THE PAPER PROJECT BUILDING WITH LOCALLY RECYCLED PAPER. Jan Samuel Kees van Til

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1 THE PAPER PROJECT BUILDING WITH LOCALLY RECYCLED PAPER Jan Samuel Kees van Til Student number: Delft University of Technology, Department of Architecture 11 th Graduation Lab Architectural Engineering Teachers Monique Smit, Marcel Bilow, Pieter Stoutjesdijk January 15th 2014 Abstract In this technical research paper the possibility of constructing a building out of locally recycled paper is examined. The first part of the research focusses on the production of paper and the basic paper products; tube, corrugated board, honeycell board, sheet and molded paper. It is concluded that it would be possible to produce honeycomb building elements on a small scale such that the necessary machines can be transported easily. In the second part of the research is done by designing the paper building. In this way a specific solution is developed that tries to solve the problems that occur when building with paper. Where possible the design solutions are verified but because literature and reference projects on this topic are very scarce a start has been made with prototyping to put the design to the test. Keywords -- architectural engineering, paper, cardboard, local production, recycling, temporary building, honeycell board, honeycomb board 1. Introduction In today s society there is a growing urge for people to live their lives in a more conscious way. A growing amount of people have realized that what has become our standard of living today is in many ways not sustainable and cannot be justified against the majority of the world population and neither against future generations. During the last century our society has become a consumer s society. Everything has to be produced for the masses on a most cost effective way and be sold to the lowest price possible. This has led from a decentralized production to a more and more centralized production, further and further away from the actual consumers, thereby becoming more and more invisible to the people. Our milk no longer comes from a cow but from a factory. Our meet does not come from animals but from the shelves in a supermarket. With a rising attention in the last decade for environmental problems and a demand for a more sustainable society the problem of centralized production begins to become clear. For those people that wish to live in a more sustainable and conscious way it is hard to find out what is in fact more sustainable. Because we don t know where most of our products come from and how they are made we don t know the impact that they have. A part of a solution to this problem is to have economies on a smaller scale. Not only does it lead to a more sustainable world it also brings back the feeling of connection to the people. Many recent examples can be found that support this feeling of local connection ranging from time banking to the internet of things. Two other examples and sources of inspiration I d like to mention are the tosti fabriek and the mobile fruit press. Both examples use local materials to produce products consciously for a local market.

2 Thinking about sustainability in architecture isn t new either, in the last decade it has even become a major part in most designs. Priority goes out to improving the climate design related aspects to reduce energy consumption, and the embodied energy of the building materials. This is not enough. People want to know where did the building materials come from and what is their actual influence on the environment. Objective The objective of this graduation project is not to research the origin of all building materials, their impact and the impact of their transportation, as this is far too complex. Instead the objective is to give an alternative. Would it be possible to build with local resources and close the waste cycle so people know exactly where their building materials come from and where they will go after their service life so that they also know what the exact impact of their building is? The answer could be building in paper. Because paper is one such recyclable material that could be locally produced and recycled and because it has many more positive properties. 2. Research Methods When looking at the history of papermaking the fabrication of paper has increased in scale. With new inventions that increase the quality and making the process ever more efficient. A consequence of this has been the decentralization of the papermaking industry. Because the goal is to enable the production of paper building elements at a local scale the paper making process will be researched with an emphasis on small scale production techniques. To get an insight in the possibilities and difficulties of using locally recycled paper as a building material it is important to first know the general paper properties. Secondly, it is important to know how the paper can be locally recycled, which machines can be used and what their effects might be on the paper quality. With the knowledge of the first chapters in mind we can then elaborate further and think of a possible building system. Because no solution exists yet this elaboration is mostly done through research by design where possible it is linked to references in practice or in literature. However, literature and building references are scarce so this research is an open elaboration of the possibilities. To test the ideas a start in prototyping the design has been made. 2. Paper Properties Paper is a very diverse material. It is omnipresent in our daily lives. Sometimes it is very valuable as many artworks can prove, sometimes it is worthless as we flush it down our toilets. An average person uses 200 kilograms of paper a year. (recyclingplatform) Negative Impact Even though the material is so common in our daily lives most people do not realize how it is produced and what the consequences are of the production. In both Canada and the United State the paper industry is the third largest industrial polluter to air, water and land releasing over hundred million kg of toxic pollution each year. (Environment Canada, 1996) On a worldwide scale the main source of the 300 million tons of paper produced each year is virgin fibers is trees. Although trees are a renewable resource the wood farms do harm the environment because they are almost always forest with a monoculture and thereby don t provide the plant and animal diversity found in natural forests. Moreover nine percent of the trees used for papermaking come from old growth forests. To save trees recycling is by far the most common way. (Martin, S, 2011) Recycling An estimation of the amount of trees that can be saved by recycling can be made. 1 ton of recycled paper can save 3,3 trees. In the Netherlands this means that in the course of a year 8,5 million trees are saved on a yearly basis. Despite the digitalizing of our world the worldwide paper consumption has risen four times in the last forty years.

