THE CREATION OF A LOUNGE CHAIR DESIGN THAT INTEGRATES
PRINCIPLES OF THE MODERN MOVEMENT IN FURNITURE
DESIGN AND CARRIES IT FORWARD
INTO THE 21ST CENTURY
Dustin Dewey Wickham
A Plan B project submitted in partial fulfillment
of the requirements for the degree
MASTER OF SCIENCE
Darrin Brooks, MFA Steve R. Mansfield, MArch
Major Professor Committee Member
Paul Schreuders, PhD JoAnn Wilson, MArch
Committee Member Program Director
UTAH STATE UNIVERSITY
Copyright © Dustin Dewey Wickham 2009
All Rights Reserved
The Creation of a Lounge Chair Design that Integrates
Principles of the Modern Movement in Furniture
Design and Carries it Forward
into the 21st Century
Dustin Dewey Wickham, Master of Science
Utah State University, 2009
Major Professor: Darrin Brooks, MFA
Program: Interior Design
The evolution of the Modern Movement in furniture design began in the mid 19th century and has yielded many well-known chair designs. There is no reason to suppose that this evolution will not continue into the 21st century.
The purpose of this project and accompanying paper is to research notable advancements in the Modern Movement and create a design that incorporates them. The resulting design will be in the tradition of the movement but will further incorporate lightweight methods into the creation of a lounge chair that is knock-down and packaged compactly for shipping or storage. Successful designs of the past were studied and their incorporating principles were noted. These principles were directly applied to the design project to ensure that the product could be inexpensively designed, manufactured, packaged, and shipped to the end user.
The design process was followed through phases of analysis and synthesis while continual feedback yielded 13 versions of the design. The final ½ scale study model consisted of a planar form of 1/16 in. recycled plastic sheeting less than 2 ft. x 4 ft. in size.
It was found that the resulting planar form could be rolled and packaged in a compact container and shipped inexpensively. Once received, the consumer could then assemble the 2D sheet into a 3D form. The assembled design was comprised of several compound curves bio-morphically arranged to create “tensioned loops” that comprise the three sections of seat, backrest, and footrest. These loops were designed to be held in tension using inexpensive cord laced similarly to common shoe lacing.
The resulting object naturally conforms to the varied physical geometry of the individual. A system was devised so that the angle of the backrest is adjustable from upright to fully reclined.
Packaging options were developed and evaluated based on varied physical requirements, dimensional weight, and volume. Data was collected and compiled relating to currently available shipping methods and variable costs associated with each.
The forms and packaging were nearly completely developed. Future research may include studies into structural integrity, variable tensioning techniques, alternative materials, and color and finish options.
This paper is dedicated to my grandfather, Walter C. Wickham, whom I endlessly admire for his honesty and integrity. He has taught me by example to make the most of any task by staying positive and enduring even that which is adverse. He is a shining example to me.
I would like to thank Darrin Brooks, Steve Mansfield, and Dr. Paul Schreuders for their willingness to serve as advisors on my graduate committee. I offer a special thanks to Darrin Brooks as he has served as a father-figure looking over my years of higher education. I owe acknowledgment to Polly Richman for her much appreciated critiques and for sharing her vast knowledge of technical writing and the English language. Additional thanks go to my family, friends, and colleagues for their help and encouragement. Lastly, I cannot offer enough thanks to Carol Nicholas for her academic support and enduring positive example. She is truly a great friend.
Dustin D. Wickham
LIST OF FIGURES x
Problem Statement 1
REVIEW OF LITERATURE 3
What is Design? 3
Historical Studies of Design Classics 5
Knock-Down Packaging and Mass-Production 6
Structural Design in the Form of Cantilevered Chairs 7
Compound Curves 9
Single-Piece Construction 11
Initial Concept 13
Development of Form 14
Creating “Tensioned Loops” of Planar Material 15
“Front Foot” Concept 17
Seat Tabs for Backrest Support 18
“Rear Feet” Concept 19
Addition of Footrest Loop 20
Introduction of Creasing 22
Side Planes for Footrest Section 24
Methods to Facilitate Tension 25
Conversion of Form to Computer Aided Drafting (CAD) Software 27
Recline Adjustment Methods 27
Headrest Component 30
Side Planes for “Rear Feet” 31
Form Revisions for Anthropometric Compliance 31
Explanation of Material Options 32
Methods Considered for Fabrication 35
Injection-Molded Polymers 35
Plastic Sheeting Cut Using CNC Technology 36
Compact Packaging Plan and Marketability 37
Packaging Configurations 38
Shipping Options for Marketability 41
Resulting Design 47
“Spinal Gap” Theory 52
Structure & Tension 53
Aesthetic Issues 53
Alternative Types of Seating 53
LIST OF FIGURES
Figure 1. Model No. 14 by Michael Thonet. 7
Figure 2. Brno chair by Ludwig Mies van der Rohe. 9
Figure 3. LCW chair by Charles and Ray Eames. 10
Figure 4. Stacking Chair by Verner Panton. 12
Figure 5. Historical Comparison of Furniture Design Principles. 14
Figure 6. Illustration of “Tensioned Loop” concept. 16
Figure 7. Annotated Form Study of Version 2. 17
Figure 8. Annotated Form Study of Version 3. 18
