|
|
|
jobst incorporated
P.O. Box 8 Prior Lake, MN 55372
Phone: 952.447.3904 Fax: 952.447.3709121
| Abrasion Resistance | Holds up against wear caused by friction. back | |||
| Anisotropic | exhibiting properties with different values when measured in different directions back | |||
| Modulus | The relationship between stress (force) and strain (extended length). Modulus is usually given as the stress (or force) required to extend a rubber or urethane (e.g. 100%, 200% extended). Molded Dimensions | |||
| EMI | Electrical Magnetic Interference dc to 300 GHz Vanguard Products Corporation | |||
| RFI | Radio Frequency Interference -unwanted radiated electronic noise (boadcast) 10 kHa to 1000 MHz Vanguard Products Corporation | |||
| ESD | ElectroStatic Discharge.
A Transient Phenomena Involving Static Eletricity-Friction
Vanguard Products Corporation |
|||
| PCF | pounds per cubic foot, abbreviated PCF | |||
| Micro- (µ- or mc-) | Metric prefix meaning 10-6 (one millionth). The prefix comes from the Greek prefix mikro-, meaning small. The prefix is abbreviated mc- when the Greek letter mu (µ) is not available. | |||
| Microinch (µin) |
A traditional unit of distance equal to 10-6 inch, 0.001 mil, or 25.4 nanometers (nm). The microinch is used rather widely to state the roughness of optical surfaces, precise tolerances in machining, and for other industrial purposes. |
|||
| Micrometer (µm) |
A common metric unit of distance equal to 0.001 millimeter or about 0.039 370 mil. The name micron is also used for this unit. |
|||
| Quasi-isotropic |
quasi-isotropic composite laminate plate, which has constant properties of extensional stiffness in all in-plane radial directions
|
|||
| Materials | ||||
| Carbon Fiber | A polymer which is a form of graphite.
Graphite is a
form of pure carbon used to reinforce materials. It is very strong for their weight. It is often stronger than steel, but much lighter. It can be used to replace metals in many uses, from parts for airplanes and the space shuttle to mountain bike frames. |
|||
| back to top | ||||
| Composites | Reinforced material.
They have more than one component.
Thermoplastic Forged Thermoplastic Composites - Oribi Manufacturing Thermoset
Cosmetic Hand Lay-Up & Bagged Processing - Fiber-Tech Inc |
|||
| BUTADIENE RUBBER (BR) | Thermoset rubber.
Properties some what similar to natural rubber. Although
its properties are not quite that of Natural Rubber, in some cases its low temperature characteristics are better. Specific gravity....0.91, Elongation, max.....6x, Hardness, Shore A.... 40-80, Brittle point (F)...............-100 |
|||
|
go to Everseal
Gasket and Stamping Die Cut go to Molded Dimensions Molded |
||||
| back to top | ||||
| Butyl
Rubber (IIR)
|
Thermoset rubber. Unsaturated copolymer of isobutylene and isoprene butyl.
Good
resistance to ozone, UV light, moisture and mineral acids.