3 A lot of effort has been done to make the Dutch paper production more sustainable, and with success. On a yearly basis tons of paper is being recovered from households and companies. Not all of this is being recycled because the fibers brake down more and more after each recycling cycle until they are too short to be usable. They can then be burnt and even the ashes are given a new purpose. (prn) Positive Side Despite the negative impact of the paper industry on our environment this must be seen in perspective with the quantity of paper that is being used and with the environmental impact generated by other building materials. Apart from the obviously critical influence paper has had in our history, making knowledge available to a much wider public. Even today paper is more valuable than it seems. In applications in the building environment cardboard has several advantages over traditional building materials as stated in Cardboard in Architecture (2008) -Low weight. Lightweight materials have many advantages in the building industry, for example saving in transport costs. -Recycling, the ecological advantage is large as the paper fibers are a renewable resource. -Low price. The raw material is very cheap. This generates a margin in the costs of designing and developing an effective product. (Eekhout, M, 2008) Paper is very diverse in its appearances, whether tube, corrugated, sheet, honeycomb or molded all these are a source of inspiration for artists, furniture designers and architects, who make designs mostly based on the paper characteristics: foldability, printability, ability to shape, transparency, tearing, bending or stiff, texturing. (Eekhout, M, 2008) 3. Paper Production Processes The Goal Because the goal is to make a temporary building from recycled paper against a minimal investment. The method to produce the paper building elements should be cheap and with minimal labor. Therefore this research is limited to processes which are almost completely continuous. In this hypothesis we will assume that the machine will be used in many more projects to come and therefore the costs of the machine itself will not be considered. Paper can be shaped into almost any shape. Various production methods lead to their own typical paper products. In this research we will compare six of the most common paper producing methods. The production process can be divided into several stages. All production methods start collecting waste paper followed by a process where water is added called pulping. From the raw pulp the paper can be either pressed into a mold or made into a continuous sheet of paper. Feeding this continuous sheet into another machine will lead to the other different paper products that we will discuss. For every paper product the production process will be discussed as well as the typical applications of the paper product. The final goal is to select one of these production processes to make the building elements Collecting In large scale paper recycling plants almost all the waste paper can be recycled after sorting it into different grades. Those paper recycling plants will output a wide range of quality in their paper. Furthermore they have the ability to strengthen the paper by adding virgin, non-recycled, pulp. Because our small scale recycling paper plant is limited in size and can t contain a sorting section we will only consider one source of recycled paper, namely corrugated cardboard. This corrugated cardboard is widely available as waste, it can either be collected for free from the streets or it can be bought from local waste collection plants or directly from shops and companies that might otherwise have to pay for their disposal services.(fnoi) Corrugated cardboard in the Netherlands has a recycled content of 80%. (vereniging

