HELP: infusing goalie masks

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#1

i have been experimenting with infusing goalie masks. i have a fiberglass female mold and a silicone male mold, and a plenum ring which goes on top to seal the too together. i have no problem getting 28+" vacuum. the problem that im having is that my parts are delaminating on impact.

i am trying to infuse carbon and innegra but when i infuse fiberglass i have the same problems. i have tried normal iso infusing resin, derakane and cray valley vinyl, and cass epoxy. i have the same problems every time no matter what the resin is. i also have the same problems irrespective of how much resin i use. (i know it sounds weird but i tried putting 1500 grams of resin in for 350 grams of fabric and i still had same problems.)

i calibrated the molds with 2mm wax, and my part is 3.5mm thick. i thought that perhaps if i calibrated it differently the problem would be resolved but when i calibrated it with 3.5 mm wax i still have the same problems.

i have tried coremat and veil as vent tabs as well as bleader as vent tabs and still the same problems. i have used as few as 2 and as much as completely surounding the permimeter and still have the same problem.

hopefully someone with some experience with infusion could give me a hand. im sure im just missing something small here.

thanks…

Gabe

#2

Goalie masks are actually my specialty so maybe I can help.

For all my mask molds I just use a female mold with peel ply with no male mold.
What’s your layup like? Are you using an adehsive to keep your layers in place?

You can PM me directly if you want.

#3

its not allowing me to pm you. when you get a chance could you email me at gabriel@hackva.com please.

thanks in advance.

i am using blue tac to hold my layers in place.

laminate schedule is:

innegra
biax carbon
innegra
innegra
biax carbon

i have a fiberglass female mold with a silicone male mold. it doesnt make sense for me to bag them with disposable things as i need to produce 100+ parts a week.

#4

Hey Gabriel!

I watched the “factory tour” video on your website. I’m very curious…what’s the point of the single carbon layer on the inside of the helmet?

#5

Pm’s are disabled for new users, reason being that spammers would sign up and then send PM’s to users without my knowledge.

#6

off topic, but what is innegra? Is it the same thing as kevlar?

making 100 masks a week it seems infusion set up would be time consuming for 15 to 20 parts a day?

#7

It didnt occur to me that you were Gabe from Hackva. So I see Hackva is experimenting with Infusion now.

Im not sure what your issue could be. I’ve had issues with delaminating on impact when I used to use standard 3m spray adhesive while setting up my laminate but havent had any issues after switching to an epoxy specific spray adhesive.

#8

i find the layer of carbon on the inside makes the masks more rigid. people also like the carbon look on the inside as well. when i tried putting the carbon closer to the outside of the shell i found it was more prone to cracking on impact as opposed to on the inside.

the company which produces the yarn for innegra is called innegrity. it was explained to me that it had many of the same qualities as kevlar but less expensive and easier to work with. the reason why i have been experimenting with innegra is because i am trying to get the wait down in my masks. the problem that i have been having is when i weight the fabrics of my laminate before i add resin i can tell if it will be too heavy. i am having problems finding a combination of fabrics that will be light enough. my goal is a 1:1 ratio of fabric to resin.

i am experimenting with infusion because it is clean and fast for me. it takes me apx 7 mins to load a mold and another 10 to get everything ready and fully infused. i am using a silicone bag so its not like im messing around with bags, infusion mesh, peel ply and stuff like that. im using a snappy resin as well so i can demold after an hour curing at 32 degrees c.

#9

Care to share any pics of your tooling?

#10

I only have heard this from others, but innegra is crap. It’s made from one of the least surface energy plastics out there, so it’s really hard to keep it bonded to rigid materials like carbon. I haven’t worked with it yet, but I have used PP has an infusion table, so I don’t have to use release agents!! The carbon will form a solid layer, and the innegra will be a soft flexible layer…impact it, and the carbon will delam from the innegra very easily. THAT might be your problem, not necessarily using the wrong resin/too much/too little. You might have luck with a co-mingled fabric, instead of layers of each type.
But again, that is just from hearsay from my director…i’ve already gone to him about using it.

#11

For what I read of it, Innegra is comparable to Dyneema. I hope it has improved properties, as dyneema had its share of problems, and is hardly used in composites anymore.

#12

im happy to use ANYTHING. if the innegra is the problem i would gladly try something else. the problem that i am having is finding a laminate schedule that will be light. i would gladly drop the innegra. the main issue is that i cannot find a combination of fabrics that will allow me to get my part weight down.

my goal is to produce a shell that is 600 grams once it is trimmed. it means untrimmed the part would need to be about 750 grams.

i cant seem to find a combination of fiberglass, carbon, and kevlar that will be light, rigid, and impact resistant.

#13

Will changing resin systems help with brittleness?

Would a thermoplastic resin deflect a puck better?

#14

You could try a flexible resin, together with loads of aramide (kevlar), with glass on inside and outside.

#15

ive tried using a iso resin, darakane, a cray valley vinyl, an sp epoxy, and a cass epoxy. im starting to think it is the innegra…:mad:

the problem in the past when i experimented with several layers of kevlar is the trimming is a nightmare. my parts are trimmed with a robot but i still have to break the edges by hand and having 3-4layers of kevlar will be pretty fussy. im not sure how to clean that up so the edges would be clean and smooth.

im also not sure how rigid the part would be if it was mostly kevlar?? i know strength doesnt equal stiffness but in my industry the first thing a person does when they pick up a mask is give it a squeeze. they assume if it is rigid it is strong.

i m going to try the following laminate schedule later in the day once my samples arrive. hopefully they work.

carbon-kevlar
1.5 oz csm
carbon-kevlar
rovicore
carbon-kevlar

this should give me my weight/rigidity/impact resistance…i hope.

#16

When I use kevlar I stay an inch or so away from the trim line and place either carbon or glass tape around the perimeter of the part so the thickness is consistent. This will yield the nice crisp lines you’re used to without the hassle of trimming the kevlar.

#17

Have you used them?

It would require using pellets of the desired plastic, melting them, and injecting them into the mold before it cools too much and stops flowing.

#18

on my masks there are 8 vent holes, 3 strap holes, and a large opening over the face. i do what your suggesting with my current hand lay up parts but on all of these openings 3 x the kevlar will be a challenge.

someone told me that they use a heat gun to sear the edges of their parts which burns the kevlar. they then sand the burnt part off and it is effective. i havent tried this though.

#19

I don’t know why I didn’t think of that… I wonder if it would be possible to build those openings into the mold then have the fabric die cut (or other…) so when you place the dry material in the tool it fits perfectly. This would save a ton of trimming time on the back end. Just trim the back side of the helmet.

Have you ever tried a thin core in these helmets?

#20

Indeed die-cutting the fabric could be an option. You need a small press to cut the fabric to size, but you can cut multiple layers. (hope this works with kevlar, though. Carbon and glas are OK that way.)

You can go high tech with either Twintex fabrics (with polypropylene as a resin, as in a prepreg), or use vacuumfilm as a resin (nylon). Use multiple layers of nylon film, and bag it in place at 250 degrees C.
Another option is PEEK prepreg, or infuse caprolactam which turns into nylon.

All pretty high-tech stuff…

About your layup: stiffness-wise the layer of c/k in the middle does not bring much. You could move that to the back of the mask.