2. Members
• Imtiaz Ahmad(BSME01113115)
• Khawer Saeed(BSME01113139)
3. Elastomer
• Synthetic-rubber like material which, at room
temperature, can be easily bent, stretched, twisted, or
deformed and, when released, quickly returns to its
approximate original dimensions and shape.
7. Elastomer
Unsaturated rubber that can be vulcanized (Thermosets)
are
1=>Natural rubber(NR)
2=>Polyisoprene(IR)
3=>polybutadiene(PB)
4=>choloprene rubber(CR)
Saturated rubber
1=>Epichlorohydrin rubber(ECO)
2=> Silicone rubber(SI)
3=Flourosilicone rubber(FVMQ)
Thermoplastic
8. Aliphatic Thermoset Elastomers
• These are the most common elastomers
• These have a double bond after polymerization has
occurred
• These are noncrystalline
• These are highly flexible
10. Natural Rubber
H H Gutta percha or Balatta
C H (trans-polyisoprene)
H
C H
C H
C C
H
H
H
H H
H C
H
C Hevea Rubber
C
(cis-polyisoprenene)
H C C H
H H
13. Thermoplastic Elastomer (TPE)
• These materials are not crosslinked, have some distinct processing
advantages over traditional thermoset elastomers and physical properties of
vulcanised elastomers
• TPEs are able to be molded like thermoplastic (injection molding, extrusion,
etc)
• Thermoplastic elastomers are more temperature sensitive
• Scrap and reject of these materials can be recycled-environmetal friendly
behavior
• Normal crosslinked polymers cannot be recycled because they don't melt.
They don't melt because the crosslinks tie all the polymer chains together,
making it impossible for the material to flow.
14. PROCESSING OF ELASTOMER
Common machine used for rubber
compounding:-
1. Banbury mixer
2. 2-roll mill
16. calendaring
• Calendar is consist of rollers(known as Bowls)
by using this we can control the thickness of
elastomer sheat.the bowls can be horizontal of
vertical the material from the mixer is fed
between the nips of the bowls. the desiered
sheet thickness can achieved by adjusting the
nips.
typical calendar
17. Extrusion
• Screw Extrusion
The
elastomer is first fed into the barrel via a
hopper and then forced down the barrel
by the screw whilst heat is added (created
by the shearing action and via the heated
barrel and screw). At the end of the barrel,
in the extruder head, is a die through
which the material is forced out.
18. Extrusion
Ram Extrusion
For a ram extruder the
elastomer needs to be rolled and warmed,
usually by placing it in a bath of hot water
or taking it directly from the mill/calender.
This roll is then placed into the cylinder
housing the ram. The head of the extruder
containing the die is then locked in place
at the front of the extruder and the ram
traversed forward, forcing the material
out of the die orifice.
19. Compression Molding
Compression moulding describes the
forming process in which an elastomer
profile is placed directly in a heated
mould, then softened by the heat, and
forced to conform to the shape of the
mould as the press closes the mould.
20. Injection Molding
• Injection molding is a process where
heated elastomer is injected into a closed
cavity via a runner system. Uncured
elastomer is fed into the injection cylinder
where it is preheated and accurately
metered into the mould. This is done by
controlling the pressure, injection time
and temperature.
21. Transfer Molding
Elastomer of set
weight is placed in the transfer pot, and,
as with compression moulding, the pot is
closed by the press forcing the elastomer
down the sprues and into the cavity.
A small amount of excess material
flows out of the cavity through vents, with
other excess material lying in the sprue grooves
and a mat of material left in the transfer pot.
22. Application of Elastomers
• Automotive
Tuned mass dampers, rubbers seals, tyre and tube manufacturing, pipes and hoses, boots, sleeves and covers.
• Aerospace
Air management ducts, diaphragms, interior foils, hose and hoselines, air spring systems.
