Melissa Meikle
Jonathan Hromalik
Christopher Bivins
Keith Malkassian
TENSILE TEST COMPARISON OF PLASTIC
WELDS
ENGR 45 Property of Materials, SRJC
Section 4214
Instructor: Dr. Younes Ataiiyan
Property of Materials Project, Fall 2011
December 12, 2011
MAKING SAMPLES
JOINING SAMPLES
SAMPLES
•
Polyethylene
•
Acrylic
•
Acetal (Delrin ®)
•
ABS
STRENGTH OF PLASTICS
Sample
Tensile Strength (psi)
ABS
3855.40
Acrylic
16070.38
Delrin
13409.79
Polyethylene
3909.75
POLYETHYLENE
Sample
Initial Area (in)
Maximum Force (lbf)
Tensile Strength (psi)
Polyethylene
0.2031
794
3909.75
Polyethylene
(Polybonder Epoxy)
0.5800
35
60.35
POLYETHYLENE
Initial Diameter (in)
0.5085
Final Diameter (in)
0.1505
Percent Reduction in Area (%)
91.24
Initial Interior Length (in)
0.3955
Final Interior Length (in)
2.4340
Percent Elongation (%)
515.42
POLYETHYLENE
• Vinyl polymer, made from monomer ethylene
• Simple structure (simplest of all commercial polymers)
• Molecule is a long chain of carbon atoms, with two hydrogen atoms
attached to each carbon atom
• Some carbons will have long chains of polyethylene attached instead of
hydrogen, which is called branched or low-density polyethylene (LDPE)
• When there is no branching, it is called linear polyethylene (HDPE)
• HDPE has a low degree of branching and thus stronger intermolecular
forces and tensile strength than LDPE
• LDPE is cheaper and easier to make.
POLYETHYLENE
• Most popular plastic in the world
• Annual production of approximately 80 million metric tons
• Polymer that makes grocery bags, shampoo bottles, children’s toys, and
bullet proof vests
• Polyethylene with molecular weights of three to six million is referred to as
ultra-high molecular weight polyethylene (UHMWPE), which can be used to
make fibers which are so strong they replaced Kevlar for use in bullet proof
vests
• Large sheets of it can be used instead of ice for skating rinks
• HDPE is used in products and packaging such as milk jugs, detergent
bottles, margarine tubs, garbage containers and water pipes
• 1/3 of all toys are manufactured from HDPE
ACETAL (DELRIN ®)
Sample
Initial Area (in)
Maximum Force (lbf)
Tensile Strength (psi)
Delrin
0.1521
2039
13409.79
ACETAL (DELRIN ®)
ACETAL (DELRIN ®)
• Also known as Polyoxymethylene (POM)
• Thermoplastic produced by the addition polymerization of an aldehyde through the
carbonyl function, yielding unbranched polyoxymethylene chains of great lengths
• Acetal resins are among the strongest and stiffest of all thermoplastics
• Characterized by good fatigue life, low moisture sensitivity, high resistance to
solvents and chemicals, and good electrical properties
• Acetals may be processed by conventional injection molding and extrusion
techniques
• Two types: homopolymer and copolymer
• Homopolymer: semi-crystalline polymer, harder, have high resistance to fatigue,
more rigid, higher tensile and flexural strength with generally lower elongation
• Copolymer: remain stable in long-term, offers exceptional resistance to the
effects of immersion in water at high temepratures
ACETAL (DELRIN ®)
• Used in precision parts that require high stiffness, low friction
and excellent dimensional stability
• Main area of application for acetal is industrial and mechanical
products
• Gears, Bearings, Bushings, Rollers, Fittings, Electrical insulator
parts
• Music: picks, Irish flutes, Bagpipes
• Sports: Paintball accessories (machined parts of paintball
markers that do not require the strength of aluminum such as
handles) and airsoft guns
ACRYLIC
Sample
Initial Area (in)
Maximum Force (lbf) Tensile Strength (psi)
Acrylic
0.0968
1555
16070.38
Acrylic (Heat Weld)
0.1321
69
522.24
Acrylic (Solvent Weld)
0.1502
85
566.04
ACRYLIC
• A common plastic material containing one
or more derivatives of acrylic acid.
• The most common derivative is polymethyl methacrylate (PMMA), better
known as Plexiglass.
• PMMA is made from the Methyl
methacrylate monomer (C5H8O2).
• Acrylic is transparent, and resistant to UV
radiation and weathering.
• It a brittle material but not so much so that
it can’t be cut, drilled or formed.
ACRYLIC
• Acrylic is a very common polymer that has many practical
applications.
• It is used for airplane windshields, skylights, automobile
taillights, and outdoor signs.
• The ceiling of the Houston Astrodome is composed of hundreds
of double-insulating panels of PMMA
• The high tensile strength of this material makes it ideal for
submarine windows and aquarium windows as well.
ABS (ACRYLONITRILE BUTADIENE STYRENE)
Sample
Initial Area (in)
Maximum Force (lbf) Tensile Strength (psi)
ABS
0.1893
730
3855.40
ABS (Epoxy Weld)
0.5957
199
334.04
ABS (Heat Weld)
0.0614
42
683.59
ABS (Solvent Weld)
0.1798
164
911.99
ABS (Solvent Weld, Trial 2)
0.1629
158
970.01
ABS (ACRYLONITRILE BUTADIENE STYRENE)
ABS (ACRYLONITRILE BUTADIENE STYRENE)
ABS (ACRYLONITRILE BUTADIENE STYRENE)
• Full Name: Acrylonitrile Butadiene Styrene
• Light weight an injection moldable
• A material of choice for rapid prototyping
• Combines the strength and rigidity of the acrylonitrile and
styrene polymers with the toughness of the polybutadiene
rubber.
• Drain-waste-vent pipe systems, musical instruments,
automotive trim components, automotive bumper bars,
enclosures for electrical and electronic assemblies,
protective headgear, canoes, small kitchen appliances, Legos
RESULTS
Sample
ABS
ABS (Epoxy Weld)
ABS (Heat Weld)
ABS (Solvent Weld)
ABS (Solvent Weld, Trial 2)
Acrylic
Acrylic (Heat Weld)
Acrylic (Solvent Weld)
Delrin
Polyethylene
Polyethylene (Polybonder Epoxy)
Initial Area, AO (in) Maximum Force, Fmax (lbf) Tensile Strength (psi)
0.1893
0.5957
0.0614
0.1798
0.1629
0.0968
0.1321
0.1502
0.1521
0.2031
0.5800
730
199
42
164
158
1555
69
85
2039
794
35
3855.40
334.04
683.59
911.99
970.01
16070.38
522.24
566.04
13409.79
3909.75
60.35
ACKNOWLEDGEMENTS
• We would like to thank Tap Plastic for their donation/student discount on the
plastics.
REFERENCES
•
http://www.santarosa.edu/media/images/srjc/New-Logo-white.jpg
•
http://www.tapplastics.com/
•
http://en.wikipedia.org/wiki/Acrylonitrile_butadiene_styrene
•
http://pslc.ws/macrog/pe.htm
•
http://en.wikipedia.org/wiki/Polyethylene
•
http://www.sdplastics.com/acetal.html
•
http://www.ides.com/info/generics/2/Acetal-Acetal
•
http://en.wikipedia.org/wiki/Polyoxymethylene
•
http://machinedesign.com/BDE/materials/bdemat2/bdemat2_3.html
•
http://www.answers.com/topic/acrylic-plastic
•
http://www.hydrosight.com/applications/acrylic_applications.php