4 golfkarton) Since most corrugated board contains almost no contaminants like ink it is better recyclable than printed paper. (jaarboek afvalstoffenkaarten 2010/2011, 2010) Although by recycling the paperboard, the fibers become smaller, corrugated board can be made from 100 percent recycled fibers. (Diana, T., Selke, S., 2005) It just needs to be made thicker to contain the same strength properties. implement in a continuous paper making machine. Hydrapulpers exist in wide variety of sizes. Although the smaller sized units are not used in the Netherlands they are still being used extensively in developing countries where it is still more economical to recycle paper on a smaller scale. Pulping Because we have chosen to only use corrugated cardboard as input material for our recycling process we can skip some more complicated steps that would have to be performed otherwise. This means that we don t need a deinking installation, the screening of small contaminants can be done in the pulping machine itself. Example of a small hydrapulper Small contaminants like staples and sticky tape can be removed in the hydrapulper. A mesh at the bottom filters the pulp so only the fibers can pass, contaminants like paper can be removed. At the top of the vat a belt can drag out floating contaminants like sticky tape. Process of recycling newsprint Process of recycling clean corrugated cardboard Images(Venditty, R) For the pulping on a small scale there are two options, a hollander beater and a hydrapulper. A hollander beater can make paper also out of crude materials but it takes longer to process, the capacity is mostly lower. Therefore we will use the hydrapulper, this machine also has a continuous output so it is also easier to The hydrapulper (ricestrawpapemakinge) The papermaking process The papermaking process can be divided into three sections, the forming section, the press section and the dryer section. This is a continuous process where all machines have to be in a linear position relative to each other.

5 The forming section The pulp comes in with a consistency of about 0,5 to 2 %. The most common forming machine is the Fourdrinier method. Hereby the pulp is spread over the forming wire by a headbox. The simplest headbox is the gravity headbox where the gravity is used to pressurize the water and spread it over the forming wire. Gravity fed headbox (ricestrawpapemakinge) Another option is to use the forming cylinder machine. This machine has a simpler layout and can run at a lower speed without the additional measures that have to be taken to ensure an even division of the pulp in the Fourdrinier machine. Cylinder mold (ricestrawpapemakinge) Press section After passing though the forming section the pulp has turned already in a sheet still contains vast amounts of water, in the press section this is reduced to fifty percent. The press section contains several drying felts that reduce the consistency to forty percent. A heavy duty press raises the consistency to fifty percent. Drying section This is the final section of the paper machine where the paper is fed over a series of steamheated drying cylinders where the paper is dried to its final consistency of ten percent. The amount of drying cylinders determines the maximum speed at which the whole machine can run. In large scale paper mills there can be up to 60 cylinders which allow for paper speeds up to 2000 meter/ minute. Before the finished paper sheet is rolled on to the reel it is pressed by a calendar, two smooth heated cylinders, under great pressure to give it a smooth surface. Basic Paper Products After finishing the continuous paper sheets they can be temporarily stored on reels. The sheets then can be further machined and made into the basic paper products. All basic paper products that will be discusses starts with the continuous paper sheet except the method of molding. Molding To mold the paper in its desired shape the dense pulp can be directly poured into the mold. Most of the water can be squeezed out by a hydraulic press but the rest of the water has to gradually come out which takes a lot of time due to its small contact surface. An advantage of this process is its simplicity. Among the disadvantages are: -High density, meaning a lot of pulp has to be generated. -Limited size. To create a building would mean that the molds have to be created in huge quantities. -Uniform elements. Making the mold is complex and therefore a limited amount of molds can be used which leads to repetition of the elements. Existing applications of molded elements:

6 Paper molded bricks.(greenoptimistic) Corrugated cardboard The continuous paper sheet can be used to make corrugated cardboard. Three reels with paper feed the corrugator machine. Two of them supply the sheet as liner materials, the top and the bottom layers of the cardboard and one is formed into a wave pattern to form the middle part, called the medium. Starch is applied to the medium and glued to the liners. The continuous corrugated cardboard is then cut to plates. This is all done using one machine. Paper molded chairs.(designboom) Paper and Paperboard Corrugated cardboard machine. Corrugated cardboard can be used in a wide variety of ways. It can be stacked to form any shape or it can be folded into other paper products such and bloxes. Paperboard is made by layering several sheets of paper on top of each other while they are still in the forming section (wet end), this allows the different paper layers to bond together before the water is pressed and dried out. Paper sheet and paperboard can be applied in their most basic forms. The diffuse transparency of thin paper sheets allows it to be applied in lamps and in windows. Paper is also used as thermal insulation in houses called cellulose insulation. Bloxes applied in an interior wall.