• Defense
Coating for radar and other defense equipments
23. Application Of Elastomer
• Biomechanics and the medical/dental professions
Surgery devices, prostheses, orthopedics, orthodontics, dental implants, artificial limbs, artificial
organs, wheelchairs and beds, monitoring equipment
• Highway safety and flight safety
Seat belt design, impact absorbers, seat and padding design, passenger protection
• Sports and consumer
Helmet design, shoe design, athletic protection gear, sports equipment safety
• Others
• Dental Products, paints and coatings, cement and concrete adhesives, special wood protection
coatings, biocompatible materials, medical and dental adhesives
24. Comparison B/W thermoplastic and Thermo sets
Thermoplastic Thermosets
• These soften and melt on heating. • These do not soften on heating but rather
• These can be remolded recast and reshaped become hard in case prolonged heating is done
• These are less brittle and soluble in some these start burning.
organic solvents. • These can not be remolded or reshaped.
• These are formed by addition polymerization. • These are more brittle and insoluble in organic
• These have usually linear structures.Ex. solvents.
Polyethylene, PVC, Teflon. • These are formed by condensation
polymerization.
• These have three dimensional cross linked
structures. Ex.
Bakelite, urea, formaldehyde, resin.
25. Industries In Pakistan
Ideal Industry
Mailing Address: Plot # 109, Kerbath Soling, 1 km Off Main Bedian Road, Lahore Pakistan.
Pabx: 92 42 35600211/12
Cell: 92 344 6001111
Fax: 92 42 35600209
Email: sales@idealindustriesm.pk
Rainbow Rubber Industry
Factory Address:
Near Rabbani Masjid, Mirza Adam Khan Road, Karachi-Sindh, Pakistan
Telephone: 0092.21.32521070 & 0092.21.32542033
Fax: 0092.21.32542033
Director Marketing's : 0092.300.9279057
Director Product's : 0092.300.2172782
Email: contact@rainbowrubberindustry.com
contact@rainbowrubber.net
27. Composites
• Composites can cut weight by not being isometric and still
maintain the strength in the desired directions
• Composites are, by definition, solid materials composed
of more than one substance in more than one phase
29. Processes
• Thermoplastic processes –Very short fibers
• Matched die/compression molding
• RTM
• Spray-up
• Hand lay-up for wet and prepreg materials
• Filament winding and fiber placement
• Pultrusion
30. Matrix Materials
• Resins
– Both thermosets and thermoplastics can be used
– Short fibers are generally used in thermoplastics
– Long fibers are generally used with thermosets
31. Matrix Materials
• Short fiber composites
– Less than 0.2 inches (whiskers)
– Processed through standard thermoplastic processes
• Must pass through gates, runners, and gap between processing screw
and barrel walls
– Thermoplastics generally benefit greatly from even the short
reinforcement materials
32. Matrix Materials – FRP
• Intermediate length fiber reinforcement
– The longer the fibers, the more difficult it is to coat the fibers
enough to reap strength benefits
– Low viscosity thermosets ―wet-out‖ the materials better than
high viscosity thermoplastics
– Generally use unsaturated polyester and vinylester resins for
FRP
33. Reinforcements
• Three main types of fibers
– Fiberglass
– Carbon fiber or Graphite
– Organic fibers, aramids (kevlar)
34. Fiberglass
• Spin molten glass
• Different types of glass can be made
– E-glass (improved electrical resistance)
– S-glass (high strength)
– C-glass (high chemical resistance)
35. Carbon or Graphite Fiber
• Originally some distinction was made—now the two refer
to the same material
• Made from PAN fibers, pitch or rayon fibers
• Through heating, raw material looses most non-carbon
atoms in the chain
• Processing also aligns carbon chains
• Carbon fibers have very high modulus (stiffness)
36. Organic Reinforcement Fibers
• Aramid fibers have greatest strength and modulus
properties of organic fibers
• Kevlar is the most commonly used aramid fiber
• Aramids are strong and stiff but their greatest value is in
impact applications
– Front of airplane wings
– Armor applications
37. Reinforcement Forms
• Fiber manufacturers package the fibers on spools called
tows
• Fibers are generally converted to other forms after
manufacturing
– Chopped fibers (including whiskers)
– Mat (random)
– Woven fibers
– Tapes
– Prepregs
38. Manufacturing Methods
• Thermoplastic processes using short fibers
– Injection molding
– Extrusion
– Minor changes are made to accommodate the fiber
reinforcements
• All gaps in flow path should be increased
• A resin viscosity decrease may be necessary
39. Manufacturing Methods
• Matched die or Compression molding
– Reduced flow path over injection or extrusion
– SMC compression molding allows for continuous fibers, mats or
weaves
– These processes offer parts that are finished on both sides
where most other composite processes do not
40. Manufacturing Methods
