Going it Alone, Part III: Injection Molding

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The first half of Going it Alone, Part III: Inside the Factory Walls appeared on CrunchGear yesterday. We pick up our survey of how consumer electronics are made with …

Injection Molding

“One Word: Plastics”. Injection molding is the process by which hot, liquefied plastic is injected into steel (or sometimes other materials) cavities called moulds, under high-pressure. There is a real art to injection molding that includes proper design of the parts themselves, the moulds that form the parts and the various parameters that can be tweaked during the injection process itself. For now, suffice to say that all of the plastic components of your product are made – one at a time – using this process. In the photo at the very top of this post, this would include the white housing components, black belt clip and battery door, translucent LCD cover, rubber buttons and even that tiny, little white spec which is the “Set” button from the rear of the unit. One or two workers typically operate the station. A first worker runs the injection molder, removing each newly molded part by hand. A second worker removes flash – excess unwanted plastic – from the finished part using a knife. The final parts are carefully stacked in bins for transport to the assembly area mentioned above or, if injection is an outside process, for shipment to the main factory.

Tool & Die Making

Closely related to injection molding is the tool shop. Again, not every factory has injection molding in-house and even those that do may outsource the creation of the steel tooling to an outside specialty house. Creation of the steel tooling is one of the longest stages of the product design process – typically taking 6-8 weeks from beginning to end. Steel blanks are machined using CNC (Computer Numerical Control) Machines or by another process called ECM (Electrochemical Machining). In another post perhaps I’ll talk a little about the design of plastic parts which, in addition to serving their intended purpose in your product, need to be designed in such a way that they can be easily injected. Smart design of your plastics will allow you to avoid features that are difficult to mold, resulting in mechanical apertures called “actions” which make your tools more complex and more expensive. A basic understanding of plastic part design is important for this reason. As someone new to this world, you may have a state-side company design a basic CAD database and they may not do it well. The Asian factories you ask to quote your part will typically not question your design and you may get back extremely expensive quotes (thereby deflating your entrepreneurial spirit) for a part which, if designed slightly differently may have resulted in tooling charges a fraction of the cost. Even slight knowledge – “talking points” type of knowledge – of every aspect of the design of your specific type of item will go a very long way. This is akin to the consumer who gets ripped off by the local garage because they don’t understand that cars no longer have carburetors, distributors or batteries that need refilling. A basic knowledge of your car may save you a lot of money at the repair shop.

Painting & Deco
Painting of plastic parts that are not molded in color is typically done using masking and spray booths. One of the nice touches that we added to the Klip! timer is a rubberized paint on the rear housing, belt clip and battery door. This rubberized paint makes the product nicer to hold and gives it a higher-quality appeal. It is worth noting, that this rubberized paint is not without a cost. I believe the upcharge is something like 10-12 cents, which by the 4x rule, is approximately forty cents at retail, but we felt it was important. Determining your target retail price point and understanding whether or not you can make your item for a cost that will allow for that retail price is extremely critical and should predate any discussion with designers or factories. Alas, this subject is again a topic for another day.

“Deco” refers to lettering or other graphics which are applied to the product using processes known as pad-printing or silk-screening, to name two. I won’t get into the details of these processes but typically the results from silk-screening are better but the shape and size of your part may limit your ability to use this process in some cases. Pad printing is a more flexible alternative in that case.

Quality Control (QC)
Quality Control is such an important topic that I can not possibly address it in a paragraph or two. Suffice to say that QC is not a single “station” – it is a thought process, a way of factory life and something that takes place (or should take place) throughout the plant. There’s inbound QC, in-line QC, outbound QC and third-party QC. For today, your take away should be that if you visit a potential manufacturing partner you are going to want to grill them on what their QC process is and any good factory will want to show-off their attention to this aspect of the manufacturing process.

What To Look For


Figure 8: Welcome Sign At Entrance To Factory – We Have Arrived!

The day of your visit has arrived! Above, I’ve outlined the major processes that go into the manufacture of your garden-variety consumer electronic product. So what does all this mean to you? How are you going to apply this knowledge when you walk into that Asian facility for the first time. The key is to think about the steps that I’ve outlined below. Think of assembly as the hub of the factory. How many assembly lines are there? More importantly, what percentage of them are actually in use during your visit. If there are a lot of idle lines that may be a red flag. Find out why. Ask the representative who is giving you the tour how many workers the factory has. They will give you a range. The reason for this has to do with the seasonality of the business and should not be cause for alarm. Dig deeper – ask how many of the total workers are on the line, in QC, in the engineering department, or in other disciplines. A mid-sized factory (say 400-700 total workers) is probably a good size for a first project – not too big and not too small. That said, there are large factories that are willing to invest in small, new companies and there are new, smaller factories that are destined for greatness.

As the tour continues, make a note of which of the sub-disciplines mentioned above are present and which are not. Ask questions about this. If there is no injection moulding present, ask why. Ask who they work with (they may not tell you). Ask if they plan to bring it in-house in the near future.

Ask for numbers. One easy way to compare factories (even without visiting) is to ask things like:

  • How many injection molding machines do you have?
  • How many SMT machines do you have?
  • Is IC bonding in-house and, if so, how many of those machines are on-hand?
  • How many assembly lines are there?
  • How many shifts do you run?
  • What percentage of the year are the lines occupied?

Believe it or not, the marketing managers are used to being asked these things and will typically have the answers to these questions at their fingertips.

If examples of the factory’s items are not in the conference room where your visit will begin, be sure that you tour their showroom. Look at the items and the name brands (if they are visible – they often will be). Observe the complexity and quality of the items that are on display.

Try to meet one or more of the product engineers, if the engineering offices are adjacent to the factory. See how well the engineers speak English, if at all. Try to get a sense of who you will be working with from day to day. One single face-to-face meeting goes such a long way in a relationship that will take place over e-mail for months to come.

Finally, make sure you look around. How clean is the factory? How well organized is the layout? How happy do the line workers look? Observe how the director and the mid-level managers interact with the engineers and even the line workers. These sniff-tests will all serve to give you a sense of what the factory culture is like and whether or not this factory is a good fit for you and your project.

The factory will take you out to lunch and pay for it. Try everything except for the chicken feet. They may kid you but the factory reps know that Americans don’t care for chicken feet and they’re ok with that – you will not offend anyone. I heard on the radio just this week that chicken feet go for 40 cents a pound in China and 2 cents a pound in the United States. Can you say arbitrage opportunity?! Now you know what to pack in the available corner of your suitcase, before you depart. Good luck! You’ll do great.

Adam Hocherman, 34, is an entrepreneur and founder of the consumer electronics company American Innovative in Boston, MA. Adam founded the company in 2003 with the help of the US Government’s SBA loan program and is currently the 100% owner. He holds a BS in Mechanical Engineering and an MBA, both from Cornell University. Adam’s writings can be found on his blog at DesignTheatre.net and through his Twitter feed. He welcomes your comments. Read more about sourcing in China here.

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