"Must have experience with molded plastics..."

Hi guys,

Employers seem to routinely ask for the ubiquitous “2+ years experience in a similar role” and invariably “Must have experience with molded plastics…” or similar. What I have never really asked is what level of knowledge or interaction are you expected to have with the latter as an industrial designer?

So, if we started with entry level or at that 2+ year benchmark, are we expected to be able to conceive of and fully resolve a molded product for tooling solo, or is a theoretical technical knowledge and sympathetic approach to design all that’s required here? To what extent is learning on the job generally acceptable at this early career stage? Do consultancies/manufacturers often employ industrial designers and manufacturing engineers to collaborate on such matters, or is there preference that you can work from concept to manufacture unaided with confidence?

Should I be expecting disappointment when applying for positions requiring experience when I technically have none. In this scenario I have a product design degree, 4+ years experience as a Solidworks design engineer (steel+timber fabrications) and a working though not practical knowledge of most mass-manufacturing processes.

Words of a designer looking to expand his horizons.

I’d imagine that the level of knowledge required depends mainly upon two things:
Do the company manufacture in-house? If so a higher level of knowledge may be required as you will have to do everything (including all the little corrections/alterations that an external manufacturer might do without telling you about it just to get the job done).
Will you be the only person there responsible for the molded plastic parts? If there is going to be a more senior member of staff who also works on molded plastic parts they are most likely expecting to offer some on the job training. If it’s only you, you’ll need to hit the ground running.

I’d say this is definitely something to clarify during the interview or to ask in the pre-interview stage.

A solid understanding of moulding should be expected from a design graduate but I don’t think employers can expect a young designer to fully understand the intricacies of different moulding materials and processes.
A small but precise plastic part for a CE product will have different requirements, materials and processes than a rotational moulded chair.

Generally, I think that there should be room for lots of on-job training and that you should be allowed to gather experience through projects.
It doesn’t hurt though to read up on that particular employers products and how they generally are made.

If this is a specific requirement for the job, it could be a nice talking point during an interview where you have maybe prepped a few comments and questions regarding process that show that you are interested, know some but not everything and that you are happy to learn.

Some consultancies do a lot of work going from sketch to factory hand off files. I personally as an industrial designer have gone from sketch to pretty close to tool ready cad. (With the watchful eye of an engineer)

If I had to guess what 2 years experience with plastic molding would mean I would say a applicant should understand (at least at the modeling level). Draft and Slide management. Wall thickness, Ribs and Bosses and their relations to sink. Tolerance stack up and reveals: how to manage parts that fit together. How to properly dimension a drawing, also Things like mold textures/cmf and how they impact the part. How to review plastic parts samples and effectively communicate with factories. Also if doing lots of big multi level assemblies, knowledge of top down modeling might be necessary too.

All this stuff isn’t that hard to learn, once you do it a few times you sorta get it, but my guess would be they just don’t want someone coming in an not knowing what undercuts are (pretty basic) or some one who hasn’t drafted a part for production, and not realizing how it can really affect how surfaces come together.(pretty eye opening the first time you do it)

Hi Oli,

Most places obviously want the best qualified people and your SolidWorks experience alone gives you a leg up on other entry level IDers. At a “2+ years experience level”, though, most employers just want someone with common sense knowledge of molding principles so that the ideas they contribute take into account a technical approach that will be closer to feasible than impossible.

As for the “2+” itself, the talent you show in your portfolio & samples is far more valuable than however long you’ve been previously employed as a designer.

Any reputable place is going to have hybrid CAD people supporting any 2+ ID person, or a senior ID person passing higher level SW assemblies over to manufacturing (factories, etc). I have seen a few start-ups where the 2+ ID person was asked to be field researcher, ID proposal creator, brainstorming coordinator, sketch maestro, hybrid CAD person AND manufacturing liaison - and in that case it either results in bad products, organizational failure or the coming of another Leonardo da Vinci.

Just my 2 cents. :slight_smile:

In my experience pretty much at all levels of design skill the work gets passed to an engineer at some point in the process. Either an in house engineer or a outside engineer at the factory. Also if you are making products in Asia they will a lot of times rebuild any model sent to them to better integrate with there systems. Generally I would say there are usually a number of check points along the road for people with specific experience with making the parts to way in and add there perspective. So I would agree with the above comments that what is important is basic understanding of molding plastic not so much a complete formal understanding. Such terms as undercut, draft angle and knit line are terms you should recognize but how to deal with all the problems and there solutions might not necessarily be expected. Same would hold true for plastic properties there is a lot of them and that more then likely would not be expected of you to know. But you should be familiar with the families of plastics such as LDPE, HDPE, PP and so forth and so on.

Thanks Sain,
I feel like I’m able to recount definitions and practical examples of most of these terms with some confidence, but certainly not from a standpoint of personal experience.

Yes, this is exactly my feeling. In any case I think I’d much rather be collaborating with experts in each phase of the process rather than trying to be a one man band and solo the entire journey. I’m definitely more interested in producing the right product than in any personal acclaim. Also, I think it’s rare to truly learn from yourself.

Yes, thankfully I’ve been able to keep up to date with the CAD, technology and materials sides of things in my recent positions so the base knowledge should be fresh.

I think it may have been on Core recently they had an article about ‘the wall’ where a project is sort of blindly thrown over in the hope that someone with the necessary skills to fill the gaps in a concept would catch it the other side and run with it.

I never want to be the guy ‘throwing’ the project. I find it embarrassing when I’ve had to hand projects over to the engineers earlier than I feel I should but it does serve to help you identify where your skills are lacking. Just got to make sure you do something about it!

Well, I already feel a bit more positive about throwing myself at positions I may have felt slightly under-qualified for so thanks for the responses so far.

All good replies above. I started my design career working closely with US domestic polycarbonate and ABS molding so had a crash course right out of school. I didn’t learn much in school; from recent portfolio reviews it still doesn’t seem to be widely taught.

I might add a few other things to get a grasp on, depending on industry: scale, and material shrink.

In large scale rotomolding, you can design parts that can effectively ‘shrink out of the tool’ so can achieve forms that would be impossible in high pressure molding applications.

Also, knowing what kind of tolerances to expect in larger scale parts in any material, and the corresponding reveals you might add, will be important if said company does large products. Most of the work I’ve done falls into the “larger than a breadbox” category - I’m better with designing for that scale than the hand-held calculator size!

As mentioned I think it depends on the company.

In general I think an understanding of what a draft angle is and why it is needed, what sink marks are, basic differences in mold types such as split and open/close.

But hopefully it wouldn’t mean that the designer with 2+ years experience would be able to prepare files for the creation of a $100k+ tool. Myself for example hand over my CAD to a CAD engineer who has 20+ years experience in the job and turns my final design in to something that can be made. All under the supervision of an engineer as well as finally being signed off by the mold engineer too.

Most of it is said before. Don’t be intimidated too much by job descriptions - it is more important to have general awareness and some knowledge and experience, more important usually is that you are a reliable employee willing to enter a long-term relationship. And don’t be intimidated by the amount of knowledge required either, even though there is vast literature on plastic moulding, if you read a few design guides about the materials and processes used by the company, practice with a few parts in CAD you will have a head start. Often these guidelines also depend on the manufacturer and developing the CAD part will happen conjointly with that party since they know all about their machines - for example some factories can produce 0 draft files or certain undercuts because they have more advanced ejection capabilities.