Printer Friendly

How to pick a top-quality moldmaker.

What criteria do sharp molders use to select an equally competent moldmaker? And how do the best moldmakers maintain their own quality? Here's what they told us.

Deciding on the right moldmaker is often a matter of satisfying two goals that may conflict with each other: On the engineering side, it means procuring the best mold in terms of tight tolerances, long service, and low maintenance, all within a short time frame. On the purchasing side, it means obtaining the best mold at the lowest possible cost, and this can be a serious constraint, especially for custom molders who themselves are competing for a molding job.

Ultimately, both concerns arrive at the same thing: the optimal balance between price and performance. In order to get there, moldmakers agree that customers must first have a good understanding of their own needs in terms of complexity of the part and size of the job run. The next step is to look for the moldmaker most capable of servicing those needs. Here, the specialty of the moldmaker is important. According to Al Robinson, president of the moldmaking division of Husky Injection Molding Systems Ltd. in Auburn, Mass., "It's important to focus on a tool supplier's core business in order to make an informed engineering decision and purchasing decision." Having a specialty is important for the moldmaker as well, he adds, because it allows the moldmaker to develop engineering standards.

Once these preliminary decisions have been made, customers can begin to narrow their choice of moldmakers, a process that should involve visiting the tool shop to evaluate capabilities in benchwork, engineering services, and follow-up service with the customer. Here is a look at some key questions that customers may ask and the lengths toolmakers may go in satisfying their needs.


One key to a successful relationship between the moldmaker and customer is good communication. Armand Pirro, an injection molding consultant and engineer in Amherst, Mass., says that molders and moldmakers often do not have "a good technical bond." Better mold shops will ask molders the types of questions that enable them to build the mold that's needed.

Charles Payson, senior development engineer at Dow U.S.A., Midland, Mich., agrees that it's important to determine how well a candidate moldmaker relates to customers. "I like to feel welcome coming through the door, and have them say, without my having to ask, that I can visit their shop at any time." Payson adds that it's the moldmaker's responsibility to feel out the customer's experience level and help him understand what the tool shop can do for him. A willingness to educate the customer on machining capabilities and provide help with part design can smooth the way to a finished mold.

David Baldwin, national sales manager for injection machine supplier YCI Inc. in Compton, Calif., used to be involved in evaluating moldmakers as a consultant to the Coca Cola Co. in Atlanta. He measured the quality of a toolshop by its openness and responsiveness to a potential customer's needs. "When you walk into a first-class tooling outfit, people ask, 'How can I help you?' Not as good are some companies that try to tell you what you want. The biggest thing is to talk to the toolmaker himself. See what his responses are to your questions and if he is willing to work with you."

Paul Stoll, president of Armin Tool & Mfg. Co. in South Elgin, Ill., views face-to-face contact with customers as a basis of maintaining longstanding partnerships with his key customers. "We pride ourselves on being out there with the customer one-on-one. I go to our key accounts frequently to talk to them about our programs and to gain an understanding about where our strengths and weaknesses are. We are showing our desire to be part of a team."

Nypro, a large custom molder based in Clinton, Mass., has developed an evaluation form, or "report card", which is issued to the moldmaker after the completion of each job. It evaluates mold quality, engineering, and delivery, and is reviewed with the tool vendor in the spirit of continuous improvement, according to Joseph Rizzo, Nypro's man in charge of evaluating moldmakers.

James Clary, a buyer at the tool procurement division of Eastman Kodak in Rochester, N.Y., says, "The key is to try to work with shops that have performed for us before and not to keep switching. As long as the shop continually improves its investment, we keep them."


Overall appearance of a mold shop is key to its quality, say several moldmakers and their customers. When touring a shop, Dow's Payson directs his attention to the cleanliness of the shop floor. "It says a lot about the kind of people who work there and how well they maintain their machinery." Payson looks for maintenance records attached directly to lathes, mills, and grinders as an indication of how serious a shop is about upkeep of the machinery.

He also makes it a point to talk to machine operators to get a feel for what's important to them in making a mold. "I look for a sense of their ability to improvise to get the machine to do what they want. A lot of people will run a mill or lathe based on what they learned from the machine manufacturer or a school. I look for something beyond that. I want someone who sees the machine's quirks and how to get around them. They are the ones who will be able to innovate."

