Reinforced Composite material molding methods
Manufacturing methods of composite materials are becoming more and more popular due to the many benefits they offer. Composite materials are made from two or more materials that are combined together to form a new material. This can be done in a number of ways, depending on the desired properties of the final product.
There are three main manufacturing methods for composite materials: fiber-reinforced plastics, laminates, and sandwich panels.
The use of fiber materials to reinforce plastics is widespread. Injection molded parts such as water tanks, helmets, trays, ducts, etc.,
An Introduction to Composite Manufacturing Methods
Composites are materials composed of two or more components that have been combined together. These materials are often stronger than their individual parts, making them ideal for many applications. In fact, composites are now being used in everything from cars to airplanes to boats to construction projects.
The first use of composites was in the aerospace industry. Aircraft manufacturers began using composites to make planes lighter and stronger. Today, composites are widely used in the automotive industry. Car makers are incorporating composites into vehicles to improve fuel efficiency, reduce weight, and increase safety. Composites are also being used in the medical field to create implants and prosthetics that are strong enough to withstand everyday wear and tear without breaking down.
There are three basic types of composites: thermoset, thermoplastic, and hybrid. Thermoplastic composites are created from polymers (plastics) and fibers. Thermoplastics are heated until they become soft and moldable. Once cooled, they harden and retain their shape. Thermoplastics can be recycled easily, making them environmentally friendly.
What are the benefits of composite manufacturing?
Composite manufacturing is a process where two or more materials are combined together to create a stronger material than either of them could have been created separately. Composite manufacturing is commonly used in the construction industry to make things like bridges, buildings, cars, boats, etc. However, composite manufacturing is becoming increasingly popular in the manufacturing industry.
There are many different types of composites, including fiberglass, carbon fiber, and epoxy resin. Each type of composite has its own unique set of advantages and disadvantages. Fiberglass is the most widely used composite in the world today due to its low cost and high tensile strength. Carbon fiber is often preferred over fiberglass because it is lighter and stronger. Epoxy resins are the most common type of composite used in manufacturing. Epoxies are strong, flexible, and durable.
The Advantages of a Composite Manufacturing
• Lower Cost-Composite manufacturing is cheaper than traditional manufacturing methods. In fact, some composites are even less expensive than steel.
• Higher Strength-Composites are much stronger than their individual components. A typical bridge built using composite materials would weigh about half as much as a bridge built using steel alone.
• Durable: Composites are extremely durable. If something breaks, you just need to replace the broken piece.
Disadvantages of Composite Manufacturing.
There are several disadvantages of composites.
- They are not recyclable. Once the composite is finished, it cannot be recycled back into raw materials.
- Composites are heavier than their individual parts.
- Composites are difficult to work with.
- Composites are brittle.
- Composites do not conduct electricity well.
- Composites are not as resistant to corrosion.
- Composites are not biodegradable.
- Composites are not environmentally friendly.
- Composites require special tools to use.
- Composites are not easily molded.
- Composites are not fireproof.
- Composites are not waterproof.
- Composites are not magnetic.
- Composites are hard to weld.
- Composites are difficult for humans to work with.
- Composites are dangerous to animals.
- Composites are not suitable for food packaging.
- Composites are not edible.
- Composites are not reusable.
- Composites are not safe for children.
- Composites are not recyclable at home.
- Composites are not eco-friendly.
- Composites are not renewable.
- Composites are not natural.
- Composites are not sustainable.
- Composites are not water resistant.
- Composites are toxic.
- Composites are not breathable.
- Composites are not odorless.
- Composites are not transparent.
- Composites may cause cancer.
- Composites may cause birth defects.
- Composites may cause respiratory problems.
- Composites may cause skin allergies.
- Composites may cause eye damage.
- Composites may cause headaches, dizziness, fatigue, vomiting, and nausea.
- Composites can be flammable.
- Composites can explode.
- Composites can burn.
- Composites can melt.
Methods of manufacturing composite materials
Polymer reinforced composites (PRC) are materials composed of two or more components, where at least one of them is a polymeric material. PRCs have been widely used in aerospace, automotive, marine, construction, sporting goods, electronics, and many other industries.
In general, they consist of three basic elements: reinforcement fibers, matrix resin, and additives.
Reinforcement fibers are long strands of fiberglass, carbon fiber, Kevlar, etc., which provide tensile strength and stiffness to the composite. Matrix resins are thermosetting plastics that bond the reinforcement fibers together and hold them in place. Additives are substances added to the matrix resin to improve its performance.
There are several methods of manufacturing composite materials. These include
- filament winding,
- hand layup,
- tape laying,
- injection molding, and
- compression molding.
Filament winding is the oldest method of making composite materials. It involves wrapping continuous filaments around a rotating mandrel called a spool.
Pultrusion is similar to filament winding except that instead of using continuous filaments, chopped fibers are pulled through a heated die and then wound onto a mandrel.
Hand layup is a technique that uses pre-impregnated woven fabrics or mats of chopped fibers to make PRCs.
Tape laying is a method that uses strips of fabric impregnated with resin to build up layers of material.
Injection molding is a process that uses a heated metal mold to shape molten plastic into desired shapes.
Compression molding is a process in which sheets of fiberglass mat are placed between steel plates and pressed under high pressure.
PRCs are manufactured in various ways depending on their intended use. For example, aircraft fuselages are made of PRCs that are strong enough to withstand the extreme forces exerted by the airframe. However, these same PRCs cannot be used in cars because they would not be able to withstand the crash loads.
On the other hand, PRCs are often used in sports equipment because they are lightweight and durable.
PRCs are classified according to their type of reinforcement fibers.
