Provide (All Photos) | CDCQ, LxSim and Argon 18
Thermoplastic composites (TPC) are on the forefront of the revolution in provides and processes for the biking commerce, says Vincent Lemay, VP of R&D for Argon 18, a high-quality bike producer in Montreal, Canada. “I really feel the commerce will go this way inside the near future, because of these provides permit quick, atmosphere pleasant and fewer labor-intensive processes [see CW’s 2022 feature on bike frames]. Nonetheless inside the biking commerce, now we have now very detailed, tailored layups, which is why they’re carried out manually correct now.”
These layups are moreover nearly utterly thermoset composites, notes Lemay, using carbon fiber-reinforced polymer (CFRP) based mostly totally on epoxy prepreg for freeway racing fashions, the place lightweight effectivity is paramount. “That’s what we wanted to cope with,” he explains. “How can we develop comparable carbon fiber (CF) layups with thermoplastics however retain the extreme effectivity of typical epoxy-based CFRP?”
To answer this, Argon 18 labored with the Quebec Composites Progress Centre (CDCQ, Saint-Jerome, Canada) and engineering simulation specialist LxSim (Bromont, Canada), along with composites automation agency Addcomp (Sherbrooke, Canada) to guage six completely completely different TPC provides. It developed an optimized layup for 2D blanks which had been made using automated fiber placement (AFP), shaped onto a mandrel and then compression molded using a bladder-based course of to provide and examine two of these provides in a motorcycle seat submit demonstrator.
Problem companions and targets
The enterprise began with Addcomp’s arrange of a personalised robotic AFP cell at CDCQ. “We had been completely completely different initiatives to exhibit what this cell may do,” explains Yoann Bonnefon, CEO of Addcomp. “We had been already working with CDCQ to guage completely completely different TPC provides and as well as wanted to collaborate with LxSim ensuing from their expertise in composites optimization.”
Argon18 was moreover occupied with testing diverse TPC provides. “CDCQ is a longstanding confederate serving to us uncover how to provide further atmosphere pleasant, lighter and safer bicycles,” says Lemay. His employees steered the bike seat submit as a basis for comparability. The enterprise began with supplies characterization and selection, adopted by fabrication and testing of the demonstrators.
Six completely completely different carbon fiber-reinforced thermoplastic composite (TPC) tape provides had been examined using automated fiber placement (AFP) to make plaques for coupons.
“We started in 2023, and carried out the provides testing in our lab,” says Yves Mathieu, enterprise supervisor at CDCQ. “Our preliminary checks had been on flat coupons made using robotic AFP layup with completely completely different angles after which scorching press molded into plaques.” The employees examined six completely completely different unidirectional (UD) tape provides made using commonplace modulus CF with diverse thermoplastic polymers — along with Rilsan polyamide11 (PA11), polypropylene (PP), Maezio and Gordon Plastics polycarbonate (PC), Toray TC910 with polyamide 6 (PA6) and PA12 tape from Suprem — and in distinction their properties to the baseline CF/epoxy supplies, deciding on two TPC provides to utilize for the demonstrator parts.
LxSim used the preliminary property info for these two TPC provides in its finite ingredient analysis (FEA) design and optimization of the demonstrator, aiming for parity with baseline CF/epoxy parts. “We then used the robotic cell to place up optimized 2D blanks and used a bladder molding course of to remodel these into gap bike seat posts,” says Mathieu. “These demonstrators had been then examined by Argon 18.”
“We chosen a seat submit because of it’s a simple kind,” explains Lemay. “Nonetheless because of it attaches the saddle [seat] to the bike physique, it has pretty a elaborate load case that we’re in a position to simulate. Our preliminary intention as a motorcycle producer was to characterize and look at the TPC provides after which use that info to feed our FEA simulations to match with present CF/epoxy parts. Nonetheless we moreover wanted to optimize the layup for the seat submit and develop the manufacturing course of on the equivalent time. These are the most important roadblocks for us to start out out using TPC: learn to optimize and produce the weather successfully. If we’re in a position to simulate the failure mode exactly, we’re in a position to then optimize our half using FEA and from there the layup for larger and additional superior parts.”