7 Tubes Cardboard tubes are probably the most famous application of cardboard in architecture. The Japanese architect Shigeru Ban has successfully applied cardboard tubes in many of his works, both temporary and permanent. The tubes can be used as structural elements thanks to their strength. Although Shigeru Ban always uses virgin paper as the source for the tubes it would also be possible to use recycled paper if the tubes are dimensioned accordingly. The difficulty with paper tubes are the joints, in many cases the joints become very complex and expensive that they become an obstacle for many of the design principles. To produce the cardboard the continuous paper sheet must first be cut up and rolled on several smaller reels. A series of small continuous sheets is then fed to the tubing machine. Cardboard walls by Shigeru Ban Honeycomb paperboard Mostly known for the application in sandwich doors and packaging products, honeycomb paperboard offers great strength for its weight. The thickness can vary greatly, in contrary with corrugated board, in most products from about 4mm to 100mm but it can even be produced up to several meters thickness as the Molo Softwall proves. Cardboard tubing machine Those layers are then glued together and form a continuous tube that can be cut to the desired size. Honeycomb core & laminating machine There are several ways to produce honeycomb paper boards. Two traditional ways are the honeycomb from corrugated board method and the honeycomb expansion method both shown below. Honeycomb from corrugated board Roof structure by Shigeru Ban Honeycomb expansion method (lightweight honeycomb furniture) A newer method which is especially interesting in architectural applications is the one described below, it produces honeycomb paper panels economically by automated in-line processes, which are made possible by recent developments in the machinery technology. (Engelen, G, 2003) The machine that makes the honeycomb paper boards is fed by 4

8 continuous paper sheets. Two sheets will form the medium, the honeycomb structure, and the other two will form the liners, the top and bottom layers of the board. The honeycomb structure is made by first applying glue in continuous lines to two sheets where the lines of glue of the first sheet are placed in the middle of the lines of glue of the second sheet. The continuous sheets are then cut in strips that are alternately stacked. When this stack is stretched the honeycomb structure is formed. Then glue is applied at both sides of the honeycomb structure and the liners are applied to form the boards. The boards are then cut to their appropriate size are then stacked for storage. The use of honeycomb paper in architecture is far from common. There are however a few examples where it has been used. The best documented is the Cardboard Pavilion from the TU Delft in Cardboard in Architecture (2008). Cardboard Pavilion, TU Delft, 2006 Molo Softwall 4. The Design Design Brief As can be seen in the previous chapter the possibilities of paper in the field of architecture are enormous. To develop a practical building system the design brief has to be limited to a concrete practical application. Location: Sloterdijk The area of Sloterdijk, which was developed from an old, scenic village to an office area with many huge, multinational companies, could stand symbol for the change in our society. Also in the case of Sloterdijk, people have realized that a mono-functional office park, away from any dwelling, does not lead to a successful area. Therefore the city planners want to re-unite living and the practices of the multinational companies. The goal of the city planners is to change the percentage of housing area from 0%, of today, to 40% percent by To achieve this goal a lot has to change, the area has to change from an unpleasant, unfriendly office park to a pleasant livable habitat. Activities At the center of the Sloterdijk area, directly next to the train station there is a bus station. Everyday thousands of people pass this place as a transit between train and bus. At the moment this area is very unpleasant. The atmosphere is dominated by the fly overs of metro and rail road on one side and the office blocks on the other side. Next to the bus station there are a series of shipping containers that function as a cantina for the bus drivers. All in all this location could use a new temporary building that provides comfortable shelter for the people waiting for the bus and a suitable place for the bus drivers to take their brake. The central location creates the possibility to improve the appeal of the whole area. To improve the social connection between people and the location there will also be an exhibition space and a small café to provide people with a place to meet. Design Although this is a very specific description of the design brief the design should be easily applied in other locations and adopt to the needs of other places and people. Therefore the building and designing methods should be parametric. A part of the program is fully climatized to prove the concept could work in most other applications. Because paper is very sensitive to moisture it is unrealistic to build a permanent building, the design will focus on a temporal building that can stand for one year.