Figure 9. Annotated Form Study of Version 5. 20
Figure 10. Annotated Form Study of Version 6. 21
Figure 11. Annotated Form Study of Version 9. 23
Figure 12. Section View of “Tensioned Loops” Showing the Positive Effects of Crease Lines 24
Figure 13. Annotated Form Study of Version 11. 28
Figure 14. Photo Showing Recline Adjustment System. 30
Figure 15. Variations of Form Toward Anthropometric Compliance. 33
Figure 16. Packaging Option 1. 39
Figure 17. Packaging Option 2. 40
Figure 18. Packaging Option 3. 41
Figure 19. Packaging Option 4. 42
Figure 20. Size, Weight, and Cost Comparison of Packaging Options. 43
Figure 21. Size and Weight Comparisons to Existing Lounge Chairs. 44
Figure 22. Illustrations Showing Persons of Various Heights in Relation to the Lounge Chair. 48
Figure 23. Perspective Illustration of Finished Product. 49
Figure 24. Orthographic Views with Dimensions. 50
Figure 25. Illustration of Assembly Steps. 51
Figure 26. Study Model of Version 2 58
Figure 27. Study Model of Version 3 59
Figure 28. Study Model of Version 4 60
Figure 29. Study Model of Version 5 61
Figure 30. Study Model of Version 6 62
Figure 31. Study Model of Version 7 63
Figure 32. Study Model of Version 8 64
Figure 33. Study Model of Version 9 65
Figure 34. Study Model of Version 10 66
Figure 35. Study Model of Version 12 67
Figure 36. Study Model of Version 13 68
Figure 37. Layout of Version 1 showing separated seat and backrest sections 69
Figure 38. Annotated Layout of Version 1 70
Figure 39. Annotated Layout of Version 2 71
Figure 40. Annotated Layout of Version 3 72
Figure 41. Annotated Layout of Version 4 73
Figure 42. Annotated Layout of Version 5 74
Figure 43. Annotated Layout of Version 6 75
Figure 44. Annotated Layout of Version 7 76
Figure 45. Annotated Layout of Version 8 77
Figure 46. Annotated Layout of Version 9 78
Figure 47. Annotated Layout of Version 10 79
Figure 48. Annotated Layout of Version 11 80
Figure 49. Annotated Layout of Version 12 81
Figure 50. Layout of Version 13 82
Figure 51. Explanation of Layout to Assembly 83
*All figures were created by the author.
The Modern Movement in the history of seating design began in the mid 19th century. Since then, designers have continued to introduce new concepts that enhanced the evolution of modern seating. These enhancements were formulated for a number of reasons. Some designs offered advancements in material characteristics while some introduced new aesthetic styles. Some designs appealed to functionality and some merely existed for artistic statement (Fiell & Fiell, 2002). This evolution necessitates development as a continuation of the Modern Movement.
The purpose of this project was to design a lounge chair that continued the evolution of the Modern Movement into the 21st century. The project utilized principles documented from specific past designs and implemented additional concepts to make it a viable product available to a wide range of consumers.
Three objectives were developed for the purpose of this project. First, this project will examine specific principles demonstrated in historical chair designs throughout the evolution of the Modern Movement. Second, a chair design will be developed that will incorporate aspects of the principles examined. Lastly, the resulting design will integrate the use of lightweight materials and specify a compact packaging plan.
REVIEW OF LITERATURE
The initial phase of the project included a period of research on current design processes. This information was obtained from various texts which outlined principles of design and refinement. Additional sources were used from interviews and articles of well-known designers of the past.
This review of literature specifies a definition for design and presents the steps of a common design process. Various types of design process limitations are also defined. This review also includes specific historical studies that highlight some of the most important pieces of modern furniture as well as the characteristics that have made them successful.
What is Design?
A keyword search for the word design will yield many variations on subject. The reasoning for such a broad result is simple. Design is everywhere and in everything that surrounds us. We can think of every object having some level of design whether perceived as good or bad. “Whenever we design something, we do so in order to get an intended result. Along with that we get unwanted results” (Pye, 1964).
In order to answer the stated question, we can look to one of the seminal design teams of the 20th century, the husband and wife team of the Charles and Ray Eames. The Eameses’ design approach was simply to arrange elements in the best way to accomplish a specific purpose (Dachs, Hintze, Remmele, & de Muga, 2007).
Laurel Saville follows up this idea by pointing out that there are adversities to design that we call constraints. He specified the following types of limitations: client needs and desires, needs defined by human anatomy, and laws of physics (Saville, 2006). The Eames’ highlight the idealistic view that good design consists of working within constraints while “getting the most of the best to the greatest number of people for the least” (Dachs, et al. 2007).
In order to execute design successfully, designers must alternate between considering constraints and executing ideas. This process is iterative in nature so many designers adopt a system of approach that facilitates feedback between steps.
