Over the years, fiber-reinforced composites have become a more important element of modern engineering than many metals. The reasons are obvious. Composite materials combine the material properties of multiple material types into one, leading to construction materials surpassing the strength and structural integrity of steel at about a fifth of the weight. One outdated method of creating such composites is the organo sheet production process. However, this system of manufacturing standard sheets for preform layup has since been surpassed by direct fiber placement techniques allowing the creation of component specific organo sheets.
From Layup to finished Part
When producing composites, one of several processing methods can be used in order to provide the resulting composite part with the beneficial attributes of the combination of its materials, such as:
- Automated Fiber Placement (AFP)
- Filament winding
- Non-crimp fabric (NCF) sheet molding
The most advanced production technique among these is Automated Fiber Placement, a method of carbon filament or fiberglass application which makes extensive use of robotics or linear axis. An AFP system such as the patented Compositence system uses e.g. mechanical arms to create a three-dimensional layup of pure continuous fibers or prepreg composites, which is then heated for curing.
Organo sheet molding, in contrast, is a variation on the more traditional method of composite production. Here, broad thermoplastic tapes are layed up into standard shape sheets. These fabrics are then cut into the required shape and stacked. Most steps of this process are performed by hand, making it slow and prone to human error. The organo sheet made by Automated Fiber Placement (AFP) is an attempt of simplifying some of these steps prior to preforming. The sheets are pre-manufactured according to specified parameters such as the exact properties of individual layers. This allows for large numbers of organo sheets to be produced as unshaped workpieces prior to actual preform manufacture
An organo sheet can be manufactured from various material combinations, allowing for the individualization of the workpieces. However, AFP is capable of doing the same while also saving on waste materials resulting from the cutout process.
Creating a number of organo sheet workpieces before preforming essentially requires certain steps in the traditional layup procedure to be performed long before preform production. Having a number of standard sheets in storage thus puts costs on the creation of composite parts. Organo sheet made by Automated Fiber Placement are pre-configured for a specific purpose. Therefore AFP works from pure rovings or prepregs to create preforms according to the data inserted into the controller software. The patented Compositence manufacturing system also uses an edge fixation technique to minimize the time required for production from scratch, resulting in the method being not only more flexible, but also as quick as organo sheet molding – while at the same time significantly saving on waste material.
Producing Complexity at low Cost
Conventional sheet production techniques suffer from the same problems which all composite manufacturing processes working with non-crimp fabrics have: It is inflexible, prone to human error, time and labor intensive and ultimately wasteful and costly. The organo sheet processing technique is capable of creating workpieces according to the required component specifications.
Since the patented Compositence manufacturing system based on AFP is capable of producing preforms from pure rovings, prepregs or towpregs automatically according to parameters determined during software simulation, this also makes tailored organo sheet a cost effective solution.