MILL Wiki - User contributions [en]

Acrylonitrile Styrene Acrylate (ASA)

2025-11-09T18:11:12Z

Mtanjutco3:

ASA (Acrylonitrile Styrene Acrylate)

=== Specific Properties ===

* Printing Temperature (oC): 240 - 260
* Hot bed Temperature (oC): 90 - 110
* Printing Speed (mm/s): 50
* Density (g/cm3): 1.05 - 1.09
* Bending Strength (MPa): 60

=== On the Atomic Level ===
At the molecular level, ASA is very similar to ABS in structure: a matrix of styrene-acrylonitrile copolymer with finely dispersed, partly cross-linked acrylic-ester rubber particles functioning as impact modifiers. Wikipedia+1
Key structural features and implications:

* The styrene units provide ease of processing and rigidity; the acrylonitrile units improve chemical and heat resistance. Wikipedia+1
* The acrylic ester rubber (e.g., n-butyl acrylate) does ''not'' contain double bonds (unlike butadiene rubber), which enhances UV- and weather-resistance significantly—claimed to be ~10× that of ABS. Wikipedia+1
* ASA’s glass transition temperature (Tg) is around ~100 °C (slightly lower than ABS’s ~105 °C) thereby providing slightly better low-temperature performance. Wikipedia+1
* The improved weathering resistance means that ASA retains its colour, gloss and mechanical properties under outdoor exposure much better than many standard thermoplastics.

=== Production Process ===
ASA is an amorphous thermoplastic copolymer developed as an alternative to Acrylonitrile butadiene styrene (ABS) with enhanced weather- and UV-resistance. Wikipedia+2SyBridge Technologies+2

The polymer is typically produced via a '''graft process''' in which a rubbery acrylic ester elastomer (powder form) is introduced during the copolymerisation of styrene and acrylonitrile. Wikipedia+1

Alternatively, all three monomers (styrene + acrylonitrile + acrylic ester) can be reacted together in one polymerisation process. Wikipedia

Because ASA lacks the butadiene rubber phase found in ABS, the resulting material exhibits superior outdoor durability.

=== Safety, Hazards, and Environmental Measures ===
'''Safety and usage aspects:'''

* ASA is generally processed like other thermoplastics (injection moulding, extrusion, thermoforming). Typical safety controls (ventilation, temperature control, protective equipment) apply as with other polymers.
* One hazard: when ASA is burned or degraded, it can produce toxic smoke. PR Newswire
* Because ASA has better UV-resistance and long-term stability in outdoor use, it is a safer choice for exterior parts that would otherwise degrade or crack under sun exposure.

'''Environmental / disposal considerations:'''

* Although ASA is more durable and weather-resistant (which is a benefit for long-life applications), its durability also means that without proper recycling or disposal, ASA parts may persist in the environment for a long time.
* Designers and manufacturers of outdoor applications should consider the end-of-life stage: reuse, recycling, or recovery of ASA components rather than simple disposal.
* Given its increased usage in automotive, building, outdoor furniture and 3-D printing, efforts to establish recover/recycle streams for ASA will support more sustainable use. PR Newswire+1
* Because ASA resists weathering, colour-fading, and mechanical deterioration, its lifetime is extended — this can contribute positively (less frequent replacement) but also raises material-life-cycle questions (longer persistence if not recycled).

=== Prints ===

Polylactic Acid (PLA)

2025-11-09T18:06:00Z

Mtanjutco3:

[[File:Untitled design (2) (1).png|thumb|600x600px|The relative property levels of PLA.]]PLA (Polylactic Acid) is a commonly used '''thermoplastic filament''' in FDM 3D printing. It is recyclable, non-toxic, and the primary filament used by the MILL's processing team.

=== Specific Properties ===

* Printing Temperature (oC): 190 - 220
* Hot bed Temperature (oC): 60
* Printing Speed (mm/s): 30 - 70
* Density (g/cm3): 1.21
* Bending Strength (MPa): 68 ± 2

[[File:PLA Atomic.png|thumb|The atomic structure of PLA.]]

