Materials and Structures. Paul Meikle

Materials and Structures.

1Assignment 2:Rotation Moulded Street Furniture for a festival Application.

Introduction.

The brief for this project is to create a piece of street furniture for a Festival of my choice, immediately I thought to design my piece of furniture for the Edinburgh Fringe Festival. As a regular visitor and enthusiast of the Fringe I seen this as a prime opportu-nity to design something beautiful for the Festival enjoyed my thousands of people every year.

Traipsing around the streets of edinburgh going for show to show seeing many weird and wonderful acts can get tiring so I have opted to design a cluster of tables that can be put together in any given destination in order to let the people of the Fringe take a second out to enjoy a spot of food or maybe even a beer if the occasion calls for it.

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Product Location

I looked into a few different potential loca-tions for where to put my outdoor bar stand/ table and decided that outside the Edinburgh Art Gallery overlooking Princes street gardens would be an ideal location.

With a nice view and with it being a open area it means that people will not be cramped into a small area. As well as this there are often street performers in this area so people can enjoy the surroundings at the same time.

Other potential locations for the table could be:

Near Bristo square another spacious but active area during the fringe. With the Ud-derbelly close it makes for a prime loca-tion.

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Research 2

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When looking into existing designs of outdoor bar style tables I came across a few designs with a simi-lar concept to mines.

Although most of these structures are wooden rather than plastic they hold similar attributes.

Most outdoor food and drinks area’s provide seats as well as the table for users but my design will not in-clude seats and will allow for users to rest against the table or stand and enjoy their food or drink or to en-joy a conversation.

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Although outdoor bars and places to eat are already openly available through out the Fringe festival there is not a commu-nal area to rest where there is no pressure to buy a drink or something to eat.

With my outdoor table design it allows people of any age to come along and enjoy their own food or drinks whilst enjoying all the festival has to offer.

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In order to make the tables fit in with the surrounding things associated with the Fringe I’ve decided to base the colours around the 2013 Fringe colour scheme for their bro-chures, leaflets and posters.

With the bold bright colours it will attract more attention with users and will entice to check out the tables.

Design Development3

Rotational Moulding.

The design will be rotational moulded; this is the process of heating up the plastic be-ing used to a high temperature and having the mould rotate in order to produce a hol-low product.

By using rotational moulding as the produc-tion process it allows for the product to be weighed down using water or sand when it gets to its destination. This means that transport of the product is easier and more lightweight than usual products.

The advantages of using rotational mould-ing are that it allows to make larger com-plex products fairly easily with a consistent finish and wall thickness through out the product.

Within the rotational mould I am going to use High Density polyethylene due to the fact that it is a hard wearing plastic with good rigidity and resistance to outdoor conditions as well as general wear and tear.

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The table is a temporary piece of street furniture during the Fringe festival which runs for 4 weeks so it is ideal that its rotational moulded so it can be delivered and uplifted with ease with out any risk of it being stolen whilst the festival is running due to the fact that the ma-terial inside it can be dumped out easily before transport.

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Combination of materials.

For the main rotational moulded section of my design I have opted to use Hight Den-sity polyethylene due to the fact that it is impact resistant and tough so it will be less likely to give in due to heavy weight or stress.

Due to the weather during the Fringe festi-val being so unpredictable HDPE is also an ideal material due to its thermal resis-tance; it can withstand warping, cracking or melting from -40ºC to 100ºC.

Since the Festival is only on for 4 weeks during the month of August the tables can be recycled at the end since HDPE is widely recyclable.

Another benefit of using HDPE is the fact that when it is rotational moulded it is light in weight meaning that transportation costs will be significantly less than for other products.

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The second material that I have used within my design is stainless steel for the ashtray part in the middle of the table.

The main advantages of using stainless steel are:

- It is corrosion resistant so its not going to rust or corrode from weather conditions.

- Ease of fabrication; stainless steel can be cut, welded, formed, machined and fabri-cated relatively easily.

- It is available in many surface finishes. It is easily and simply maintained resulting in a high quality, pleasing appearance.

