Composites Manufacturing Methods | Thermoset Fabrication Process | Thermoplastic Manufacturing Process

Thermoset Components Fabrication Methods:

1. Hand layup method:

The method is simple and suitable for simple components. A coat of resin is applied on a tool surface and a layer of mat or fabric reinforcement is placed on the tool surface. The process is repeated till the required thickness of the laminate is reached. This is cured at 25 – 40 degree Celsius. No pressure is required.

01-hand-lay-up-process-for-composites-composite-fabrication-process

2. Vacuum bag method:

Lay-up of laminates is covered by an airtight rubber membrane and the air under membrane is evacuated, which helps compaction and removal of air bubbles. This is cured at 25 – 40 degree Celsius at a pressure of 1 bar.

01 - vacuum bag method

3. Autoclave method:

This method is similar to the vacuum bag method. The laid up assembly is covered with an airtight assembly and sealed against the tool. The assembly is then placed in an autoclave where vacuum, pressure and the cure process is tightly controlled.

01-autoclave molding

4. Resin injection:

This method requires top and bottom halves of tools whose shape corresponds to the desired thickness and configuration of the part. The reinforcing materials, in the form of fabrics or mats, are placed between the tool halves in dry plates. The resin is injected by means of vacuum. The system is cured at 25 – 40 degree Celsius at a pressure of 1 bar.

01- resin injection molding

5. Pultrusion:

This is the reverse of extrusion. Material is pulled through a die. This method is used for producing straight lengths of solid or hollow cross section.

01 - pultrusion process - composite manufacturing

6. Filament winding:

Resin covered continuous rovings, bands or mats are placed on a rotating mandrel and cured. This method is used to produce parts with elliptical or oval cross-sections and circular cross sections.

01 - filament winding

7. High and low temperature compression moulding:

As in the case of resin injection, the top and bottom tool halves are required. Resin is poured into the lower tool half, followed by placement of a prepared staple of weaves or mats. Closure of the tool under pressure causes the resin to penetrate the reinforcing material.

01- composite compression molding

Thermo plastic resins Manufacturing methods:

The following methods are used for producing components:

1. Hot stamping:

To produce plane or simple curved parts.

01- composite hot stamping

2. Super plastic forming:

To produce parts with medium geometric complexity

01- super plastic forming process

3. Autoclave technique:

To produce flat laminates

01-autoclave molding

4. Filament winding:

To produce components with regular geometric cross section

01 - filament winding

5. Melt impregnation techniques:

To produce laminates for sandwich type assembly.

01- melt impregnation process

Composite Materials Introduction | Basics Of Composite Materials

What is a Composites material?

Composite materials may be defined as materials made of two or more dissimilar materials, brought into adhesive combination by application of heat and pressure over a period of time. The property of composite materials is different from and superior to any of its constituents and constituents do not react chemically. One of the constituents of the composite material is called the Matrix. It acts as a binder. Its function is to retain the shape of the structure, protect and stabilize reinforcement and to transfer load to and between reinforcement materials. The other component is called Reinforcement. The reinforcing material provides strength, stiffness and low thermal expansion.

01- what is a composite material - aluminium composites

The following materials are used as a matrix:

1. Polymers

2. Glass

3. Carbon

4. Metals

The following materials are used as a Reinforcing material:

1. Alumina ( Al2O3)

2. Aluminium (Al)

3. Boron Nitride (BN)

4. Beryllium (Be)

5. Glass graphite

6. Aramid (Kevlar)

7. Silicon carbide (Sic)

8. Silicon nitride (Si3N4)

9. Titanium (Ti)

10. Tungsten (W)

Reinforcing materials are used as particles, whisker, wire or fibre (Continuous, Discontinuous, Woven or Foils)

Thus we have:

01- composite layout - what is a composite material

Composites are one of the most broadly utilized materials due to their adaptability to diverse circumstances and the relative simplicity of blend with alternative materials to serve specific needs and shows desirable properties.

Fibre reinforced polymer components are grouped into thermosets and thermoplastics. Thermoset composite parts are fabricated by lay up of unidirectional tape on a mold of desired shape and configuration. The laid up tape is compacted and subjected to a cure operation. This operation turns the resin and fibre combination into a stiff structural component.

Thermoplastic resins are polymerized before the fibre reinforcements are added. These are capable of being softened by increasing temperature and hardened by a decrease of temperature. These materials are commercially available as pre-pregs, tapes and sheets.

01- pre preg composite structures

Utilizing a diversity of reinforcements, polyester has continued to be employed in improving the system and other applications. The vast majority of thermoplastics are combined with reinforcing fibres in numerous proportions. Several methods are used to manufacture vehicle parts from thermo plastics. Selection of the material is formed from the final nature of the part, the volume required, aside from cost-effectiveness and mechanical strength.

A reinforced-plastic composite is likely going to cost more than sheet steel, when considered on the premise of expense and performance. In such a case, different qualities should essentially justify the high expenditure. Mechanical properties of the parts, that have an impact on the thickness and weight, ought to give enough savings to render them more effective than steel. It however demonstrates a higher machining waste than reinforced plastics. The manufacturing costs of reinforced plastics is steered by the devices and tooling used for built-up them. In turn, it is subjected on the basis of the quantity of components needed.

An important consideration in the utilization of composites is lightweight. Experimental studies of specific components have demonstrated that utilizing all composite structures a saving of 20 to 45% can be attained whereas selectively reinforced metal structures offer around 10 to 25% only.