=== On the Atomic Level ===
Formula: (C3H4O2)n

At the molecular level, PLA is an '''aliphatic polyester''' composed of repeating '''ester linkages''' derived from lactic acid (2-hydroxypropanoic acid). The basic repeating unit has the structure:

[-O–CH(CH₃)–CO–]ₙ

Lactic acid exists in two mirror-image forms, '''L-lactic acid''' and '''D-lactic acid'''. As a result, PLA can be synthesized as poly(L-lactic acid) (PLLA), poly(D-lactic acid) (PDLA), or a mixture of both. The combination of these enantiomers can form '''stereocomplexes''', which have higher melting points and better thermal stability than pure PLLA or PDLA.

Key thermal properties include:

* '''Glass transition temperature (Tg):''' ~60–65 °C
* '''Melting temperature (Tm):''' ~130–180 °C (depending on crystallinity and stereochemistry)

The degree of crystallinity significantly influences PLA’s mechanical strength, transparency, and heat resistance. These atomic-level features — the chiral centers, ester bonds, and chain flexibility — also make PLA biodegradable under suitable environmental conditions.

=== Production Process ===
Polylactic acid (PLA) is a biodegradable thermoplastic polymer produced mainly from renewable biomass sources such as corn starch, sugarcane, cassava, or sugar beet pulp. These materials provide the monomer '''lactic acid''', which is polymerized into PLA.

There are two primary industrial methods of production:

# '''Condensation (poly-esterification) of lactic acid:''' In this route, lactic acid monomers condense, releasing water with each new ester linkage formed. The reaction is typically carried out below about 200 °C to prevent excessive formation of lactide.
# '''Ring-opening polymerization (ROP) of lactide:'''[[File:PLA Reaction.jpg|thumb|The reaction formula for PLA through condensation of Lactic Acid or ring-opening polymerization of lactide.]]The cyclic dimer of lactic acid, called ''lactide'', is polymerized using metal catalysts (commonly tin(II) ethylhexanoate). This method yields higher molecular-weight PLA and is the dominant industrial process.

After polymerization, the PLA resin can be processed by casting, extrusion, or injection molding. Depending on cooling rate, additives, and stereochemical composition, it can form either '''amorphous''' (transparent) or '''semi-crystalline''' (opaque) structures

=== Safety, Hazards, and Environmental Measures ===
'''Safety and consumer aspects:'''

PLA is generally recognized as '''biocompatible and non-toxic'''. In medical uses (such as sutures or implants), it degrades naturally into lactic acid, a compound easily metabolized by the human body. However, its relatively low heat resistance (softening around 60 °C) limits its use for hot-liquid or high-temperature applications.

During manufacturing, workers should maintain adequate ventilation and temperature control, though PLA is safer to handle than many petrochemical-based plastics.

'''Environmental considerations:'''

PLA’s renewable origin gives it a lower carbon footprint compared to conventional plastics derived from petroleum. However, despite being marketed as '''biodegradable''' or '''compostable''', it generally requires '''industrial composting conditions''' (temperatures around 60 °C and controlled humidity) to fully break down. In regular soil or marine environments, degradation is much slower.

PLA can be '''mechanically recycled''' or '''chemically depolymerized''' back into lactic acid through hydrolysis or thermal processes. Expanding these recycling pathways is important to prevent PLA from ending up in landfills or natural ecosystems.

To ensure safe and sustainable use, manufacturers are encouraged to:

* Develop closed-loop recycling and composting systems.
* Avoid using PLA in applications exposed to prolonged heat or sunlight.
* Clearly label PLA products to direct them to appropriate disposal or recycling facilities.

=== Prints ===

Polyethylene Terephthalate (PET/PETG)

2025-11-09T17:57:03Z

Mtanjutco3:

[[File:PROseriesPETG (2).png|thumb|600x600px|The relative property levels of PETG.]]
PETG (Polyethylene Terephthalate) is a commonly use filament FDM 3D printing. It is a more durable version than PLA so can be used in higher impact strength related prototypes. Notably, PETG is used commonly in the Take-a-T Make-a-T project at the MILL.
[[File:Screenshot 2025-10-26 133956.jpg|thumb|382x382px|The atomic structure of PETG.]]

