This article is for companies that are developing their own innovative product(s) from scratch. Many products include plastic parts, and getting tooling right is fraught with risks.
Suppose you have been working with an industrial designer or a mechanical engineer, and your product includes custom-designed plastic parts. In that case, you are probably getting some ‘suggestions’ for a ‘good supplier that can take care of the tooling and production’.
This is based on nearly 20 years of hearing designers tell their clients “Oh, I know just the right supplier in China for that”. Some clear patterns have emerged…
Good designers vs. Good supply chain managers
Sometimes listening to suggestions works well. Some product development professionals put their customers’ interests first, and they really want the project to succeed. They have worked extensively with overseas manufacturers, including in China. They were involved in contract negotiations. They spent weeks and weeks on factory floors. They will send you in the right direction and give you solid advice.
Other times, however, it may lead to a heavy loss of money and time. Why is that?
Many people know how to design a nice enclosure, put it nicely in CAD, and point to ‘design for manufacturing’ good practices… but they lack experience when it comes to setting up a supply chain. They don’t know their blind spots.
So, they might want to remain involved in your project and learn along with you (hint: that learning may be at your expense, as you are taking all the risks).
To make things worse, plastic & tooling suppliers are abundant in China that may not be qualified technically to satisfy export customers’ aesthetic requirements for B2C products, but that have found LinkedIn and email blasts to be effective in discussing with design studios. They promise excellent support in answering technical questions. They usually extend a commission for any orders sent their way.
If you feel people are a bit too eager to send you into a particular supplier’s arms, that may be the reason!
Risks of working with the wrong suppliers
Let’s look at the main risks and how to mitigate them.
Risk 1: Extending too much trust and forgetting to ask for basic protections
Working with the wrong supplier can be catastrophic.
You may need to invest tens of thousands of dollars (or more) in tooling, which will be in the supplier’s hands.
It means they might decide to keep it hostage and extract concessions from your side — for example, they might require full payment after they completely mess up a production order (wrong color, serious shrink marks, etc.). That’s not a hypothetical risk! It happens every day and is very, very frustrating.
Here are some important questions to ask about them:
Q: What is the company name of the supplier?
(This is important to clarify from the start, as some people are tempted to simply say “Let me be your agent” and then they act as a trading company, making an undisclosed margin, and keeping the actual factory’s name a secret.
Needless to say, that tends to work rather poorly with the contract manufacturer that will need to buy those parts and will typically refuse to buy from a trading company.)
Q: What is the full company name of the supplier in Chinese characters?
(This allows you to do a bit of due diligence if you hire a firm that will look in TianYuanCha and other sources of important information.)
Q: What parts did this supplier make for your other customers? Looking at your portfolio of past projects, please point them to me.
(This will help establish if there really is a long-lasting cooperation between the designer and the supplier.)
Q: Based on the classifications of The Four Levels of Plastic Injection Molding Suppliers in China, what grade is this supplier?
(If they are not sure, that’s not a good point… They should be able to elaborate a bit and mention some examples of difficult things that suppliers achieved.)
Q: Can I ask them some questions directly about their company?
- Do you design the tooling by yourself?
- Do you do CNC machining in-house?
- Do you do EDM machining in-house?
- Do you do wire cutting in-house?
- Can we come at any time during tooling fabrication?
(The more they do in-house, the higher their technical understanding, and the tighter their control over quality.)
Q: Can I ask them some questions directly about their supply chain?
- Is tooling fabrication done in the exact same manufacturing facility, and the same company, as plastic injection molding? If not, where (company, and full address) do they take place?
- Can we come at any time during plastic injection molding?
- Can I see a photo of how you store the molds between 2 production runs? [This is best asked during a video call, actually.]
(In China, you’d be surprised how often you design with 2, 3, or 4 layers of companies where you expect all to be done within the same facility. This comes with inefficiencies, slow reactions, and potential loss of control.)
Q: Can we sign a contract directly with the plastic supplier that allows us to pull the tooling at any time for no reason, with penalties in case they don’t make the tooling available within 5 working days? And that contract will call for litigation in China since the tooling will be in China.
(The typical low-technical-maturity plastic suppliers will baulk at that. Or they will sign a contract, while still clinging to the idea that molds should not just get pulled. So, asking this question in a call is more revealing than in an email.)
Q: Will you include the exact polymer model number, and polymer supplier’s name, in your quotations?
(The performance can be very different from one model to the next, within the same family of polymer… just saying “ABS”, for example, is far from sufficient.)
