The Evolution of Automated Fiber Placement: Early Developments to Modern Applications

Introduction

Automated fiber placement (AFP) technology has undergone significant development since its introduction in the late 1980s. This article will provide an overview of the evolution of AFP systems from 1990 to 2023, with a focus on the development of thermoset and thermoplastic applications. The benefits and limitations of AFP systems will also be discussed, as well as potential applications. Article concludes with a summary of the key points discussed.

Jump to the right section

• Development of Automated Fiber Placement (AFP) systems from 1990 to 2000

• AFP developments that focus on thermoplastic

• Development of Automated Fiber Placement (AFP) systems from 2000 -2012

• The Current State of Automated Fiber Placement: A Review of the Latest Developments in AFP Technology

• Benefits and limitations of Automated Fiber Placement systems

• Potential applications of Automated Fiber Placement systems

• Summary

Development of Automated Fiber Placement (AFP) systems from 1990 to 2000

Evolution of Automated Fiber Placement CNC gantry (illustration)

AFP head [2]

• AFP systems were introduced in the late 1980s, combining the features of ATL and filament winding

• Limitations of the previous approach were overcome through separate bobbins and individually driven tapes

• AFP machine demonstrated with an offline programming system in 1991

• AFP System demonstrated controls of layup speed, pressure, temperature, and tape tension

• Layup speed of 7 m/min resulted in productivity of 5 kg/h, comparable to Automated Tape Laying (ATL) in 1992

• Layup reliability was improved in 1992 by using cooled creel houses

• Mechanical properties of laminates made with AFP and hand layup were found to be comparable in 1992

• A number of technical issues prevailed during the development of AFP, including tension in the tows, reliability, productivity, and layup accuracy

• 1992 saw an increase in the number of tows and the integration of the system with the CAD system which increased productivity.

• The 1992 steering program improved productivity by focusing on the reliability and delivery of tows along curvilinear paths (steering). Steering allows for additional design freedom and potential improvement in mechanical performance with smaller tape widths.

• The AFP reduced material wastage rates from 62% to 6% and increased productivity by 450% for a single 12.7 mm wide tape.

• AFP reduces cost by 43% compared to manual layup.

• AFP systems were extremely expensive, up to $6 million, with a limited range of affordability, reliability, and productivity

AFP developments that focus on thermoplastic

Continuous press style process [1]

Long soak AFP process [1]

• Early approaches to developing thermoplastic layup with AFP identified trade-offs between layup pressure, temperature, and speed.

• Layup quality is affected by layup speed, which is limited by the time needed to heat material above the melting point.

• Layup speeds of 3.6 m/min to 5 m/min were reported, resulting in lower productivity compared to thermoset materials

• Optimal processing conditions for reduced void growth and improved interfacial bonding were explored

• Heating methods include hot gas torches and lasers

• Curing of thermoset prepregs with electron beam or UV light for faster processing and reduced thermal stresses achieved with limited layup speeds and reduced mechanical properties.

Development of Automated Fiber Placement (AFP) systems from 2000 -2012

Large AFP machine [3]

• From 2000, the focus shifted to addressing issues of affordability, process reliability, and productivity

• AFP was mainly used in military and space programs until 2000

• Process reliability improved through the use of automated splicing and layup error detection systems

• Infrared heating of thermoset tape used to increase tack levels and reduce layup errors

• Material delivery improved through the reduction of feed length and minimizing redirects and twists in the tow

The Current State of Automated Fiber Placement: A Review of the Latest Developments in AFP Technology

• Industrial robots and advances in sensors, networks, and software have allowed for more powerful and smart AFP systems.

• These systems can now be created using any industrial robotic arm or CNC, rather than being limited to complete CNC unit integration.

• The cost of accessing new AFP systems has decreased about 100x, with one of the best AFP systems starting at around $3000-$4000 per month for a lease ready for industrial use.