9 To be in contrast with the existing surrounding buildings that all have closed, straight facades, the design has to be freeform and have a very open façade. Why Honeycomb board? Because our possibilities of production space and resources are limited a selection has to be made of which type of basic paper product would be the best option to implement in our project. Honeycomb paperboard seems to give a high degree of architectural freeform. It can be bended, it can span several meters and it does not need much manual labor to implement in a building. Furthermore the other basic paper products seem to have more negative aspects. Although corrugated cardboard is slightly easier to manufacture and shares many of the properties of honeycomb board it has some disadvantages over honeycomb board. It allows air to move though the cavities. When stacked it also needs much more material and labor because of its limited thickness. The possibilities of cardboard tubes in architectural applications have already been researched extensively and the architectural freedom is limited because it can only be applied in series or in a space frame type of construction. It is very hard to imagine molded elements in another configuration than where they are stacked. In a stacked position they are not able to span any significant length without the help of other materials. The proposal for a Shipping Container Sized Continuous Paper Making Machine To be able to use local materials in a building the building materials have to be produced locally therefore the production should be transportable to the building site. To see if it is possible to move the entire production line for making recycled honeycomb paperboard conveniently to the building site it has to fit in a shipping container. The following is a hypothetical setup dimensions are mostly estimated from pictures and videos. The size of the shipping container is 12 meter in length and 2.5 meter in width. This is ideal for the linear production line. With about 0,7 meter to allow side access to the machine it would mean a maximum machine width of 1.8 meters. This would mean a paper width of about 1 meter is realistic. The above pictures depict the twelve meter long container with the estimated machine site. From left to right, it starts with the hydropulper(1) which supplies the forming section(2) that makes the sheet which is then rolled to the press section(3) and they drying section(4). The paper is then stored(5) and made into honeycell core(6) and laminated(7) before it is cut(8) and stored. Stacked method As given in the design brief the building should be freeform, and because the building is temporal it should also be manufactured with ease and so with a minimum of manual labor. By stacking the honeycomb boards on top of each other the actual building can be done easily and fast but still allows for a freeform design. The method of stacking honeycomb paper boards has been applied before and has been documented so we can learn from earlier designs. Reference Projects The best documented example is the Cardboard Pavilion at the TU Delft from The pavilion was made with four types of paper construction materials. One of them was the stacked honeycomb panel method. Several observations were made according to the behavior of the honeycomb panels. These

10 observations should lead to improvement of the design. The fire resistance of the honeycell wall was acceptable after impregnation. List of problems: -Creep. Cardboard bends easily under lasting loads. To avoid this any substantial moment forces should be avoided leading to only small spans. -Bending. Tests have shown a large bending effect before rapture of the honeycell board therefore the walls have to be separated from the floor. The stacking of honeycomb panels has also been applied in the Office Interior of Ad Kil en Ro Koster. They value the paper for its exceptional texture and positive sound effect Design features Production The amount of cardboard needed When the cardboard is collected either from companies, where the cardboard is already compressed, or from consumers where it can be compressed during the collection. The compressed bales will typically be about 1m3 with a weight of kg. Knowing the density of the final product, honeycomb board, is about 50 kg / m3 it is possible to make an estimation of the amount of paper bales needed to complete the building. The same applies when the paper is bought from a local paper waste collecting company. The typical price for waste cardboard bales is about E80,- per 1000 kg. (oudpapierprijs) To minimize the manual labor for producing the paper building elements the paper production line is almost completely continuous. There are only three stages. -In the first stage the waste paper is pulped, then pumped to the forming section where it starts to become a sheet, the sheet is dried as it rolls through the press section and the drying section. The continuous paper sheet is then rolled on to big reels. The paper is then temporary stored on the reels before it can go to the second stage. -In the second stage there are four reels with continuous paper that feed the machine that makes the honeycomb paper boards. Two sheet will form the medium, the honeycomb structure, and the other two will form the liners, the top and bottom layers of the board. The honeycomb structure is made by first applying glue in continuous lines to two sheets where the lines of glue of the first sheet are placed in the middle of the lines of glue of the second sheet. The continuous sheets are then cut in strips that are alternately stacked. When this stack is stretched the honeycomb structure is formed. Then glue is applied at both sides of the honeycomb structure and the liners are applied to form the boards. The boards are then cut to their appropriate size are then stacked for temporary storage. In the third and final stage the stack of recycled honeycomb paper boards is fed into a CNC routing machine. To maximize the easy of construction it is necessary to make the freeform building elements by cnc-manufacturing, in the most ideal situation the building elements consist of only one material. If a cnc-router is used the paper plates can be cut to their appropriate size, and shape, furthermore it is possible to remove the top or bottom layer making it possible to generate bending planes. As a consequence the design has to be done in a CAD environment. If a parametric model is developed the 3D digital model can be divided and the building elements can all be cut out with a minimum amount of manual labor.