Good resistance
to polar liquids such as oxygenated solvents, ester type plasticizers,
vegetable oils and synthetic hydraulic fluids, MEK, Phosphate ester type hydraulic fluids (e.g. Skydrol®, Attacked by non-polar solvents, such as hydrocarbon oils, greases and fuels, di-ester based lubricants, hydrocarbon solvents and oils Good damping and shock absorption characteristics. Extremely low gas permeability. Application Ideas: Electrical insulation, curing bladders, membranes, gaskets, diaphragms, fenders ASTM D1418, ISO 1629 Designation: IIR |
|||
| back to Everseal
Gasket and Stamping Die Cut
go to Molded Dimensions
|
||||
| Elastomer | General term used to
describe all natural and synthetic polymeric materials which have rubbery
or "elastic" properties. Some polymers, which are elastomers, include:
polyisoprene or natural rubber, polybutadiene, polyisobutylene, and polyurethanes. What makes elastomers special is the fact that they rebound or have memory. They can be stretched to many times their original length, and can bounce back into their original shape without permanent deformation. back Molded Dimensions |
|||
| EPDM | (Ethylene
Propylene Diene Monomer) resistant to most water based chemicals, very inert structure, remains stable over long periods of time, can withstand temperatures of up to 130°C for extended periods of time (months), very good weathering resistance, easily compounded and processed, outstanding resistance to phosphate ester type hydraulic fluids. performs well in Alcohols, Automotive brake fluids, Dilute acids and dilute alkalies,
Ketones (MEK, acetone), Silicone oils and greases, Steam (up to 400° F, 204° C),
Water ASTM D2000, SAE J200 Type/Class: AA, BA, CA, DA |
|||
| Epichlorohydrin (CO, ECO, GECO) | A synthetic rubber designed
for more extreme heat and oil resistance applications.
very good high temperature resistance, up to 150°C, good low temperature properties, good ozone resistance, expensive, relatively low physical strength combines low gas and solvent permeability with high resistance to hydrocarbon oils and fuels. Attacked by Aldehydes, Brake fluids, Esters, Hydrocarbons (chlorinated, nitro), Ketones ASTM D2000, SAE J200 Type/Class: CH |
|||
| Fiberglass | Reinforcement material. Composites
|
|||
| back to top | ||||
| Fluorocarbon (FKM) | The best material for
resistance to hostile chemical and oil environments at normal and elevated
temperatures.
good resistance to fuels, oils and most chemicals limited use at low temperatures, -20°C being the limit for flexibility expensive does not resist Ketone solvents
Specific gravity...........................................1.85 Tensile strength...........................................2,500 Elongation, max...........................................3x Hardness, Shore A........................................60-95 Brittle point (F).............................................-40 |
|||
| Fluorosilicone (FVMQ) | Fluorovinylmethyl silicone
rubber
The best rubber to use in hostile environments where fuel, oil, solvents, chemicals or high and low temperatures are encountered ( -60°C to 200°C). resistant to oils and fuels (particularly at low temperatures) good electrical strength not physically strong but are resilient, with low compression set characteristics. Widely used in aerospace fuel systems and auto fuel emission controls. very expensive ASTM D2000, SAE J200 Type/Class: FK |
|||
| Foam | Dispersion of gas bubbles
in a solid. back to Everseal Gasket |
|||
| Natural Rubber (NR) | wild range of hardnesses
very strong (naturally self-reinforcing) and extremely resilient good compression set good resistance to inorganic chemicals lack of resistance to oil and organic fluids relatively low maximum temperatures (75°C continuous, 100°C intermittent) poor ozone resistance, with tendency to perish in open air (can be improved to some extent by careful compounding). |
|||
| Nitrile
(NBR, XNBR), (HNBR)
Carboxylated nitrile rubber compounds (XNBR)
Highly saturated nitrile (HSN)
|
Buna N, nitrile is a copolymer of butadiene and acrylonitrile
(ACN).
Trade Names: Trade Names: |
|||
| Neoprene
(CR)
|
Polychloroprene rubber is resistant to a wide range of
hostile environments, resistant to oils and chemicals, weather and water
resistant, can withstand temperatures from -30°C to 95°C, easy to process
and compound, offering cost benefits, flame retardant, can be produced in any color
required, unsuitable for applications requiring contact with fuels, tendency
to tear once there is initial damage.