=== Specific Properties ===

* Printing Temperature (oC): 220 - 250
* Hot bed Temperature (oC): 70 - 90
* Printing Speed (mm/s): 40 - 80
* Density (g/cm3): 1.28
* Bending Strength (MPa): 67.5 ± 2.5

[[Index.php?title=File:PLA Atomic.png|link=https://millwiki.mse.gatech.edu/File:PLA_Atomic.png|thumb]]

=== On the Atomic Level ===
At the molecular level, PET is a '''thermoplastic polyester''' composed of repeating '''ester linkages''' between '''aromatic terephthalate units''' and '''aliphatic ethylene glycol units'''. Its repeating structural unit is:

[−O−CH2−CH2−O−CO−C6H4−CO−]n

* The '''benzene ring (C₆H₄)''' in terephthalate provides rigidity and strength, while the '''ethylene (CH₂–CH₂)''' segment imparts flexibility.
* The '''ester groups (–CO–O–)''' form strong dipole interactions, giving PET its high tensile strength and thermal stability.
* '''Crystallinity''' plays a key role:
** '''Amorphous PET''': transparent, flexible, lower barrier properties.
** '''Semi-crystalline PET''': opaque, higher strength and resistance to deformation.
* PET’s '''glass transition temperature''' is around 70 °C, and its '''melting point''' is approximately 250 °C.

These atomic-scale characteristics make PET highly suitable for both '''structural''' and '''packaging''' applications.

=== Production Process ===
Polyethylene terephthalate (PET) is produced through a '''polycondensation reaction''' between '''ethylene glycol (EG)''' and '''terephthalic acid (PTA)''', or alternatively '''dimethyl terephthalate (DMT)'''. Two industrial routes are widely used:

# '''Direct Esterification Route (PTA/EG Process):'''
#* PTA and EG are combined at elevated temperatures (~250 °C) to form '''bis(2-hydroxyethyl) terephthalate (BHET)''' and water.
#* The mixture then undergoes '''polycondensation''', releasing excess ethylene glycol and forming long PET polymer chains.
#* Catalysts such as '''antimony trioxide''', '''titanium butoxide''', or '''germanium dioxide''' are used to accelerate polymerization.
# '''Transesterification Route (DMT Process):'''
#* DMT reacts with EG to form BHET and '''methanol''' as a by-product.
#* The BHET is then polymerized under heat and vacuum to yield PET.

The resulting polymer can be processed into '''amorphous''' (transparent) or '''semi-crystalline''' (opaque) forms depending on cooling rates and crystallization conditions. Rapid cooling prevents molecular alignment, while slower cooling promotes crystalline structure formation.

=== Safety, Hazards, and Environmental Measures ===
'''Occupational and consumer safety:'''

* PET itself is '''chemically stable and non-toxic''', but '''catalyst residues''' (particularly '''antimony compounds''') can migrate in trace amounts from containers into food or beverages under high temperatures (e.g., prolonged sunlight exposure).
* Workers in PET manufacturing must control exposure to '''ethylene glycol vapors''', '''antimony dust''', and high-temperature processing conditions, typically using '''ventilation systems''', '''PPE''', and '''temperature-controlled reactors'''.

'''Environmental impacts:'''

* PET is '''non-biodegradable under normal conditions''', contributing to long-term plastic waste accumulation and '''microplastic pollution''' through fiber shedding or fragmentation.
* Recycling mitigates this impact. PET can be '''mechanically recycled''' into new bottles or '''chemically depolymerized''' back into its monomers (BHET, EG, PTA).
* Certain microorganisms, such as ''Ideonella sakaiensis'', have shown the ability to '''enzymatically degrade PET''', offering future solutions for biorecycling.