11 Assembly As the method of assembly should be easy and without much manual labor it is an important input for the design of the boards. The boards should be lifted by one or two unskilled workers. In the reference projects the cardboard boards have been glued on top of each other. This causes problems as the adhesive dissolves into the board that softens and loses its original shape, after the glue has dried the diffusion becomes permanent. (Eekhout, M, et al, 2008) A simple solution is to wait per layer for the glue to dry, this would of course mean the construction time would stretch too far. In the design for the Paper Pavilion of the TU Delft it was observed that during the close down during Christmas, when humanity went up, it lead to deformation of the floor and stresses appeared in adhesive layers. They further state: Highly important is that in the manufacturing process the introduction of residual stresses is avoided to prevent local high stress concentrations. Elsewhere in the book it is stated that it is a general problem when working with cardboard. Failure caused by delamination is often observed, much research has to be done in this field. (Eekhout, M, et al., 2008) Maybe the problem of using adhesive could be avoided by not using any adhesive at all. Instead a system with counterweights a solid top layer and connecting cables between then could keep the boards stable and in place. High compression should not be a problem since we will see further on that the load bearing capacity of honeycomb board is well above the minimal necessary. al) With this fact we can assume dimensions of other spans. Intrusion of floors To protect a floor from intrusion a top layer of solid board can be added. (Eekhout, M et. al) This solid board can be paperboard but will most likely be a more durable type of board. Density and load bearing Density is about 50 kg/m3 but depends on the type of honeycomb board, in this case, craft paper, 20mm thick. Wang, D, Wang, Z, Experimental Investigation into the Cushioning Properties of Honeycomb Paperboard (2008) Pflug et al(2004) measured the compression strength of honeycomb paper panels in a range between 0,25 N/mm2 up to 0,94 N/mm2. If we take the least advantageous measurement and convert to kg/m2 we get at 2500 kg/m2 in effect, only taking the vertical loads into account, this means that we can theoretically stack 50 meters of honeycomb paperboard before it collapses. Bending stiffness In the case of the cardboard pavilion the combination of low bending stiffness of the honeycomb wall and the low density resulted in an unstable situation. A minor force applied at the top could move the entire wall with considerable amplitude. A solution brought forward in Cardboard in Architecture (2008) is to apply girders as seen in the picture (b) below. picture Construction Although honeycomb sandwich panels are being used for decades the information of the strength properties is scarce. (lightweight honeycomb furniture) Therefore a lot of guessing and assuming has to be done before testing the construction. Dimensioning spans With a floor thickness of forty centimeters it is possible to span four meters.(eekhout, M et. In this paper I am proposing another, somewhat more elegant solution. To abolish the need for girders either separate wall elements can be concatenated to provide stability and in addition to that the wall elements can be compressed and anchored to the ground by means of a weight at the floor pulling a solid board at the top layer downwards.