YCI's Baldwin recommends examining tools the shop has built for other customers. "World-class tool shops really finish a tool. They round the edges and put the eyebolts where the molder can get at them. They think of the little things that can help the molder."

The financial health of the moldmaker is also high on Payson's list of criteria. "Moldmaking takes time, and it's unfortunate if a company goes Chapter 11 in the middle of building your mold." He advises researching the financial stability of the moldmaker.


An active equipment replacement program indicates that a mold shop is aware of current technology and has some plans to get it in-house, according to Rizzo of Nypro. "There's always new and better equipment coming out, and moldmakers have to make their own decisions whether or not it is good for them or affordable."

Robert Brohas, v.p. of manufacturing at Plastic Moldings Corp., a molder in Cincinnati, regards CNC machining centers as a virtual necessity to achieve cavity and core repeatability. "The better equipped shops are not always the higher priced ones any more, because with the CNC equipment they turn out things much faster than with manual equipment, and the repeatability is greater."

Rizzo adds that machine quality isn't necessarily a question of age. The Bridgeport mill, for example, has been an industry standard for decades and still has a legitimate place in today's shop. Dow's Payson agrees: "It isn't fair to look at the newness of the machine and not at the base capabilities. A 15-year-old CNC mill, if well maintained, is about as good as anything coming out now."

Interestingly, Payson says the real improvement in CNC technology is in better software. Servo motors, which gave CNC machining centers their unprecedented accuracy when they were first introduced, are still undergoing incremental improvements, but software is making big leaps in expanding an existing machine's usefulness. "The early software for three-axis machines was simple and could not do complicated tool paths. Now, if you buy one of the more advanced CAD/CAM packages, it will do these complicated tool paths easily." New software, Payson says, can often narrow the performance gap between new and older machinery.

Among the newer technology worthy of investment, according to Payson, is five-axis wire EDM, which can handle complicated draft angles; and universal grinders, which are more versatile than standard grinders.

Incidentally, one useful capability among moldmakers is the ability to try out molds in a press. Nypro, for example, requires that its moldmakers either own or have access to injection molding machines for functional testing.


Moldmaking quality is not all hardware or software. The most important area of the mold shop, according to consultant Pirro, is the bench area: "If you don't have good quality men at the bench, you'll never make a good mold." Dow's Payson agrees and tries to gauge the level of experience when touring a mold shop. Payson looks for the number of master moldmakers and how they are employed. In his view, the high skill level of a master moldmaker enables him to be innovative; if necessary, he can invent a new way of machining a piece of metal. "If a shop has an experienced journeyman or master squaring up blocks for electrodes, then his time is being wasted. If the master moldmaker is spending a good part of his time teaching journeymen or apprentices and the rest of his time doing very complicated work, then his time is well spent."

According to Jerry Lirette, president of D-M-E Co., Madison Heights, Mich., mold buyers should ask about the turnover rate of shop employees. "The length of time a company has been in business and the longevity of the people in an organization is often an indication of stability and consistency in the area of product quality." Similarly, George Baldwin of Lakeland Plastics, Inc., a consulting organization in Mount Arlington, N.J., recommends paying attention to the range in age of a shop's employees: Are they all reaching retirement are or are they all young? The former presents a long-term problem when all of the old hands are gone; the latter a current problem, because of lack of experience.

Payson looks to see if there is an internal training program in place, and would like to see more formal training of apprentices in general. That reasoning is shared by Stoll of Armin Tool, who says, "Our best toolmakers are those who have served their apprenticeship with us." Armin Tool runs a formal four-year apprenticeship program in conjunction with the National Tooling and Manufacturing Association in Chicago. Apprentices are allowed to accumulate 2000 hr per year of practical shop experience toward their apprenticeship training. After 8000 hr of experience, a graduate is considered a journeyman moldmaker. In his shop, 10% of moldmakers are considered masters.


Potential customers should inquire whether a moldmaker's design work is in-house or farmed out, says Baldwin of Lakeland Plastics. Mold design performed on the outside could lead to inconsistent quality, depending on whom the job is given to, he says. Other things to look for are a moldmaker's level of design experience, the CAD/CAM system, and the compatibility of his CAD system with that of the customer.

