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ForMatter/Processes/formative/Extrusion

proc_extrusion

Extrusion

formative · aluminum extrusion, polymer extrusion, profile extrusion

highlast updated 2026-04-28

Compatible materials

Aluminum 6061

ABS (Acrylonitrile Butadiene Styrene)

PETG (Glycol-Modified PET)

PLA (Polylactic Acid)

Aluminum 6063+ 18 more below

Material is pushed through a die — like toothpaste through a tube — and emerges as a continuous profile of whatever cross-section the die holds. The reason aluminum window frames, plastic gutters, pasta, and the entire 80/20 framing system exist.

Continuous forming process where a billet (metal) or melt (polymer) is forced through a die opening. Aluminum extrusion runs at ~450–500 °C; thermoplastic extrusion at 150–280 °C depending on polymer. Cross-section is constant along the length; complexity limited by die-design rules (uniform wall, no thin tongues).

Scale & Tolerance

scale (mm)1 – 30000
tolerance (mm)0.3
skilladvanced for die design; beginner for specifying off-the-shelf profiles
min skillexpert
whereindustrial
costvery low per meter at volume; die cost moderate to high

Equipment

school shoprare — desktop polymer extruders (Filabot) for filament making
professionalpolymer single- and twin-screw extruders; aluminum extrusion presses 1500–10000 tons
industrialhorizontal aluminum extrusion lines with quench, stretch, age

Environmental

energy usemoderate to high (especially metal billet preheat)
waste streamoff-cuts, butt-ends — recyclable in-process for both metal and thermoplastic
consumablesdie wear, lubricant

Trade-offs

constraints · what is lost · what is gained

Aluminum 6063

constraints
- constant cross-section along length (the defining constraint)
- wall-thickness uniformity within ±10 percent across the profile to prevent die wear and finish defects
- no sharp internal corners (radius ≥ 0.5 mm)
- enclosed hollows require porthole / bridge dies, doubling die complexity
what is lost
- extrusion lines along the length are inherent — visible in raking light unless polished
- mill finish is matte and slightly orange-peel; cosmetic surfaces require anodizing or polishing
what is gained
- continuous-length structural profiles at very low per-meter cost
- complex cross-sections (T-slot, compound multi-cavity) impossible by milling
- integration of multiple fastener channels and cable raceways into a single profile

Plain language. Neutral framing — perfection is contextual, defined by use. Cf. Winchester, The Perfectionists (HarperCollins, 2018).

James Carpenter (living — quote)

The extruded glass tubes with a prismatic internal profile gather, concentrate, and display ambient light while refracting views and reflections.

James Carpenter, Refracted Light Field, Salt Lake Courthouse, Salt Lake City, Utah (2003–2011), as documented in Schröpfer, Material Design: Informing Architecture by Materiality (Birkhäuser, 2011), 'Capturing the Ephemeral' chapter. The passage is the canonical demonstration that extrusion is a process — not a material — and that anything which can be pushed through a die can take a die-shaped section: aluminum profiles for window frames and 80/20 framing on one end, glass tubes with internal prismatic geometry for architectural light-refraction installations on the other. James Carpenter (b. 1949) is founder of James Carpenter Design Associates, New York; verified living 2026-04-28.

Compatible materials

Aluminum 6061

ABS (Acrylonitrile Butadiene Styrene)

PETG (Glycol-Modified PET)

PLA (Polylactic Acid)

Aluminum 6063

Aluminum Extruded L-Angle (Structural)

Aluminum Extruded U-Channel (Structural)

Aluminum T-Slot Extrusion, 1010 / 25mm Imperial Series (80/20-style)

Aluminum V-Slot Extrusion, 2020 (OpenBuilds-style)

ASA (Acrylonitrile Styrene Acrylate)

PHA (Polyhydroxyalkanoate)

Magnesium AZ31B

Natural Rubber (vulcanized)

Neoprene Rubber (Polychloroprene Solid Sheet / Gasket Grade)

PEEK (Unfilled)

PET (Polyethylene Terephthalate, Clear Bottle Grade)

PLA (Marine-Degradable Variant, BioPBS / Mango Materials Blend)

High-Density Polyethylene (HDPE)

Polypropylene Homopolymer (PP)

Polystyrene (GPPS, General-Purpose / Crystal)

Thermoplastic Polyurethane (TPU)

Silicone Foam (Closed-Cell Medical / Footwear / Gasket Grade)

TPE (Thermoplastic Elastomer, SEBS / SBS Family)

Second life

reversibilitylow for the extruded profile; high for the alloy / polymer — extrusion scrap re-melts.

output recyclabilityyes

waste streams

butt-end and front-end scrap (re-melted in-house)
die-lubricant residue
cooling-water

repair compatible withTIG Welding, CNC Milling

The Aluminum Extruders Council technical literature; ASM Handbook Vol. 14 Forming and Forging.

