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A workspace building slingshots, HDPE ammo, and knock down targets is pretty much guaranteed financial success.
Yeah, the drift bike is much safer…you don’t need a helmet…just a safety tie
@ppboys , When you are tired of assembling shredder bits, take a break and make one of these. It even comes in the official @ppboys colors.
I do like the roadrash ready shorts, tank top, no gloves safety kit.
I have not made phone cases, but both HDPE and LDPE should be softer
Given all the video documentation PP is planning, a basic “here is what a V3 shredder can and can’t do” video would help. And here is what it can do with just a some simple plastic preparation.
I guess one of the tricky parts is how to describe the capability so that performance expectations/limits are agreed to. For example what HDPE thickness? 2l soda bottles one at a time. etc. I was looking at the commercial shredders/granulators (for example: http://compactorsinc.com/granulators-fx700-series/ )and they avoid any performance specification other than Kg/hr. They expect the user to be experienced enough to choose the right size. The bazar customer may not have that experience and have unrealistic expectations.
@plasticupcyclingkat , Thank you for going through a review cycle of your paper. Hopefully PP will also publish the results of their V4 fume study described here https://davehakkens.nl/community/forums/topic/v4-fume-extraction-4/ . There are also a number of other threads on the topic.
From my personal experience with HDPE, unfortunately I did not find the recycling process benign. Working with an injection machine in a typical 2 car garage, with the door open, I found the fumes affected me temporarily (hopefully). I added a DIY fume extraction system and an additional fan to manage the fume issue.
The research I’ve done online, identifies the polyethylenes as lesser evils but not blessed as safe, especially once additives are considered. Hopefully you will also get some feedback from a chemical engineer, chemist, or biochemist.
The blue LEDs and clear sides on the gamer boxes are pretty cool. On the other hand there must be piles of used PC cases in the electronics recycling world. They may need a splash of paint or a new fan and hopefully don’t affect certification. I think the customers would appreciate that some part of the system was repurposed.
On the other hand, heat pipe or liquid cooling of the SSR’s would look really cool.
@irismongolia , Thank you for the link. It would be great if PP could post a summary/conclusion in this thread.
In general is it appropriate to compare your results to the safety criteria in your first post?
The maximum 3-hour concentration of hydrocarbon content is 0.24 ppm, not to be exceeded for more than a year .
Thank you for your work.
@racheyc05 , I would definitely go check out the machine available in Brisbane and talk to some users. There are alternative designs https://davehakkens.nl/community/forums/topic/portable-desktop-injection-machine/ to the PP injection machine that can be easier/cheaper to build. They can also be easier to add a fume hood and vent to. If you are planning to use this indoors, you want to consider that.
Since you have a shop press, you could make a sturdy container and try crushing the parts before heating them.
I just noticed there is sort of a pay for help desk/tech support described on the news page.
*Sidenote: we also have a few channels for Patreon supporters only. Here members of the core-team answer questions.
This is probably a good funding idea. This should have an icon on the top of the forum so people with more specific machine/process questions can get direct PP help.
The melting points are a little higher than that http://polymerdatabase.com/polymer%20physics/Polymer%20Tm%20C.html . If I put plastic in our smoker I’d be sleeping out on the patio. Though buying one just for ribs is highly encouraged.
I’m not sure what you mean by densify. If it is solid LDPE then its density is not that much lower then HDPE https://www.usplastic.com/knowledgebase/article.aspx?contentkey=508 . If it is in foam form then some experimentation with shred/heat/compress to get the air out, I have not tried this. It may take somewhat higher temperatures to get the viscosity down. Maybe search the forum on recycling foam (there was some Styrofoam activity). It may need the extrusion process to really work the material.
Good question, sorry, not much help.
@heidimylo , Yeah, the label removal issue does not get a lot of attention. It does not appear to be one of the PP V4 topics so I’m not sure what they do in Eindhoven.
You could potentially buy a gallon of a light oil like WD-40 and use that, but then you need to clean the oil off and you have a bunch of oily labels to get rid of. I use the heatgun methods described in the other thread and then deal with the small amount of residue. I also have not seen anything on whether residual adhesive affects the recycling process.
The problem I found with the hot water approach is that it leaves all the adhesive on the jug. The slow peel approach takes most of it off.
