[Topic 9] Rubber Industries Flashcards
Types of Rubber (2)
- Natural Rubber
- Synthetic Rubber
Is a natural occurring polymer synthesized from “rubber trees” in the form of latex.
Natural Rubber
Rubber that is synthesized from byproducts of petroleum.
Synthetic rubber
Tree that produces latex
Hevea brasiliensis
Tree that produces balata
Manilkara bidentata
Tree that produces chicle
Manilkara chicle
Widely used synthetic rubber
Styrene-butadiene rubber (SBR)
Classification of rubbers according to class (4)
- Elastomers (Class I)
- Hard Plastics (Class II)
- Reinforcing Resins (Class III)
- Paint Vehicles (Class IV)
Types of Elastomers (2)
- Vulcanizable
- Nonvulcanizable and other elastomers
Types of vulcanizable rubbers (2)
- Diene rubbers
- Nondiene rubbers
Classification of rubbers according to chemical composition (coded)
- M rubbers
- N rubbers
- O rubbers
- R rubbers
- Q rubbers
- T rubbers
- U rubbers
- Z rubbers
having a saturated chain of the polymethylene type
M rubbers
Having nitrogen in the polymer chain but not oxygen or phosphorous
N rubbers
Having oxygen in the polymer chain
O rubbers
Having an unsaturated carbon chain
R rubbers
Having silicone and oxygen in the polymer chain
Q rubbers
Having sulfur in the polymer chain
T rubbers
Having carbon, oxygen, and nitrogen in the polymer chain
U rubbers
Having phosphorous and nitrogen in the polymer chain
Z rubbers
A symbol for rubber in making acronyms for rubber names
R
Generally process via emulsion polymerization
Copolymers
What is SBR?
Styrene-Butadiene Rubber
What is NBR?
Nitrile-Butadiene Rubbers
Also known as polychloroprene, is one of the first synthetic rubber products ever made.
Neoprene
Other rubber products in the industry (7) aside from SBR
- NBR
- Neoprene
- Thiokol
- Silicone Rubber
- Butyl Rubber
- Urethane Rubber
- Hypalon
Is spandex a brand or a product?
Product
Advantages of synthetic natural fiber (7)
- Better color
- Uniform in quality
- Lower odor
- faster processing breakdown and mixing
- Better extrusion and calendering
- Excellent mold flow
- Controlled molecular weight
Production process for rubber making
Natsyn Process
This catalyst is used in Natsyn Process in rubber making.
Ziegler-Natta (Alkyl Lithium)
It means termination of polymer chain using chain termination agents.
Short Stop
Used as roofing materials where they are replacing hot asphalt and used in wire and cable insulation.
Ethylene-Propylene Polymers and Tetrapolymers
It is the process of cross-linking rubber molecules chemically with organic/inorganic substances through the action of heat and pressure using vulcanizing agents.
Vulcanizing (Bulkit)
Temperature required for vulcanizing
140-200 deg Cel
Temperature required for vulcanizing of latex dipped goods.
60-120 deg Cel with no pressure
Any numerous chemical additives that encourage the suspension of one liquid in another.
Emulsifier
A solution that lessens the impact on pH from the addition of acid or base.
Buffers
Chemicals that are added to improve the properties of the product.
Modifiers
The watery part of the rubber mixture.
Serum
A class of rubber chemical which are added to a compound to increase the speed of vulcanization.
Accelerators
Substances other than the catalyst that facilitate the start of a catalytic reaction.
Activators
Substances added to slow down the rate of chemical reaction.
Retarders
Substances that interrupts free-radicals chain reactions and thus prevent further degradation.
Antioxidants
Substances that is added to protect against damage from ozone.
Antiozonates
Substances added to the polymer to improve the properties and reduce cost of production.
Fillers
Substances that makes the product flow with ease.
Softeners and extenders
Substances capable of producing a cellular structure via foaming process in a variety of materials that undergo hardening or phase transition.
Blowing Agents
Substances that promote plasticity and flexibility.
Chemical Plasticizers
It serve as either oxidation catalysts or radical acceptors, which essentially remove free radicals formed during the initial mixing of the elastomer.
Peptizers
Extruder used to remove water from a material or product, often before further processing. This process might not involve heat and relies on mechanical pressure.
Extruder Dewatering
Usually involves heat to remove moisture from the product after it has been extruded. It’s a subsequent step where the extruded product is sent into a low-temperature dryer to remove moisture.
Extruder Drying
Tire Manufacturing Steps (6)
- Mixing
- Extrusion
- Calendering
- Tire Building
- Curing
- Measuring and Testing
Natural and synthetic rubbers are mixed with many other chemicals to create a compound that serves a particular purpose within the tire.
Mixing
Rubber is pushed through a die to create shapes made of one or more different compounds in different locations to be used in the tire.
Extrusion
It is pressed into a rubber sheet or impregnated into fabric or steel to create a rubber-coated reinforced sheet to be cut into components for the tire.
Calendering
Takes all the components listed on the specification to create the uncured (green) tire.
Tire Building
True or False: The tire is assembled from the inside out by wrapping the components around a drum and forcing them together using internal air pressure and rollers pressing from the outside to consolidate the components together.
True
The uncured or green tire is placed into a mold which is mounted into a press.
Curing
True or False: Once the tire is loaded into the press, a bladder inflates into the tire at high pressure to hold the tire in place as the mold closes around the tire.
False: low pressure
True or False: In curing, once closed, low pressure steam or gas fills the bladder forcing the tire into the mold to take the final shape of the tire.
False: high pressure
The cured tire goes to a machine where it is inflated and ran against a wheel at a certain load and inflation pressure.
Measuring and Testing
This measures variation in forces that would be exerted against the road.
Measuring and Testing
A machine used to balance the tire.
Balance Machine
Who discovered vulcanization?
Charles Goodyear
Rubber was named by him.
Joseph Priestly