One of the main problems that the aerospace sector faces, regarding component manufacturing, is how to maintain product quality while targeting higher production rates. HP-RTM is one solution with potential, but until recently it has not been considered as a viable alternative to prepregs or more traditional infusion processes. What we propose, called Active RTM, allows manufacturers to overcome the traditional challenges of using high-pressure technologies: maintaining control over in-mold pressure, eliminating voids, improving aesthetic and mechanical characteristics and using fragile inserts.
Active RTM is Cannon's advanced high-pressure technology for delivering aerospace-grade composite quality with higher productivity. Using the patented Dynamic Overpacking System (DOS), it improves pressure control, reduces voids and shrinkage, enhances part performance, and enables the use of fragile inserts.
June 22, 2026
Active RTM helps manufacturers overcome traditional high-pressure challenges
What is Active RTM?
Active RTM is a process that takes advantage of our patented Dynamic Overpacking System (DOS), coupled to a mold, and a more controlled version of high-pressure resin transfer molding (HP-RTM). This combined technology allows manufacturers to actively control the pressure inside the mold during and after the injection phase, which is a longstanding issue for HP-RTM.
Why is this important? The impingement mixing achieved in self-cleaning high-pressure mixing heads has a lower flow rate threshold below which it becomes difficult to dose. The DOS makes it possible to achieve a flow rate of just a few cubic centimeters per minute, which is what allows the manufacturer to use fragile cores without crushing them and avoid fiber washout. Freely changing the flow rate, in a closed loop with the set pressure value, allows manufacturers to control the process.
Benefits of Active RTM
The DOS is a self-cleaning accumulator which allows for a post-injection of the resin, actively compensating for chemical shrinkage and controlling the pressure inside the mold. We have tested this process and employed it on structures that used an aeronautical-grade resin system with a high chemical shrinkage rate.
Compared to standard HP-RTM, components produced using Active RTM showed:
- Greatly reduced void content
- Higher mechanical properties
- Significantly improved aesthetical properties
- Reduced fiber washout
- Reduced chemical shrinkage
- Ability to incorporate fragile inserts
- Increased FVF
How Active RTM works
The Active RTM process happens in 6 steps:
- The mixing head opens and injection into the mold begins;
- At a certain point, a pressure threshold will be reached: this is where the traditional HP-RTM process would end, and the reason certain applications avoided using this technology;
- But, with Active RTM, the DOS opens and accumulates a set amount of mixed material from the injection head;
- After the mixing head closes, the DOS then actively injects the accumulated material at a much slower rate to maintain the in-mold pressure in a closed loop;
- Once the gel time is reached, the “Active” phase ends, and the component polymerizes;
- Finally, the cured part can be removed from the mold, and the process can be restarted. No solvents or consumables are needed in the process, and the DOS is self-cleaning.
The equipment Cannon offers
A turnkey Cannon plant for Active RTM includes:
- E-System dosing unit
- LN EPX mixing head
- Dynamic Overpacking System
- Mold tooling
- Stacking lines
- Preforming lines and presses
- High-tonnage presses
- Single control system for the entire plant
Are you looking for a tailored solution?
Contact us today to discuss your specific needs and find out how our custom solutions can enhance your production process. Don’t wait — let’s create excellence together!
