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.
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.
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.
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.
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.
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.
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.
Thermo plastic resins Manufacturing methods:
The following methods are used for producing components:
1. Hot stamping:
To produce plane or simple curved parts.
2. Super plastic forming:
To produce parts with medium geometric complexity
3. Autoclave technique:
To produce flat laminates
4. Filament winding:
To produce components with regular geometric cross section
5. Melt impregnation techniques:
To produce laminates for sandwich type assembly.