Design strategy came out of experimenting with bending of 0.5 mm polypropylene. After finding the appropriate dimension of pp flat sheet that could be bent with minimal deformations, more investigations were done in field of attaching already bent pp surfaces one to another. Joints for this connection required some fine tuning in analogue models because of the material properties that couldn’t been simulated in digital model. Variations in component were designed in order to direct the light and to accomplish appearance of less and more dense areas. These variations consider different angles of attached bent surfaces.

3D Printer _ FormLab
Design was based on combining 3D printed joints and Metacrylate sticks.

4 different types of joints were used, depending on how many sticks are being joined together. One half-circle is moving/rotating around straight sticks, making different spatial configurations.

Problems occurred during assembly were caused by too short joints, that couldn’t hold the pressure from the sticks.

At first we did design of aluminium sphere as constructive assembly of joints and folding. Design strategy was based on using the 0.3 mm thick aluminium and the EndCut Mill tool 0.3 mm in diameter. In this case one mill cut matches thickness of material, making joints possible.

As we starded to mill our material, we realized that parts designed for joints are too thin and fragile to be succesfull. Because of that we focused only on the folding of aluminium. This was done by engraving the folding lines.

We also had problems with melting of aluminum during the milling process. But we were able to cut of the melted part manually.

Sphere_laser cutting

Laser cutting time – 14 minutes.

Size of the sheet – 68×36 cm

Size of the spheres – 12 cm in diameter

Sphere_strategy 1

We divided sphere into 10 equal slices by cutting the sphere with radial planes, after that  we applied twisting to these slices by 60 degrees. By unrolling surface of the slice we were able to have 2D element on which we made joints suitable for flexible material such as polypropylene.

Sphere_strategy 2

The second sphere was created by dividing sphere into 12 equal slices, also done by cutting the sphere with radial planes. Here, we experimented with folding detail on two points of sphere where slice sheets meet.

CHEMICAL COMPOSITION/FORMULA:

(C3H6)n

MATERIAL DESCRIPTION:

Polypropylene is a semi-crystalline thermoplastic. It is a linear hydrocarbon polymer, which serves both as fiber and plastic. It is used in packaging, textiles, thermal underwear, carpets, laboratory equipments, loudspeakers etc. PP has an intermediate level of crystallinity between low density polyethylene (LDPE) and high density polyethylene(HDPE) and has a low level of electrical conductivity. Polypropylne is close to polyethylne but has higher working temperatures and tensile strength than polyethylene. It also has a high melting point compared to other plastics.

EXTRACTION PROCESS:

Propylene is obtained, along with ethylene, by cracking naphtha (crude oil light distillate). It is separated by low temperature fractional distillation. After the propylene monomer is subjected to heat and pressure, PP is manufactured from propylene gas in the presence of a catalyst. Polymerisation is achieved at relatively low temperature and pressure and the product yielded is translucent, but readily coloured.

BASIC PROPERTIES:

Compressive Strength (N/m2)                             40000000

Tensile Strength (N/m2)                                      950000 – 1300000

Stiffness (N/m2)                                                   1.5 – 2.0 x 109

Density (kg/m3)                                                   905

Carbon Footprint (average,KGCO2E/KG)         3,456 ( Less CO2 equivalents by weight than PET,PS and PVC.)

Recyclable                                                             Yes (Polypropylene recyling rates are increasing by year.)

Laser                                                                      Yes

Small Laser                                                            Yes

Milling

3D Printing                                                            No

ADVANTAGE IN THE CONTEXT OF DIGITAL FABRICATION:

Polypropylene is a material which is shapeable. It is easy to give a form. PP is normally though and flexible. It can be used also by twisting, bending or folding. It has good resistance to fatigue. It is lightweight, and does not absorb the water. On the other hand, it is economical.

MATERIAL SUPLIERS:

Complas                     http://www.complasbcn.com/

Servei Estacio            http://www.serveiestacio.com/

Lork Industria           http://www.lorkindustrias.com/

Sunclear                     http://www.sunclear.es/

PRICE : 

3.86 eu/m2 (Complas)

5.20 eu/m2 (Servei Estacio)

REFERENCES:

Generative Installation, Diaphanous

Mexico, 2011

Instituto Tecnológico y de Estudios Superiores de Monterrey

Advanced Prototypes / Department of Industrial Design

By Gabriel Esquivel & David Hernandez

http://archinect.com/people/project/15906375/diaphanus/15909988

____________________________________________________________

Exhibition Minimal Complexity MC/2*, Complex Surfaces

London,2012

International Architecture & Design Showcase

Office of Surface Architects

By Vlad Tenu

http://www.arch2o.com/mc2-london-2012-vlad-tenu-surface/