Ray_li

Looking to product different surface finishes from injection moulding but I'm not clued about surface finishes.

Is there a chat like RAL/Pantone for surface finishes?

I have a simple sparked finish chat but thats about it.

Thanks

mart360

depends what you want Ray,

you can have a grained finish in varying levels of coarseness (sp) you also need to be aware of what you are graining, some moulds respond better than others. colour of the part & material is another factor to address.

also the grain pattern is individual, dependent on what you require. your tool/ mould maker should be aware of all this


mart

Ray_li

I'm designing a few plastic medical products.

historically we've always gone for white Nylon 6 with a highly polished gloss finish which i find plain and boring.

Want an interesting finish but don't know what I want yet. Maybe something like satin, frosted, egg shell kind of finish.

Nylon 6 may also be a thing of the past if i can find a better plastic

Usually our tool maker would be more than happy to help but due to management sending everything to China no body is willing to help us and our Chinese tool makers dont know jack ****

john banks

Probably stating the obvious as a purchaser/user/maintainer of medical equipment, but presumably a polished surface will be easier to keep clean. For the image of your equipment, something that appears clean would also be nice. Antimicrobial additives may be a nice feature if possible/economical?

Ray_li

a polished surface would be easier to clean but the market has headed away from polished finishes.

we already do a plastic thats antimicrobial

mart360

If its medical, / pharma then you will prolly have a set of industry standards on what you can or cant do with regards to supplied stuff.

Also nylon 6 is prolly used for a certain reason, you need to ask around as to why.

i,m surprised nylon is used, given that its hydroscopic.

If i were you, i,d talk to your mould dept, and get some pointers from them, and then your raw material supplier.

its a complete industry in its own right, and i doubt if i can full advise of what & where.



the toolmakers in china are very good, we used to use them. it was the graining / etch company in the UK that let us down


Mart

Ray_li

What would you recommend instead of Nylon?

mart360

you need to talk to your material supplier, we used glass filled nylon for automotive applications, its very abrasive and can wear out tools V quickly.

As as said its an industry in its own right. GEC used to supply lots of raw plastic, there tech dept was very good, when i needed some alternates & info on material

Mart

Gutmann pug

If you are talking about injection moulds then yes there are surface finish differences. These vary massively.

The lightest textures give the smallest degree of protection against marking, the heavier the texture the greater the protection. Smooth surfaces with no texture are a nightmare, the lightest touch and they mark. Not great if you are heavily into your quality control.

We tend to go for a medium spark on our products. They give reasonable protection while retaining a quality smooth looking finish.

It is however worth remembering that depending on the degree of texture you go for you must allow varying draft angle on the product to allow it to be removed from the tool. A good tool maker will help you with this.

We mainly go to China these days. I currently have around £400K (25 tools) in manufacture.

The lead times vary depending on the number of iterations you need. By rule of thumb I reckon on 6-8months to get a textured tool correct and passed the part apprival process.

We generally use Mold-tech for texture samples or Yick Sang

Oh and finally don't put two varying textures together without really researching and trialing them. They can look awful and a different colour due to the shadows.


You probably didn't need any of that info but hey I was bored and thought I would type it

mart360

Tell me about it spent 2 years in and out of Ford car plants, due to issues with a polished surface

lol, and the next set of issues i picked up, yup graining issues


Mart

Ray_li

good stuff there

I've not had much experience with plastics. I come from a metal background