new product was still as durable as the original article, with no deterioration in quality or appearance.

Although the student group had some previous experience of soda-lime glass, notably with the glass blowing activities, the melting temperature and working properties of the glass in the UCE furnace differed considerably from the SiO(2), Na(2), CO(3), CaCO(3) mix used for industrial mass production.

As the characteristics of the furnace and bottle glass were fundamentally different, it was decided that the major thrust of the project should be focused on kiln formed glass rather than blown glass.

Exploratory stages

The exploratory stages embraced a wide range of processes which included slumped, sagged and fragmented glass together with sand blasting techniques, but the initial experiments related to the firing of unsupported glass, and the effects that could be obtained by the bending and deformation of wine and beer bottles, at comparatively low temperatures 700 deg C - 750 deg C.

While some unusual shapes were produced, there was a general realisation that greater control of the material was required to produce specific designs rather than ad hoc results. Consequently, further developments related mainly to mould formed designs.

Choosing materials

The choice of materials for mould making was essentially governed by the intended temperature range, the repetitive demands of the moulds and the separating qualities of the cast from the mould. In practice, the most commonly used materials proved to be fired clay, plaster, crystobolite and a variety of sands, together with odd pieces of metal used in a supporting role.

For uncomplicated slumped forms, where the glass is simply bent over a former by the weight of gravity, the most convenient material was found to be biscuit fired clay, used either as a cast piece or as a slab of clay formed to the desired shape. Due to the nature of the material, this type of ceramic former can be used repeatedly and is capable of withstanding temperatures well in excess of 1000 deg C.

For more complicated shapes involving incised/relief decoration or structural undercuts, the rigidity of the ceramic material is a disadvantage, as it lacks the flexibility to release the cast or allow ease of separation. In comparison, potter's plaster, which is employed extensively in the department for making prototypes and ceramic moulds, provides a greater versatility as a glass moulding material. When used without the addition of other ingredients it has a tendency to fragment at temperatures of between 750 deg C - 900 deg C, enabling complex forms to be easily removed.

The obvious disadvantages are that firstly, the mould can prematurely disintegrate and flood the kiln with molten glass and secondly, plaster is prone to sticking and is difficult to remove from nooks and crannies, textured backgrounds or intricate surface patterns.

However, a balanced mix of plaster and crystobolite(**) tends to offset the cracking and sticking problems associated with plaster. Yet, even this remedy has its disadvantages, as crystobolite is expensive and has to be shared judiciously among a group of 24 students.

In addition to crystobolite, both silver sand and red builder's sand have for a long time proved invaluable moulding materials, together with the empirical use of ball clay and china clay, as variable additives to the plaster mix, especially at the firing temperature in excess of 750 deg C.

Glass colours

The choice of colour for the trophy was left entirely to the students' discretion. Initially there was a temptation to use all three recycled glass colours, flint, amber and green, but over a period of time an overall preference was shown for a combination of flint and green. Although small quantities of blue glass can be mixed with green without detrimental effects, it does cause problems for the recycling process, mainly due to its chemical composition. For this reason blue glass was omitted from the design brief.

Additional colours and decorative elements, particularly with the clear glass, were achieved by the use of enamels and lustres. In practise the lustres proved less popular in application due to the material costs and the delicate nature of the colours, which often appeared subtle to the point of obscurity.

The enamels, in comparison, produced some very positive results, not only in the strength and variety of the colours, but also in the range of the firing temperatures, 500 deg C - 750 deg C, depending on the effects and the vagaries of the kilns.

Design development

During the four years that the competition has been running, there has been a noticeable progression in the design development, from a very literal interpretation in the early stages, with bottles and jars remaining vaguely recognisable, to a far more abstract and sculptural resolution in subsequent years.

While this design progression has been partially due to students not wishing to copy or emulate their predecessors' work, the undoubted influence has come from Colin Clapshoe and Andy Parkinson of BGRC, in the increasing breadth of the design briefing and the sensitivity of judgements in selecting the annual winners.

Linking education and industry

Since the start of the competition, the direct links between education and industry have been further strengthened by the advent of a design placement within the glass recycling sector.

One UCE student, Gillian Swales, who was BGRC Trophy Competition winner in 1996, recently undertook a six week placement in the design department of Rockware Glass before embarking upon an MA in Industrial Design at Birmingham.

The project, which was to carry out investigative research and design into a new soft drink container, received very positive feedback from the company which has since expressed an interest in future collaborative schemes, both with Gillian and the University.

It is envisaged that with the backing of British Glass Recycling Company, further links with the industry will be established, ideally to benefit the realms of product design and applied research into glass recycling while, of course, still maintaining the challenge of the glass Trophy Competition.

The seeds of opportunity exist and can undoubtedly grow in the right environment!

(*) David Puxley, University of Central England, Birmingham, UK. Fax + 44(0) 121 331 5821.

(**) Crystobolite is a specific casting material often used by jewellery manufacturers.