ASTM D2000, SAE J200 Type/Class: BC, BE |
|||
| Acrylonitrilebutadiene | very good resistance to petroleum based fluids, good high temperature resistance - up to 100°C (120°C with EV cure systems), economical to compound and produce, very low level of permeability to gases, poor resistance to outdoor weathering without special compounding, comparatively low strength, flammable and burns with toxic fumes | |||
| Nylon | Polyamide plastic. High
heat & chemical resistance. Low coefficient of friction. High moisture
absorption. Tough and flexible.
back
|
|||
| back to top |
|
|||
| PE | Polyethylene [päl´ eth´ ln] a hard-to-soft, ductile, easily molded thermoplastic that is chemical resistant and has good insulating properties; it has many industrial uses, primarily in the form of packaged film for food products and garment bags, and in pipe, electrical insulation, and molded products. | |||
| Plastic | Plastics tend to either
deform permanently, or break, when you stretch them too hard. Plastics
resist deformation better than elastomers. It takes more energy to
stretch the plastic, making it resistant to deformation. If you pull hard
enough it will stay in the shape you stretched it into once you stop stretching
it.
See Thermoplastic, TPR, and Thermoset Plastic |
|||
| PVC | Poly(vinyl chloride) PVC. Resists: fire and water. | |||
| Reinforced | Materials used to add strength. | |||
| Rubber | Highly elastic material.
Go to Molded Dimensions
Go to Everseal Gasket |
|||
| SBR | good physical strength, good tear and abrasion resistance, range of colors, one of the cheaper rubbers, does not resist oil or fuels, prone to weathering | |||
| Silicone | Poly(dimethyl siloxane)
inorganic polymer-can stand high temperatures without decomposing.
wide temperature range, extremely good resistance to weathering, excellent electrical properties, good resistance to oils, easily colored, low level of toxicity, not a very strong material, poor resistance to fuels, expensive compared to other rubbers Go to Molded Dimensions Go to Vanguard Products Corporation |
|||
| Thermoplastic | A material that can
be repeatedly molded and shaped after heat and pressure are applied. It
hardens when it is cooled. This melting and refreezing can be repeated
indefinitely.
Thermoplastics are made of building blocks called hydrocarbons, typically
derived from petroleum or natural gas. These monomers (small molecules)
are bonded into chains called polymers or plastic resins. Different combinations
of monomers yield resins with special properties and characteristics. Characteristics of thermoplastic polymers:
Examples:
|
|||
| Thermoset Polymers: Plastic & Elastomers | Any material which melts
on heating but then undergoes a permanent chemical change. Characteristics
of thermoset polymers:
Less temperature sensitive than thermoplastics. Crosslinked network structure exists throughout part. Crosslinking provides thermal stability. It will not melt or flow upon heating. Examples: Rubber, Epoxy, Unsaturated polyesters, vinyl esters, phenolic, phenol formaldehyde, bismaleimide, cast urethane |
|||
| Thermoplastic
Rubber, TPR or TPE
|
Also know as thermoplastic
elastomers (TPEs). Reversible crosslink material. Processed like
a thermoplastic but behaves like an elastomer. They are made by copolymerizing
two or more monomers, using either block or graft polymerization techniques.
One of the monomers develops the hard, or crystalline, segment that functions
as a thermally stable component (which softens and flows under shear, as
opposed to the chemical crosslinks between polymeric chains in a conventional,
thermosetting rubber); the other monomer develops the soft, or amorphous
segment, which contributes the rubbery characteristic.
These materials can be processed in plastic injection tooling, and the scrap can be recycled and reused. Can be used for flexibility, non-abrasive /non-marking, or skid resistance. |
|||
| Thermoset | A crosslinked material.
Any material which melts on heating but then undergoes a permanent chemical
change. It is then it is heat stable. Thermosets are different
from thermoplastics, which become moldable when heated. Thermosets are
crosslinked, so they don't.
See Rubber, Urethane, and Thermoset Polymer Go to Molded Dimensions Composites |
|||
| Thermoset Polymers: Plastic & Elastomers | Any material which melts
on heating but then undergoes a permanent chemical change. Characteristics
of thermoset polymers:
Less temperature sensitive than thermoplastics. Crosslinked network structure exists throughout part. Crosslinking provides thermal stability. It will not melt or flow upon heating. Examples: Epoxy, Unsaturated polyesters, vinyl esters, phenol formaldehyde PF, or Phenolic, bismaleimide, urethane |
|||
| Polyurethane | Polyurethane rubber
of organic Chemistry. Know for high levels of abrasion resistance.
