Plastic Extrusion & Molding: Difference between revisions

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{{Template:Category=Digital Fabrication}}
{{Template:Category=Bioplastics}}
{{Template:Category=Bioplastics}}


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


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'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).  
Plastic Extrusion and Molding (PEM) - It does not appear eco-friendly to discuss manufacture of plastics here, but if we are talking about working with bioplastics, such as cellophane from trees, for purposes such as year-round greenhouses for local food systems - then plastics have a highly relevant place in an ecological, localized economy. Extruded plastic forms include sheets, tubes, and others. Relevant for greenhouse glazing with polycarbonate extrusion (Lexan Thermoclear), or even UV-stabilized polyethylene (Solexx). Tubing for water pipes or 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). This is one example of a product where cheap feedstocks (ex, <15 cents/lb for virgin polyethylene resin (50 lb/cu ft)) - where each square foot of Solexx weighs on the order of a quarter pound) produce very expensive products (about $1/sq foot for Solexx) - where the feedstock price in that dollar of product is under 5 cents. If an extruder is available - combined with the knowhow - 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 producuring the knowhow for extruder fabrication and material extrusion - where the material costs for the device are expected t 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.
 
With these tools, cheap feedstocks 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.


=Collaboration=
=Collaboration=

Revision as of 20:14, 15 February 2011

Main > Digital Fabrication

Main > Materials > Bioplastics

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

'Extrusion' means squeezing out a long shape; extruding a circle gives you a cylinder. Extruded plastic forms include sheets, tubes, and others. Greenhouse glazing made of polycarbonate, or UV-stabilized polyethylene, 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 feedstocks 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/m2). 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.

Collaboration

Review of Project Status

Start with some websites:

Consultancy options from SPE: http://www.4spe.org/cc/searchform.php

PEM - Current Work

PEM - Developments Needed

PEM - General

PEM - Specific

PEM - Background Debriefing

PEM - Information Work

PEM - Hardware Work

PEM - Sign-in

Development Work Template

  1. PEM - Product Definition
    1. PEM - General
    2. PEM - General Scope
    3. PEM - Product Ecology
      1. PEM - Localization
      2. PEM - Scaleability
      3. PEM - Analysis of Scale
      4. PEM - Lifecycle Analysis
    4. PEM - Enterprise Options
    5. PEM - Development Approach
      1. PEM - Timeline
      2. PEM - Development Budget
        1. PEM - Value Spent
        2. PEM - Value available
        3. PEM - Value needed
    6. PEM - Deliverables and Product Specifications
    7. PEM - Industry Standards
    8. PEM - Market and Market Segmentation
    9. PEM - Salient Features and Keys to Success
  2. PEM - Technical Design
    1. PEM - Product System Design
      1. PEM - Diagrams and Conceptual Drawings
        1. PEM - Pattern Language Icons
        2. PEM - Structural Diagram
        3. PEM - Funcional or Process Diagram
        4. PEM - Workflow
      2. PEM - Technical Issues
      3. PEM - Deployment Strategy
      4. PEM - Performance specifications
      5. PEM - Calculations
        1. PEM - Design Calculations
        2. PEM - Yields
        3. PEM - Rates
        4. PEM - Structural Calculations
        5. PEM - Power Requirements
        6. PEM - Ergonomics of Production
        7. PEM -Time Requirements
        8. PEM - Economic Breakeven Analysis
        9. PEM - Scaleability Calculations
        10. PEM - Growth Calculations
      6. PEM - Technical Drawings and CAD
      7. PEM - CAM Files
    2. PEM - Component Design
      1. PEM - Diagrams
      2. PEM - Conceptual drawings
      3. PEM - Performance specifications
      4. PEM - Performance calculations
      5. PEM - Technical drawings and CAD
      6. PEM - CAM files whenever available
    3. PEM - Subcomponents
  3. PEM - Deployment and Results
    1. PEM - Production steps
    2. PEM - Flexible Fabrication or Production
    3. PEM - Bill of materials
    4. PEM - Pictures and Video
    5. PEM - Data
  4. PEM - Documentation and Education
    1. PEM - Documentation
    2. PEM - Enterprise Plans
  5. PEM - Resource Development
    1. PEM - Identifying Stakeholders
      1. PEM - Information Collaboration
        1. PEM - Wiki Markup
        2. PEM - Addition of Supporting References
        3. PEM - Production of diagrams, flowcharts, 3D computer models, and other qualitative information architecture
        4. PEM - Technical Calculations, Drawings, CAD, CAM, other
      2. PEM - Prototyping
      3. PEM - Funding
      4. PEM - Preordering working products
      5. PEM - Grantwriting
      6. PEM - Publicity
      7. PEM - User/Fabricator Training and Accreditation
      8. PEM - Standards and Certification Developmen
      9. PEM - Other
    2. PEM - Grantwriting
      1. PEM - Volunteer grantwriters
      2. PEM - Professional, Outcome-Based Grantwriters
    3. PEM - Collaborative Stakeholder Funding
    4. PEM - Tool and Material Donations
    5. PEM - Charitable Contributions
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