Composite Fab

Compression molding is no longer confined to thermoset materials and is used to mold glass mat thermoplastic (GMT). These materials are used in the automotive industry on hoods, fenders, scoops and spoilers. Natural fibers used in this process are:

All the above

The function of a vacuum bag is to:

All the above

What is matrix material?

All the above

What is the variable of the fiber/resin weight relationship?

All the above

Which bagging requirements must be met to obtain a good vacuum?

All the above

Which environmental effects are moderately protected with matrix materials?

All the above

Which of the following are matrix-dominated properties?

All the above

What is the technical term for the internationally recognized system for controlling fiber orientation on engineering drawings called?

Counter clock

Three common composite reinforcement fibers are Glass (fiberglass), carbon (graphite) and aramid (Kevlar)?

True

Three types of matrix material are:polymeric (plastic), metallic and ceramic?

True

Warp yarns always run the length of the roll in all conventional bidirectional woven fabrics, and is always used for orientation purposed in composite panel manufacturing?

True

Composite are comprised of

Two or more materials working together

[1] is one of the most common forms of carbon fiber reinforcement

Unidirectional tape

A few disadvantages of composites are:

All the above

Common examples of a hybrid fabric are:

All the above

Which matrix system is considered the workhorse of the advanced composites industry?

Epoxy

Composites are easy to corode?

False

Concrete is not a good example of an everyday composite material

False

Plain weave and twill weave fabrics have a visible warp or fill-dominant face on which to refer.

False

Pre preg layup is usually done in the resin room.

False

The breather and bleeder layers are a step that should be elimantated and isn't important in achieving good vacuum.

False

The first layer that goes against the uncured laminate is typically the breather.

False

The selvage is the stitched or looped edge that runs through the center of material when coming off the roll.

False

Warp face recognition is not critical to proper nesting and symmetry in a layup using harness-satin weave fabrics, and to panel stiffness properties in the laminate design?

False

What does (Tg) mean?

Glass transition; this refers to the transition in behavior from rigid to rubbery.

A balanced laminate refers to a laminate with equal numbers of plus and minus angled plies.

True

A laminate is considered quasi-isotropic when laid up with an equal number of plies at each of 0, 90, +45 and -45 angles?

True

A matrix material is a material that binds the fiber together. A good example of fiber reinforced matrix composites is short glass fibers?

True

A solid or perforated release film is used to restrict or prevent resin flow.

True

A typical three step process for advanced composites is lay-up, vacuum bagging and placing part in the oven or autoclave for processing.

True

Boats, bridges, snowboards, bicycle frames, race cars and aircraft structures are all good examples of continuous or long fiber reinforcement?

True

Carbon fiber is often called "graphite". Graphite is very soft, but brittle, like pencil lead.

True

Composites can be easily molded to shape?

True

Fibers plus matrix equals composite?

True

Fill yarns run across the roll 90 degrees to the warp yarns and are also called "weft" yarns in the textile industry?

True

Glass transition temperature is the temperature at which increased molecular mobility results in significant changes in the properties of a solid polymeric resin or fiber?

True

Kitting material into smaller packages is recommended to preserve the materials out-time?

True

Laminate performance is almost totally dependent upon fiber orientation?

True

Mixed reactive resins and adhesives have a designated amount of time in which to use the material before it eventually becomes gelatinous and unusable in the cup?

True

Prepreg materials should always be allowed to fully thaw to room temperature prior to removal from the moisture barrier?

True

Prepreg materials that have exceeded their shelf life or out-time can usually be tested and re-qualified for a shorter period of time?

True

Previously labor intensive hand-placed material processes are now more streamlined automated processes with the advent of computer aided design (CAD) and computer aided manufacturing (CAM)?

True

Pultrusion, filament winding, automated tape laying and fiber placement technologies are a few of the more common processes that have evolved since the 1960's?

True

Resin matrixes are a two-part system consisting of a resin and a catalyst, or hardener which acts as a curing agent?

True

Solid laminate panels are typically built using either woven cloth, unidirectional tape, or a combination of both.

True

Symmetric-weave fabrics are woven fabrics that have an equal number of identical yarns in both the warp and fill directions.

True

The material selection, complexity of the shape, and production rate requirements often drive the choice of molding methods for a specific composite structure?

True

The role the bleeder plays in the vacuum bag schedule is to allow resin to move or "bleed" into the layer during processing.

True

The role the breather plays in the vacuum bag schedule is to maintain a pathway for air and gas to escape from the processing laminate to the port of vents within the bag?

True

The yarn count is typically listed in yarns per inch.

True

Thermoset resins are a plastic that cures by the application of heat or by chemical reaction resulting in a cross-linked insoluble molecule; considered an irreversible process.

True

The two basic categories of composite processing are:

open molding and close molding