Plastic production

big fella · 12-03-2007, 10:33 PM

Does anyone have first hand experience or knowledge of what is involved in getting moulds made and products produced. My brother in law has come up with an idea we think has potential, we've made prototypes out of fibreglass, but to go further will require production in plastic.

Yellow_Festiva · 12-03-2007, 10:43 PM

hmmmm

There was a company that did a talk while I was at uni, called "Ark Silhouette" I think??? They did rapid prototype moulds for injection moulding.

Yellow_Festiva · 12-03-2007, 10:45 PM

Arrk... close enuf!

http://www.arrk.com.au/

**GasoLane** · 12-03-2007, 10:56 PM

Before you let anyone even see your prototype find out what is needed for a patent or copyright or something.

If it looks like it will make money someone will steal it... Look at Microsoft

big fella · 12-03-2007, 10:57 PM

Thank you yellow festiva, I'll get on to them tomorrow

big fella · 12-03-2007, 10:58 PM

Quote:

Originally Posted by GasOLane

Before you let anyone even see your prototype find out what is needed for a patent or copyright or something.

If it looks like it will make money someone will steal it... Look at Microsoft

We are heading down that road too. I'm being as coy and cagey as i possibly can until we are sure of protection.

JADED6 · 13-03-2007, 02:04 AM

What do you need to know about the moulding process?

I've worked in injection moulding for over 10 years now, die setting, trouble shooting, tool trialling, processing the damn parts they make etc etc.

Definitely get a patent on the plans. Pretty easy process although I know very little about it, the sooner the better. When i started working in plastics I thought making a particular product would be good. A few years later another company started doing that and is still making a killing out of an idea that wasn't even original.

We use plenty of toolmakers. Depending on the part required it usually goes to the cheapest one but the work is not as good. Think of a fine cabinet maker vs apprentice chippy. (fine for basic stuff though)

My brother is a tool maker but the company he works for is a bit pricey for us

For the average Joe to pull this off you'd want your product to be on the smaller side of things & light in weight.

If you're thinking of making an entire custom bumper or something of that magnitude, forget it. (Seriously)

Any tool requiring hydraulics, usually cylindrical products like PVC elbows or products with internal thread etc will cost a bit more.

Basic tools are simply a few plates of steel bolted together with work being required to the cavity to "form" your product shape. This is done by CNC machining. Add ejector plates & pins to eject the part and to put it simply, an inlet for the molten plastic.

As you've already got an idea & even fibreglass prototypes you'd only need to draft up some drawings stating ALL of the dimensions of the size of the part you want to make. A tool maker can enter this info & let the CNC machines do the rest.

As I doubt you have MASS production in mind a single cavity tool should suffice. Obviously if you want it to spit out 10 of the same part per shot the tool will be a lot bigger & for on going costs, the machine it runs in will cost more per hour to "hire"

Then comes tool trialling, A decision on the most suitable plastic. Is the part shiny, does it need to be strong, soft, hard wearing, UV stabilised, coloured or basic like an air box?

First trial is to simply see if it works. Plastic is injected through the sprue bush and into the mould, it's left closed to cool, then opened and ejected off the tool. If the size, fit & look of the part are ok the tool doesn't need much more than to have water channels drilled through the tool (water is pumped through most tools so the parts cool quicker and the tool doesn't get heat build up) The tool is then hardened to assist in preventing damage.

If it needs slight modification it's back off to the tool maker and then re-trialled til you're happy with it.

Your outlay will vary greatly from the design process, tool trialling, material cost & machine hire.

What state are you in? If in SA i can recommend tool makers & even do the tool trialling. (can also recommend a custom moulder in NSW) anywhere else and you're stuck with the yellow pages.

What you'd be after is a "custom injection moulder" as they carry out work for anyone. We mould plenty of plastic bits for our leading car manufacturers, pool, spa & stormwater bits etc.

In respect to your last post "coy & cagey"

if you offer up some vague details via PM I can be more specific, Even something like "the part we want to mould is the size of a box of matches"

Regrind material will be the cheapest. Plenty of plastic parts are moulded with imperfections or insufficient plastic, these parts can be re-ground and re-used.

The price of new material is ever increasing due to oil price rises as plastic is made of oil, chemicals, stabilisers etc
add transport/shipping costs & profits.
Vague range depending on the material is around $3 to $8 per kg & they come in 25kg bags so at a minimum your looking at $75 per bag. This covers most of the common types of plastic used.
This can rise to $75 per kg if you want plastic resembling "harlequin" paint for your house light fittings like one prominent SA businessmen that may or may not have his company sponsor a recent V8 super car race in Adelaide. The plastic looks awesome though and does change it's colour appearance.

That'll do for now.

EDIT - I see you're in Vic. The company yellow fiesta posted is the sort of thing you're after. If they do custom moulding I'm sure they'd be happy to do it all for you. If you get some drawings done call them and set up a meeting with the managers or directors. If it's a large company they may not take on small work & if they do they will charge you through the roof for it.
Moulding suffers the same fate as the automotive industry in regards to overseas competition so a locally based company should be willing to help you but they need to run profitable operations or their work will be off to korea etc.

big fella · 13-03-2007, 11:04 AM

Thankyou for the info Jaded6. The product isn't auto related at all. It is reasonably simple but needs to be sealed. Can things be made in two halves then joined?

JADED6 · 13-03-2007, 07:34 PM

Quote:

Originally Posted by big fella

Thankyou for the info Jaded6. The product isn't auto related at all. It is reasonably simple but needs to be sealed. Can things be made in two halves then joined?

Yes, they certainly can.
Easy if it's just a basic housing type part. Bit more critical if it needs to be water tight or submerged in water
Again using an air box as an example (excluding the intake holes of course), they're made of 2 parts and joined but you wouldn't guarantee they're water tight.