An understanding of your Chinese mold supplier's capabilities and market is essential to getting the right tool for the job.
Purchasing injection tools in China to be run in the United States is a fact of life for U.S. molders. Many tens of thousands of injection tools are bought in China each year and sold in the United States. If you have not already bought a tool in China, you will. The cost difference is too great to ignore, and, unfortunately for North American toolmakers, the quality of the tools coming from China can reach North American workmanship and durability standards for the majority of applications.
However, the quality and capabilities of Chinese toolmakers run the gamut, from the great to the downright ugly. Having visited more than 60 toolrooms and purchased tools from a dozen of them in southern China and the Shanghai region, I can attest to the wide gulf that exists between the best and the worst. If you are buying tools for North American molding operations, how can you tell the difference? Well, the obvious solution is to visit. That, frankly, is a must.
There is a fundamental difference between two general groups of Chinese toolmakers, however, and being aware of this difference can save you a lot of time and trouble. They are the "domestic" toolmaker and the "export" toolmaker. Domestic toolmakers supply either themselves or molders within China. Export toolmakers send most of their tools overseas to be run by molders primarily in North America, Europe, and Japan. All toolmakers in China, naturally, are of one variety or the other or a combination.
We've all heard stories about the incredibly low-cost Chinese-made injection mold--perhaps a fairly complex, albeit low-cavitation, tool, say four cavities, but Class 101 (at least specified as such!), with lifters and cam actions--one that you might quote for about $50,000 in North America. The quote from China: $8000. We could barely buy the steel for that price! you may have exclaimed. This is an example of the domestic toolmaker delving into the export market. My advice: Run away as fast as you can. Take my word, and it is, unfortunately, the word of experience, you will get what you pay for: the world's heaviest paperweight.
The same tool from a Chinese shop that makes tools specifically for the export market will cost $20,000-$25,000. Add in the cost of duty and transportation (by air probably) and the price becomes $25,000-$30,000. Apples-to-apples, delivered, you will pay (on average) about 50-60% for a Chinese-made tool for the export market vs. a North American-made tool of like quality. That's reality. It's not as fantastic as the rumors, but still an impressive savings, and worth having.
Domestic moldmakers make tools for a market that pays $0.80/hr in molding floor direct labor, runs low-cost injection machines (generally smaller machines running lower-cavitation tools), and incurs low-cost tool repair and maintenance expenses ($5-$15/hr). Export toolmakers serve a world that pays $8-$15/hr in molding floor direct labor, runs higher-cost injection machines (generally larger injection machines running higher-cavitation tools), and faces high-cost tool repair and maintenance ($40-$60/hr).
Domestic vs. export tools
Following are some examples of domestic/export differences and their ramifications as they relate to a domestic Chinese moldmaker. (The following references to "they" refer to the domestic moldmaker.)
1 Characteristic: The domestic Chinese tool uses Chinese-made steels. They are softer and less durable than the Northern European, Japanese, and North American steels you favor.
Effect: Shorter tool life, loss of detail definition over time.
Why they don't care: Tools are so cheap that they just make another set once the current one wears out. One of my Chinese domestic tool suppliers provided me with a one-million-shot warranty on a tool that it was going to run itself. I knew it couldn't get 100,000 shots. When I inquired, the reply was that the moldmaker didn't care; it would just build a new tool when the old one wore out. I'm sure it would do just that, again and again, as long as the molding orders kept coming.
2 Characteristic: The domestic Chinese tool doesn't adhere to the same workmanship standards as an export tool. Components are made by "Zhou Blou," not Progressive, D-M-E, Precision Components, or another name. Attention to details that result in quicker setup times are not there.
Effect: Shorter tool life, slower setup.
Why they don't care: See the paragraph above regarding tool life (a recurring theme). Setup techs in China, as in the United States, are better paid but still $2-$3/hr on the high end vs. $15-$20/hr or more in the States.
3 Characteristic: The domestic Chinese toolmaker uses all metric dimensions no English units.
Effect: If this tool is exported, finding replacement components may be difficult and expensive; reworking the tool accurately may be difficult.
Why they don't care: The domestic toolmaker builds for a metric audience.
4 Characteristic: The domestic Chinese tool will have lower cavitation for the job vs. a tool designed to run overseas. In China, the moldmaker may choose to build four four-cavity tools instead of one 16-cavity tool. Several factors drive this decision. First, a lot of Chinese toolmakers have little confidence in their ability to achieve cavity-to-cavity consistency (and they are right to be concerned). Second, many Chinese molders are shy about running multiple-cavity tools. Third, larger-tonnage machines are scarcer in China than in North America.
Effect: Greater molding production cost in both labor and machine time.
Why they don't care: We already know that labor is cheap. However, smaller (30- to 150-ton) Chinese-made presses are dirt cheap 20-30% of the cost of a Japanese, North American, or European press. Even the latter frequently cost less in the Chinese market since machinery makers have to meet local market price level expectations or be totally shut out.
5 Characteristic: The domestic Chinese tool will have poorly designed, unbalanced, and inadequate cooling. When the tool is run, moreover, the molder will likely loop waterlines back and forth through the mold rather than use a manifold. This causes temperature differences from cavity to cavity and thus cooling rate variations from part to part.
Effect: Slower cycle times, possible
part quality inconsistency issues (perhaps warpage or splay).
Why they don't care: Getting the last tenth of a second out of the cycle time has not been a priority in most Chinese molding shops due to low labor and machine costs. Therefore, attention to waterline design and other cooling characteristics has been poor. The quality issues are real, however.
6 Characteristic: The domestic Chinese tool shop will run its EDM burns with no EDM tooling in place. When an electrode is replaced, the operator takes the time to attempt to manually reseat the electrode precisely where the old electrode left off.
Effect: Very slow electrode setups, definition of part details and consistency across cavities may suffer.
Why they don't care: They should care, for quality reasons, and because the person changing over that electrode is one of the more expensive people in the shop. However, EDM tooling is not commonly used. If you see it, it is a clear sign of a better export-oriented shop.
7 Characteristic: The domestic Chinese tool's A and B sides will have a poor fit.
Effect: Lots of flash and lots of flash trimmers with Exacto knives hunched under light bulbs next to molding machines trimming and trimming and trimming.
Why they don't care: Low labor cost, low labor cost, low labor cost.
Do yourself a favor and stay away from the domestic Chinese toolmaker. But wait: If you are just interested in getting a part, and that part isn't too tough to make, and that part is going to be made in China as a component of a larger assembly . . . then it might be fine, and certainly much lower-cost than an export-oriented shop attempting to make a tool for the local Chinese molder. But would you run this tool successfully in your shop here in the United States? Forget about it! Please be careful, and happy hunting.
Author: Carlton Harris