Provides testing, course of progress
Supplies properties checks had been carried out for six TPC provides using plaques made using AFP layups (A) positioned into matched aluminum mould items (B) that had been then consolidated in a heated press (C) and waterjet decrease into diverse ASTM coupons (D).
“We programmed the robotic to make use of the PA6 and PC composite tapes,” says Mathieu, “which was a bit troublesome because of they weren’t the equivalent areal weight as a result of the CF/epoxy that we had been used to. So, we wished to tweak it to realize the prescribed layups. The fiber areal weight of the TPC tapes was outlined by the material supplier, and though we targeted 150 gsm, some provides had been 131 gsm.”
“Our main alternative parameters had been stiffness and low density,” gives Mathieu. “Nonetheless there are limitations from the heating system inside the AFP course of — as an example, our system makes use of scorching air. So, we moreover in distinction provides with regards to processability and value to make our alternative.”
The AFP layups had been then positioned into two-part aluminum molds and consolidated in a Carver (Wabash, Ind., U.S.) 100-ton heated press. Molding time was 5 minutes as quickly as soften temperature was reached. Check out coupons had been waterjet decrease from diverse plates made to utterly characterize the two chosen provides per ASTM specs for flexural, tensile, compressive and in-plane shear properties.
The two UD tape provides Argon 18 chosen to make the bike submit demonstrators had been a CF/PA6 from Toray Superior Composites (Morgan Hill, Calif., U.S.) and a CF/PC from then Gordon Plastics (Englewood, Col., U.S.), acquired by Toray in November 2024. Lemay notes that low-melt polyaryletherketone (LMPAEK) polymer (Victrex, Lancashire, U.Okay.), and completely different high-performance TPC provides utilized in aircraft, weren’t thought-about ensuing from value. “We thought we would optimize a CF/PA6 layup to be as performant as the current CF/epoxy we use, and this was the intention of the enterprise ”
One different aim was to develop the tactic. “To make the complete half from TPC was an infinite drawback,” says Eric Allard, mechanical engineer for composites progress at LxSim. “I come from the ice hockey commerce, and we tried to do this beforehand. Nonetheless it’s not easy to create an optimized preform after which preserve the fibers straight as you mould the half.”
He explains it’s as a result of TPC provides are rigid at room temperature. They must be heated to melt temperature as they’re utilized to create a multidirectional stacked laminate after which molded proper right into a closing half. “We developed a course of that makes use of AFP to create the laminate after which we rolled that preform spherical a mandrel to kind a shaped preform which was then bladder molded. There have been moreover challenges with bladder provides because of the TPC molding temperature is bigger than with CF/epoxy.
AFP layups had been utilized onto Thermalide polyimide launch film (left) and glass fiber fabric (correct).
One different scenario was discovering a high-temperature launch layer for the first ply all through AFP. The employees used Thermalide (Airtech, Huntington Seashore, Calif., U.S.), a polyimide launch film for temperatures as a lot as 405°C, and an 8-harness satin glass fiber fabric from BFG Industries (Danville, Va., U.S., a subsidiary of Porcher).
“It was an excellent learning experience for all of us,” gives Mathieu, “to go from the raw tapes to the 2D engineered clear rolled into cylindrical-shaped preforms after which closing molding of the outlet seat submit. We labored a good way up the coaching curve and matured the tactic to get good compaction and administration of the fiber angles and gaps.”
Simulation to optimize the half
With preliminary testing and supplies alternative achieved, LxSim began to optimize the layup and half for producing the final word demonstrators. “We had developed the FEA model of the seat submit,” says Allard, noting the submit is often spherical and inserted at an angle between the bike physique and saddle/seat. “We outlined the boundary conditions and the vital factor load circumstances after which we nearly examined the half in FEA, loading it vertically from the seat, nonetheless replicating the offset, which results in bending and compression on the submit.”
Finite ingredient analysis (FEA) model of the bike seat submit and simulation of vertical load testing.