@ppboys , you can get some of the arduinos without headers and solder the screw shield directly to the board or put your connections on a separate protoboard and avoid the pin->header connection
@irismongolia , You mentioned you rented an industrial VOC sensor. If you plan to have that for a bit longer, perhaps your team could compare it to something like the low cost CCS811 sensor used in this project https://hackaday.com/2019/09/03/3d-printer-emission-monitor-quantifies-the-stench/ . If it provides useful information, that sensor is only around $20.
@florenciaortizs , Thank you for putting together the spreadsheet template. In my experience, the usefulness (or danger) of these kind of business tools is dependent on how well the assumptions and algorithms used in the template are documented. This is especially true for the costs sheet, and how these are allocated to establish the profit margin. Every workspace will need to review these and adjust both the values and potentially the algorithm to match their production flow, otherwise some misleading and expensive mistakes can be made. The most dangerous thing is for people to just enter numbers and look at the summary. So please include documentation that walks through the cost estimating and allocating process so the users can confirm that it matches their workspace.
Great start, thank you
@alitor , I think at a university you get to aim a little higher than the rest of us. There are several implementations of printing PET without going through the filament step. One example here https://davehakkens.nl/community/forums/topic/3d-printer-for-pet-particles-no-filament-ever/ . This is a topic that is just being investigated and would greatly benefit from additional research and development. The fact that you have to use very fine particles puts the burden on the shredding/grinding process. Additional research on the print head to establish print resolution vs. PET particle size, would be a great step forward, as would establishing a specific drying requirement. Plenty of opportunities to advance the knowledge base. Currently PP does not have an easily reproduced process for dealing with PET. Any research to that end is a great contribution.
I think Icarus just used the wrong thermoplastic and with a little more research…..
Without sounding negative, I read the V4 plan (actually a list of topics) several times, followed the V4 status posts, watched many of the monthly videos, followed the forum activity for much of the year, even with all that, I have no idea what direction PP wants to go. I’ve spent most of my career in complex development programs so I have some understanding of the process. With One Army, Project Kamp, and V4 as a collection of topics competing for attention, I’m not sure how you write a focused grant application or proposal to NGO’s or other potential funding sources.
I hope a little time can be set aside by the management team to either establish or communicate the focus of the future activities.
Yeah, a spring loaded cap/plug is what I was thinking. I think having pressure during the cooldown reduces the sectional shrinkage by compensating with length.
I ran an interesting experiment in my injection machine. I made a mold where two of the sides were 6 mm aluminum and two were wood laminate covered with aluminum tape. The results are shown below for two parts. The one on the left shows the side that was against the aluminum and the one on the right the side against the tape/wood. The aluminum side has the typical surface finish that shows the shrinkage patterns. The wood side is smooth. I think optimizing the thermal mass and conductivity of the wall material (basically the thermal diffusivity) can get you to a smooth finish.
If your primary school is the typical age 6-12, the machines are not really designed for that age and you will need to work out a safety and operations plan. I think @ppboys has done some planning in this area so maybe you can get some additional input.
It is not clear that the container approach is safe from a fume management point of view, looks like PP is just starting to do some evaluation https://davehakkens.nl/community/forums/topic/v4-fume-extraction-4/ .
None of these are insurmountable, but there is a lot of work to be done to implement a safe workspace at the primary school level.
@racheyc05 , It is great to see your enthusiasm for recycling plastic. The injection machine is not complicated but does require some mechanical and fabrication skill to use it safely, fabricate molds, do some trouble shooting as needed. Nobody expects you to have all those at your age. In addition to finding someone to provide the machine, It would be great if you could find a partner/mentor that has experience in those areas to help make the experience rewarding, fun, and safe.
If you look on the PP map, there are a number of people in your area that have shown interest https://map.preciousplastic.com/
There have been several threads one example: https://davehakkens.nl/community/forums/topic/roof-tiles-from-plastic-waste/ on making things like roof tiles and pavers out of mixed plastic and things like sand. Perhaps some of them are relevant.
That’s great work.
Have you weighed some of them to get an effective density or sectioned them to see what the void content is?
Yeah, HDPE or even PP is probably not a good enough material for small cross section beams to be useful unless they are supported along the way.
I wonder if you capped a fixed length mold and then applied axial compression during the cooldown, whether you would get a smoother surface and fewer voids. I do something similar with injected molds, it seems to help.