29/04/13

Materials and Structures 2 Jack Murphy

ROTATIONALLY MOULDED BIN FOR A BEER FESTIVAL

ENVIRONMENT.

1

Contents

Brief 2

Introduction 3

Final Design Proposal 4-5

Design Detail 6-8

Structural Analysis 9-10

Materials 11-13

Ergonomics 14

Design Control 15

Company policy 16-17

Case Study 20-21

Design Developmet 22-23

Part Details 24-28

References 29

2

Brief

For this report, the design that I will be proposing is a rotationally moulded bin, which is

intended for a beer festival environment. The proposed design will not only use a

rotationally moulded polymer but will also include a combination of two other materials.

This bin will be made for Oktoberfest, an annual beer festival in Germany. At this festival, it

has often been found that, due to a high number of people consuming beers from the bottle

and glasses, within small areas, smashed glass is a rising problem that leads to injury.

Therefore, the bin in question is to be designed with the purpose of allowing cleaners in this

environment, to clear broken glass quickly, efficiently and safely.

3

Introduction

This design proposal is in response to a request made by Tender, by the city of Munich,

which asked for glass recycling bins for the Oktoberfest international beer festival.

Background

Oktoberfest is an annual beer festival held in Munich, Germany that has been

celebrated every year since 1810. This festival is to celebrate German heritage, with large

tents being erected on a field by many famous German breweries. Beer is served at the

events, whilst bands play German music, with people dressed in traditional Bavarian

costumes.

One of the most distinctive features of Oktoberfest is a dark, rich beer traditionally served in one litre tankards. During the 16 day event, Oktoberfest attracts huge crowds in Munich, making it the largest fair in the world.

Facts found from research

Held in Munich, Germany

Beer drank out of Steins as it gives a traditional and authentic feel to the festival

No smoking in beer tents

Fun fair at the festival

One of the largest festivals in the world

Glass bottles have been banned due to the high number of injuries caused by smashed glass; however, litre glass steins are still regularly smashed

Approximately six million people will attend the festival each year

Approximately 7.5 million litres of beer will be consumed

Beer tents are free to access

Beer tents are extremely busy; people stand as well as sit

4

Final Design Proposal

5

This bin has been developed to allow cleaner at these festivals to quickly and effectival

sweep away broken glass, which could cause injury if not cleaned away.

The lid of this bin opens so that part of the lid touches the flooor. This means that cleaners

can sweep glass into the bin, then lift the lid back, to place the glass into the bin.

When the bin is full and needs to be taken to a glass recycling point, the expandable handle

opens up and the bin is tilted backward so that it can be wheeled similar to an outdoors

wheelie bin.

Although the handle for the bin is on the inside, where the glass would be, this will not be

an issue as cleaners for these events will be required to where gloves thick enough to

prevent injury.

6

Design Detail

7

8

The main body of the bin will be rotationally

moulded. This is where the glass will be collected

and where the wooden panels and lid will be

attached to.

The wooden panels are attached to the main body

using brass nuts and bolts, the bolts will be inserted

through pre-drilled holes.

The expandable handle will be bolted to the back of

the bin.

The handles will be moulded with the rest of the lid.

The lid will be attached to the main body using a

hinge as long as the straight face. The screws will be

bolted into pre-drilled holes.

9

Structural Analysis

Forces on the structure

Structure and Hot spots

The force pushing down will be dead weight (the weight

of the lid above). Other force’s that could be pushing

down could be the weight of snow or rain, however, with

my design that will not be an issue due to the slanted lid.

The only area where this could become a problem is the

small flat area next to the handle of the lid.

The sides of the model will be under force from the

wind. However, the circular design of this bin will act

as a counter force from the wind from all sides.

The two red arrows represent the force of

compression on this part of the bin; the weight of the

lid above is acting against the force of the ground

below. This means that if the pressure from above is

too great the sides will bend inwards.

The screws holding the wooden panels to the sides of

this bin will be under tension.

The structure I have created is a standard one, with

support coming from the base.

The main hot spots on this structure are the narrow

points on the lid of the bin as they have had the most

structural change to them.

This is a hot spot, as the hinge inside may fail/break

after repeated use.

10

Load Bearings

To work out the load bearing placed onto the main body of the bin, it was necessary to first work out

the weight of the aluminium lid on top of the main body.

To work out the total weight of the lid, I first had to work out the Surface area, then from this

calculation I had to work out the volume, and then from this I could work out the weight.

Surface Area- Width x Length

(In Inches)

18 x 22 = 396

Volume – Depth x Surface Area

5 x 396 = 1980

Weight of the Aluminium

.096 (weight, in pounds, of one cubic inch of aluminium)

1980 x .096 = 190.08 pounds

This means that the weight of the lid for my bin will be 190.08 pounds

The weight pushing down onto the main body will

be 190.08 pounds.

The tensile strength of the main body is 31 MPa.