'''Safety and sustainability measures include:'''

* Using '''food-grade catalysts''' (e.g., titanium-based alternatives to antimony).
* Maintaining '''closed-loop recycling systems''' to recover and reuse PET materials.
* Minimizing high-temperature storage of PET bottles to prevent antimony migration.

=== Prints ===

Index.php?title=Thermo-Calc

2025-10-29T20:18:40Z

Mtanjutco3: Blanked the page

Category:Equipment

2025-10-29T20:15:06Z

Mtanjutco3:

See our [https://sites.gatech.edu/mse-mill/equipment/list/ equipment status list and SOPs].

Learn more about our [https://mill.mse.gatech.edu/equipment/about/ Equipment Teams].

==Characterization==
*[[Scanning Electron Microscope (SEM)]]
*[[Sputter Coater]]
*[[Optical Microscopy]]
**Digital Microscope
**Stereomicroscope
**Inverted Microscope
*[[Optical Profilometer]]
*[[Fourier-Transform Infrared Spectrometer (FTIR)]]
*[[X-ray Diffractometer (XRD)]]
*[[X-ray Fluorescence Spectrometer (XRF)]]
*[[Infrared Spectroscopy]]
*[[Plasma Sputtering]]

==Measurement==
*[[Mechanical Tester]]
*[[Microhardness Tester]]
*[[Differential Scanning Calorimeter (DSC)]]
*[[Thermogravimetric Analyzer (TGA)]]
*[[Moisture Analyzer]]
*[[Infrared Camera]]
*[[UV-Vis Spectrophotometer]]
*[[Contact Angle Goniometer]]
*[[Analytical Balance]]
*[[Brookfield DV2T Viscometer|Viscometer]]
*[[Gas Pycnometer|Pycnometer]]
*[[Abrasion Tester]]
*[[Squidstat]]

==Processing==

=== 3D Printing ===
* [[Fused Filament Fabrication (FFF)]]/Fused Deposition Modeling (FDM) Printers
** Hyrel System 30M
** Prusa i3 MK3S
* [[Stereolithography (SLA)]] Printers
** Prusa Resin Printer
** Formlabs resin printer
* [[Filament Recycling]]
** Granulator
** Filament Extruder

=== Science of Art ===
* Hot Plates
* [[Furnaces & Kilns]]
* Vinyl Cutter

=== Textiles ===
* [[Sewing Machine]]
* [[Embroidery Machine]]
* [[Screen Printer]]
* [[Heat Press]]

=== Other ===
* Vacuum Former
* [[Liquid Nitrogen Generator]]

=== Ceramics Lab (Love 369) ===
* [[Uniaxial Press]]
* [[Ball Mill]]
* Vibratory Tumbler
* Sieve Shaker
* [[Furnaces & Kilns|Electric Furnaces]]

Polylactic Acid (PLA)

2025-10-27T20:01:18Z

Mtanjutco3:

File:PLA Reaction.jpg

2025-10-27T19:40:28Z

Mtanjutco3:

Category:Materials

2025-10-27T15:28:03Z

Mtanjutco3: Added ABS

== Filaments ==
* Regular
** [[Polylactic Acid (PLA)]]
** [[Polyethylene Terephthalate (PET/PETG)]]
** [[Acrylonitrile Styrene Acrylate (ASA)]]
** [[Acrylonitrile Butadiene Styrene]]

* Flexible/Semiflexible
** [[Thermoplastic Polyurethane (TPU)]]
** [[Nylon]]
** [[Thermoplastic Elastomer (TPE)]]
** [[Polypropylene (PP)]]

* Specialty
** [[Polyether Ether Ketone (PEEK)]]
** [[Polyetherimide (PEI/Ultem)]]
** [[Polyphenylene Sulfide (PPS)]]
** [[Co-Polyester (CPE/nGen/XT/HT)]]
** [[Filled Filaments|Filled Filaments (Wood, metals, CF)]]
** [[Polyvinyl Acid (PVA)]]
** [[Polyoxymethylene (POM)]]
** [[High Impact Polystyrene (HIPS)]]

Acrylonitrile Styrene Acrylate (ASA)