12 pictures Waterproofing Waterproofing is one of the most important properties of the shell of any building in general but especially when it comes to a building made from paper. Paper by itself absorbs water really well. In the production process it even contains a water level of ninety-nine percent. Under normal indoor conditions the water percentage is about 10 percent. If the paper absorbs more water it will become heavier, loses strength and starts to disintegrate, finally becoming pulp. In the design the water resistant shell is divided into the wall segment and the roof segment. The design of a waterproof wall In my design the water resistance plays a big role, it is made possible by dividing the wall in three layers. The first layer is the outer shell, it is meant to keep direct water out. This is done by giving the honeycomb panels a steep inclination and applying a water resistant top layer. Water that falls on the façade is led down by the shingled flaps of cardboard. Any condensation that might occur (possibly by heat radiation to the sky) or other moist at the inside of these flaps can be ventilated dry because the bottom layer of the honeycomb board has been removed and is open for ventilation. The second layer is allowed to be slightly damp therefore this layer cannot be load bearing. It does however provide insulation. Somewhere in the middle of the wall vertical cavities are placed so air can be run through. The damp that does reach through the second layer is then run off by the air and can be dried by the indoor climate system. This system secures any damp to reach to the third layer that provides the load bearing properties of the wall. For the water resistant top layer of the first wall segment the cardboard can be made more water resistant either by applying a water resistant top layer or by impregnation of the cardboard.(tu Delft, 2008) Because in the design the water resistant layer is only applied locally it is easier to apply a top layer. A minimal appliance of waterproofing material is also better to keep the recycling properties of cardboard intact. A small percentage of water resistant cardboard is not a problem in the pulping process of the cardboard industry.(tu Delft, 2008) To decide what type of waterproofing material should be used more research has to be done to their recyclability, how they are applied and their uv-resistance. Roof options For the design of the roof there are several options possible with completely different architectural values. Because the honeycomb boards suffer from crimp over time the momentum forces should be kept small so either small spans only or constructing vault like structures. When it comes to waterproofing the vault like structures is also a good option because there is a natural inclination of the roof. In the case where a flat roof construction is chosen the roof cannot be made from paper which means it is divided from the rest of the building but in being so it can also take a more permanent shape. Another option is to construct the building under the cover of an existing building. In the case of Sloterdijk this could mean that the building location has to be changed to sit under the railway overpasses. pictures Separate Permanent Roof System Integrated Below the Subway Climatization The thermal conductivity of paper itself is 0.05 watts per meter Celsius. The heat capacity of paper is 1.4 kilojoules per kg. (paperonweb) However honeycell board consists for 95% from air so we can neglect the heat capacity altogether and for the thermal conductivity the panels have to be tested because it is impossible to calculate. It is dependent mostly on the amount of air that penetrates the paper, and on the insulation value of not moving air itself. The absence of a water barrier foil will most likely not lead to condensation because of the moisture distributing property of paper. The

13 same principle might work as in cellulose insulation where this property is preventing the buildup of moisture in one area, furthermore it helps to dry the moisture more quickly in the construction as a whole. (Green Fiber, Use of Vapor Retarders) In the design for the building there is a division between different climatic zones. These zones correspond with the needs of the activities housed inside the space. The first zone is outside, it has to be further researched if it is possible to keep cardboard furniture outside year round, and maybe a division between summer and winter has to be made. The second climatic zone is a semi-climatized zone, it functions as a buffer for the third, fully climatized, zone and allows minor adaptations in temperature according to the outside temperature. The third, and fully climatized, zone houses spaces where people stay more permanent. The installations will be placed in a central position in the building. Activities that are dependent on installations will be placed around them, such as a kitchen and toilets. Other installations like electricity sockets and venting ducts should be integrated in the structure where possible. If integration is not possible, then separation, in a way that they can be easily taken away and recycled separately from the paper building. pictures Flame resistance As tests have proven, a chemical flame retardant can be added to the open cell structure of honeycomb board. The test result was very positive, even after five minutes the specimen did not ignite. The flame resistance of honeycell board can be marked as moderate so only the open cell structure has to be impregnated. (Veer, F., van Kranenburg, C., 2005) Flooring Because of the lightweight nature of the honeycomb structure the building does not need to be founded. A plastic foil could be put under the building to prevent moist from entering from the ground. Then a few layers of honeycomb board have to be placed as insulation and on top of them a type of hardboard has to be placed to prevent intrusion. Openings One could think of an inventive system of windows where a layered combination of semitransparent sheets passes through daylight and an external coated honeycomb board shutter can prevent rain from falling in. Achieving a proper relation between inside and outside must involve full transparency; thereby the use of glass is inevitable. The glass can be detailed to deflect precipitation directly. The same assessment has to be made in the case of doors. pictures Installations Prototyping Because literature research does not give enough data to be able to give a realistic prognosis of how the proposed design is going to act in real world circumstances. Even the proposed production processes based mostly on assumptions. The design can only really be verified by prototyping. In the best case of prototyping the whole process of production and design has to be simulated. In this research paper the prototyping described will not involve the production of the honeycomb production method. It will only point toward a possible setup of the cnc-router and associated software. The output geometry is scaled and simplified. But the whole process