“There’s moreover a clamping on the physique,” gives Lemay, “which creates a extraordinarily compressed area. That’s why this submit was a terrific demonstrator, because of it included quite a few the failure modes that we’re in a position to see on a bicycle factor.” Every LxSim and Argon 18 used Hyperworks (FEA model) and Optistruct (solver) simulation software program program from Altair Engineering (Troy, Mich., U.S.).
“We had the reference layup for the CF/epoxy seat posts, so we had their stiffness and weight,” says Allard. “And other people had been our targets for creating the model new layups, considering the stiffness-to-weight ratio of the CF/PA6 and CF/PC provides.” He notes there have been some drawbacks with the PA6 and PC supplies stiffness not being as extreme as a result of the CF/epoxy. “Nonetheless, we would match this effectivity along with fatigue loading by optimizing the TPC layup. Nonetheless we wished to make sure we wouldn’t get completely different failure modes.”
LxSim obtained right here up with two completely completely different layups associated in stiffness and weight. “We used an entire of 14-16 plies counting on whether or not or not it was PA6 or PC,” says Allard. “And the reference half in CF/epoxy was 20 plies.” Although the laminate was not quasi-isotropic, it did have fiber orientations starting at 0° and rotating at 15° increments. “So, we would tune the fiber angles, and though it’s doable to do fiber steering with TPC tape, we didn’t attempt it on this enterprise.”
These layups had been then utilized by CDCQ to optimize the tactic. “Working with the employees at CDCQ, we developed a technique to translate the optimized layups to an AFP-produced laminate,” says Allard. “We would have liked to make a prototype to get correlation between the FEA and the exact layup. We then wanted to make some adjustments.”
“The PA6 laminate was correct on observe,” he continues, “nonetheless the PC laminate wished iteration. That reveals why it’s good to do the material characterization to start out with to feed the FEA — it reduces the trial and error and progress time to realize the entire targets. These flat panels had been then original via a rolling course of over a mandrel to make the preform that was bladder molded into the final word half. So, the complete course of started from a flat laminate with staggered plies.”
FEA simulation was moreover used to analysis failure on the ends of plies (above) and optimize staggering of plies to kind the spherical tube.
Why staggered plies? “We wished a form of step joint the place the flat panel met itself to kind the tube,” explains Allard. “And other people wanted to be distributed throughout the tube. As soon as we rolled these plies to make the tube, we wished to see if we might get any failure on the ends of the plies or any defect inside the kind. In the long term, it labored excellent.”
Manufacturing the demonstrators
Seat posts had been made by wrapping a 2D preform spherical a Mosite1453 silicone bladder (left) and placing proper right into a matched metallic mould and heated press. The opening between the preform and mildew (crimson arrows excessive correct) must be near zero for good supplies compaction, illustrated inside the cross half at bottom.
It took 20 trials to realize an applicable half, all through which a variety of factors had been addressed, along with bladder leaks, mandrel sizing and the rolling course of for making use of plies to the mandrel. “That was not as simple as with CF/epoxy prepreg, the place the laminate is utilized onto the mandrel ply by ply,” notes Mathieu. “With TPC, you possibly can have a semi-consolidated layup, so the rollup course of is not as tight because of the plies are all there already and the TPC tape is further rigid, even when heated. So, we wanted to go further slowly and truly work with the material.” In the long term, the employees was able to make a element with the designed dimensions, reaching good compaction whereas minimizing voids.
Mathieu elements out that for the tooling, CDCQ labored with a confederate R&D coronary heart, St. Clair School (Windsor, Canada). “The instrument was partially designed and machined by mechanical engineering school college students who moreover helped out inside the manufacturing of the tubes as part of their composites teaching program,” he says.
A bracket compression molded from tape scraps (left) was moreover fused to the bike seat submit (correct) in a form of welding/fusion course of.
After bladder molding, CDCQ moreover trialed fusion welding a bracket onto the seat submit, which went comparatively properly, says Mathieu. “After we consolidated the tube inside the bladder mould, we had a definite instrument we positioned on the highest of the seat submit and into which we positioned a bracket created from compression molded tape scraps. We then closed the tooling and heated inside the press so that we primarily co-melted and fused the two parts collectively.”