This means that it will be able to withstand the

force pushing down.

11

Materials

The two most common materials and most suitable materials for this process are Polyethylene and Polypropylene.

Polyethylene

Characteristics- High density, good stiffness, good chemical resistance

Common uses- Crates, bottles, buckets, bowls

Polypropylene

Characteristics- Lightweight, food-safe, good impact resistance even at low temperatures, good chemical resistance

Common uses- Kitchen products, medical equipment, string and rope

The material that I have chosen for the main body of my bin will be Polyethylene as it will colour well and its high stiffness will be ideal with the heavy metal on top

Primary Material - Polyethylene

Manufacturing

For the main body of my bin, the chosen polymer will be rotationally moulded.

Rotational moulding process is a high-temperature, low-pressure plastic-forming process that uses heat and rotation to produce hollow, one-piece parts. This process can manufacture large, hollow parts such as oil tanks. Very little material is wasted using this process, and excess material can often be re-used, making it to a certain extent, an economically and environmentally friendly manufacturing process.

Rotational Moulding consists of four stages:

1. Inserting a powdered form polymer into a mould.

2. Heating the mould in an oven while it rotates, until the entire polymer has melted and stuck to the mould wall.

3. Cooling the mould by fan, the polymer is cooled so that it solidifies and can be handled safely this typically takes tens of minutes.

4. Removal of the part.

To better understand this material I have collected data regarding its performance:

Maximum Temperature: 248°F 120°C

Minimum Temperature: -148°F -100°C

Melting Point: 266°F 130°C

12

Tensile Strength: 31 MPa

Hardness: SD65

Rigid

Oak Wood

Oak Wood

For the wood on the outside of the bin, I will be using an oak wood, similar to the type used on beer barrels.

Properties of Oak wood

To get a better understanding for the material I will be using, I have researched into its properties and characteristics.

Appearance

Straight grained

Medium-coarse to coarse texture.

Light tannish

Physical

Heavy

Hard

Strong

Wear-resistance

Moderate stability in use

Steam-bends very well

Working

Nails and screws satisfactory

Glues satisfactory

Stains and finishes

Manufacturing the panels

To manufacture the panels required for my bin I will buy panels measuring 10cmx56.39and drill holes 5mm in radius from the top in the centre top and bottom for the brass bolts to attach it to the main body.

Aesthetics choice

The reason that I have chosen this wood for the exterior of my bin is because it will give the bin an authentic look that resembles a beer barrel look. This is ideal as this bin will be located in beer festivals so therefore look in place with the rest of the festivals style.

As Oak wood corrodes steel screws, I will have to use a brass nut and bolt to attach the wooden panel to the plastic main body.

13

Alumnium

Aluminium

The metal that I will be using for the lid of my bin will be Aluminium.

Characteristics of Aluminium

Weight - 2.700 kg/m3 Strength - Tensile strength of 700 MPa Elasticity - E = 70,000 MPa Machining - Easy to machine Joining - Welding, soldering, adhesive bonding and riveting. Conductivity - The thermal and electrical conductivities are very good. Process for moulding the lid The process I will be using to mould the lid will be press forming. In the mould for this, I will include the handles for the top of the lid.

Aesthetics choice

The reason that I have chosen Aluminium for the top of my bin is that this metal will be durable enough to withstand being banged against the floor and this attractive looking metal contrasts nicely with the wooden panels.

Finishes

Main Body

The main body will not have a finish as it will be cover on the exterior by wooden panels

The Oak Panels

The oak panels will be varnished as it will add to the overall aesthetics of the exterior and it

will also increase its durability outdoors as the wood will be less likely to be damaged by the

rain.

The Lid

Other than sanding down any potential sharp edges around the edges, the lid will not have a

finish to it, as the contrast between the wood and the metal is what is sought after. Also the

exposed metal creates the impression that it is functional rather than decorative.

14

Ergonomics

To aid me in the design process I have used an anthropometric table to ensure that I am designing

for the 5th and 95th percentile. With this table I have designed my lid height using these

measurements:

To ensure my handle is the right width I have used these measurements

This is the data that I used to ensure that my handle width was the correct size and that I was

designing for the 5th and 95th percentil

Dimension Gender

5th percentile (mm)

50th percentile (mm)

95th percentile (mm)

Hand length Male 173-175 178-189 205-209

Female 159-160 167-174 189-191

Palm length Male 98 107 116

Female 89 97 105

Thumb length Male 44 51 58

Female 40 47 53

Thumb breadth Male 11-12 23 26-27

Female 10-14 20-21 24

Index finger length Male 64 72 79

Female 60 67 74

Hand breadth Male 78 87 95

Female 69 76 83-85

15

Design Control

To ensure the control of my design I will use a change control form. If at a later stage of

development this design needs to be changed, this form will ensure that I can quickly change the

design.