Citations

book · Lefteri, Making It: Manufacturing Techniques for Product Design, 2nd ed. (Laurence King, 2012), 'Extrusion' p. 96.
book · Schröpfer, Material Design: Informing Architecture by Materiality (Birkhäuser, 2011), 'Capturing the Ephemeral' chapter — James Carpenter's Refracted Light Field (Salt Lake Courthouse, 2003–2011) as the canonical case for glass-tube extrusion with internal prismatic profile.

Concordance

House vocabulary — terms ForMatter uses with intent.

anisotropic: Direction-dependent. Wood reads differently along the grain than across it; rolled steel is stiffer along the rolling direction. The Principled-BSDF anisotropic input rotates the highlight to match.
anodize: Electrochemical oxide layer grown on aluminum (Type II / III), titanium, or niobium. Type II accepts dye for color; titanium / niobium use voltage-driven thin-film interference instead of dye. The CMF entry covers the seal step that locks the color in.
application: What the thing IS, in the world. The third entity, peer of material and process. A water bottle, a chair, an extruded-aluminum profile.
BRDF: Bidirectional Reflectance Distribution Function. The math behind how a surface returns light for any incoming and outgoing direction. The PBR model is a parameterized BRDF.
channeled: A voice block written within a dead author's philosophy, marked and cited. Distinct from a verbatim quote. Roland Barthes channeled on PMMA reads like Barthes; the citation attributes the lineage.
CMF: Color, Material, Finish — the trio designers specify together when handing a part off for production. ForMatter's Finish entity is the F in CMF: 10 categories — polish / anodize / patina / plate / coating / texture / cut / mold_finish / glaze / stone_finish — and entries under each. Every finish entry pairs to the materials and processes it suits.
choral fugue: ForMatter's register. Subject stated plainly (freshman tier), answered in technical and sensorial registers, countersubjects from linked processes and applications, citations as final stretto. Voice blocks where canon attaches.
clearcoat: A second specular layer over the base surface. Glossy plastics and lacquered woods get a clearcoat term in the PBR table. IOR 1.5 by default.
compatibility (process): Each process entry lists which materials it can work. The cross-ref renders as sphere pills so the gallery feeling extends inward.
confidence: Each entry tagged high / medium / low. A senior's low-confidence-with-three-citations beats a freshman's high-confidence-with-none. The label is a contract with the reader, not a brag.
crystalline (finish): A faceted-surface read — gemstones, glassy minerals, ice. Drives PBR defaults: IOR 2.42 (diamond), transmission 1.0, low roughness.
derive_pbr(): The build's single source of truth — sphere palette + finish enum → Principled-BSDF starter values. One function feeds the entry-page table, the per-host snippets, the glTF export, and the Three.js Live Preview.
finish (entity): ForMatter's CMF layer — surface treatments and conditions a designer chooses for a given material and process. Categories: polish, anodize, patina, plate, coating, texture, cut, mold_finish, glaze, stone_finish. Distinct from the sphere `finish` enum (metallic / matte / glossy / etc.) which is the visual register of the proxy.
freshman / senior register: Two registers in every entry — the plain freshman description and the technical / sensorial one. Same database, two readers, no extra subscription.
glTF: GL Transmission Format — the open 3D-asset standard every modern app reads. ForMatter emits a .gltf material doc per material. Open standard, designer-friendly handoff.
IOR: Index of Refraction. How much light bends entering the surface. Air 1.0, water 1.33, glass 1.5, diamond 2.42. Drives transmission and the specular term.
iridescent (finish): Hue-shifted accent over base. Anodized titanium and niobium, opal, paraíba. Drives PBR defaults: low metalness, full iridescence, clearcoat.
iridescence: Thin-film interference layer over the base material. KHR_materials_iridescence in glTF, MeshPhysicalMaterial.iridescence in Three.js. Tunable from the FOCUS slider on iridescent / pearlescent entries. The ior and thickness range together set the visible color sweep — opal uses a 100–800 nm thickness range (film, not wavelength) to span the full visible band.
lite-PBR: ForMatter's PBR approach — Principled-BSDF starter values per entry, no measured BRDFs, no commercial assets. Reasonable defaults from the finish enum, per-entry numeric overrides where you have a real reason.