Polyurethane is typically processed as either a compression molded millable gum, a cast thermoset, or an injection molded thermoplastic. The most desirable combination of characteristics is that corresponding to a "hard" and "tough" polymer. Go to Molded Dimensions Structural Parts and Foam |
|||
| Viton | FPM-fluorocarbon. DuPont
Dow Elastomers tradename. Resistance to hostile chemical and oil environments
at normal and high temperatures. It is strong, has good resistance to water
and good resistance to fuels, oils & most chemicals
It has limited flexibility at low temperatures, -20°C being the limit for flexibility. It does not resist Ketone solvents and is expensive. Go to Molded Dimensions |
|||
| Pressure Sensitive Adhesive (PSA) | Adhesive joining method. Alternative to mechanical methods. Adhesively joined structures and products are inherently smooth. | |||
| Processes |
| Cast | Pouring materials that are liquids at, or near, room temperature into various types of molds, and then cured, or solidified, by the addition of heat. The viscosity of most thermoset resins enables them to be poured readily into molds without the need to force them in under pressure. | |
| Advantages | Inexpensive tooling, Smaller production runs, cost efficient. | |
| Processors | Molded Dimensions Composites | |
| Extruded | Producing continuous lengths of melted material with a constant profile by forcing it through a die under pressure and vulcanizing it. It passes through one or more die orifices to produce products of the desired configuration. | |
| Advantages | Inexpensive tooling, Cost effective. | |
| Processors | Vanguard Products | |
| Die-Cut | Material is cut to a specific design/shape through the use of a die. Steel Rule Die Cutting is the most common. The steel rule die acts like a cookie cutter. | |
| Advantages | Inexpensive tooling, Precise 2D parts. | |
| Processors | Everseal Gasket | |
| Molded | ||
| Atmospheric Pressure Molding (APM) | |
| Similar to hand-lay up but the last step of the process before curing is to place a bag made of flexible film over the part. Vacuum is pulled. The pressure eliminates voids and increases adhesion of each layer. | |
| Advantages: High glass content and lighter weight, better control of wall section and a superior inside finish. | |
| Processors: Composites | |
| back to top | |
| Compression Molding | |
| A
puck of uncured rubber is placed between two halves of a heated mold. The
mold is closed in a press under a pressure of around one ton/sq in. As
heat and pressure are applied, the elastomer liquefies and is forced into
the exact shape of the cavity with any excess material flowing away from
the cavities in a runner system. The rubber gains heat by conduction from
the mold surfaces and "cures". When the rubber has had sufficient time
to cure, the mold can be opened and the part removed.
