PLASTIC COMPRESSION

[anusca]

Hello,
I would like to know if anyboby knows about rapid manufacturing of plastic pieces aplying compresion. I mean, once you have the mold, you introduce the plastic with something manually and then you put the other part of the mold and press manually or with something. I need to know which plastic (is for a cap, nothing special)and which tools to put the plastic on the mold.

Thank you

 

[chaving]

There is a process manufactured by an Italian company called Sacmi. They use compression moulding for caps and can produce around 1200 caps per minute.

 

[anusca]

Hello, this is not what i am looking for. I need something manual. I want to build the mold and apply manually the plastic and then press with something and get the piece. It is not for big production.I don't know what plastic material to use

Thank you

 

[chaving]

To process the plastic you have to melt it, this then gives you a handling problem, you could try manufacturing a heated syringe from metal and squirt it into a punch and die set up. However you do it you will have to employ the skills of a toolmaker.

Usual materials for caps are either PP or PE.

My thoughs are that a manual process will lead to very poor quality with a high variation in part quality.

Why do you want to use this method, do you have budgetary constraints ?

 

[anusca]

Thank you. I am going to use this to make a kind of cap to protect a piece during a process. I don´t need many precission, only this have to fit a protect from something solid. I was thinking about a liquid or spray that apllied on the mold I am going to make then after press, it solidifies.

 

[chaving]

Does the cap need any mechanical properties ? could you use wax ? How thick were you planing to have the part ?

 

[anusca]

What is wax?
I don´t need any special property in thickness, but 1 mm or 2 mm for example, it has to stand metal spray not breaking but I don't mind if it is damaged but not broken.ç
Where are you?I am from Spain

 

[chaving]

I am in Thailand .... wax is the stuff candles are made from. How is the metal spray ? is it abrasive ?

 

[anusca]

Is not very abrassive, it is used to elimate some grease or metal surface defects but small.

 

[chaving]

How many peices will you need ?

 

[anusca]

less than 10

 

[chaving]

Then why don't you machine them on a lathe ?

 

[anusca]

Because I think that is faster and cheaper to do it in the way I told you,and the form is difficult to machining, then I prefer to machine once the mold and then to take from it the plastic pieces.

 

[Soupcat]

Have you considered Vacuum Casting the parts? Vacuum Casting is a process used to create Polyurethane parts that simulate production plastics such as ABS, Nylon, and Rubber. From intricate buttons and connectors to large casings and car bumpers,
Using a long life silicone rubber, it is possible to cast up to 50 off from one mould, depending on complexity of part.
Surface finishes can be as per any requirement from gloss to spark finish.

Regards

Kieran

http://www.moulddesigner.com

 

[dukane]

How about dipping them in Plastisol (which is the coating used on handles of pliers, cutters, etc.)? This is available at hardware stores in the USA but I don't know about Spain.

 

[kennedyg]

Plastisol will give you a rubbery part. If you want something harder, you could always mold it from epoxy. Either way, be sure to use mold release.