Modular Molds Contribute to Lean Manufacturing Success
by Ken Jenkins, Pleasant Precision, Inc.
Focus Spring 2009
The economic downturn has U.S. manufacturing looking for ways to do more with less, pushing the limits of optimization, efficiency, and cost effectiveness. Never has the term lean manufacturing meant more than it does today. The mold-making process notoriously adds time to pre-production and can be very costly, especially for shorter production runs. Modular molds shorten the time to production, decrease the costs associated with mold-making, and compress mold changeover times all of which contribute to an increasingly lean molding operation.
Modular Molding Systems
In 2003, Pleasant Precision, Inc. (PPI) launched Modular Mold Systems, a division that provides a proprietary line of standard round interchangeable insert molding systems (called Round Mate) that offer cost- and time-saving solutions to mold makers, molders, and OEMs processing injection molded parts. Modular molds are commonly produced as round and rectangular interchangeable systems to compress the overall mold design and mold build process.
Modular molds are provided in a range of round interchangeable systems that feature a variety of standard sizes and include Micro Systems, multi-position systems, and machining and loading fixtures with many available options, such as hot manifold, parting line runner, parting line interlocks, and unscrewing molds.
Rectangular interchangeable systems also come in standard sizes and feature interchangeable inserts that lock and remove from the parting line, built-in water cooling lines, stepped pocket inserts, guided ejection, stainless steel plates and protective coating in water jackets, and full-size leader pins and bushings.
In 1990, Intralox, Inc. of New Orleans, La., was looking for a solution to molding a couple of round parts for its products and discovered a lot more at PPI. While the Round Mate system proved to be a good solution for Intraloxs round components, the company also manufactures complete conveyor belt assemblies for baking, food processing, and other applications that require hundreds of configurations of the components for its products.
We found that our product fits well in a round cavity block situation, which is great for round parts, said Chris Ordeneaux, a mold engineer for Intraloxs New Product Development. We have so many round parts, each that are slightly different, that were able to implement the Round Mate solution. Its ideal in how the mold is cooled and how the material is injected.
Today, Intralox has hundreds of core/cavity blocks to mold hundreds of configurations of its products that fit into about 10 mold bases. It turned out to be a cost saver over the years as weve grown from only a couple of these round configurations to the hundreds of configurations we do today, Ordeneaux said.
Applying a modular mold philosophy within your shop does benefit the tool design and fabrication process, because you can simply order off-the-shelf components; however, modular molds can provide much more than simple open and shut tooling. Modular molds are designed with unscrewing, slides, heated, hot manifolds, and cavity pressure sensors, to mention a few.
Modular molds can help to reduce time design and fabrication time. Because the concept portion of traditional tool design encompasses all aspects of base, cavity, ejection, and machine, there are significant time and financial savings when the parameters of the program line up within the boundaries of a modular mold. You can realize additional savings when standard components can be produced, on demand, from pre-designed and pre-programmed machine setups. The unique benefit occurs when your product mix is married up within a standardized modular molding application and the savings are realized after just a few tools.
An OEM expects its mold suppliers to offer reduced lead times, and modular molds offer a way to compress the overall process of building plastic injection molds. Modular molds offer cost savings by reducing design time, mold making hours, repair costs, inventory, material costs, and more.
Dedicated to Lean Manufacturing
Survey results from Plante & Morans 2007 North American Plastics Industry Study, distributed through the Manufacturers Association for Plastic Processors, show that when it comes to Quick Mold/Die Exchange, the mean of the 162 companies surveyed was only 2.2 (1 = Not using; 5 = Fully deployed), which means that most companies were in the Early Development Stages of implementing quick mold changeovers.
The studys operational data relating to the time for a mold setup was 40 minutes at the low end, with 60 minutes being the median, and 120 minutes on the high end. Modular Mold Systems, on the other hand, offers about a 10-minute changeover. Molders are primarily selling press time, so whatever you save in setup time goes toward production. If you do 25 mold changeovers in a day and can save 15 minutes on each one, that equals more money in the bank.
Another one of PPIs customers, a division of the Fenner Group, molds hydraulic and pneumatic seals for construction, agriculture, and forestry equipment. We switch tools as often as 10 times a day, said Ryan Webster, applications engineer. Another challenge for us is that our customers will not pay for the tooling or will only pay a small amount for tooling. That means I dont have the option of buying a traditional tool that costs $10,000 or $15,000. In looking around, Ive had several tool shops say they cant do what I needed done for that price. PPI, on the other hand, said well start with our Round Mate product and tweak it to meet your needs. By using a modular mold system over traditional molds, Webster has been able to reduce costs for both bases and inserts.
When Modular Doesnt Make Sense
Using a modular mold system would not benefit an injection molder in cases when:
- Multiple tool actions are required to mold a part
- A tool is dedicated to several secondary operations that occur concurrently with the molding process, driving down the benefit of changeover time
- Changeover time and ease are of little importance to the user
- There are large part sizes
- Theres a demand for long production runs and low product mix
Molding Optimization at PPI
PPI understands the benefits of modular molds, because the company also has a molding division in its 54,000-square-foot facility. PPI operates 10 injection molding presses, ranging from 50 to 400 tons, from which it serves the automotive, medical, industrial machine, and electrical industries.
The Lean manufacturing process that PPI has implemented proves the benefits of modular molding systems (MMS) in its own molding production. There are five areas in Lean: value, value stream, flow, pull, and perfection. PPI specializes in the flow category and that is the area that MMS comes into play the speed at which you get the mold into the press and start producing product. PPI uses standard components on the shelf along with standard design, so what would normally take 8 to10 weeks to produce the tool, PPI does in 2 to 3 weeks.
PPI also doesnt hold inventories for molded product, which costs money, but produces the product the day before the due date, thus keeping its cash on the shelf. The time and costs associated with preventive maintenance also is reduced, because the molder is maintaining only the core and cavity inserts instead of the entire mold.
For Pleasant Precision Inc. (PPI), Lean isnt new. Team PPI, the name that company founder Ron Pleasant adopted to show the commitment of all PPIs team members to Lean thinking, demonstrates these principles in every segment of the organization from mold manufacturing to its molding operations to its Modular Mold Systems division, which innovated the first Round Interchangeable Insert Molding System called Round Mate. Today, the entire PPI organization has become what Pleasant calls Leaner than Lean. And now the goal is to bring that same understanding of Lean and the value stream to its customers. For more information, visit www.modularmoldsystems.com or call (800) 860-3974.