One design method that was researched is the Kilmer Process. This process breaks design into analysis and synthesis with four subcategories in each. The analysis phase is comprised of commit, state, collect, and analyze. The synthesis phase is made up of ideate, choose, implement, and evaluate. It is through the advancement from analysis to synthesis that design solutions are realized and subsequently implemented. This sequential system is repeated by way of a feedback loop until the intended outcome is achieved (Kilmer & Kilmer, 1992).
Historical Studies of Design Classics
Many factors exist that have made designs of the Modern Movement successful in the past. Through the presentation of several historical studies, this section examines such factors and draws a direct correlation to the successes of past products. Furthermore, this review of literature also examines material choices for some classic furniture pieces and explains how such criteria have contributed to the success of those designs. It has been noted which aspects of each historical study have been directly applied to the synthesis of the project that accompanies this paper.
Knock-Down Packaging and Mass-Production
Michael Thonet enjoyed much success as a designer in the mid 19th century. His use of the bentwood technique helped secure him as an influential designer for many that would follow him. Fiell & Fiell (2002) point out that Thonet’s chairs were really only modern in their manufacture, since they kept the same aesthetic of many chairs that already existed at the time. His products were easily shipped due to their ability to be disassembled and packaged flat. This principle is known as knock-down (KD) furniture.
Furthermore, Thonet embraced the idea of mass-production. He designed Model No. 14 which sold over 1,000,000 units per year for the first 40 years of its existence. This chair sold more units than any other chair in history and is still being produced today (Gandy, 1981). It is also known as the Vienna Chair and can be seen in Figure 1.
Thonet perfected a new manufacturing process, through the steamed bentwood technique, that revolutionized the Modern chair (Fiell & Fiell, 2002). Although he was not the first to use the process, he is regarded as the master of
Figure 1. Model No. 14 by Michael Thonet.
the technique. Furthermore, Thonet is credited as the first to adapt the most important concept of modern furniture design: “the elimination of the extraneous, the unification of the essential, the celebration of the natural, the quest for the comfortable, and the popularization of the beautiful” (Filler, 1992).
Thonet’s principles of mass-production and KD furniture have been adapted to the project that accompanies this paper. The implementation of these principles is further explained in the methods section.
Structural Design in the Form of Cantilevered Chairs
Structural design combines the typically separate components of structure and aesthetic to be shown in the final form. As a result, simple forms are often created. Tubular steel chairs such as van der Rohe’s Brno chair exhibit structural design as shown in Figure 2 (Kilmer & Kilmer, 1992).
It was not until the late 1920s that the cantilevered chair was introduced. Designers Breuer and van der Rohe both introduced designs for chairs that used steel frames and omitted the use of rear legs, but the first person to utilize this principle was Mart Stam in 1926 (Fiell & Fiell, 2002).
These designs used cantilevering aesthetically as well as structurally. It was this unification of structure with form that made their designs unique to those that came before. The cantilevered technique has been employed ever since then and continues to serve as an effective way to simplify form.
Structural design was implemented into the creation of the lounge chair in this project. Where Stam, Breuer, and van der Rohe chose to cantilever using steel, this project used the planar properties of plastic to create a balance of structure and surface. This implementation is further documented in the methods section.
Figure 2. Brno chair by Ludwig Mies van der Rohe.
The concept of compound curves is useful for furniture design because it is a way for simple planar forms, which can be thought of as two-dimensional (2D), to substantially occupy the third dimension. Furthermore, the technique facilitates complex curves that can be manipulated to conform to the biomorphic geometry of human physiology.
Charles Eames and Eero Saarinen were classmates at the Cranbrook Academy when they first gained attention for their plywood furniture designs that exhibited curves on both the X and Y axes. They were the first to laminate wood into three-dimensional (3D) compound curves. This principle represented an industrial breakthrough that created revolutionary possibilities for future furniture designs
Figure 3. LCW chair by Charles and Ray Eames.
(Fiell & Fiell, 2002). An example of compound curves in plywood can be seen in Figure 3. In addition, they realized and employed mass-production as an important principle for the success of their furniture designs (Dachs, et al. 2007).
In Filler (1992), Charles Eames describes his concept:
It would be a chair on which mass-production would not have anything but a positive influence; it would have in its appearance the essence of the method that produced it.
The methods section documents the ways that compound curves of planar materials have been heavily implemented into this project. Where the Eameses’ designs exhibited compound curves in wood, this project applied the same principles to the manipulation of plastic. In addition, this project aims to follow the examples set by both Thonet and the Eameses to embrace mass-production techniques.
Verner Panton introduced his all plastic stacking chair in 1960. As seen in Figure 4, it was a radical new approach that had a form that resembled Gerrit Rietveld’s Zigzag chair of 1934, yet it substituted flowing organic lines in place of the strict linear geometry of its counterpart (Stimpson, 1987).
Fiell & Fiell (2002) make the distinction that it was the first chair to achieve single-piece construction in plastic. It laid groundwork for an array of other designs that would push the limits of plastic structure.