Live Preview: The Three.js shader ball that replaces the static CSS sphere on every entry page. One render path for every category — metals, woods, polymers, ceramics, paints, textiles, gemstones, glass. Same derive_pbr() values, real-time lit by a synthetic studio environment, draggable. Optional — toggle in Preferences.
material: What the thing is MADE OF. The first entity. Aluminum 6061, white oak, soda-lime glass.
metallic (finish): Specular highlight, deep shadow rim. Drives PBR defaults: metalness 1, low roughness, IOR 1.45. Polished steel, gold, copper.
mood board: Folded into the Project workspace at /project.html. The mood-board upload, palette extraction, character chips, and matcher results all live alongside the collected items grid and the save .formatter / save PDF / open .formatter actions — one feature, one page.
Ollama: Local-LLM scaffold on the Project page. Off by default. When toggled on in Preferences AND Ollama is reachable at localhost:11434, the natural-language input box ('something soft and warm with a wet read') asks the model to translate the description into character-chip toggles. Never invents material properties; the LLM only translates intent into existing chip vocabulary. The keyword fast-path (chips alone, no LLM) is the default — see suite-wide ai-integration pattern.
project: The full workspace at /project.html — collected materials, processes, applications, finishes plus an optional mood-board image whose dominant colors search the library for matches. Save / open .formatter files round-trip the project state.
patina: A chemical color shift on metal — heat-blue on steel, fume-black on silver, verdigris on copper, gun-blue on tool steel, ferric on copper. CMF-layer entry; cited by both the material and the process pages that produce it.
PBR: Physically-Based Rendering. The shading model every modern 3D app uses, parameterized by metallic / roughness / IOR / transmission / clearcoat / sheen. ForMatter publishes starter values for every material entry.
SPI mold finish: Society of the Plastics Industry mold-cavity finish standard. A1 / A2 / A3 (diamond polish, mirror), B1 / B2 / B3 (paper, semi-gloss), C1 / C2 / C3 (stone, matte), D1 / D2 / D3 (dry blast, textured). The finish prints from the mold cavity onto the molded part — a designer picks the SPI grade with the molder when specifying the tool.
Principled BSDF: Blender's name for the consolidated PBR shader. Most other apps ship the same shader under different names (Standard Surface, ShaderGraph, Substance). One node, every output.
process: How the material is MADE INTO the thing. The second entity. Cast, machined, kerf-bent, anodized, planished, granulated. Process is a peer of material, not a footnote.
quote: A voice block carrying a verbatim quotation from a living author, with citation. Distinct from a channeled block. Living = quote only; the rule is enforced at the schema layer.
roughness: Microsurface scatter. 0 is mirror-smooth; 1 is fully diffuse. Most real surfaces sit between 0.2 and 0.8.
sphere proxy: ForMatter's visible-character stand-in for every material. CSS-gradient driven by the entry's palette and finish, not a baked render. Honest about being a proxy, scales cheaply, tweakable in one place.
substitute: A peer material that could fill a similar role. Cross-references render as sphere pills inside an entry — the gallery feeling extends inward.
transmission: How much light passes through. 1 is fully transparent; 0 is opaque. Glass, gemstones, clear plastics carry transmission.
PVD: Physical Vapor Deposition — vacuum-chamber sputter or cathodic-arc deposition of a thin ceramic film onto a metal substrate. The CMF-layer's modern coating chemistry: TiN (gold), ZrN (champagne), CrN (pewter), TiCN (warm bronze / rose-gold), AlTiN (charcoal-anthracite, near-black), DLC (deep black). Hard, doesn't tarnish, paint-thin.
VDI 3400: German engineering reference standard for mold-cavity texture (Erodieren bearbeitete Werkstückoberflächen). The full scale runs reference plates 0–45 by Ra value; production specs typically draw from 12–45 because plates 0–11 require diamond-mirror polish on the mold cavity and are rarely commissioned in commercial tooling. Pairs with the SPI standard; both define what gets cut into the mold.
voice block: A versal block where a real authored voice attaches to the material or process. Schema-tagged with status (living / dead) and mode (quote / channeled). Citations always.
woodgrain (finish): Directional sheen with grain ring. Drives PBR defaults: anisotropic 0.6, medium roughness, no metalness. Every wood entry.

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Extrusion

Scale & Tolerance

Equipment

Environmental

Trade-offs

Second life

Citations

Further reading

Concordance

ForMatter

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