• Resin transfer molding
– Fiber preform is placed in the mold cavity
– Preform doesn’t move—resin is pulled/pushed in
43. Fiber Orientations
• Isometric materials have equal strength in all directions
• Composites can be lighter weight by not having strength
in the directions that it is not needed
• Lay-up still has to have some balance and symmetry
45. Manufacturing Methods
• Filament winding and fiber placement
– Fiber placement has greater accuracy
– Fiber placement can wind on less symmetrical and even
partially concave mandrels
• Tubes, tanks, wind turbine blades and rockets
47. Manufacturing Methods
• Pultrusion
– High volume production
– Comparable to extrusion but the main processing force is
tension
– Profile is pulled from the machine
48. Plant Concepts
• Many of the processes require considerable space
• Curing equipment for large parts can be very large (and
expensive)
• Controlling volatiles (solvents and resins) must be taken
care of
• Molds can be both expensive and fragile
50. Honeycomb structures are natural or
man-made structures that have the
geometry of a honeycomb to allow the
minimization of the amount of used
material to reach minimal weight and
minimal material cost. The geometry of
honeycomb structures can vary widely
but the common feature of all such
structures is an array of hollow cells
formed between thin vertical walls.
51. Today honeycomb cores are manufactured via the
expansion process and the corrugation process from
composite materials such as glass-reinforced plastic
(also known as fiberglass), carbon fiber reinforced
plastic, Nomex aramide paper reinforced plastic, or
from a metal (usually aluminum)
52. Recently a new process to produce thermoplastic
honeycombs has been implemented, allowing a
continuous in-line production with direct lamination of
skin to cost efficient sandwich panel production.
Continuous in-line production of metal honeycomb can
be done from metal rolls by cutting and bending.
Today, a wide variety of materials can be formed into a
honeycomb composite. For example paperboard
honeycomb is used in paper pallets and package
cushioning, blocking and bracing
54. Expansion method
• In this process thin metal sheet is first cut into panels and strip bonded
• This process is referred to as the ―honeycomb before expansion‖ or HOBE method. This
can be cut and stretched perpendicular to the strip bonds to create a hexagonal structure.
The expansion process requires moderately high inter-sheet bond strengths (sufficient to
enable sheet stretching). For low density honeycombs with very thin webs
55. Corrugated method
• In this approach, a metal sheet is corrugated, and then
stacked into a block. The sheets are bonded by welding
(or any suitable method) together and the core sliced to
the desired thickness and the corrugated layers either
adhesively bonded or welded to face sheets.
56. Corrugated method
• the process for forming a hexagonal honeycomb core;
however this process may be used for numerous
additional topologies including square and triangular
shaped cells
57. Slotted metal strips
• slotted metal strips can be assembled in the form of square and triangular honeycombs
• Since no metal bending is required, this slotted sheet process is also well suited for
making honeycombs from low ductility materials. The honeycomb cores are bonded by
welding/brazing (or any suitable method) together and bonded to face sheets to form a
sandwich structure. Even brittle composite or ceramic honeycombs can in principle be
made by this approach.
59. Application of honeycomb
Lightweight honeycomb solutions are used in a wide range of
industries, including the
aerospace, marine, military, construction and automotive
markets. Aluminum honeycomb, for example, is used as
flooring material in various aircrafts, as it provides exceptional
strength and low weight. It is also suitable for use at high
temperatures and can withstand a variety of environmental
factors
60. Application of honeycomb
• Aramid fiber honeycomb is also used in aerospace applications, but
often in more advanced capacities, such as missile and hull
components. This type of honeycomb also finds use in various
marine and military structures. Polypropylene honeycomb, on the
other hand, is used in various noise and vibration reduction
applications, such as acoustical panels. It also offers relatively high
strength for its weight and is easily formed by various thermoforming
techniques.
61. Application of honeycomb
• Honeycombs utilize far less material than a solid panel
but still provide exceptional strength, making it a highly
economical option for many applications. In addition, the
strength of the honeycomb increases with its
thickness, meaning it is well suited to structures needing
considerable core materials. Honeycombs are available in
a wide range of standard and custom shapes and sizes.
