Composite - Revision history

SpookySimon: bolding first use, linking, cleaning up blank space

2023-01-09T19:30:41Z

bolding first use, linking, cleaning up blank space

Kremdog12: /* Matrix */

2021-11-21T22:55:48Z

Matrix

Kremdog12: /* Matrix */

2021-11-21T20:32:13Z

Matrix

Kremdog12: /* Hygrothermal Effects on Epoxy Resin Systems */

2021-11-21T17:57:06Z

Hygrothermal Effects on Epoxy Resin Systems

Kremdog12: /* Hygrothermal Effects on Epoxy Resin Systems */

2021-11-21T17:56:34Z

Hygrothermal Effects on Epoxy Resin Systems

Kremdog12: /* Hygrothermal Effects on Epoxy Resin Systems */

2021-11-21T17:56:07Z

Hygrothermal Effects on Epoxy Resin Systems

Kremdog12: /* Matrix */

2021-11-21T17:54:55Z

Matrix

Someguyinracing: /* Prepreg */

2021-11-17T07:00:40Z

Prepreg

Someguyinracing: /* Resin Infusion */

2021-11-17T06:48:30Z

Resin Infusion

Someguyinracing: /* Wetlay */

2021-11-17T06:47:50Z

Wetlay

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-A composite is a material which is composed of two physically distinct and mechanically separable phases. One material serves as the fiber while a second serves as the matrix.
+A '''composite''' is a [[Materials|material]] which is composed of two physically distinct and mechanically separable phases. One material serves as the fiber while a second serves as the matrix.
 ===Matrix===
 The matrix binds the fibers together and transfers external loading to the fibers. Matrix type has a large influence on the service temperature, impact strength, toughness, and abrasion tolerance of the finished composite. The most common matrices used in large structural composites are the following:
 ====Thermoset====

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 * Softens Matrix
 ** Lower E
-** Lower<span>σ</span>Max
+** <span>Higher σ</span>Max
 ** Higher ε Max
 Moisture:
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 =====Bismaleimide Resins=====
 =====Polyester Resins=====
 ====Thermoplastic====

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 =====Bismaleimide Resins=====
 =====Polyester Resins=====
 ===Fiber===

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 Epoxy resins are by far the most commonly used thermoset resin in Aerospace and other high performance applications. Epoxy resin systems are generally 2 part systems, with a base and hardner being mixed together to start and complete the curing process. Epoxies are easy to process (little PPE is required when processing), have great strength and other mechanical properties.
 ======Hygrothermal Effects on Epoxy Resin Systems======
-Epoxies can be highly susceptible to Hygrothermal effects; the more moisture absorbed by the matrix, the more it degrades in higher temperature environments. This property degredation is driven by the following parameters
+Epoxies can be highly susceptible to Hygrothermal effects; the more moisture absorbed by the matrix, the more it degrades in higher temperature environments. This property degradation is driven by the following parameters

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 ** Lower E
 ** Lower<span>σ</span>Max
-** Higherε Max
+** Higher ε Max
 Moisture:
 * Much Softer Matrix

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-Temp:
+Temp:[[File:tempsnip.png|right|middle|thumb|Hygrothermal Effects on Epoxy Resin]]
 * Softens Matrix
 ** Lower E
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 *** <span>Very Low σ</span>Max
 *** Much Higher ε Max
 =====Bismaleimide Resins=====

← Older revision		Revision as of 17:54, 21 November 2021
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	===Matrix<br />===		===Matrix<br />===
		+	The matrix binds the fibers together and transfers external loading to the fibers. Matrix type has a large influence on the service temperature, impact strength, toughness, and abrasion tolerance of the finished composite. The most common matrices used in large structural composites are the following:
		+	====Thermoset====
		+	=====Overview=====
		+	Thermoset matrices are a "set and forget" matrix. Once cured they cannot be melted down and re-cured. Epoxy resins are the most commonly used thermosets for high performance composites in low to medium service temp ranges (up to ~250<span>°</span>F with a proper post cure). Bismaleimides are used in higher temperature environments such as hot structural sections of aircraft, and generally retain their properties at service temperatures up to ~500°F. Polyester and vinyl ester resins are rarely used in high performance composite structures, but are used where cost is one of the most important engineering requirements.
		+	======<br />======
		+	=====Epoxy Resins=====
		+	Epoxy resins are by far the most commonly used thermoset resin in Aerospace and other high performance applications. Epoxy resin systems are generally 2 part systems, with a base and hardner being mixed together to start and complete the curing process. Epoxies are easy to process (little PPE is required when processing), have great strength and other mechanical properties.
		+	======Hygrothermal Effects on Epoxy Resin Systems======
		+	Epoxies can be highly susceptible to Hygrothermal effects; the more moisture absorbed by the matrix, the more it degrades in higher temperature environments. This property degredation is driven by the following parameters