Risk 2: Forgetting to require the basic commitments
Here is another list of questions you might want to ask:
Q: With the chosen polymer, how many shots is the mold likely to withstand?*
Without that information, you can’t make an informed decision. Just over the past year, I have been involved in 2 separate cases where the customer thought they had a mold ready for making tens of thousands of shots, and they discovered that they had to start making a new mold after only a few hundred shots were made.)
*Note: What if you DON’T ask about the mold’s lifetime?
You might get the opposite of what you need… when the tooling supplier has no objective about lifetime, they can cut their costs dramatically:
– They buy lower-quality and non-hardened steel. Sometimes we see steel that is so bad it has marks and it can’t be nice and smooth even after much polishing.
– They save money in machining, since the steel is much softer.
– They rationalize that it’s “just a fast prototyping mold”, so they do rough machining. Sometimes we see very clear CNC marks on the steel… and of course, this translates into a lot of quality issues on the plastic parts.
And, you might ask, what about timing? Will it be much cheaper, since it’s “fast prototyping molds”?
The sad truth is, it’s only about 8 to 10 days faster… count 4 to 5 weeks vs. 6 weeks.
Q: Will you prepare a DFM report when your tooling designer starts to work on this project?
Will it include:
- Plastic polymer shrinkage rate
- Tooling materials (for the cavity, the core, but also the lifter and the sliders if any)
- Type of machine needed (what clamp force?)
- Gate analysis, with visual(s)
- Parting line analysis, with visual(s)
- Appearance analysis, with visual(s)
- Draft angle analysis, with visual(s)
- Wall thickness analysis, with visual(s)
- Mold configuration analysis (how the various parts come together), with visual(s)
- Ejection analysis, with visual(s)
- Mold layout, with visual(s) and key dimensions
- Other issues noticed, and suggested solutions
(All tooling suppliers say they will do DFM when asked, but not all do it carefully and exchange about it clearly with their customers.)
Risk 3: Opening tooling too early
This is a trap inexperienced product developers are quite likely to fall into.
You have some 3D-printed parts, things are looking good, and a gentle hand is pushing you to start working on tooling… you want to get to market fast, right?
Not so fast. If you have been working on designing a new product, you need to think of how to validate the product design before you start developing the manufacturing & testing processes.
This usually involves questions such as:
- Q: Are target users/customers happy with the prototypes?
- Q: Are all performance requirements met? Are you sure you haven’t forgotten any such requirement (e.g. ‘can connect to a smartphone with Bluetooth from 50 meters away’)?
- Q: Have you done accelerated reliability testing, to confirm there are no design weaknesses (e.g. a waterproof enclosure)?
- Q: Was the entire product design reviewed by manufacturing professionals to ensure it is manufacturable with a low risk of quality issues (in other words, a ‘design for manufacturing’ and ‘design for quality’ review)?
- Q: Is there any other important assumption that needs to be validated now? Maybe putting together one more prototyping build is necessary?
Remember, once the tooling fabrication has started, changing the product design becomes much more expensive in time and money. Some molds may even have to be re-made from scratch at great expense.
Another approach altogether: Picking a contract manufacturer first and relying on them
If your product requires assembly and testing, you will need to pick the factory that will take care of those operations. Since it’s the last factory that will touch the products before shipment, it is your “main supplier” and they will naturally orchestrate the rest of the supply chain. Let’s call them the contract manufacturer (CM).
Now, you may have heard of cases where a factory sells a product directly to its customer’s competitors or even to its customer’s customers. That’s one of the main things you need to watch out for.
You may be tempted to compartmentalize your supply chain. Sometimes the plastic supplier, the PCBA supplier, and others are already decided when the CM enters the picture. In a way, that makes sense, and the customer feels they have more control overall. For example, the PCBA supplier needs to get their hands on the firmware, but the CM doesn’t need it.
However, there may be a few issues with that:
Can you do a better job of picking those suppliers than your CM? Probably not.
If (or ‘when’) there are issues with the product’s function and someone needs to do troubleshooting, that someone may need access to the firmware. If the CM has engineers who can look into it, will you forego that option?
The CM will be much better able to control a supplier that they have picked, that is (probably) very close to them, and that has signed their contract. The cooperation with a supplier you direct may have bumps and you will have to manage that.
That’s why picking the right CM is so important. You have to trust them, at least to a certain point.
If there is no such trust, you are probably not working with the right people.
They can manage the supply chain while leaving the suppliers in the dark about what the end product does, as explained in Compartmentalizing the supply chain – IP Protection in China when Developing Your New Product [Importer’s Guide]. They might be able to make a lot of parts internally, which means you don’t even need to worry about picking the right plastic supplier and controlling them…