Open Source Ecology - User contributions [en]

Plastic Extrusion & Molding

2011-11-03T23:53:06Z

Servant74: /* See Also= */

{{Breadcrumb|Digital Fabrication}}
{{Breadcrumb|Materials|Bioplastics}}

==Overview==
We aim to develop computer-controlled tools that can make plastic parts of any shape.

==Details==
'Extrusion' means squeezing out a long shape; extruding a circle gives you a cylinder. Extruded plastic forms include sheets, tubes, and others. [[Greenhouses|Greenhouse]] glazing made of polycarbonate, or UV-stabilized polyethylene, [[:Category:Water|water]] pipes for plumbing and irrigation, plastic shapes and sheets are all doable with slight modifications of a basic extruder. The key may be a ram extruder (simple design) with inductive heating, to which various dies are adapted for profiles (extrusion), or molds for shapes (injection molding), or blowers and molds (blow molding).

With these tools, cheap feedstock can produce very expensive products. For instance, polyethylene resin costs less than 15 cents/lb (at a density of 50 lb/cubic ft (800g/l)). When extruded into panes of Solexx glass, the end product costs $1/square foot ($10.76/m<sup>2</sup>). This makes the end product about 20 times more valuable than the feedstock. If an extruder is available - combined with the know-how - then localized production of such glazing could probably yield cost predictions of something marginally higher than material costs, under the DIY-flexible enterprise scenario.

The challenge is procuring the know-how for extruder fabrication and material extrusion. The material costs are expected to be around $5k for the machine - structure, hydraulic ram, inductive heating, and die. This is a prime example of market inefficiency - where middlemen, R&D costs, company overhead, competitive waste, and proprietary technique - make the price so much higher than the open source flex fab scenario. The flex fab innovation required here is the fabrication of a generalized device for die extrusion, injection molding, and blow molding in one, where dedicated machines serve each purpose today.

==See Also==
{{Bioplastic Extruder}}
{{3D Printer}}
*http://plastics.turkavkaz.ru/processes/extrusion/
*http://en.wikipedia.org/wiki/Plastics_extrusion
*http://www.strictly-extrusion.com/
*[http://www.4spe.org/ Society of Plastics Engineers]
*Society of Plastics Engineers (SPE) [http://www.4plasticsresearch.org/ Online Technical Library]
**[[Emails to SPE]]

[[Category:Digital Fabrication]] [[Category:Bioplastics]]

Plastic Extrusion & Molding

2011-11-03T23:52:17Z

Servant74: /* Overview */

{{Breadcrumb|Digital Fabrication}}
{{Breadcrumb|Materials|Bioplastics}}

==Overview==
We aim to develop computer-controlled tools that can make plastic parts of any shape.

==Details==
'Extrusion' means squeezing out a long shape; extruding a circle gives you a cylinder. Extruded plastic forms include sheets, tubes, and others. [[Greenhouses|Greenhouse]] glazing made of polycarbonate, or UV-stabilized polyethylene, [[:Category:Water|water]] pipes for plumbing and irrigation, plastic shapes and sheets are all doable with slight modifications of a basic extruder. The key may be a ram extruder (simple design) with inductive heating, to which various dies are adapted for profiles (extrusion), or molds for shapes (injection molding), or blowers and molds (blow molding).

With these tools, cheap feedstock can produce very expensive products. For instance, polyethylene resin costs less than 15 cents/lb (at a density of 50 lb/cubic ft (800g/l)). When extruded into panes of Solexx glass, the end product costs $1/square foot ($10.76/m<sup>2</sup>). This makes the end product about 20 times more valuable than the feedstock. If an extruder is available - combined with the know-how - then localized production of such glazing could probably yield cost predictions of something marginally higher than material costs, under the DIY-flexible enterprise scenario.

The challenge is procuring the know-how for extruder fabrication and material extrusion. The material costs are expected to be around $5k for the machine - structure, hydraulic ram, inductive heating, and die. This is a prime example of market inefficiency - where middlemen, R&D costs, company overhead, competitive waste, and proprietary technique - make the price so much higher than the open source flex fab scenario. The flex fab innovation required here is the fabrication of a generalized device for die extrusion, injection molding, and blow molding in one, where dedicated machines serve each purpose today.