In evaluating design capability, Larry Loser, a senior program engineer with furniture maker Herman Miller Inc. in Zeeland, Mich., likes to see a certain mix of practical shop and tool-design experience, as well as formal engineering training.

Good communication between moldmakers on the bench and designer/programmers in the tool shop is important, according to Payson. "If they don't have a good relationship, they are not going to build a good mold." In addition, he prefers that mold designers have experience either in running machining equipment or in CNC tool-path programming. "I frequently see parts designed in which a mold designer asks moldmakers on the shop floor to stand on their heads to accomplish something that could have been done more easily." He also looks for mold designers to have a working knowledge of good plastic part design practices as well as molding practices--someone who can raise a red flag if there is a missed detail in the part design, such as an inconsistency in the nominal wall thickness.

There should be good communication between the part designer and the tool designer as well, according to some customers. For example, computer maker Digital Equipment Corp. in Maynard, Mass., which buys about a third of its molds directly from toolmakers (and two-thirds subcontracted through custom molders), has focused its efforts on early involvement in the tool design. To that end, according to Raymond Vino, who is involved with product development at DEC's Plastics Technology Group in Littleton, Mass., DEC has gone over almost exclusively to electronic data interchange (EDI) of a dimensionless database in communicating its part design to the molder and toolmaker. "I want to make sure that our part designer can talk to their tool designer, because those two folks, at the end of the day, know more about the part and tool than anyone else ever will."

Good record-keeping is important to avoiding misunderstandings when making changes in a tool design. Armin Tool, for one, documents all changes, noting revisions on the tool drawing. Loser of Herman Miller questions toolmakers on how engineering changes are documented; he wants to be sure that "ECs" are communicated to the shop floor as soon as possible.

Early cooperation between the end-use customer, molder, and moldmaker makes possible so-called concurrent or "parallel-path" engineering, which can considerably shorten a product's time to market, according to George Freeborn, president of Textek, a custom molder in San Antonio, Texas. He says that he is participating more often in this approach, which allows some manufacturing to take place during the design phase of the project.

Given the wide range of CAD software and operating systems on the market, from PCs to workstations, customers such as DEC require some translating capability from their tooling sources. DEC's Vino points to a trend toward 3-D solids modeling in CAD/CAM software, for which the more powerful workstation-based systems are better suited. That trend may present some difficulty in translating CAD data, because IGES lacks a mechanism for transmitting 3-D solid models.


One of Nypro's requirements is that its moldmakers assign multiple toolmakers to each mold. This requires a systemized approach to moldmaking and a higher degree of coordination within the shop, says Rizzo, but helps ensure a higher degree of repeatability than if just one toolmaker works on each mold.

Vincent Lomax, v.p. of Tech Mold Inc., part of the Tech Group in Tempe, Ariz., notes that 10 years ago if a shop got an order for 14 molds, it would probably give each job to one toolmaker who had responsibility for that tool. When the molds were delivered, the customer would have 14 slightly different and distinct molds. "That's no longer acceptable in a world-class environment. Today, a customer must be assured that the quality of the mold is consistent and representative of that shop's quality, not the personality of the moldmaker."

To that end, Tech Mold divides its shop into teams, each with its own specialty. As a mold progresses through the shop, each team of "precision specialists" performs its specialized function, such as grinding or EDM, on every mold. A master moldmaker is responsible for that project and orchestrates it through the whole shop. "We are no longer in the business of moldmaking, we are in the business of mold manufacturing," says Lomax.

The approach requires a high level of communication between the various specialists in the mold shop. After the final design is completed, Tech Mold holds a "kick-off" meeting between the designer, lead moldmaker, purchasing agent, team leaders, and foreman to go through the drawings in detail and plan the job. "The reason for the meeting is that every department leader knows what's coming, knows what the customer's expectations are, and has input on how jobs are prepared for his department," says Lomax.

Because the mold is divided into subassemblies, a dependable scheduling system is crucial to provide a good grip on shop loading and ensure that the delivery date is met. At Tech Mold, shop loading and department loading are tracked by a computerized scheduling system, and the status of each job is reviewed once a week at a staff meeting. Job status is measured not only in number of hours spent in labor, but also in terms of the actual completion of the mold.


