Press Molding

[dorifto240]

Alright, I'm a bit of an environmentalist and i had an idea to use fiberglass resin and shredded plastic bags or shredded paper to mold things like body panels or fairings for motorcycles (if it works, discount for Ohio Riders members of course).

A few things though:

1) Does anyone know a good place to get resin? I know Autozone and places like that have it, but they can be expensive when it comes to body work supplies.

2) Anyone have experience with press molding fiberglass? What would I need to do to set it all up and try it out?

3) Is this crazy?

[magley64]

Anyone have experience with press molding fiberglass? What would I need to do to set it all up and try it out?

Expensive start-up costs, for press molding. (even temporary molds are machined out of large blocks of aluminum, then coated with layers of brass and chrome.) Not to mention you need a press capable of several tons of force.

lay-up/spray-up is cheaper set up, and requires no press.

[mello dude]

I'll throw out some tidbits and thoughts for you - In my past life I was an automotive engineer and have some familiarity on plastics processes.

-If you are talking about some molds, It would take someone with CAD experience to sit down and spend time on designing a functional mold. It would be made out of some kind of tool steel. - Lots of bucks. -- High 5 figures, maybe low 6

- Then the above mould would require a large press sized for the mold - more bucks.

- If you were going to do body panels with a fiberglass impegnated resign, there is a style of that material used called "sheet molding compound: or SMC. It a big square of material to what ever size you would want, say the size of a top of a desk. You would set this flat sheet into a female mold and then mate up the male mold to it. Again it takes a big ass press to apply heat and pressure.

- Plastic and paper garbage such as bottles, newpapers and other stuff are sold from the recyling centers to plastics vendors and they in turn sell that to big plastics makers. The major raw plastic makers in turn then add the recycle scrap to virgin plastic. So this blended raw material ends up in lots and lots of consumer products. (We bought a lot of it to use in auto instrument panels.)

- In a utopia world, there would be enough recyled plastic material to use for all the new products that eveybody wants and needs. The fact is there just isnt enuff recycled plastic for all the new products that business want to make and people want to buy. So new raw plastic needs to be made.

- Is this crazy? SMC is good for relatively simple curved shapes. Would it be good for a MC body panels? m'be - but I really doubt it would match the quality of OEM body panels. Fibreglas with recycled plastic bags and newpapers? That's probly not a good material for body stuff.

(The aftermarket mc body panel industry is probly using some kind of spray lay up process I am not familiar with.)

-(my experience is with product run in the tens of thousands.)

------Just my 2 cents, this is just stuff I picked up in working in production engineering (for way too long)

-- Anybody else in the business , please chime in.

Edited August 7, 2010 by mello dude

[magley64]

adding to mello dude's write-up, I worked in the industry on both sides (smc production, and molded parts) fiberglass is a thermoset material, where most of your plastic bottles are PET (a thermoplastic)

thermoplastics are typically injection molded, where as thermosets are typically compression molded. I have a lot of experience with both, but most of my knowledge is in the thermoset industry.

[Uncle Punk]

Alright, I'm a bit of an environmentalist and i had an idea to use fiberglass resin and shredded plastic bags or shredded paper to mold things like body panels or fairings for motorcycles (if it works, discount for Ohio Riders members of course).

A few things though:

1) Does anyone know a good place to get resin? I know Autozone and places like that have it, but they can be expensive when it comes to body work supplies.

2) Anyone have experience with press molding fiberglass? What would I need to do to set it all up and try it out?

3) Is this crazy?

First impression is, yes this is crazy but more information is needed to verify that assumption.

Are you trying to make fiberglass motorcycle body panels to compete with racing plastics or imported knock off plastic panels?

What price point are you trying to get to and what are your anticipated volumes?

How much start up money are you willing to risk to bring a product to market?

I have knowledge of tooling, injection molding, compression molding and bringing products to market. The answers to the questions above will help point you in the most appropriate direction.

[ReconRat]

What's been said is all true. So you're looking for methods that don't require high amounts of heat or pressure. Too expensive.

There are hobby methods for smaller parts that might work. Using a double mold, of the inside and the outside. The amount of material would have to be laid in just right. I'm not sure I've ever seen a really large and thin part done that way.

Or a resin spray gun could be used on a one sided mold. Those use choppers to throw shredded material into the spray mix.

But... from a structural viewpoint, using shredded paper or plastic bags probably won't make an epoxy resin part any stronger. It might actually weaken it. But it is possible. Anything is possible.

I'd experiment with various methods and techniques to see if you can get some strength in a mixture of resin and other recycled material. I'm sure it can be done, but it's the mix and method that need to be determined. Wood fibers (paper) can be very strong. That's basically what chip board and plywood are now. A mix of epoxy and wood.

Normal resin and fiberglass mat or strands is what you'd be comparing it to. I'd think it needs to equal or out perform that.

Don't forget that there are two basic types of fiberglass resin. The epoxy, and the polyester or vinyl ester plastic types.

An example of something that can't be done yet now exists; Aircraft parts can now be made from aluminum mixed with shredded rice husks. Very strong parts.

Most of the major hardware stores will sell quarts or gallons of resin. I preferred supplies from boat shops. Better selection and quality. And sometimes even a better price.

Edited August 7, 2010 by ReconRat

[dorifto240]

Ok, here's my thoughts:

Plastic bags are readily available, and difficult to recycle. If I shred them into something similar to chopped glass, and mix with resin (either epoxy or polyester) and then work it into a body panel.

Paper pulp can be pressed fairly easily into shape and soaked in epoxy. Or I can press it, and then skin it with a layer of fiberglass.

Both should work out to be inexpensive and fairly light.

With that said, it seems like a spray and lay would be the better option currently.

Price point will depend on amount of work involved. What I'd like would be something higher quality than what's coming out of China right now and hopefully a lower cost.

What I'm thinking is because my raw ingredients are fairly inexpensive, I could turn out fairings for track days or salvaged wrecks rebuilds. Especially if I could get the price in the $100-$300 range.

[ReconRat]

I'm thinking the resin won't stick to the plastic bags. Better check that first.

[Uncle Punk]

Your price point seems unrealistic based on your labor especially if you are going to hand lay the job. The material may be cheap but warehousing and processing it will add to the cost at an unknown factor since you don't know what process will be needed to make things work. Not that it couldn't be done but how green is it if you have to shred or grind it plus add an additional chemical to make it process.

Let's assume the materials are free and you are going to make six different body panels per bike by hand. How much time do you think you would have involved in that process? How much is your labor worth per hour? Now store your inventory and make sure to pay the tax man. At $600 a set you aren't making money, plus we haven’t addressed the environmental issues with controlling the fumes from your process and depending on how legal you want to be in the manufacturing process adhering to the E.P.A. guidelines is expensive. You have really gotten away from being green if you factor in all the manufacturing process adds to the project.