Glass fiber composites are made of glass fibers that are either unidirectional or bidirectional. Unidirectional glass fiber composites are stronger than bidirectional ones.
Carbon fiber composites are made from carbon fibers that are either uni-directional or bi-directional. Bi-directional carbon fiber composites are stronger and stiffer than uni-directional ones.
Kevlar composites are made from Kevlar fibers that are either uniaxial or biaxial. Biaxial Kevlar composites are stronger and tougher than uniaxial ones.
Composite materials are further classified based on their matrix resin.
Polyester composites are made of polyester resins that are either thermoplastic or thermoset. Thermoplastic polyester composites are weaker than thermoset ones.
Polyurethane composites are made of urethane resins that are either rigid or flexible. Rigid polyurethane composites have higher modulus values than flexible ones.
Composite materials are also classified based on their type of additives. Resin modifiers are substances added to the resin to modify its physical properties. Fillers are substances added
In such application, the reinforcing material is normally in the form of short rovings (Definition: rovings are long and narrow fiber), mixed with and injected with the carrier material. A considerable industry has also built up using woven materials as well as rovings, mainly with epoxy and polyester resins (bending agents), to provide large reinforced plastic parts, or to provide strength to vacuum-formed parts.
Techniques for making such large parts involve the use of liquid resin systems in combination with fibrous reinforcement. A male or female single-surface mold is used, giving a good surface finish on one side only. The molds are inexpensive, such materials as wood, plaster of paris, or reinforced plastics are often used.
The technique is to apply a gel coat to the surface to ensure a good surface finish, then follow this up with layers of reinforcement and further resin, ensuring that the resin thoroughly impregnates the material.
Hand layup is the simplest and oldest process for molding reinforced plastics. It is a popular method for large and complex item manufacturing. It is a low-volume production method. Resin and mat are placed on the mold by hand, with brushes and squeegees used to distribute the resin and eliminate air bubbles.
Since parts are normally large, and the process is relatively slow, slow room temperature curing resins are normally used, with external heat, usually radiant, applied to speed up the curing as appropriate and when required.
The process is unpleasant, and many of the materials used to give rise to allergic reactions. There is some concern for the health of the workers involved.
The spray-up process is essentially similar. Continuous glass fiber roving is fed through a fiber chopper and spray gun. Roving and fiber are sprayed together onto the mold surface building up the part wall thickness as desired. Since chopped roving is being used, as against woven mat or preform, the strength of the finished article is not equal to that of a good hand-laid product.
To achieve denser, higher quality products, hand or sprayed parts may, during the curing process, be subjected to compacting forces by bag-molding, i.e., by placing a flexible sheet over the lay-up and using vacuum or pressure to apply uniform force over the surface of the molding. This may take place in an autoclave, providing heat as well as pressure.
Another technique used is filament winding. In this, a continuous roving or tape is passed through a bath of resin and then wound on a mandrel. When cured the resultant product is very strong, due to the high reinforcement content and its excellent disposition. The process is, of course, limited to axis-symmetric products.
Other Manufacturing Methods of Composite Materials
Other than these methods, a lot of methods are followed in the reinforced fiber industry. Some of the methods currently in use are:
1. Matched die moulding
2. Compression molding
3. Low-pressure, low-temperature compression molding
4. Transfer compression molding
5. Resin transfer molding
6. Reaction injection molding
7. Injection molding
8. Vacuum bag molding
9. Vacuum infusion molding
10. Autoclave molding
12. Continuous laminating
Similar techniques are also utilized, using preforms of reinforcing material, coating these preforms by immersion, or applying resin by spray (or both) before and during positioning on the mold, to give the optimum distribution of reinforcement.
Types of Polymer Reinforced Composite Materials
Polymer-reinforced composite materials (PRCMs) are composed of two components, reinforcing material, and a matrix material. The matrix material holds the reinforcing material together and provides strength and rigidity. The reinforcing material is added to increase the strength and stiffness of the composite. PRCMs have been widely used in aerospace, automotive, sporting goods, construction, and many other industries.
1. Fiberglass Composites
Fiberglass composites are a type of PRCM that uses glass fibers as the reinforcing material. Glass fiber composites are commonly used in boats, cars, airplanes, and other vehicles due to their high tensile strength, low density, and ease of processing.
2. Carbon Fibers
Carbon fibers are long strands of carbon that are extremely strong and stiff. They are often used in aircraft, automobiles, and sports equipment. Carbon fibers are stronger than steel and lighter than aluminum.
3. Graphite Composites
Graphite composites are similar to carbon fiber composites except they use graphite instead of carbon. Graphite composites are used in applications where weight is critical, such as in rockets and missiles.
4. Ceramic Matrix Composites
Ceramic matrix composites are a type of PRCM that uses ceramic particles as the reinforcing material. Ceramic matrix composites are commonly used for structural parts in jet engines, gas turbines, and rocket motors.
5. Metal Matrix Composites
Metal matrix composites are a PRCM that uses metal particles as the reinforcing material and a binder to hold them together. Metal matrix composites are commonly found in the aerospace industry and are used to make parts that need to withstand extreme temperatures.
6. Epoxy Resin Matrix Composites
Epoxy resin matrix composites are a popular PRCM that uses epoxy resins as the matrix material. Epoxy resin matrix composites provide excellent mechanical properties and chemical resistance.
7. Polyester Matrix Composites
Due to their adaptability throughout the polymer chain formation process, polyesters are flexible. They have been found to be almost infinitely useful in every facet of the composite industry. These resins’ key advantages include their good mechanical, chemical, and electrical compatibility, dimensional stability, low cost, and ease of processing.