		+	Temp:
		+	* Softens Matrix
		+	** Lower E
		+	** Lower<span>σ</span>Max
		+	** Higherε Max
		+	Moisture:
		+	* Much Softer Matrix
		+	*** Very Low E
		+	*** <span>Very Low σ</span>Max
		+	*** Much Higher ε Max
		+	<a><img alt="" src="/images/thumb/8/8e/Tempsnip.png/300px-Tempsnip.png" decoding="async" width="300" height="363" srcset="/images/thumb/8/8e/Tempsnip.png/450px-Tempsnip.png 1.5x, /images/thumb/8/8e/Tempsnip.png/600px-Tempsnip.png 2x"></a> <a class="internal" title="Enlarge"></a>Hygrothermal Effects on Epoxy Resins
		+
		+	=====Bismaleimide Resins=====
		+	=====Polyester Resins=====

	===Fiber===		===Fiber===

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 Manufacturing of composite is an essential factor which should be considered when design composite components. The type of material, the form of material, mold design and processing method are all factors that need to be considered. Below are common forms and processing methods used by teams, but there are various other methods available.
 ===Prepreg===
 ====Curing====
 Ramp
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 Cool down
 ===Dry Weave===

← Older revision		Revision as of 06:48, 17 November 2021
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	While regular lamination resin can be used, specially formulated infusion resins are highly recommended. Infusion resins are have lower viscosity for improved flow, and pot life & gel times designed for the infusion process. In addition to having the proper resin, warming mold surface will aid in the infusion flow.		While regular lamination resin can be used, specially formulated infusion resins are highly recommended. Infusion resins are have lower viscosity for improved flow, and pot life & gel times designed for the infusion process. In addition to having the proper resin, warming mold surface will aid in the infusion flow.
−


	The laminate is placed into the mold dry. Vertical walls or complex geometry may require adhesive to be used to tack the laminate in place. Super 77, Super 71 or generic adhesive spray are commonly used for this. When the lamination is complete, peel ply is applied over the entirety of the lamination. Flow mesh is then placed in the proper direction; where the diamond patterns are placed going along the intended direction of the resin flow. Failure to draw the resin in the same direction of the flow mesh will inhibit the flow severely. It is good practice to lay the flow mesh approximately 30mm from the all edges except where the inlet and outlet hoses are. This allows the peel ply to act as a resin break which prevents resin from being pulled into unwanted regions in the vacuum bag. For the outlet, leave a 30-50mm space between the outlet tube and flow mesh.		The laminate is placed into the mold dry. Vertical walls or complex geometry may require adhesive to be used to tack the laminate in place. Super 77, Super 71 or generic adhesive spray are commonly used for this. When the lamination is complete, peel ply is applied over the entirety of the lamination. Flow mesh is then placed in the proper direction; where the diamond patterns are placed going along the intended direction of the resin flow. Failure to draw the resin in the same direction of the flow mesh will inhibit the flow severely. It is good practice to lay the flow mesh approximately 30mm from the all edges except where the inlet and outlet hoses are. This allows the peel ply to act as a resin break which prevents resin from being pulled into unwanted regions in the vacuum bag. For the outlet, leave a 30-50mm space between the outlet tube and flow mesh.
−

← Older revision		Revision as of 06:47, 17 November 2021
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	====Wetlay====		====Wetlay====
−	~~Resin~~ is applied, ~~usually~~ by pouring	+	The wet layup method has several variations and techniques. It can be used to make parts, molds, repairs, and is great for bonding. The resin is applied directly onto the weave via squeegee, paint brush, or rollers. This method allows the user to control the resin ratio and it can be done in the mold or on a table. Wetlay can be done without vacuum bagging or an autoclave, rendering the best option for those whom lack the equipment.
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		+	If vacuum bagging is done, bagging, bag tape, release film (perforated), and breather cloth is required. Peel ply can be used in areas where bonding is to occur or in place of perforated release film. Caul plates can placed in areas where the user does not want texture (the breather and release film leave an undesirable texture on the bagged side of the part). Breather is used to distribute vacuum pressure evenly as the bagging alone can seal itself to regions of the part. Lastly, vacuum ports should be placed OFF the part, to the side, or in a "pleet" or area where there is excess bagging, and typically on a pad of breather cloth.
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		+	Wet layup can also be done by placing the weave onto a plastic film, pouring resin onto the weave, and then placing a second piece of film over top. The user can then use a squeegee to fully wet out the weave, visually seeing the areas that require more or less resin. Once fully wet, one side of the film can be slowly removed. The exposed side can now be placed into the mold and the other plastic sheet removed. This is an excellent way to avoid distorting the weave.
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