There are two characteristics of Panton’s stacking chair that have been emulated in this project. The first being his use of plastic and the second being his use of only one piece of material. However, for this project a second material was introduced in order to help the chair retain its tensile form.
Figure 4. Stacking Chair by Verner Panton.
Once the objectives were defined, there was a period of brainstorming about how all constraints could be observed while producing a successful seating concept. This brainstorming was conducted to decide the type of seating to produce. The options considered included a side chair, an arm chair, a lounge chair, and a stool.
Ultimately, the decision was made to produce a lounge chair because it is theorized to be more complex in nature than a side chair or a stool. A typical lounge chair generally consists of a seat section and a back section but many lounge chairs also integrate an additional section to support the user’s legs. This three-section approach was selected because of the many potential opportunities for creation.
Considerations were made so that alternate types of seating could be adapted from the initial prototype this project would yield. As such, decisions were made to overdesign the product so that alternatives such as side chairs, stools, tandem seating, and other variants in the same style could be easily adapted by way of simplification or subtraction from the lounge chair design.
Development of Form
Many of the principles researched and documented in the review of literature were considered for the design. Each of those principles was somehow integrated into the resulting design. The presence of such principles in past designs was compiled into Figure 5.
Figure 5. Historical Comparison of Furniture Design Principles.
Creating “Tensioned Loops” of Planar Material
The concept for the chair form resulted from a desire to create a unified approach to the commonly separate components of structure and surface. This idea correlated directly to the principle of structural design presented in the review of literature.
The research of compound curves, based on the designs of Eames and Saarinen, was implemented into the design as well. The form was theorized to be created by curving the planar material and then holding the resulting shape in tension. As a result, this tension assisted the plane in keeping its looped structure (see Figure 6).
Tension combined with the pliability of the material provided resiliency and shock absorptive qualities against downward forces applied to the structure. This idea is also diagramed in Figure 6.
The “tensioned loop” was utilized to offer ample structural integrity to hold the form of the planar object. However, the amount of additional load the loop could support was uncertain. Many variables including thickness, rigidity of material, degree of tension, and other factors would likely affect the ability for the loop to carry a specified load. Therefore, at the onset, it was decided that creating areas of increased thickness or ribbing, as can be done with the laminating or injection-molding, could be efficient methods for applying stiffness in areas where it would be required.
Figure 6. Illustration of “Tensioned Loop” concept.
After the “tensioned loop” idea was conceived, it was sketched on paper and subsequently modeled using cardstock. The initial mock-up model was comprised of seat and backrest components that were each made of separate “tensioned loops.” These separate sections were sketched into a butterfly like shape and re-assembled with a joint forming near the bottom rear of the chair (see Figure 7). The cardstock loops for the mock-up models were held in
Figure 7. Annotated Form Study of Version 2.
place using common staples and transparent tape. At that stage, proportional scale and its relation to anthropometrics was only approximated.
“Front Foot” Concept
A “front foot” was conceived and implemented by cutting a flap from the seat loop and curling it forward toward the front of the chair (see Figure 8). This addition elevated the “tensioned loop” so that it no longer rested on the ground plane. This change was useful because it raised the seat height of the form without increasing the length of required material. This solution also added more
Figure 8. Annotated Form Study of Version 3.
shock absorbency because it incorporated an additional curving plane.
Seat Tabs for Backrest Support
At this stage, there were two separate “tensioned loops” but a system had not yet been devised to keep their orientations perpendicular to one another. It was decided that the tabs could be formed extending from the top of the seat surface. These tabs would then extend back and be attached to the backrest structure to help the backrest section achieve an upright orientation (See Figure 8).
“Rear Feet” Concept
After elevating the front portion of the seat loop off of the ground plane, a desire arose to elevate the rear section as well. In addition, it became obvious that a solution would be required to assist the seat tabs in keeping the backrest loop of the chair upright in relation to the seat loop when force was applied.
First, a type of fold was considered, located in the waist, that connected the two sections. The kink was held in place with a sort of fastener near the back leg (see Figure 7). This solution was favorable in the way that it allowed front-to-back movement of the backrest but it was ultimately decided that the fastener would not create enough support, adversely allowing the backrest component to recline much too easily.
This evaluation and feedback gave way to a second idea to create a narrow “U-shaped” flap at the center of the waist that could be pulled tight and attached higher on the rear of the backrest (see Figure 9). The resulting tension combined with the bowing effect created “rear feet” between the seat and backrest components. This tension effectively held the backrest section upright while still allowing some
Figure 9. Annotated Form Study of Version 5.
dynamic front-to-back range of motion. It also offered an effective manner for elevating the rear portion of the form from the ground plane.
Addition of Footrest Loop
After the fifth refinement of form, it was decided to add a third section which would support the legs of the user. This footrest section was devised of a “tensioned loop” similar to those used to create the seat and backrest components. However, this new “tensioned loop” was oriented opposite of the seat section. This addition is documented in Figure 10. By extending the outsides of the seat section and making a curve at the apex, the footrest section would descend to the ground plane, reverse direction, and eventually reconnect with the previously mentioned “front foot”. See the photo in Figure 10 for a visual representation of this idea.
