Sawdust Paper Log Press Project

[Christophe]

Because for the mould, you just have to cut a large steel cylinder and drill it... Less risk of deformation of the matrix... less welding... but yes, the cylinder is more boring to store *

250 mm is already a bit of a hole for the filling, isn't it? And nothing prevents to make a funnel...

But in my opinion for combustion and drying, it should be kif kif...

Why imperative that it be open? For unmolding?

* incidentally it is to compare with your configuration...

[Ahmed]

Yes, that was one of my working hypotheses at the start: since a cylinder receives equal pressure evenly distributed, a plastic tube is even conceivable, which greatly simplifies drilling. However, the development of a central hole is not easy in this case. The open hole accelerates drying and also allows good combustion in this case of a fairly massive brick: as I have already specified, the edge of the brick ignites first and then it is through the two holes that the flames are active...

Note: the demoulding does not intervene in the choice of a through hole or not because I could very well make it non through by shortening the two tubes without it interfering with anything at the exit of the log...

[Ahmed]

I watched paper recycling videos to see how heterogeneity of incoming material is handled at an industrial stage. In fact, it also looks quite complicated for them and it requires a lot of energy, water, very complex equipment and a lot of unsavory processes: enough to get a much less "green" idea of ​​recycling ...

In the same vein, I did a dry press test to get rid of what cannot decently pass through my wet process, such as the water-repellent kraft papers of certain bags (those with handles), as well as the papers which are incorporated or are coated with a thin film of polyethylene. My beginning device is inspired by the lawn press that claimed Christophe and produced a few small bundles, but it's still very laborious. It would be better with a larger format, but I had aimed small by betting on compression..
On the other hand, I have just discovered a video which shows a device which offers a more interesting approach. And this, especially since a simple scrap of PVC pipe and a log as a pusher can advantageously replace this product. I also "dry" made a first log and it looks pretty good; remains to be tested in the combustion phase...

[sicetaitsimple]

remains to be tested in the combustion phase...

Yes... not sure it's extraordinary. Once the "packaging" has been burned, it risks disintegrating in the hearth. You tell us.

[sicetaitsimple]

Alright, so what? Almost 3 months without news!
Do you heat yourself, even very partially, with your logs?
And if so, what gives?

[Ahmed]

For the moment, the objective was above all to assess the feasibility and the constraints of this production. From another point of view, it was a question of reabsorbing a stock of raw material under a more restricted volume and a usable configuration. On this last point, I am satisfied, but I am content to accumulate since I currently have more conventional fuel.
With the cold, it becomes difficult to produce mainly due to longer drying times (=0 in freezing weather!).
The main difficulty remains the preliminary fragmentation which remains manual, but must imperatively evolve towards a mechanized form. Indeed, it is necessary to go through this phase given that the usual alternative of the direct technique in a "pulper" is downright incompatible with the energy end sought: it is too greedy in electricity and the EROI would be disastrous.

To answer the question concerning the "dry" logs mentioned above, there is indeed some disintegration, but it is still limited and acceptable. It can't be compared with the log reduced to moist and pressed pulp, but it is an interesting complementary possibility.

[sicetaitsimple]

The main difficulty remains the preliminary fragmentation which remains manual, but must imperatively evolve towards a mechanized form. Indeed, it is necessary to go through this phase given that the usual alternative of the direct technique in a "pulper" is downright incompatible with the energy end sought: it is too greedy in electricity and the EROI would be disastrous.

Do you have any leads? (I'm not going to redo the blow of the meat grinder).

[Ahmed]

After studying the different systems offered both by the industry (for businesses or activities seeking to reduce the size of cardboard packaging) and by DIYers of paper/cardboard logs faced with the same problem of fragmentation, I have nothing found that is both very convincing and simple. However, I perceived several tracks which, put end to end, if possible skilfully (!), could lead to an operational tool.
I have run out of time so far to move on to a more practical phase. It's not wasted time as I keep it all in the background in order to bring together ideas and materials that could "merge" harmoniously. At this stage of reflection, I would go for a cantilever horizontal single-axis shredder, which would be equipped with two types of alternating knives. One radial, the other, shorter but transverse, to make the two cuts necessary to obtain small squares. This would overcome the defect of many amateur realizations which obliges the user to move the cardboard laterally, since the notches do not overlap. As for the cantilever arrangement, I have observed it on a commercial model and it allows any width to be passed with a not too wide grinder: for large formats, it is enough to make several passes, like with a ham slicer...

[sicetaitsimple]

Alright, we'll follow that. Commissioning for the production season in the summer of 2023? Good continuation.

[Ahmed]

Thank you for your support! Yes, I hope to take advantage of the winter period to be, as you say, operational in the right season.