14 is designed such as it can be scaled up and expanded to full scale situations. The prototyping will in principle involve the same processes as in full scale. To keep the costs down a custom made cnc machine was made specifically for this project. To produce the full scale building the same thing can be done at a fraction of the costs of an industrial cnc-machine. The geometry is designed in the CAD program rhinoceros. With the plugin, Grasshopper for rhino, the geometry can be sliced in the desired thickness which is the same as the cardboard boards. The contours of the slices can then be placed on the horizontal plane, tags can be added automatically for later identification of the parts. From rhinoceros the contours are exported as dxf files to be imported with HeeksCNC an open source CAM software. Here engravings, full cuts and scrapings can be programmed to their appropriate sequence, speeds and depths. HeeksCNC can output the code that will go to the machine. Before the job is started it is a good idea to see if everything is correct in another open source program, OpenSCAM, which can simulate the router paths. When the code is finally send to the machine a program called GRBL translates the code to motor pulses. Geometry imported in heekscnc Simulated program using OpenSCAM The cnc router after finishing its job. Screenshot of rhinocerous, freeform and sliced. Contours of the slices placed in plane. An assembled simplified scale model of a part of the design.

15 5. Conclusion & Discussion From the two parts that make up this research paper conclusions can be drawn regarding the main objective. In the paper production we know that it is possible to make new paper products in a relatively simple production method. Because the paper fibers degrade further after each recycling cycle the recycling of the building cannot be repeated and the paper building therefore ends up in the normal industrial recycling plant. It is also possible to conclude that the production of respectively, pulp, continuous paper sheet, honeycomb board and the building elements is possible at a local level and that the necessary machinery fits in a standard shipping container. For the second part of the research only an assumption can be made that it would be possible a building out of paper honeycomb boards. Not enough data could be found to confirm if everything would work the way it was designed. Further prototyping might be able to prove whether or not it would indeed be possible to build in paper. answered by the packaging industry as they have very specialized knowledge. These questions are mainly about the measures against humidity. The relation has to be found between humidity and strength. What would be the best material to apply as waterproof layer on the shingles regarding to uv-light, recyclability and ease of application. Another question remains if the assumption that the first and second layer of the wall will dry by themselves in dry weather. The effects of sagging from the humid part could not be predicted. To find the right dimension of the wall layers it is important that the insulating value of honeycomb board is found. Further research has to be done in the exact production of the building elements. A fully parametric model of the façade should be developed and the amount of waste paper during production should be kept to a minimum. When the building is further detailed more questions will come up and have to be answered. Difficulties solved in the design In the proposed design several solutions were designed to solve problems that occurred in earlier honeycomb layered structures. These original solutions still have to be put to the test. Delamination is a common problem and might be tackled by tensioning the boards in vertical direction the same accounts for the deformation during the gluing process as no glue will used. Creep can be handled by minimizing the spans and using vaulted structures. Water is kept out by a layered outer wall where the first layer keeps out the direct rain by a shingled pattern of overhanging waterproofed flaps. The second layer can absorb the outside moist but provides insulation so the third section can ventilate the humid air and provide structural stability to the façade. Further research Some problems and uncertainties still exist and have to be further researched and tested. Many of the remaining questions might be able to be

16 6. References Literature Engelen, G., 2003, Die Homag AG geht innovative das Thema Leichtplattenbau an Homag Press Release F.A. Veer and C. van Kranenburg, Vergelijking van de brandwerendheid van het Bee Wall binnenwandsysteem met verschillende afwerkingen, Delft, 2005 Environment Canada (1996). "National Pollutant Release Inventory, 1996." npri/#factsheets Martin, Sam, Green Fiber, Use of Vapor Retarders, l_documents/vapor_retarder_use.asp Prn, De kringloop van papier en karton, jaarboek afvalstoffenkaarten 2010/2011, 2010 Diana Twede, Susan E. M. Selke, Cartons, Crates and Corrugated Board: Handbook of Paper and Wood Packaging Technology, 2005 Recyclingplatform, Papier & Karton karton Vereniging golfkarton, Paper Recycling Technologyhttps:// Venditty, R, Presentation108HOdetailedpart2.pdf Ricestrawpapermakinge /hydropulper.html Greenoptimistic - /paper bricks created from recyclingwaste/#.utwal_tulju Designboom and future traditions by lei christophjovana of innovo design/ Oudpapierprijs - Paperonweb - Fnoi, hoe recylen we papier - we papier.html