The template of this form would look similar to this

Part NO Description of Part Name of request originator

Change Request Submission Date

0001 LID JPM 20Apr13

0005

16

Design Review

Design Review taken from this point of the design

Is there a clear brief?

I feel that at this point in the project there is a clear brief; a bin is needed to enable a

way to quickly and efficiently clean away broken glass.

Is the design response clearly expressed by intention?

Yes, the design of the lid allows for a simple way to clear away smashed glass.

Is each element fit for purpose?

The main features of this design are the main body, the lid and the main body. These are

both fit for purpose as the lid allows for quick easy disposal, and the main body is fit for

purpose as it is hollow which allows for storage of broken glass. However, the main body

is unfit for purpose as there needs to be a side for wheels to allow for mobility which

would not be possible due to the entirely circular design.

How can the design fail and what action has been taken to prevent this? (How does it

fail and what affect does this have on the system)

The design can fail by the hinges attaching the lid to the main body breaking; this would be catastrophic to the design as it would no longer be possible to sweep glass into the lid.

If there are design elements that are not fit for purpose, what is the remedy to the

situation?

The main design fault was that it did not allow for mobility, this has been remedied by making two sides of the flat as this allows for a space to insert wheels.

Are the chosen materials appropriate?

The materials being used are Oak wood for the panels, Polyethylene for the main base

and Aluminium on the lid. These materials are appropriate as the Oak is vaguely similar

to a beer barrel, the polyethylene is both strong enough to support the lid and it is

suitable to rotationally mould. Finally the Aluminium is both strong enough not to break

when being banged against the floor and light enough to easily move.

17

Are manufacturing and assembly choices appropriate?

The manufacturing is appropriate as the main body is rotationally moulded as this makes for a hollow object. Press forming is an appropriate manufacturing choice too, as it will create the flat bends required for the design.

18

Company Policy

Companies’ policy statement

It is the companies’ policy to ensure that all materials, where possible, are bought from recycling plants rather than buying new materials.

Any unused materials will be re-used.

When buying wood, it will only be bought from manufacturing who manufacture in a responsible way by replanting trees that are cut down in the process.

All those employed by this company will receive proper and efficient training in how to both manufacture the individual parts and assemble the whole product.

The company will reduce CO2 emissions and waste to the best of their abilities.

When designing, the product must keep the environment in mind.

Must make universal designs.

19

Appendix

20

Case Study

Outdoor Furniture

In this section of my report, I will be exploring different types of outdoor furniture, what

materials they are made from and what manufacturing methods have been used.

Material- Tubular steel

Manufacture- Has been bended using press bending

Finish- Polished

Colour- Shiny Metallic

Method of Placement- Appears to be bolted to a

concrete base

Material-Steel

Manufacture- The metal of this chair has been

formed by press bending sheets of steel into

position. The wood will have been attached using an

adhesive.

Finish- Unpolished Steel at the base with possibly

varnished wooden panels

Colour- Dull metallic with wooden elements

Method of Placement – Flat metal panel at the

bottom of the seat has been bolted into prepared

concrete panels under the tiles on the pavement

Material- steel

Manufacture- Roll formed, the fold folded to the top

Finish- Painted

Colour- Black with gold letters

Method of placement- Bolted to a pre-existing

concrete base

21

Street Bins

To get a better understanding of the product that I will be designing, I have gathered a range of

images of existing bins to deduce what common features they share. Reflecting upon these existing

designs, I will decide what features I like and what I don’t like, in order to make creative decisions for

my own design.

Having researched similar products to the one I will design, I have found that the standard

sizes of a litter bin are:

Height: 1020mm

Depth: 328mm

Width: 450mm

Though, when considering my design, I do feel that these measurements do not need to be

used, as my design may need to be shorter or taller.

Considerations after research

Bin needs to have a way of allowing glass recycling collectors to easily put it onto the

vehicle.

Needs to be mobile to allow it to move about during the festival, Similar to a wheel

bin.

Recycled glass when small enough is collected in boxes at the side of roads.

22

Design Development

Initial Ideas

When generating my initial ideas, it was important to remember that my design needed to address

the issue of smashed glass within the festival. Therefore the unique selling point of this bin will be

that broken glass can be swept into the bin directly.

23

Length of the lid needs to be as tall as the main body for it to act as a scoop

The lid will be made of a metal

The lid will have a handle in order to lift the scoop over the main body

24

25

26

27

28

References

www.rotationalmouldings.net

www.woodbin.com/ref/wood/oak_white.htm

www.plastics.ides.com/generics/27/polyethylene-pe

www.bluescopesteel.com.sg/forming_7_press_forming

www.webelements.com/aluminium/

www.allthingsgerman.net/blog/festivals/10-important-facts-about-oktoberfest/

www.sustland.umn.edu/implement/selecting_wood

www.oktoberfest.ca

www.bottleman.co.uk/bins-and-dimensions.php