Im still trying to work out the best material to use for the outer wrapping of the product. Ive collected a few bits of food packaging as it is possible the end result of this project is to provide a template people can print out/receive in the post and then transfer onto a cereal box for example.
Ive used;
Orange juice carton packaging as it is designed to hold liquid and could work well being exposed to the elements and holding wet soil.
Cereal box packaging which i have stuck two sides together making it shiny on both sides. if this works it could well be a winner as cereal boxes are large and could fit the net on their comfortably
Polypropylene sheet i had lying around. I don't really want to use this however thought it would test well being exposed to moisture and is very light
plastic coated card label i pulled of a bag
As an initial test Initially i placed the scrap in a glass of water for half an hour to see how they behaved and then left them to dry out ...... All the pieces were not drastically affected however the cereal packaging became a little warped as the water had soaked up between the two sheets, however it did dry out pretty well.
I went to to try and recreated the condition the be box will be in but to a more extreme level. Ive placed the following materials in a pot of wet soil outside to see how it is affected, ideally i would leave this in there for a good few weeks however i don't have time... therefore i have applied a lot of water to push it to its limit nd will leave for a week.
All of these materials are light, cheap and stand a chance of being water resistance to some degree but need to put them to the test to see how they perform.
Testing the NEW Outer wrapping template
I printed out my template design to see if it works and what alteration i may need to make, What i found from this was
I need to make the flaps around the edges slightly wider to make folding easier.
need to get the exact thickness of the paper ill be using to adjust the space between the handle flap as there was a bit of over hang
I need to change the angled edges on the handles as they are overlapping the edges when folded
How am i going to secure the handles together?
Further testing
I need to make the fold lines the same thickness as the paper? as at the moment when the outer wrapping is folded around the wall it becomes shortened.
Make the slot holes larger to allow for movement when folding around the walls
I need to work out where to put the slots for the roof
Testing Image transferring onto polypropylene
Although I have used this method before so have some prior knowledge i have not transferred images onto polypropylene. From working with the press before I have learnt that changes in material and even colours of material can affect how well the images transfer as well as the timing and temperature.
I initially started off using a low temperature of 100 degrees as I had researched that polypropylene can only with stand heat up to 130 degrees. However as you can see from the table the image did not transfer at that heat. I could have left the image on the press for longer at a lower temperature however I was reluctant to leave the material under the heat for long periods of time as it smelt awful! I checked that PP does not emit toxic fumes when heated to make sure I wast poisoning everyone. Despite the stated melting points for PP i found that the material did cope with the hotter temperature however did warp the material slightly, which I combated by placing a heavy flat object onto top while it cools (as i need it to be flat to be placed into the laser cutter)
Cutting polypropylene PP
I used one of the failed image transfer to cut out one of the walls on the laser cutter. I wanted to make sure that the image doesn't react badly to being under the laser and also how well the PP copes.
After the first cut I realised that I needed to tape the material onto the bed as it moved around during cutting, also the material wasn't completely flat after it being heated in the press so taping it also enabled me to make it lie flat on the bed.
I used the power and speed for cutting PP from the chart on the wall which did work correctly however the laser cutter auto focus broke and had to continue by setting it manually. As a result of this all the power and speeds changed and had to spend time to figure out how to now cut the material
I found that after it broke the only way to successfully cut out was to go over the material many times as to not melt the material.
Test Cutting out net on Cam1
The paper detect function on the cam1 cuts of a large chunk of the paper therefore this affected my net design as it fitted perfectly onto an A2 sheet! unfortunatly we had no A1 paper of 290GSM ..... the only solutions to this would have been to go and buy A1 paper from a stationary shop or reduce the size of my design (which i didn't want to do as it would affect all the other pieces of the product and i didn't have the time to do so)
The paper cutter can cut card upto 300gsm and i was using 290gsm ....Howver the cutter blade wasnt cutting through, i went over the design 20 times and it had only managed score lines even though i had the blade on the highest force. Although i have cut vinyl and thin sheets on there before perfectly, i have found in this case it is not well suited to thicker materials. I need to try something else, It is still an option to cut the template out by hand which i have done with all my models however i want my net to be perfect and i cannot cut out the circles very well. I have decide that i should see if i can cut out card on the laser cutter.