2025-10-27T15:27:38Z

Mtanjutco3: Added Template

ASA (Acrylonitrile Styrene Acrylate)

=== Specific Properties ===

* Printing Temperature (oC):
* Hot bed Temperature (oC):
* Printing Speed (mm/s):
* Density (g/cm3):
* Bending Strength (MPa):

=== On the Atomic Level ===

=== Prints ===

Polyethylene Terephthalate (PET/PETG)

2025-10-26T18:21:38Z

Mtanjutco3:

Polyethylene Terephthalate (PET/PETG)

2025-10-26T18:08:05Z

Mtanjutco3:

File:PROseriesPETG (2).png

2025-10-26T18:07:46Z

Mtanjutco3:

Polyethylene Terephthalate (PET/PETG)

2025-10-26T17:54:19Z

Mtanjutco3: Images/template

[[File:PROseriesPETG (1).webp|thumb|597x597px|The relative property levels of PETG.]]
PETG (Polyethylene Terephthalate) is a commonly use filament FDM 3D printing. It is a more durable version than PLA so can be used in higher stress related prototypes. Notably, PETG is used commonly in the Take-a-T Make-a-T project at the MILL.
[[File:Screenshot 2025-10-26 133956.jpg|thumb|382x382px|The atomic structure of PETG.]]

=== Specific Properties ===

* Printing Temperature (oC): 220 - 250
* Hot bed Temperature (oC): 70 - 90
* Printing Speed (mm/s): 40 - 80
* Density (g/cm3): 1.28
* Bending Strength (MPa): 67.5 ± 2.5

[[index.php?title=File:PLA_Atomic.png|link=https://millwiki.mse.gatech.edu/File:PLA_Atomic.png|thumb]]

=== On the Atomic Level ===

=== Prints ===

File:Screenshot 2025-10-26 133956.jpg

2025-10-26T17:40:37Z

Mtanjutco3:

File:PROseriesPETG (1).webp

2025-10-26T17:37:29Z

Mtanjutco3:

Polylactic Acid (PLA)

2025-10-26T17:29:22Z

Mtanjutco3:

[[File:Untitled design (2) (1).png|thumb|600x600px|The relative property levels of PLA.]]PLA (Polylactic Acid) is a commonly used thermoplastic filament in FDM 3D printing. It is recyclable, non-toxic, and the primary filament used by the MILL's processing team.

=== Specific Properties ===

* Printing Temperature (oC): 190 - 220
* Hot bed Temperature (oC): 60
* Printing Speed (mm/s): 30 - 70
* Density (g/cm3): 1.21
* Bending Strength (MPa): 68 ± 2

[[File:PLA Atomic.png|thumb|The atomic structure of PLA.]]

=== On the Atomic Level ===

=== Prints ===

Polylactic Acid (PLA)

2025-10-26T15:30:07Z

Mtanjutco3: Add images and sections

PLA (Polylactic Acid) is a commonly used thermoplastic filament in FDM 3D printing.

It is recyclable, non-toxic, and the primary filament used by the MILL's processing team.

=== Specific Properties ===

* Printing Temperature (oC): 190 - 220
* Hot bed Temperature (oC): 60[[File:Untitled design (2) (1).png|thumb|600x600px|The relative property levels of PLA.]]
* Printing Speed (mm/s): 30 - 70
* Density (g/cm3): 1.21
* Bending Strength (MPa): 68 ± 2

[[File:PLA Atomic.png|thumb|The atomic structure of PLA.]]

=== On the Atomic Level ===

=== Prints ===
[[index.php?title=Category:Materials]]

File:PLA Atomic.png

2025-10-26T15:28:41Z

Mtanjutco3:

Atomic

File:Untitled design (2) (1).png

2025-10-26T15:24:27Z

Mtanjutco3:

pla

File:Pla3.png

2025-10-26T15:21:50Z

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props

File:Pla.png

2025-10-26T14:50:11Z

Mtanjutco3:

Properties of PLA related to 3D printing

File:Image.png

2025-10-26T14:47:01Z

Mtanjutco3:

Properties of PLA