The ability to machine interchangeable components becomes critical in shops using a systemized approach to mold manufacturing. Interchangeability means that every insert should be identical and meet specifications. The concept applies to the same components within a mold or in different molds. According to Lomax, "We've gone as high as 15 molds over a 10-year span where every component is 100% interchangeable from the first mold to the last. Cavity #1 in Mold #1 will fit and function in Mold #15 in any cavity position."

Lomax claims the demands for ever tighter tolerances are changing the rules for what is acceptable in a world-class quality environment. One old rule that has gone by the wayside, he says, is that moldmakers can consume up to 50% of the tolerance on a critical component. "Today we are being asked to build molds to within tenths of a thousandth of an inch, and that every insert be 100% interchangeable with any other insert in the mold."

Nypro, for example, allows moldmakers only 20% of the tolerance on any critical dimension on part drawings. "If the tolerance is 0.001, they can only have 0.0002 to play with. In our own tool shop, we have only two or three moldmakers who can machine to that," says Rizzo.

Dow's Payson looks for the ability and willingness of the shop to check the accuracy of its own machining with coordinate measuring equipment or a comparable checking device. "The operator who set up the machine may have been off 0.003 to 0.004 in. in the X-direction when they found the center of the block," he notes. Conscientious checking at every stage of the process helps to ensure that tight tolerances are kept.

According to some moldmakers, the ability to perform as much work as possible in-house helps to ensure interchangeability because it increases the control a moldmaker can exercise over tolerances. Richard Lappine, general manager of Comet Tool Co. in Williamstown, N.J., advises customers to ask moldmakers how much work is being done outside the shop. "In some cases, outsourcing is not a bad practice. But get familiar with the company's sources. Ask the moldmaker to let you see what he's buying and where he's buying it."

One way to help guarantee that molds are machined to tight tolerances is to periodically calibrate the equipment. Tech Mold, for example, contracts a company to come in and calibrate its equipment once a year.

As important as calibration is, however, it's still only a snapshot at a point in time. More valuable, says Tech Mold's Lomax, are a regular maintenance program and employee training. The most subtle change in the mold manufacturing environment or measuring equipment may be enough to alter the process, he explains, and moldmakers must be trained to recognize that. "You need always to have checks and balances. On every job done at Tech Mold, each employee checks it to make sure it is right before handing it on to the next person. If something is out of calibration, he will surely detect it long before a calibration program finds it."

Tech Mold uses a technique called Gauge R&R to maintain the repeatability and reliability of its measuring equipment and of the individuals using them. It's a method for determining if the gauge is consuming a portion of the tolerance, and if so, by what percentage. In this procedure, an individual checks a random dimension repeatedly on 10 inserts or gauges, and a second person documents the dimension each time. The results are put through an equation that calculates the percentage of gauge R&R that is introduced into the process by either the gauge or human measurement error. "It's extremely difficult to get below 10% gauge R&R |when working with tolerances under 0.0005~," says Lomax.


Lappine of Comet Tool remarks that quality control is becoming an increasingly important issue for moldmakers. "We have to be able to record and maintain traceability of all steel and tooling," he notes. Comet has a full in-house metrology lab to satisfy customers that demand complete certification of all mold components. The in-house metrology department must itself be certified by outside organizations.

Some tooling buyers, such as Nypro, require that their moldmakers have the ability to provide certification of the heat-treating process and of the metallurgical content of the steel. Moldmakers depend on outside sources that specialize in heat treating, including some steel suppliers that perform heat treating as a value-added service.

Tech Mold, as part of a growing industry trend, is in the process of preparing itself for ISO 9000 quality certification (see PT, Jan. '91, p.53). ISO 9001, which applies to companies that provide design, manufacturing, and product development, is a quality assurance program that makes sure that a company has the systems and documentation in place to produce a quality product. Lomax breaks ISO 9000 into four main questions:

* Where are we going? The answer to that would be defined by a mission statement.

* Who does what? That question would be addressed by a quality manual.

* What do we do? That would be addressed by a procedures manual.

* How well do we what we say we do? That would be answered by quality audits.


A tooling job is complete when a customer's expectations are met, or even exceeded, is the answer given by several moldmakers. Many of them avoid written guarantees. According to Steve Ballek, v.p. of Ballek Die & Mold in Hoffman Estates, Ill., "There are really no written guarantees from any mold shop in the Chicago area. Most people stand behind their work if it is a reputable shop." He adds that on critical tolerances, his shop machines a tool to be "steel-safe." If required, he will "tune it in" after the initial run and inspection by the molder.

