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 XILOFANES: BENCH DESIGN


The planning of a wood bench has demanded a problem of attitude in the comparisons of a complex topic. The difficulty consisted of having to make less than a dedicated literature that review of the production was not one, of having to make less than an excellent example, of having to make less than a paradigm, not only formal, of reference.
It is not succeeded to think next to a designer or a planner that has legacy its notoriety to the design of a bench, that is often perceived like an invisible object: us other does not expect that is comfortable and pleasant to look at itself. It has seemed indispensable to decrease itself in a kind of intimate suggestion, to try to insert the physical and psychological relationship with this object in the own shape forma mentis: to connect the new argument, never inquired, to the nodes of just the cultural carpet.

The first consequence of this attempt has been to imagine an ideal positioning, traced in the Mediterranean, marine context, reason for which the possible one uses of circular section wood has been discarded, that it would have led back to alpine atmospheres. The choice of this habitat has not prevented to try some virtual installations in some continental cities, also remaining in European within.
The plan started from the choice to partially renounce to the social adhesive function in order to inquire the individual dimension of sitting as a moment of aware leisure, as a privileged emplacement of watching: attempt at the same time to put in evidence the double possible reading of a public object but center of a private gesture.
The study has been translate in the search of a wrapping shape that it was connoted like shelter but that, at the same time, offered an escape space; the tipology of the sailing boats interior seemed to be the model that better conciliated this feeling with the use of the wood. This last one has been arranged, according to curved lines, in parallel and overlapped strips to form one webbing to plating. In agreement with individuality desire, the general dimensions have been reduced until concurring the comfortable sitting of two persons.

The title it of the thesis – Xilofanes: bench design – reveals the scope of the job: to tie the requirement of formal originality to the innovation in the research and the culture of the material field and, contextually, to verify the effective realizability.
The collaboration with IVALSA institute (Institute for the Valorization of the Arboreal Wood and the Species) of the C.N.R. has carried to concentrate the study on the employment of small dimensions lumber , in the within of a plan of valorization of the national production, inherent the local arboreal species. The design has been then developed holding the criteria of sustainable uses of the wood, making therefore particular attention to the constructive method, to the reduction of the hill, to uses of low impact varnishes.
The executive phase and the prototype construction, has been developed with the company Tecnolegno Fantoni that has placed like tie the realization of one low cost bench to propose the local administrations. A bench that has been studied in two versions, even if with the same formal genesis; the first version answers to the requirements of control of the production costs of the company, the second one constitutes the result of a search that has hit to the logical of the industrial processes and the criteria of marketing becoming a design exercise.

The reasons of wood
In relation to the attempt to resolve some problems legacies to politics of the raw materials available ones – like the risk of exhaustion of the same ones –, the energetic cost and the acclimatize them impact of the production processes and recycling, the use of the massive wood and of the derived products, above all in the industrialized countries, is in constant increase.
The first advantage of the use of this material is its abundance and its complete renewable where the previewed coltural indications from corrected plans of forest management are put into effect.
If the lumber captures do not exceed the produced medium increments of wood mass between two successive participations, it is possible to maintain the stability of the forest making it become an inexhaustible source of raw materials.
In the industrialized countries grows more wood than it's consumption and the greater part of the refuses of the industrial workings and the recovered lumber are recycled or used in order to produce energy.
In Europe, as an example, it comes only captured 65% of the increase of the forests. The Italian forests introduce a mass of lumber of beyond 1 billion of m3, mass that grows annually of approximately 30 million m3.
Such biological production comes only partially used (access difficulty, respect of protect areas, insufficient economic value, etc): in fact in average it is used every year approximately 9 million m3, that minimally cover the raw materials requirementses, used from the Italian industry, for the production of sawed wood, panels, paper, etc.

Another advantage deriving from the use of this material is the low demanded energetic cost to product it.
The energy in order to obtain a ton of product is of 1.000 Kwh/t that, if confronted to the energy demanded from concurrent materials is extremely reduced: the steel production, as an example, needs of 4.000 Kwh/t and the aluminium until 70.000 Kwh/t.

The use of the wood, although indirectly, contributes in determining way to the emitted carbon dioxide reduction in the atmosphere from years of materials made up of fossil fuel massive use.
The forests and the produced lumber, in fact, represent the carbon tanks that the trees absorb and withhold through the photosynthesis.
Also after the discouragement and the sawing, the carbon remains stored in the wood and in the derived products that, at the end of the life cycle, can be recycled or taken advantage of as biological fuel going to replace fossil fuel and reducing the responsible gas emission of the greenhouse effect.
The convention of the United Nations on the climatic change attributes great importance to the forest basins.
The countries participants, gathered to Marrakech in November 2001, have adopted norms and line-guide in reforestation matter, deforestation and management of the forests.
The role that the wood covers in attenuating the climatic change is emphasized also in the Sixth Program of environmental action of the UE, in which it asserts that the use of the wood and the derived products should be mainly overworked in virtue of the ability to this material to absorb carbon.

Small dimensions lumber
Part of the research in the field of the technology of the wood is oriented to resolve the problem of the valorization and of the use of the small dimensions lumber and the wood productions of smaller quality, often coming from operations of the forest maintenance.
Institute IVALSA of the C.N.R. faces these thematic ones with particular attention to the local arboreal species.
In Tuscany, the wood production comes especially from coppice forests, in which the renewal of the trees is entrusted to the stumps remained after the cut (agamic reproduction), and only in smaller measure from high forests, in which the reproduction it happens through plantation or seed.
The coppice forest produces above all lumber that generally does not catch up the minimal dimensions for the working to saws.
The dimensional limit of the working to saws is what it identifies the lumber of small dimensions and insufficient value: the minimal diameter in tip of 13 cm. and length of 1 m.
The trading truth imposes, to here of the definitions, a median diameter of 22 cm. Also this type of wood production is in constant increase: the search has been addressed towards the study of the possible technologies that they can find an industrial reply, so as to start a production on wide scale of manufactured articles constituted from this type of lumber, to forehead of one great amount of wood imported from the foreign country.