Figure 10. Annotated Form Study of Version 6.
Introduction of Creasing
Once all three sections of seat, backrest, and footrest had been created, it was observed that the surfaces where the user would contact the chair were convex. It was believed that this attribute would be alleviated as soon as a substantial load, such as the weight of the user, was applied. When the seat was occupied, the seating forms would flex and conform to yield a more desirable concave shape in the contact areas. However, it was further observed that the convex aesthetic of the vacant chair was visually unappealing and ergonomically uninviting.
This evaluation led to the notion that flatter, less convex contact surfaces would be more desirable. Such surfaces were achieved by implementing creases that ran lengthwise along the top outside edges of the seat and backrest sections. The locations of these creases are represented as dashed lines in Figure 11.
The addition of crease lines effectively changed the perceived appearance of the “tensioned loops” from a “C” shape to a “D” shape. In addition, it was noted that locating such creases at the outside and top of the
Figure 11. Annotated Form Study of Version 9.
“tensioned loops” prevented potential pinching that could occur at the leading edges of the “spinal gap.” This idea is diagramed in Figure 12.
Lastly, the crease lines were observed to have added a high degree of side-to-side, torsional stability to the chair form. As a result, the chair exhibited more stiffness throughout the seating surface. This stiffness was unexpected but was considered to be a favorable characteristic.
Figure 12. Section View of “Tensioned Loops” Showing the Positive Effects of Crease Lines
Side Planes for Footrest Section
At Version 8 it became a concern that the footrest section was too flimsy. It was apparent that this “tensioned loop” would not support weight as well as the other two sections. Side planes were introduced as a way to stiffen the footrest section. They were able to be integrated into the single sheet and attached at the edge where the bottom of the “tensioned loop” met the floor.
Through the incorporation of some type of fastening system, the side planes could be attached to the top surface. This created a type of boxed in footrest section. It was implemented in the cardstock mock-up model at Version 9 and was found to substantially increase the structure and stability of the footrest section. This component is shown in Figure 11.
Methods to Facilitate Tension
As mentioned earlier, common staples and transparent tape were used to hold the mock-up models in tension. However, it was obvious that such fastening systems would not be viable for a full-scale production model.
The original concept was to hold the “tensioned loops” with nylon or leather straps spaced evenly along the perimeter of the “spinal gap” region. Both of these types of straps were considered favorable because they are very strong. But, these options were later dismissed as a viable method because they would likely cause uneven tension due to the incremental spacing they would require.
This obstacle led to the idea of a fastening system that would be more evenly dispersed. It was decided that a criss-cross style of lacing using common utility cord, similar to common shoe-lacing, would be better suited for the application. Lacing holes were laid out evenly along the perimeters of the surfaces that would require tension. This method was effective in equalizing the spacing of seams such as the “spinal gap”. These lacing holes can be seen in Figure 11.
It can be noted that the number of lacing holes was reduced because they seemed redundant. The total number of lacing holes was decreased by approximately one third. Figure 13 shows the increase of spacing between holes. This decision was favorable because it sped up assembly time while still holding the forms in properly distributed tension.
The lacing component is considered key because it helps achieve the principle of KD packaging. Thus, the finished form is not realized until the user receives the planar form and assembles it into a 3D object. The lacing further serves as an iconic aesthetic that is easily recognized.
Another factor that makes the lacing appropriate is the notion that common shoe lacing is a cross-cultural fastening method. This aspect lets observers from many different cultures easily identify with the chair’s aesthetic.
Conversion of Form to Computer Aided Drafting (CAD) Software
All forms through Version 8 were drawn by hand. It was at the ninth version that the forms were scanned and traced into Computer Aided Drafting (CAD) software. This switch from analog to digital helped to speed up revisions and create more accurate geometry.
The CAD drawings were also able to be created at full scale to better standardize widths and dimensions of the geometry. This allowed the forms to be printed at 1/6 scale for the mock-up models. Because the models were now at an actual scale, measurements could be taken of the forms in 3D to evaluate the actual dimensions of the assembled chair. This aspect was extremely helpful in changing the drawings to allow the chair to better follow the actual geometry of the human body. The added precision of the CAD drawings is evident in Figure 13.
Recline Adjustment Methods
Through manipulation of the mock-up models, it was noted that a varied angle of recline could be achieved by adjusting the length of the bottom flap in conjunction with the adjoining straps on the seat surface. This observation
Figure 13. Annotated Form Study of Version 11.
led to a series of refinements to offer appropriate amounts of recline adjustability.
The first iterations of this process used a block-and-tackle style of lacing for the bottom tab. A wide range of adjustment was able to be made by pulling on the loose ends of the lacing and then tying off at the desired length. The same block-and-tackle adjustment system was also added for both seat tabs making a total of three systems for adjusting recline.