Compression molding is a relatively simple process and is often used for components required in fairly low quantities. It is also the most economic method for parts with simple shapes. Parts molded by this method will always have some flash because the mold surfaces are held apart by the necessary excess rubber in the "blank". |
|
| Advantages: Tight tolerances, precision, and insert molding. Moderate tooling costs. | |
| Processors: Molded Dimensions Jobst Incorporated | |
| back to top | |
| Compression/Transfer Molding | |
| In a compression/transfer mold, the mold is closed except for an open pot on the top of the mold. Inside the pot are small holes, or "sprues", that feed directly into the cavities, or into a runner system that feeds into the cavities. A slab of pre-weighed elastomer, enough to make all of the parts, is placed in the pot, and a ram is lowered into the pot. The combination of heat and the pressure from the ram causes the material to liquefy and "transfer" from the pot through the sprues and into the cavities. Any excess material remains in the pot. | |
| Advantages: Tight tolerances, precision, and insert molding. Moderate tooling costs. | |
| Processors: Molded Dimensions Jobst Incorporated | |
| back to top | |
| Dip-Molding | |
| A heated mandrel shape is dipped in to a liquid resin like vinyl plastisol. A high temperature cure is the next step. Finally the cured part is removed from the mandrel. | |
| Advantages: Inexpensive tooling. Soft edges, noise and vibration dampening, good cosmetics. | |
| Processors: PDM | |
| back to top | |
| Hand Lay-up | |
| Pre-wet Hand Lay-up is done in an open mold. The appropriate glass is precut from roll stock and wetted out. The wet glass is then applied to the mold and then rolled out with rollers. | |
| Advantages: Have different thickness in different areas. Tooling costs are the lowest of the composite processes. | |
| Processors: Composites | |
| Injection Molding - Thermoplastic and TPR / TPU | |
| Heat plastic until it melts. Then force it under high pressure into a cool mold. It solidifies in the mold. The tool open and a solid part is ejected | |
| Advantages: intricate shapes, at high production rates and with good dimensional accuracy | |
| back to top | Processors: Jobst Incorporated TS Jobst Incorporated TP |
| Resin Transfer Molding (RTM) | |
| RTM is a matched die set, closed molding system. back to top | |
| Advantages:
Tooling less expensive then both injection molding and SMC-Low capital investment, Good surface quality, Tooling flexibility, Large, complex shapes, Ribs, cores and inserts, Parts integration, Range of available resin systems Range of reinforcements, Controllable fiber volume fraction Molded surface on both sides of the part and consistent wall sections. RTM parts are generally 20-30% lower
in price than hand lay-up
|
|
| back to top | Processors: Composites |
| Transfer Molding | |
| The heated mold is closed in a press and the rubber injected by a hydraulic cylinder through a feed hole in the cavity. The cylinder can either be incorporated in the press or sometimes in the mold. | |
| Advantages: can produce high-precision parts in moderate quantities without high tooling costs. | |
| back to top | Processors: Molded Dimensions Jobst Incorporated TS Jobst Incorporated TP |
|
Resin Infusion Infusion shares many of the characteristics of vacuum bag molding and resin transfer molding (RTM). Like RTM, infusion reduces styrene emissions by wetting out and curing the laminate in a closed system. The use of air pressure to squeeze the resin into the reinforcement fibers is a benefit that infusion has in common with the vacuum bagging process. Processors: R3Composites |
|
| Vacuum Bagging | |
| As an assist to a pre-wet hand lay-up, a vacuum is introduced into the mold after lay-up. The results are even high glass contents, better control of wall section and a superior inside finish. Also see APM. | |
| Advantages:High glass content and lighter weight without sacrificing other physical characteristics. Vacuum Bagging is generally up to 10% higher in piece price than Pre-wet Hand Lay-up but tooling is the same as Pre-wet Hand Lay-up. | |
| back to top | Processors: R3 Composites |
| SPE | Society of Plastic Engineers
founded in 1942
Mission: To provide and promote the knowledge and education of plastics and polymers worldwide. |
| back to top | |
| What is
KIRKSITE? non-ferrous alloy based on selected 99.99% purity zinc and contains precise amounts of alloying Easy to cast & to finish-free-flowing when molten and allows quite exceptional reproduction of detail as cast Inexpensive- complex contours by casting instead of expensive machining & alterations to the tools during product development are not expensive What is GELCOAT? gelcoat is resin with pigment and additives to resist wear and weathering. It is compatible with the resin system used to produce the composite part. It bonds chemically with the underlying fiberglass. During manufacture the composite structure is encased in a thin shell of white pigmented gel coat. It can be tinted with any of the pigment colors and can be wet-sanded and buffed to a high gloss. Composites |
|
| back to top | |
| Secondary Operations | Additional processes
done on a part to get a complete part.
Ultra-sonic welding, decorating, splicing, assembling |
||
All Contents Copyright © 2008-2009 jobst incorporated
P.O. Box 8 Prior Lake, MN 55372
Phone: 952.447.3904 Fax: 978.945-6121.6121