Localization of the problem: the chestnut tree
The chestnut tree constitutes one of the more important resources of the Italian and Tuscan forest patrimony by extension and produced amount of lumber.
On the base of the Regional Forest Inventory of Tuscany data, the prevailing kind of forest of the region is represented from the simple coppice, with nearly 102.624 hectares, par to 58% of the total.
The presence of high forests is instead limited: little more 9. 000 hectares of irregular forest formations and coppices in conversion, par to approximately 5% of the total.
The perhaps more important characteristic of the chestnut tree, if confronted with other wooden species usable in analogous employs, is its good natural resistance in the comparisons of the attacks of wood feeders organisms: for this reason it can be used in order to realize manufactured articles for exteriors also in touch with the ground.

The design evolution
On the base of these premises – which beyond to the cognitive value they have assumed the role of definition of the action field –, has been developed two hypothesis based on the same topic whose fate has been decided from the manifacturing company.
The first hypothesis is characterized from articulater lines, surfaces without intermediation of passing light and from curved profiles on two different plans.
The complexity of the shape, however, would have demanded too much onerous investments to propose it with an accessible price to the communal administrations.
It has been therefore transformed in a formal and technological testing ground imagining it constructed with the systems – currently in phase of experimentation – of the liquid wood and the welding of the wood.
It has been decided then to aim to an hypothesis of realizability only for the second hypothesis studying the technology with instruments currently at the field industry's disposal and trying to save and to make the design congruent to the local production of wood applying in other words the filters of economic feasibility of the industrial design.
The result has been a more rational bench from the constructive point of view and characterized from one risen of wireframe aesthetic, semi-transparent.
The arms are repeated equal until earth, where they are connected from a curved element. They are alternated, low, to connection elements that guarantee the continuity of the material; while, in the advanced part, they are alternated to the currents of the back disposed oblique regarding the vertical one in order to obtain the necessary inclination.
The sitting, inserted laterally between two arms, has been composed from two carrying elements with variable section and from a plan constituted from parallel tablets.
The continuous comparison with the technical and scientific interlocutors, institute IVALSA of the C.N.R. and the company Tecnolegno Fantoni, has produced to numerous adjustments of route and modifications to several the elements of the bench.
The necessity to contain the costs has imposed the reduction of the component pieces number.
The curve of the arms – initially extended for all its length –, has been interrupted at 90 millimetres from the posterior limit of the same arms agreeing again to a straight part.
This has concurred to more conform the four currents of the back rendering orthogonal the joint with the arm and not modeled on one curve.
The choice to use lumber of small dimensions and local origin, mainly Tuscany, has involved other changes to the design.
Initially they had been previewed elements of thickness 50 milimeter.
Considering the margin demanded from the first planing, would have been necessary crude tables at least of thickness 55-60 millimetres, dimensions that not reflect the normal production of Tuscany lumber.
The members have been reduced until one thickness of 35 millimeters, obtainable from crude tables of thickness 40 milimeter.
The consequence has been, to parity of dimensions, the increase of the number of the arms and of the connection elements that, aesthetically, has produced a thicken of the full - empty weft.
The assemblage has been realized through superimposition of elements connected with threaded bars of stainless steel.
This constructive method has allowed to restrict the use of the glue, that has become necessary only for the construction of the front beam of support of the sitting, to variable section, and for the connection of the tablets that constitute the sitting to the carrying structure, ulteriorly fixed with stainless steel lives.
The used polyurethanic monocomponent glue, also introducing a sure degree of toxicity to the liquid state, becomes inert and toxicologically not dangerous to the dry state.
It is moreover possible to burn wood glue with this type of adhesive in a whichever controlled incinerator.
The bench directly supports to earth with two arms and a connection current.
The elements to contact with the ground have been previewed as substitutable pieces.
It is worth the pain remembering as the root cause of deterioration of a bench is not from searching in the decay of the materials with which it has been constructed, but in the consequent damagings to vandaliche actions.
The anchorage to earth has been realized with a passing screw.
For the paint job has been chosen a not toxic filler, containing an amount of resin inferior to 12%.
This type of varnish, applicable to paint-brush or bath, is antifungal and antimildew, turning out adapted for uses in exteriors.
The obtained pigmentation concurs to obtain a range of colours that maintains the wood grain very visible.
The edges have been worked with the technique of the "break of the angle", minimal condition in order to re-enter in the safety norm.
The sitting plan is tilted of approximately 5° regarding the horizontal plan for ergonomic reasons and in order to make to flow down eventual water, while the back is tilted of approximately 10° regarding the plan of the sitting.


Text and images are extracted from the thesis of Bernardo Monti: Xilofanes. bench design discussed in April 19th, 2004; relator prof. Lino Centi, co-relators Michele Brunetti and Michael Ribardiere, Technology of the Architecture and Design Department "Pierluigi Spadolini" (TAeD), Faculty of Architecture in Florence, Italy, a.a. 2002-'03.


Bernardo Monti
bernardomonti@centonuvole.com

Istituto I.V.A.L.S.A.
www.ivalsa.cnr.it

Tecnolegno Fantoni
www.tlf.it

Text by: 
Bernardo Monti 
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