Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here


How is this item made?

How is this item made?

How is this item made?


Is this made with injection molding or some thermoplastic process? I am completely new to plastics manufacturing and it doesn't seem possible that this part is made with injection molding because of the different appearance of the clear display window, vs the marbled resin looking edges. This is a piece made by a previous supplier of ours who went out of business, and we are looking to replace it. Thank you

RE: How is this item made?

How big is it? A ruler in the photo might have helped a little.

Cut it in half with a hand hacksaw using a Rem-Grit blade.
Capture the shavings/ dust that falls off, separately for the rim and for the transparency.
Describe how it smells as you cut each.
Burn the shavings/dust, separately for the rim and the transparency.
Describe how difficult it is to light, and whether it wants to stay lit.
Do it again, and try to dissolve the shavings in various solvents.
Those simple tests will help you figure out what general type of plastics are involved, if not the exact formulation.

Before you invest that much sweat in it, chat up your former supplier's principals, and see if they will reveal the materials and processes, and sell you the tooling. Offer them a limited consultancy to help you get set up for manufacture in your facility, etc.

Mike Halloran
Pembroke Pines, FL, USA

RE: How is this item made?

The part may be injection molded, the "marbled" look would be a texture applied to the mold surfaces; the "clear" portion would have highly polished mold surfaces. Texture may be applied for appearance only or sometimes to help the part stick to the right part of the mold to make part removal consistent/easier. If it is injection molded, the texture might be there to help hide the ejector pin marks.

RE: How is this item made?

It is indeed injection molded, I was able to locate a mark on the bottom of the casing, I forgot the term, it may be ejector pin or something else, but it's obvious.

I sent the casing to a plastic supplier in my area to find out what it's made of. I was able to do some lighter tests, if I leave the flame on for 5 or so seconds it will ignite, and it turns an ugly greyish/black once ignited. The only solvent I have laying around is Acetone which greatly affected the items, made them develop a white texture which I am not able to remove.

Our ultimate goal is to reproduce these items, and I've been looking into some CAD designers who I could send the product to, although they will need to touch the 3D scan up because the cases we have now are a little damaged from being pryed apart, which are they not designed to do (like you see in the photo).

If I can't find someone for that service, I will likely get some high quality scans and try sending them to someone on fiverr to develop the 3D files. Our budget for these service/s is very large, in case anyone is interested in assisting me. Thank you for the responses

RE: How is this item made?

Imho it is not really difficult part to reproduce if you don't expect TOO low tolerances. An experienced moulder can model it even by manuel measurement. You can just find a plastic moulder in your area.

RE: How is this item made?

From the descriptions it seems very likely that the plastic is polystyrene.

RE: How is this item made?

High Impact Polystyrene seems correct, thank you for that. When you say find a plastic molder, what exactly am I looking for? I see a lot of websites such as http://rebling.com, but there's no mention of shipping items to them to be duplicated, or 3D CAD services. So I guess my issue is I don't know if I am looking for someone to create a 3D file, or a molder who can duplicate it without that. I haven't had much luck finding a "ship us your physical item we will turn it into a 3D file" services, but my assumption was once I had that file I could go to mostly any injection molding company, like protolabs, and get the item made.

RE: How is this item made?

Get on the phone, and chat up LOCAL molders listed in your area's Yellow Pages.

Not all of them will be interested, of course, but when you have a short list, go IN PERSON and get acquainted with what they do and how they do it.

Molding issues tend to be corrected sooner and cheaper with a local partner than with some outfit about which you know nothing, on the other side of the country, or the world.

Mike Halloran
Pembroke Pines, FL, USA

RE: How is this item made?

alex00: It's not High Impact PS. HIPS is not transparent.


Politicians like to panic, they need activity. It is their substitute for achievement.

RE: How is this item made?

What is it then? The transparency I thought was just polishing?

RE: How is this item made?

Have you solved the problem? I am sure it is not difficult to find manufacturer in China only if your quantity is big. If too small, it will be difficult.

If you need my help, shoot me one email.

Expert of nucleating agents

RE: How is this item made?

That is most likely polycarbonate

RE: How is this item made?

General-purpose polystyrene is clear, hard, and rather brittle according to wikipedia.

So that fits what it looks like at least (for example cd case fronts is made of this and they are very clear)

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close