The block-and-tackle method was later replaced with an incremental system facilitated by metal snap fasteners that could be unsnapped quickly and replaced in a different adjustment setting. The use of snaps eliminated the visually distracting loose ends of lacing that resulted from the previous block-and-tackle method.
The bottom tab was eventually changed to be snapped at a permanent stationary point with no increments for adjustment. This decision simplified the adjustment process and was theorized to make it more clear to the end user that recline adjustment is made only by moving the position of both seat tabs while leaving the bottom tab in its permanent position.
The adjustment system was eventually refined to include four positions specifically located to allow recommended recline angles between 83 and 108 degrees from the seat plane (Panero & Zelnik, 1979). These positions offer incremental variation from task-enabled upright seating to a fully reclined configuration. Adjustment can be made by simply unsnapping and re-snapping the incremental adjustment tabs easily accessed at the rear of the chair. This adjustment system is illustrated in Figure 14.
Figure 14. Photo Showing Recline Adjustment System.
A headrest component was considered and eventually added to Version 11. Like the other components of the chair, it was made of a “tensioned loop” although it was much smaller in scale to the other loops. An illustration of the proposed headrest can be seen in Figure 13. Ultimately, the headrest was found to distract from the simplicity of the overall design and was removed after just one version.
Side Planes for “Rear Feet”
The “rear feet” that were introduced in Figure 9 were found to require more stiffness. A process very similar to the addition of the footrest side planes was conducted for the “rear feet.” These planes can be noted near the waist in Figure 13. Like the footrest component, the addition of side planes to the “rear feet” increased rigidity substantially.
Form Revisions for Anthropometric Compliance
After the general forms of the backrest, seat, and footrest had been developed, the entire design was examined and refined to further accommodate ergonomics. It was also decided that the entire sheet should not exceed that of a common 4 ft. x 8 ft. sheet of material when laid out flat. After the seventh refinement, the forms were laid out orthographically in CAD software to refine the proportions and ensure it could fit on the specified sheet (see Figure 15).
Each of the previously stated refinements was documented and additional mock-up models were created to further examine the adjustments to the 3D form (see Appendix).
A total of ten mock-up models were created throughout the entire design process. The first five of these models were created out of cardstock and were not to scale. Proportions were merely approximated to understand the way that the forms would be realized in three dimensions.
After the sixth version of the chair, the mock-up models were adjusted to 1/6th scale. Ergonomics were considered further throughout the remaining versions. At the 13th and final version, the design was constructed at ½ scale using 1/16″ PLAS-TEX® plastic sheeting. It was at this version that stiffness and rigidity of the material were finally able to be observed and considered.
Explanation of Material Options
The choice of material was narrowed to laminated plywood, resin impregnated fiberglass, sheet metal, and plastic. All of these materials were considered based on their inherent properties of stiffness in one direction while also exhibiting pliability in another.
In the initial stages, laminated plywood was preferred for its warm, natural feel. It was also desirable due to
Figure 15. Variations of Form Toward Anthropometric Compliance.
REPLACE THIS SHEET
the fact that it is a renewable resource. However, it was discarded as a viable option due to its inherent cost as well as the type of setup and tooling required to experiment with such a medium. Furthermore, it was dismissed because plywood cannot easily be creased as the design requires.
Fiberglass was the next option considered. Ultimately it was dismissed for the same reasons of cost and necessity for setup and tooling. It should be mentioned that after the form has been fully refined, it may be viable to reconsider both laminated plywood and resin impregnated fiberglass for mass-production.
Sheet metal was favorable because it could be creased. However, it was the hardest of the surfaces considered and therefore thought to be uncomfortable. The main factor for its dismissal related to its inability to allow much flex without eventually bending. It is theorized that “tensioned loops” of metal would need to be heat-tempered in order to remain in tension yet retain their planar properties when released. The tempering process is costly and requires substantial setup and processing.
The final option of plastic seemed to be the one best suited for fabrication. It offers many desirable characteristics such as being lightweight in comparison to the other options, it is pliable, and it can be creased or looped. Plastics can be experimented with rather cheaply and was easy for the author to acquire. There are many different types of plastics available and several methods for fabrication.
Once the choice of materials was made, forms were sketched in a way that the entire structure and surface would be derived from a solid sheet of material. The material could then be rolled or folded to facilitate easy packaging and shipping.
Methods Considered for Fabrication
Although research relating to fabrication methods was not extensively conducted, the author did inform himself on some basic principles relating to viable processes. The following information is included merely as a point of reference for further research.
The fabrication method of injection-molded polymers was thought to lend itself best to the intended design. This process could certainly be used to mass-produce while creating minimal waste after the initial cost of a form and rental or purchase of an appropriately sized injection-molding machine.
In addition, the injection-molding process allows for creation of reinforced ribbing in three dimensions where the aforementioned method is generally considered to be more 2D–-or planar. In other planar methods, the third dimension could only be achieved by layering of sheeting. Layering of materials, while effective, generally equates to substantially longer fabrication and curing times as well as increased labor required for fabrication.