=See Also==
{{Bioplastic Extruder}}
{{3D Printer}}
*http://plastics.turkavkaz.ru/processes/extrusion/
*http://en.wikipedia.org/wiki/Plastics_extrusion
*http://www.strictly-extrusion.com/
*[http://www.4spe.org/ Society of Plastics Engineers]
*Society of Plastics Engineers (SPE) [http://www.4plasticsresearch.org/ Online Technical Library]
**[[Emails to SPE]]

[[Category:Digital Fabrication]] [[Category:Bioplastics]]

Talk:Community Business Models

2011-11-03T23:46:58Z

Servant74:

When expressing money issues, please reference a time frame. Inflation no matter what currency changes the economics of projects.

Thanks for the consideration.

Talk:Community Business Models

2011-11-03T23:46:28Z

Servant74: Note on Inflation...

When expressing money issues, please reference a time frame. Inflation no matter what currency changes the economics of projects.
Thanks for the consideration.

Talk:Cement

2011-11-03T23:32:31Z

Servant74:

Small batch cement mixers are great and have been used for a long time. But after doing some study, if manufacturing small cement mixers that can be efficient in people effort and $$ as well as environmentally friendly, making a small batch mixer similar to the one that Monolithic.com[http://www.monolithic.com] sells at their mixer sales page[http://www.monolithic.com/topics/concrete-mixers]. Their mixer only works on skid loaders, but a version could be made to work on the OCE Tractor!

Another option that would be very interesting is to make peristaltic mixer, that does 'just in time' mixing. It puts just the 'right' amount of aggregate, cement, and water (and optionally various other additives). Currently there are mixing trucks that are available that do this, but if there is a commercial batch plant nearby they are typically not as viable as using plants and mix-only trucks.

One of the nice things about peristaltic mixing is it is mixed on site, when requested, in the amount requested, not in larger batches. It's limitations are that it needs the supplies available when starting the project on site, but this is normally what is done if making it on site in out of the way areas. The equipment also does not have to be as 'big' as commercial trucks. Mixing is done typically with an auger arrangements, so a small amount is continuously being mixed just before being delivered into forms.

Just a few thoughts. If not on a first version, possibly ideas for the future.

Talk:Cement

2011-11-03T23:30:46Z

Servant74: It just didn't look right. Fix a few typing issues.

Small batch cement mixers are great and have been used for a long time. But after doing some study, if manufacturing small cement mixers that can be efficient in people effort and $$ as well as environmentally friendly, making a small batch mixer similar to the one that Monolithic.com[http://www.monolithic.com] sells at their mixer sales page[http://www.monolithic.com/topics/concrete-mixers].

Another option that would be very interesting is to make peristaltic mixer, that does 'just in time' mixing. It puts just the 'right' amount of aggregate, cement, and water (and optionally various other additives). Currently there are mixing trucks that are available that do this, but if there is a commercial batch plant nearby they are typically not as viable as using plants and mix-only trucks.

One of the nice things about peristaltic mixing is it is mixed on site, when requested, in the amount requested, not in larger batches. It's limitations are that it needs the supplies available when starting the project on site, but this is normally what is done if making it on site in out of the way areas. The equipment also does not have to be as 'big' as commercial trucks. Mixing is done typically with an auger arrangements, so a small amount is continuously being mixed just before being delivered into forms.

Just a few thoughts. If not on a first version, possibly ideas for the future.

Talk:Cement

2011-11-03T23:27:04Z

Servant74: A few ideas for mixing concrete.

Small batch cement mixers are great and have been used for a long time.
But after doing some study, if manufacturing small cement mixers that
can be efficient in people effort and $$ as well as environmentally friendly,
making a small batch mixer similar to the one that [http://www.monolithic.com] sells
at [http://www.monolithic.com/topics/concrete-mixers].

Another option that would be very interesting is to make peristaltic mixer, that does
'just in time' mixing. It puts just the 'right' amount of aggregate, cement,
and water (and optionally various other additives). Currently there are mixing
trucks that are available that do this, but if there is a commercial batch plant
nearby they are typically not as viable as using plants and mix-only trucks.

One of the nice things about peristaltic mixing is it is mixed on site, when requested,
in the amount requested, not in larger batches. It's limitations are that it needs
the supplies available when starting the project on site, but this is normally what is
done if making it on site in out of the way areas. The equipment also does not
have to be as 'big' as commercial trucks. Mixing is done typically with an
auger arrangements, so a small amount is continuously being mixed just before being
delivered into forms.

Just a few thoughts. If not on a first version, possibly ideas for the future.