What can a molder reasonably expect from its tool? Lappine of Comet Tool recommends that customers ask toolmakers to give an estimated cycle time. Nypro, for example, does not require a guarantee of cycle time but looks for closeness to its original estimate for that mold. Lappine adds, "There are times in which I will guarantee cycle times, but not too many people are willing to and I'm not always willing to." One reason, he explains, is that he has no control over a customer's molding operation.

When it comes to expected tool life, Lappine says customers can reasonably expect a minimum guarantee against wear for a million cycles, and he guarantees some of his molds against wear for up to four million cycles.

One key to customer satisfaction may actually lie with the customer. According to Lappine, "One of the biggest mistakes people make when buying molds today is that they look only at the bottom line for the construction of the mold. They don't take into consideration the bottom line of the project." A mold that costs an extra $5000 may have a 20% faster cycle time, he says.

When weighing competitive quotes, Lappine recommends that customers should compare apples to apples. Often, the price differential between suppliers results from differences in mold design. "Use spec sheets to make sure you are getting the same thing from everyone involved. Compare them to see the differences." For example, one moldmaker may put its water jackets into the cavity, while another may run water through the plate. Both say on paper that they have water cooling, but each method affects cycle time differently.

One last caveat: Dow's Payson advises customers to be wary of mold shops that underbid on jobs. An unscrupulous shop may deliberately bid low. "They may lose money on the mold, but make money on the ECs |engineering changes~ required to make the mold work." He looks for mold shops whose designers communicate problems beforehand to the customer to avoid unnecessary charges later on.

Profile of Moldmakers' Capabilities

In order to provide a statistical portrait of the activities and capabilities of North American moldmakers, PLASTICS TECHNOLOGY surveyed 440 moldmaking shops, asking them to score themselves in several key areas. From that number, 116, or 26%, responded to questions about design and manufacturing capabilities, tooling calibration, and customer and supplier relationships. The questions were based on quality criteria suggested by molders and moldmakers.


Of the respondents, 93% build molds for other companies' use; 7% build them exclusively for their own use; and 20% do both. Injection moldmaking was heavily represented in the survey; 97% of respondents produce injection molds, 80% build hot-runner types when required. Molds for other processes include compression/transfer (40% of respondents), blow molds (28%), thermoforming (18%), and RIM (14%). Blow molds garnered the highest average number of molds (131) produced in a year by a moldmaker. Respondents indicated that they build an average of 58 injection molds per year, about half of which (33) are hot-runner molds.

In addition to building new molds, many provide related services, including mold repair (93%), building prototype molds (86%), and prototype models (48%). A fairly large number do some molding themselves: 71% provide mold sampling/tryout and 38% also perform production molding.

Key markets served by at least half of the mold shops include consumer products (76%); automotive (69%); medical/pharmaceutical (59%); computers/business machines (51%); and appliances/power tools (50%). Others include packaging/food service (48%); recreational/toys (40%); and optical/lenses (19%).

Almost 76% of mold shops that responded are relatively small, with 50 or fewer employees involved in moldmaking; 25% employ 10 or fewer; and 24% employ more than 50. The median is 25 employees. Nearly two-thirds (63%) of the mold shops produce molds weighing under a maximum of 10,000 lb.


CAD/CAM is well represented, with over 90% of respondents indicating they have a system in place. The most common uses of these CAD/CAM systems (by about 90% of respondents) are for programming of cutting-tool paths, core and cavity design, and overall mold-assembly design. Two-thirds of respondents also use CAD/CAM for runner system design.

On the other hand, mold-filling analysis has yet to gain wide acceptance. Only 10% of injection moldmakers perform mold-filling analysis in-house. And even if they obtain outside consulting assistance, less than 13% of moldmakers perform mold analysis on more than half their molds. (The median figure is 20% of their molds use mold analysis.)

We asked which services are performed most commonly (i.e., on more than half of molds built): 89% said design of cores and cavities; 70% said design of runner systems; and 28% said part design.