“This small bracket connects the saddle to the submit,” gives Lemay, noting that such choices on bike frames are principally compression molded using thermoset composites. “So, it was good for us to exhibit it with TPC. Normally, it’s a robust half that features a fancy layup of small gadgets and stacks of plies, nonetheless we used the leftover gadgets of TPC tape from the AFP course of, which could permit a closed loop recycling course of in-house.”
On par with epoxy, future developments
Clamping checks (left) along with static load checks (correct) and rigidity checks had been carried out on the demonstrator bike seat posts.
After producing the demonstrator seat posts, Argon 18 examined them on its in-house examine bench. This included clamping checks the place the seat submit ought to withstand 200% of the 4 newton-meter clamping torque. Demonstrators from every the CF/PA6 and CF/PC provides handed, nonetheless probably the most clamping torque was 19% better for the latter.
Subsequent, fatigue effectivity was examined, making use of 100,000 cycles of a 1,200-newton vertical load. On this examine, the TC910 CF/PA6 seat submit handed whereas the Gordon 40-150 CF/PC submit narrowly failed, perhaps to a processing imperfection. Sadly, this submit could not be included inside the subsequent static load checks, the place a most load of two,000 newtons was utilized for one minute at an offset of 70 millimeters. The TC910 tube handed. Nonetheless, every posts handed rigidity checks, with outcomes inside 8% of the reference CF/epoxy seat submit.
“The outcomes confirmed that it is doable for us to provide a TPC half that’s practically nearly as good as our current CF/epoxy parts,” says Lemay. Argon 18 may examine the TPC demonstrator seat posts on an instrumented bike to characterize their stiffness and luxurious for the rider in real-life conditions. “We’ll use this to characterize the vibration absorption, which is doubtless one of many key advantages of TPC compared with thermoset composites for bike frames. By early 2025, we’ll be succesful to look at this effectivity to our current CF/epoxy, in numerous sorts of biking conditions.”
He thinks that finally, even high-end freeway racing bikes will most likely be manufactured using TPC, and maybe even using a further costlier resin system, “nonetheless the roadblocks are learn to merely fine-tune the plybook to realize the effectivity we want. For Argon 18, we gained’t aim the high-end merchandise at first, nonetheless as a substitute on the mid-range. From our preliminary simulations, I really feel it’s doable there to realize the equivalent effectivity on the equivalent value degree, nonetheless there’s nonetheless quite a few work to do sooner than we would put this into manufacturing.”
Though current Argon 18 freeway bikes are based mostly totally on thermoset CFRP, the company sees a future for TPC parts similar to the demonstrator seat submit confirmed proper right here.
“We do see an infinite shift coming inside the biking commerce,” says Lemay. “Each half is geared correct now to utilize thermoset composites, nonetheless we’ve seen corporations start to make use of TPC in mountain bikes and Rein4ced is moreover working with it in freeway bikes. Nonetheless there are moreover important challenges in creating the manufacturing processes. You can’t merely go and buy the instruments off-the-shelf. It’s not there however. So, we have now to develop the recipe and the instruments according to what we might like, and that’s why this form of enterprise was so useful — to collaborate with the CDCQ’s technological coronary heart, LxSim’s simulation expertise and Addcomp’s industrial expertise was a win-win for all of us.”
For Addcomp, this enterprise proved that revolutionary methods like AFP could also be democratized to industries like sports activities actions and leisure and along with smaller corporations, says Bonnefon. “It was a terrific demonstrator for the fairly priced, customized robotic cells that in the mean time are accessible, which could permit corporations like Argon 18 to make use of additional superior and computerized composite utilized sciences.”
And might Argon 18 proceed forward with this progress? “We achieved our preliminary targets and now we’re working to further refine the tactic,” says Lemay. “We now have a separate enterprise engaged on further superior thermoforming and to see the place we’re in a position to push the layup optimization for even further effectivity.”