2106 - MIDTERMS

Question 1

Most manufacturers of composite structures augment the strength of the finished product by applying ___________ and
_________to the matrix/fiber mix as it cures.

Answer 1

heat and pressure

Question 2

is a manufacturing process that uses a male and female mold. The reinforcing fabric is wetted with a matrix or pre-preg materials. It was laid into a female mold and the male mold is used to form the shape of the part

Answer 2

COMPRESSION MOLDING

Question 3

With this technique the object which is to be cured is placed into a plastic bag and the air is evacuated, pressure is applied to the component by surrounding components

Answer 3

VACUUM BAGGING

Question 4

is widely used because of the manufacturing benefits which include low materials cost, accuracy, automation, and repeatability.

Answer 4

FILAMENT WINDING

Question 5

This is an automated process in which tapes (unidirectional prepregs) are laid over a mandrel and compressed into place.

Answer 5

FIBER PLACEMENT

Question 6

is a relatively simple and low cost automated method of manufacturing composite components.

Answer 6

PULTRUSION

Question 7

is a manufacturing method that uses a two part mold with the dry fabric laid into the mold.

Answer 7

RESIN TRANSFER MOLDING (RTM)

Question 8

is a manufacturing technique that is simply laying prepreg material by hand into a mold.

Answer 8

WET LAY-UP AND HAND LAY-UP

Question 9

units were designed for repairing composite components when an oven or autoclave wasn’t available.

Answer 9

HOT BOND EQUIPMENT

Question 10

It senses the temperature of the part and relays the information to the controller or monitor.

Answer 10

THERMOCOUPLE

Question 11

Ovens offer controlled, uniform temperature over all surfaces.It is often used in the manufacturing process to cure many parts at the same time.

Answer 11

OVEN CURING

Question 12

This is an alternative method for curing repairs when the contour of the part does not allow the use of a heat blanket.

Answer 12

HEAT GUNS

Question 13

The purpose of applying mechanical pressure is to:

Answer 13

-Remove the excess resin from the components, ensuring the proper ratio of resin to fiber reinforcement. As the resins cure, they start to flow. The pressure will squeeze out some of the excess resin.
-Remove air trapped between layers.
-Maintain the contour of the repair relative to the original part.
-Hold the repair securely, preventing any shifting of the patches during the curing process.
-Compact the fiber layers together.

Question 14

are used for metal working. Use Bossing Mallets, Pear-shaped mallets or rounded plastic mallets to shape metal curves, fenders and/or bowls.

Answer 14

SHOT BAGS

Question 15

Is placed on one side of the repair and it allows air to flow through it and through the vacuum valve, and it is used to prevent it from sealing itself by sticking to the area to be repaired .

Answer 15

BREATHER

Question 16

Bag is sealed properly. After the Vacuum is drawn on a part, the vacuum hose is disconnected for about two minutes.

Answer 16

VACUUM LEAK CHECK

Question 17

The material commonly used for vacuum bagging come in a number of types, depending on the manufacturer, and how the repair is to be performed.

Answer 17

VACUUM BAGGING MATERIALS

Question 18

used to cover the component and seal out air. They must be made with absolutely no voids or pin holes.

Answer 18

VACUUM BAGGING FILM

Question 19

Needed to create the airtight seal to close the bagging film either to itself or to the flange of your mold, enabling your vacuum to work.

Answer 19

SEALANT TAPE

Question 20

Frequently inside the vacuum bag, so that your part can be pulled away from the bagging materials once they are complete.

Answer 20

RELEASE FILM

Question 21

A nylon or polyester release fabric may be used next to the wet resin during the curing operation to transfer excess resin to the bleeder material without sticking to the part.

Answer 21

PEEL PLY

Question 22

It provides both heat and pressure under extremely controlled conditions. They are normally used for manufacturing.

Answer 22

AUTOCLAVES

Question 23

These are used to cure composite parts for many years. But these are no longer recommended. To help monitor temperature, use a temple stick or other temperature-monitoring device.

Answer 23

HEAT LAMPS

Question 24

These are probably the most widely accepted form of applying heat to a composite component for repair work.

Answer 24

HEAT BLANKETS

Question 25

Widely used in the manufacture and repair of aluminum-skinned aircraft, it is used to temporarily fasten multiple sheets of material together before the pieces are permanently joined

Answer 25

CLECO

Question 26

Use for holding fabric in place prior to gluing or holding several pieces of sheet metal or wood together.

Answer 26

SPRING CLAMP

Question 27

are cotton like absorbent materials used to soak up excess resin.

Answer 27

BLEEDERS

Question 28

are cottony materials that allow air to flow through a valve or over the surface of a part throughout the vacuum bagged area.

Answer 28

BREATHERS

Question 29

Composite matrix systems cure through chemical reaction
between a catalyst and resin. Some matrix system require heat to cure the composite to achieve maximum strength , while others cure at room temperature but can be accelerated by applying
external heat.

Answer 29

METHODS OF CURING

Question 29

Room Temperature Curing

Answer 29

Some repairs may be cured at room temperature
(65°F to 80°F) over a time span of 8 to 24 hours.

It can be accelerated by applying low heat (140°F to
160°F).

Full cure strength can be achieved within 5 to 7 days.

This method is normally performed on parts which
are lightly loaded or nonstructural parts

Question 29

The most widely accepted method of
curing structural composites employs resins
that cure only at higher temperatures.

Answer 29

Heat Curing

Question 30

utilizes a flexible silicon heat­ing-blanket that incorporates a temperature con­trol.
This is the preferred method of curing, due to the
controlled even heating of the part. Most hot patch
bonding machines also incorporate a vacuum pump to
apply pressure during the cur­ing process.

Answer 30

Hot patch bonding

Question 30

A more sophisticated and accurate curing process may be
accomplished using a programmable con­troller.

Answer 30

Ramp and soak