1960–1980: Automated Tape Laying (ATL)
The 1960s were a Golden Age for composites manufacturing. The ongoing Space Race between the USA and USSR required innovative solutions to make the most advanced and safest space-bound structures. Considerable funding on both sides was put into R&D for these structures, and a unique manufacturing method of composites was created: automated tape laying (ATL). Since then, it grew in popularity in the space and military sectors. The so-called tapes were wide rolls of thermoset prepreg, capable of laying up 1-, 2-, and even 3-meter wide sections at a time. As great as it was, it did have some downsides, which are being realized more and more today.
Figure 1. Automated Tape Laying (ATL) Process
Using the wide rolls in ATL created considerable amounts of waste, but when beating the other guys was the only thing that mattered, material efficiency wasn't a priority. Nowadays, reducing manufacturing waste in composites is a main topic of research, and the way to achieve material savings is through using narrower tapes, or fibers.
1980-Today: Automated Fiber Placement (AFP)
In the 1980s, suppliers started taking their wide rolls of material and began "slitting" them into many smaller widths, now known as "slit tapes". This allowed for tapered sections to be laid up, creating a near-net-shape preform. Thermoset carbon fiber prepregs were the material of choice for this process, but this started to change. The common widths for these slit tapes are 1/4" (6.35mm), 1/2" (12.7mm), and 1" (25.4mm).
Figure 2. Automated Fiber Placement (AFP) Process
Thermoplastic material suppliers quickly recognized their materials might also be used in the same ways if machine technology could be adapted. This improves material savings further since the thermoplastic