It should be pointed out that the investment cost for an injection-molding machine able to produce a product of the intended size would have a very high price. Injection-molding would only be a sound fabrication method for high quantity mass-production.
Plastic Sheeting Cut Using CNC Technology
This method is very similar to how the mock-up models were created for this project. It differs in its use of computer controlled cutting of material where the model forms created for this study were cut by hand. This Computer Numerically Controlled (CNC) option can be very effective for smaller production runs, but as numbers increase for mass-production it may be more financially viable to cut the sheeting using a custom made die that would stamp out the intended forms. The die and associated hydraulic press would be considered expensive but would likely be more economically sound for higher quantity mass-production.
A product called PLAS-TEX® is already in production and would be suitable for the initial manufacture of this chair. PLAS-TEX® is made from approximately 95% recycled polyethylene and polypropylene resins. It is available in ¼” sheets and can be purchased for approximately $35.00 USD per 4 ft. x 8 ft. sheet. One sheet would be enough to build one chair and the unused portion is 100% recyclable (Parkland Plastics, Inc., 2005).
Compact Packaging Plan and Marketability
The analysis of data on current market pricing and trends helped to define the goals of affordable shipping. Furthermore, volume and weight limitations for several standard E-commerce shipping services were studied in order to further define the range of affordable shipping and packaging.
Several compact packaging options were considered to accommodate inexpensive shipping. The planar form was the primary consideration for packaging with the additional materials such as instructions for assembly and lacing cord also being included in the box. If the finished design would require supplemental methods for support, they would also be included in the box. The main planar form was arranged to be shipped in four separate configurations, all of which would then be contained with the other pieces in a standard corrugated cardboard box.
The first configuration was for the disassembled sheet of material to be folded twice across the lateral axis of the chair. This method could be thought of as a tri-fold option. The boxed dimensions for this option came out to be 48 in. x 32 in. x 4 in (see Figure 16).
The second and most straight-forward configuration involved rolling the disassembled sheet of material into a tube 10 in. in diameter by 48 in. in length. The boxed
Figure 16. Packaging Option 1.
dimensions for such a configuration would be 48 in. x 10 in. x 10 in. (see Figure 17).
The third configuration considered was a combination of folding the disassembled sheet and then rolling the resulting form into the shape of a tube. The folds were congruous with the natural assembly folds that run symmetrically lengthwise across the seat and backrest sections. After such folds were applied, the remaining form was rolled to a diameter of 16 in. and a length of 29 in. The product was not able to be rolled as tightly as in
Figure 17. Packaging Option 2.
Option 2 due to the increased thickness from the folding. The boxed dimensions were 16 in. x 16 in. x 29 in (see Figure 18).
The fourth and last configuration considered was a combination of folding symmetrically lengthwise as in the third option and then additionally folding asymmetrically widthwise as in the first option. The finished boxed dimensions for the last option were 29 in. x 6 in. x 35 in (see Figure 19).
Figure 18. Packaging Option 3.
It should be noted that options two and three would be preferred to options one and four because they do not impose additional creasing or folding to the chair. Such creasing could result in a compromise of structural integrity for intended use.
Shipping Options for Marketability
After considering the varied options for packaging the product, it became important to compare the current shipping prices for each option. A review was conducted of
Figure 19. Packaging Option 4.
popular shipping corporations prevalent in E-commerce. The shipping services compared were United States Postal Service (USPS), United Parcel Service (UPS), and Federal Express (FedEx). The results of this comparison were recorded and the findings are compiled in Figure 20.
After reviewing the data presented in Figure 20, it was decided that Packaging Option 2 was preferred in conjunction with FedEx shipping. This combination avoided undesirable creasing of the product while also delivering the package to the user at a competitive price.
It should be noted that some of the packaging options with larger volume would be evaluated by the shipping services using dimensional weight rather than actual
weight. In all cases, this factor caused the shipping weight to be higher than the actual weight.
Market research was also conducted pertaining to the size and weight for some existing lounge chairs. The findings can be found in Figure 21. These figures represent the sum of products including packaging. For the sake of comparison, the estimated size and weight is also included
Figure 20. Size, Weight, and Cost Comparison of Packaging Options.
(United Parcel Service of America, Inc., 2009)
(United States Postal Service, 2009)
for the chair designed in this project. This lounge chair comes in significantly under the competitors in both size and weight. The analysis of such data concludes that this design is compact in comparison.
Figure 21. Size and Weight Comparisons to Existing Lounge Chairs.
(Herman Miller Representative, personal communication, March 18, 2009)
(DWR.com Representative, personal communication, March 19, 2009)
Many aspects that deal with furniture design have been considered throughout the execution of this paper and the accompanying project. The project began with a period of research on various subjects from design principles to specific historical studies. After this period of research, a problem statement was devised to design and create a piece of furniture. This statement was further refined by setting specific objectives for later evaluation.
After the objectives were defined, a process of design ensued that included specific phases of analysis and synthesis. Constant evaluation and the resulting feedback caused the process to cycle back and forth between these phases while continuing to work toward a final solution that attempted to satisfy the stated objectives.
