1. Fiber Reinforced Plastic beam manufacturing process
Svetlana Capeska
Product Engineer

2. FILAMENT WINDING PROCESS
Analysis and identification of the preferred manufacturing technologies used in manufacturing of FRP beams indicate that FRP beams are still highly manual operated.
Composite products must be properly designed and fabricated in order to provide one or more of the following benefits: high strength, oriented strength, light weight, high strength to weight ratio, corrosion resistance, design flexibility, reduced life-cycle cost and dimensional stability products.
For composites industry, a true breakthrough in usage of composite would not be implemented only by reducing the cost of raw materials but more importantly by reducing the manufacturing costs.
So, in this way, our challenge is to define specifications and improvements in order to achieve a mostly automated manufacturing system for producing FRP beams.

3. FILAMENT WINDING PROCESS
What is important to provide mainly automated manufacturing process
of closed-shape FRP beam?
Design /construction of the machine - we have developed a special design of filament winding machine with six working axis.
Auxiliary equipment
Resin Bath system – Roller Type or Deep immersion system
Fiber creel – Electronically controlled tension system or Mechanically controlled tension system
Curring system – Infrared heaters, ...
Extraction system –Appropriated for extraction of the mandrel design
Specially designed tools - Collapsible trapezoidal mandrel, Special designed combs for small angle of winding .
Additional tape laying head

4. Manufacturing process of FRP beam
In order to provide best mechanical quality of FRP beam it’s very important to have technological knowledge about composites in defining the technology parameters in manufacturing process such as, angle for winding, raw material, operations and process time, ambient temperature, resin temperature and the process speed. All of these parameters are strictly controlled by the automated manufacturing process, in order to provide best performance of final composite structures
Design of control system with interface which is easy to use with integrated automated functions in relation to the flexible manufacturing system for FRP beams.

5. FILAMENT WINDING PROCESS
Filament Winding process is shown on the following picture:
The process begins with spools of dry fibre tows supported by a creel that can be mechanically or electronically controlled with tension bars. The tension can directly affect the void content and fibre volume fraction which are factors in the strength and stiffness of the composite product. Next, the fibre tow is directed into a resin wet dip impregnation or roller bath system where the tows are impregnated with the matrix resin. Fibres are spread between the rollers across the length of the resin bath system to ensure good impregnation with resin. After, winding the composite structure, next processes are: curing process, extraction process and finally assembly and testing of final composite parts.

6. FILAMENT WINDING MACHINE
The following picture shows Filament Winding Machine, produced from MIKROSAM, Macedonia for manufacturing closed - shape FRP beams.
All testing for improvements in the manufacturing process of closed-shape beam were carried out on this machine.
Collapsible mandrel
Filament Winding Equipment

7. Manufacturing process of FRP beam
Depending on the machine head that will be used, two independent software packages are developed: one for filament winding and one for tape laying.
Setup
Defining the machine to be used and modifying its parameters;
Setting up tool position and orientation together with the working environment;
Ability to import surfaces and boundaries from all the popular CAD systems.

8. Manufacturing process of FRP beam
Layup
Defining each ply’s boundaries and layup parameters;
Generating the exact courses and tows from a number of sophisticated layup strategies;
Sequencing of plies and courses to exactly define the final laminate.

9. Manufacturing process of FRP beam
Analysis
Post-processing
Analyzing each ply separately or the complete laminate for possible production issues
Analysis of thickness, steering radius violations, bridging, roller bending and other types
Generating reports on simulated production statistics

10. Manufacturing process of FRP beam
Defining machine path parameters such as lead in/out strategies, safety zones, events etc.
Generating the machine path and the process data to achieve the defined layup
Ability to modify any process and orientation parameters, at any point on the machine path
Generating the G-Code for the specific CNC system being used
Simulation
Visualization of the complete kinematic movements from the generated G-code;
Collision detection and reporting

11. Manufacturing process of FRP beam
Step I: Set-Up and Parameters definition
First stage in manufacturing process is to define the basic process parameters depending of the mechanical, thermal and other requirements for the composite structure for the beam.
Definition of raw materials and technological parameters for laminate structure;
Analyzing and pre-determination of the winding process parameters for the mandrel geometry (machine axis speed, delivery rollers system type, setting up tool position and orientation);
Generating the exact path for fibers.

12. Manufacturing process of FRP beam
Step II: Preparation the mandrel for winding
When laminate structure for the beam is defined, the next step is preparation of the beam for starting the winding process.
For preparation of the mandrel is used PP film and Viledon.

13. Manufacturing process of FRP beam
Step III: Filament Winding process
Winding process is defined with basic parameters for winding, like angle type, number of cycles, cycle length, layers length, number of tows, etc.
Winding with carbon fiber Winding with glass fiber

14. Manufacturing process of FRP beam
Step IV: Tape laying (additional step for manufacturing for specific requirements)
For specific requirements, especially for laying of composite on 0 degrees, is used UD tape laying with additional axis – ATL head.
On following picture is shown the process for laying UD tape with ATL head:
Tape Laying process

15. Manufacturing process of FRP beam
Step V: Curing process of the composite structure
The curing process starts after finishing the winding process.
For curing the composite structure is used infrared heater. During the curing process mandrel rotate on filament winding machine with continuous rotation. Temperature for curing the system depending of the epoxy resin system configuration (resin type, accelerator type).
Composite structure for beams made by epoxy resin system is usually cured on °C.
Curing on the composite structure

16. Manufacturing process of FRP beam
Step VI: Mandrel release process
After the curing stage, the next step is the mandrel release process. Mandrel release operation is a process where the mandrel is pulling or stripping out of the cured composite structure.
With this process, using the advantages of the design of the collapsible mandrel, the release of cured composite structure was easy and fast process.
Mandrel Release process
Released composite structure

17. Manufacturing process of FRP beam
Filament Winding Manufacturing process of composite structure beam is finished, BUT the next and most important stage for manufacturers and end users is the Product Quality certification.
Quality of manufactured beam could be checked by several testing methods for mechanical characteristics (bending test, shear testing) and Rheological Tests.
For composite structure analyses commonly used methods are the following:
Scanning electron microscope (SEM),
Transmission electron microscopy (TEM),
Fourier Transform Infrared (FTIR).
The testing results are used for improvement of the quality of the beam with changing some of the technological and process parameters in manufacturing process.

18. Manufacturing process of FRP beam
Conclusions:
The final features of the composite part are not only a function of the individual resin matrix and fibers features, but they also depend of the method of manufacturing process.
Equipment would have high precision, high reliability, and quick response speed.
Using the fully automated manufacturing process with addition of modular equipment, like new tape laying head, to meet the specific process parameters and the use of different tools in manufacturing process are the most important elements for successful manufacturing of FRP beam.

19. Manufacturing process of FRP beam
Thank you for your attention!