Testing card in the laser cutter
I did a few test cuts to see how the machine copes with the card as i didn't want to cause any fires and ensure this was a safe process. I did a few different power and speeds to see how well they worked. The only down side i found from cutting the card on the laser was that it left a slight burnt edges around the net however i will be spraying the card at the end so doesn't matter too much.
each circle was a different power and speed (see scribble book for more details)
Testing net on the laser cutter
The auto focus on the laser cutter broke so i had to do the auto focus manually and therefore had to do further test pieces to figure out the new speeds and powers. It took a lot more time to cut and score the card correctly and had to go over the same lines many times as i could not reduce the speed too slow as this would alight the material.
Test net.
Had hidden cut lines!
Chrome spray test
I did a few testers to see how the spray paint comes out. I was pleased to find it left a flawless finish if light layers were sprayed from a good distance away. It dried very quickly however the paint does come off on your fingers when handled. I would need to spray it over with adhesive or maybe hairspray to help seal it.
I am pleased of the effect off the paint as i am trying to mimic aluminium.
How to attach the snap clips?
I had been thinking on how i was going to attach the snap fasteners. Initially i thought they would just clip together through holes in the product however now have to attach them to the product. I thought it try acrylic glue as i had used it to bond plastics last term, however was a little dubious as it is called 'acrylic glue' and im trying to bond polypropylene and polyethylene. Unsurprisingly the glue did absolutely nothing and the snap fasteners just slide straight off.
I had a a little research and found there are special adhesives designed to bond these tow materials together such as 'TAM Tech Adhesive' and Loctite (see image) which are designed for hard to bond materials such as PP and PE. What is good about this particularly glue is it is resistant to water, chemicals and extreme temperatures so would be ideal for my product which will be exposed to the elements outside. This would also work if i was using the tetra pak as this glue also bongs High & low density polyethylene which is what tetra pak is coated with.
For my project however i am going to need to bond the snap fasteners to my card prototype, therefore I think ill have to use a super glue instead.
99P- Buy one get one free at Robery Dyus
The glue did work, however it took over an hour to bond properly. It worked better by dripping a bit of glue onto the polypropylene first then dropping the snap fastener onto it, then dropping a few more around the edge of it. The hole of the applicator was rather large so made accuracy a little difficult. Im glad i did some practice tests before doing so on my final design as i would have got the glue everywhere.
Cutting the bamboo
Before cutting out all my bamboo I thought it best to cut a small section to see how the material behaves. I tried cutting with the band saw as i thought this would be the quickest and most accurate way of making the tubes. However i think the TPI of the blade is too high as the bamboo split and left a really uneven cut. I decided to use a coping saw inside and take small fine cuts whilst it is clamped down. This gave much better results and caused no splitting to the material and this is how I will cut all the tubes.
Whilst I had the little test piece of bamboo I slotted it through the PP walls I had made to see how well it fitted and if there were any adjustments needed. From doing so I found that I need to make the nest holes in the walls a little larger to give them more movement. Although the bamboo tubes do fit it is rather tight and means it is hard to thread the bamboo through two sets of walls and makes the material a little warped.
Testing finalised net
I have reworked my template for the outer wrapping and wanted to test how this effects the final outcomes now. I have found these changes mean the product fits around the walls much better without gaps I had before. The walls all line up correctly meaning the nest tubes will sit straight and flat. I found it was very easy to slot together however will test this further by asking someone else to have a go and get some feed back. (see feedback in evaluation menu)
However further changes that need to be made include:
Make the nest holes 1mm wider
I have at some point deleted the drainage holes!? need to put them back in
I need to to change the main fold lines which run down the sides of the product from one large fold into separate little folds as it bulges when the product is wrapped around the walls.
Transferring onto card
Transferring the images onto the card via the heat press was a lot more simple than with the polypropylene and fortunately worked first time. The only issue i found was that the images came out a lot darker when printed onto the card, but think that was due to colour of my card. I was still pleased with outcome and went ahead with this for my final.
Testing final product
All the pieces of the product fit into a standard large envelope as need to be posted as a royal mail large letter. To fit the bamboo canes into the envelope i had to stick them onto a strip if polypropylene so they lay flat and do not roll around inside the envelope.
Weighing and measuring the final product
I weighted all the materials individually and then how much it all weighs put together in the envelope. It came way under the maximum weight restriction for a large letter which is 750g, my product weights just 229g,
I also measured the width of the packet which came to 20mm which is also within the restriction (25mm) this means i have achieved the royal mail specification i set for the product :D