After researching many topics, developing forms, and documenting many refinements to those forms, the yielded design was evaluated to determine the overall success of the project. The design was evaluated based on how effectively the goals presented in the introduction were satisfied.
Many of the questions presented at the onset of the project were able to be answered, even though a full scale working model of the design was not able to be created. Throughout the various steps of the project it was ultimately determined that a lightweight lounge chair design could be created primarily out of one piece of plastic. The sheeting could be manipulated to incorporate the historic principles of structural design and compound curves of a planar object.
Several options for packaging were produced after achieving knock-down construction methods. It was eventually determined that the chair could accomplish compact packaging for shipping or storage. The combination of lightweight construction and compact packaging can be assumed to equate to inexpensive shipping in comparison to many comparable lounge chairs currently being produced.
Because the final design uses an assembly process similar to that of lacing common shoes, it can be assumed that most adult consumers from varying cultures would be capable of assembling the product correctly. This lacing process is also an effective way of giving the chair an easily recognizable and iconic aesthetic in the tradition as many well-known chairs associated with the Modern Movement.
It was assessed that an average adult could fit comfortably on the assembled chair (see Figure 22). The design is crafted in such a way that the contact surfaces of the plastic can adjust to the specific geometry and varying proportions of the individual.
Lastly, it was determined that the design can be produced using a number of different methods. The preferred method for mass-production would likely be through the use of injection-molded polymers. However, the design is such that a one-off product could also be produced using consumer available materials and simple hand tools.
An illustration of the finished design can be seen in Figure 23. The overall width of the product is 20 in. The overall height varies from 30 in. to 34 in. The overall length varies between 42 in. and 50 in. The minimum seat height is 9 in. and the maximum seat height is 13.5 in.
Figure 22. Illustrations Showing Persons of Various Heights in Relation to the Lounge Chair.
REPLACE THIS SHEET
Figure 23. Perspective Illustration of Finished Product.
All of these dimensions can be seen illustrated in Figure 24.
The chair was designed in such a way that it could be removed from packaging and then manipulated much like origami to create the 3D form. The form becomes realized by curving and/or creasing certain parts and then securing the forms using lacing or metal snap fasteners. This process is illustrated step-by-step in Figure 25.
Figure 24. Orthographic Views with Dimensions.
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Figure 25. Illustration of Assembly Steps.
“Spinal Gap” Theory
In the initial conception phase, it was theorized that comfort could be ensured by integrating a “spinal gap” down the entire contact surface of the chair. This gap was intended to prevent contact between the user’s spine and any hard surface. Instead, the user’s weight would be supported only by making contact between the chair and the fleshy tissue areas of the user’s anatomy.
This decision necessitated a design that featured a lateral void of surface material down the entire length of the seat and backrest sections of the chair. This idea, as can be seen notably in Figure 10, became referred to as the “spinal gap” for the remainder of the design process.
However, after conducting research in many academic journals no conclusive evidence could be found to support this notion. Although the presence of the “spinal gap” does not seem to adversely affect the design, future developments may explore the omission of this component.
Structure & Tension
While the form of this chair has been almost fully realized, there still remains a need to analyze the structure and apply reinforcements in the form of ribbing to accommodate the weight of the user. In addition, there may be other successful options for holding the forms in tension other than the proposed lacing technique. Such options could certainly be explored further in future research and development.
Issues pertaining to color and finish have not been fully explored. Future developments could investigate these options.
Alternative Types of Seating
As noted in the introduction of this paper, the concepts of this design could be altered or adapted to create alternative types of seating in the same style. Some examples that could be explored are side chairs, stools, tandem seating, armchairs, etc.
While this design has focused on economically sound design solutions, variations of the design could be created for luxury or high-end furniture pieces as well. Some options for variation could also include different choices for materials.
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Figure 26. Study Model of Version 2
Figure 27. Study Model of Version 3
Figure 28. Study Model of Version 4
Figure 29. Study Model of Version 5
Figure 30. Study Model of Version 6
Figure 31. Study Model of Version 7
Figure 32. Study Model of Version 8
Figure 33. Study Model of Version 9
Figure 34. Study Model of Version 10
Figure 35. Study Model of Version 12
Figure 36. Study Model of Version 13
Figure 37. Layout of Version 1 showing separated seat and backrest sections
Figure 38. Annotated Layout of Version 1
Figure 39. Annotated Layout of Version 2
Figure 40. Annotated Layout of Version 3
Figure 41. Annotated Layout of Version 4
Figure 42. Annotated Layout of Version 5
Figure 43. Annotated Layout of Version 6
Figure 44. Annotated Layout of Version 7
Figure 45. Annotated Layout of Version 8
Figure 46. Annotated Layout of Version 9
Figure 47. Annotated Layout of Version 10
Figure 48. Annotated Layout of Version 11
Figure 49. Annotated Layout of Version 12
Figure 50. Layout of Version 13
Figure 51. Explanation of Layout to Assembly