- The cold work hardening properties of many stainless steels can be used in design to re-duce material thicknesses and reduce weight and costs. Other stainless steels may be heat treated to make very high strength com-ponents

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CAD MODELS.

Structural analysis4

Forces.

The maximum weight that the table should have to deal with would be the weight of 6 people potentially standing on the table:

Average person x 6: 960Kg.

The most problematic point of force upon the table would be the twist in the middle of the body due to the odd shape and bend in the material.

Due to the temporary use of the table /bar stand there should be no prob-lems with over use or wear and tear.

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Compression force from the load of food or drink on the table as well as the weight of users leaning on it

Sheer force from the wind load as well as people standing and leaning against the table.

Force of the load on top of the table is spread out evenly.

Ergonomics7

Looking into ergonomic dimensions of the table

Ergonomics.

From looking through a few different sources the standard height for a bar is around 1110mm and I have made my table height around the same height (1099mm).

Average UK male height (16+): 1752mm

Average UK male height (16-24): 1771mm

Average UK male height (25-34): 1779mm

The size of each side of the hexagon is 616mm allowing each user enough per-sonal space when standing at the table, it allows for them to comfortably stand around the table without feeling cramped and gives enough space to allow for them to rest their drink or food on the table and enjoy it comfortably without bumping the person next to them.

The average space you should allow a per-son sitting at a dining table is around 585mm.

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24. Upper limb length

The average length of a fully stretched out arm for a man is 790mm and the ashtray in the centre of the table is 555mm away from the edge of the table allowing for the user to com-fortably use the ashtray and reach anything they have on the table that is in front of the ash tray.

Design Review6

Design Review.

On a whole I would say that my design of a table/bar stand is successful, I have care-fully considered different features of the ta-ble to allow for it to be comfortable for up to 6 users per table.

Weaknesses of the design are that al-though the design is completely suited to most sizes of people not a lot of considera-tion has been put into suitability for dis-abled users or children although they can still enjoy it comfortably.

A change that could be made to the de-sign to guarantee for them to make full use of the table would be to have a few differ-ent tables of a lower height. For wheelchair users an ideal height for another table would be 700mm.

The strengths of the tables are that they can be put into different arrangements eas-ily to keep it interesting in different loca-tions.

The colour scheme of the tables have also been carefully considered to be recog-nised clearly as a part of Edinburgh Fringe Festival.

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Company Policy 7

Sustainability.

The sustainable factors of the design are that due to the fact that it is formed from plastic materials it can be sourced and pro-duced locally. As well as this once the de-sign is obsolete the plastic material can be widely recycled.

Plastics have a very good environmental profile.  Only 4% of the world's oil produc-tion is used for plastics and much less en-ergy is used to produce it compared to other materials.

The design also reduces use of fuel and larger vehicles for transport due to its light weight after production.

Since the plastic used to produce the table is already coloured it eliminates the need to paint or maintain.

Another sustainable factor of the plastic used to create the design is that there is no other additional finishing needed once the production process is finished; sand-ing, welding etc.

For the stainless steel ashtray part of the design in its use or in its production proc-ess, respects the human being, especially in terms of health and safety.

A sustainable material does not harm the people working to produce it, or the peo-ple who handle it during its use, recycling and ultimate disposal.

Stainless steel is not harmful to people dur-ing either its production or use. A protec-tive layer forms naturally on all stainless steels due to it including chromium.

The passive layer protects the steel from corrosion - ensuring a long life. As long as the correct grade of stainless is selected for an application, the steel remains inert and harmless to the people who handle it and the environment.

These characteristics have made stainless steel the primary material in medical, food processing, household and catering appli-cations.

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In terms of ethics, as a company we will consciously work towards creating good design for our clients at a reasonable price. We will make sure any clients we are working with are also trying hard to be eco friendly and sustainable with any works they are doing as well as following suit and maintaining these same ethics ourselves.

We will try and be as charitable as we can with our design work making sure we can donate what ever we can and help the best we can with design work for charita-ble organisations or any good causes in need of help.

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Company Ethics.

Final Design. 8

The final design of a Bar/table for use during the Fringe Festival 2013.