Of all respondents, 89% said that they perform conventional EDM in-house, while 28% of mold shops are equipped with wire EDM machines. Thirty-five percent indicated that more than half of their cutting machines are CNC controlled, and an equal percentage equip their cutting machines with direct numerical control (DNC). More than half (54%) use a common computer database for tool design, machining, and inspection.

Electronic data interchange (EDI) is fairly well established between moldmakers and their customers. Of the 65% of respondents who said they use EDI, the most common application (60%) is for exchange of CAD information; 14% use it for billing/quoting.

Only about one in four (26%) mold shops that participated in the survey has a formal equipment replacement program. In general, 59% said the majority of their machining equipment is from five to 10 years old. One quarter of respondents said the majority of their equipment was five years old or younger, and 16% said it was 10 years or older.

Median employee profile for responding mold shops is 10% apprentice moldmakers, 20% junior moldmakers, 40% master moldmakers, and 30% specialized machinists. Slightly better than half (52%) of respondents say they have a formal apprenticeship program. Among all respondents, 45 is the median number of hours of training required annually.

On average, about half (51%) of the moldmakers say they calibrate their machining equipment annually, 19% quarterly, 10% monthly, and 13% "as needed." Inspection equipment is checked a bit more often on average: 42% annually, 27% quarterly, 10% monthly, and 10% "as needed." Most moldmakers (86%) calibrate new machining or inspection equipment before use. Not quite half (48%) of shops have written procedures for calibrating equipment, although about two-thirds (63%) train their people in how to follow calibration procedures. Coordinate measuring machines are used for tool inspection by 41% of responding moldmakers.

Twelve percent of respondents indicated that the tightest tolerance that can reliably be kept with their machining equipment was 0.0001 in. About one in four (26%) said they can reliably hold tolerances to 0.0005 in., and another quarter can reliably hold tolerances to 0.001 in. Only 24% use SPC to evaluate machine capability, and only a third train their employees in SPC methods. Slightly less than half (48%) provide temperature/humidity control in their machining areas for the sake of machining quality.


Nearly two thirds (62%) of moldmakers usually receive certification on steel procured from their supplier, and two-thirds ensure full traceability of all mold materials. About the same proportion (61%) certify each heat-treating job, although fewer than half (47%) certify each plating or other surface-coating job. Most (63%) said they perform a full inspection of purchased mold materials.

About 40% of respondents said they have a formal, written quality policy; slightly fewer (36%) have a corporate quality manual, and a bit more (42%) have a separate quality department. On the other hand, two-thirds said they have an on-going program to train their employees in quality. Slightly fewer than half (46%) have a formal program to analyze and reduce customer complaints.

Fifty-two percent of moldmakers said they respond to requests for job quotes in three days or less. A whopping 91% said they deliver better than half of molds on time (most cite engineering changes as the biggest reason for delays). Similarly, 94% said they deliver more than half of new molds at the quoted price. Nearly two-thirds (62%) use a formal production scheduling system, and nearly every respondent (97%) has some sort of record-keeping system for each job.

Moldmakers are somewhat selective in granting certain product guarantees. More than half (52%) said they rarely or never guarantee a cycle time for a finished mold; one-third sometimes guarantee a cycle time and 15% guarantee it often. On the other hand, 62% often guarantee critical part dimensions on a mold, 30% guarantee them sometimes, and 8% rarely or never.
COPYRIGHT 1993 Gardner Publications, Inc.
No portion of this article can be reproduced without the express written permission from the copyright holder.
Copyright 1993, Gale Group. All rights reserved. Gale Group is a Thomson Corporation Company.

Article Details
Printer friendly Cite/link Email Feedback
Author:De Gaspari, John
Publication:Plastics Technology
Date:Jan 1, 1993
Previous Article:Composites Fabricators show aims at boat builders.
Next Article:Injection molding.

Related Articles
Are you prepared for EC '92?
Building higher value into injection molds.
How to achieve world-class quality.
Offshore mold purchasing made easy.
Mold to big to move? Portable CMM solves QC problem.
Let the Mold Think for Itself.
Hourly Rates Inch Up in 3rd Quarter.
New Conformal Cooling Method Speeds Mold Cycles.
New SPI committee on magnetic mold clamps. (In Brief: Your Business).
Mold designers put the web to work.

Terms of use | Copyright © 2016 Farlex, Inc. | Feedback | For webmasters