Purchasing High Cavitation Tooling
Purchasing of high cavitation tooling is one of the most crucial decisions on the success of manufacturing high production dispensing closures. Today's sophisticated dispensing closure tooling represents a significant capitol investment and requires skillful selection of a mold supplier.
Dispensing closure tooling is highly complex and requires a higher level of precision due to multiple product design functional requirements. Living hinges, linerless bottle plug seals, product shipping seals, dispensing orifices, internal or external threads, and mating component fits have a great impact on how the tool is designed.
In today's engineering environment there are a number of computer-based tools to aid in tooling design. CAD/CAM, solid modeling, full data associativity from art to part, analytical software, CAD and video conferencing all greatly contribute to reducing errors and improving delivery. However, it is important not to lose sight that tool design is as good as the designers past experience, knowledge gained through ideas and creativity.
Designing a product for high production tooling involves certain considerations that must be closely evaluated: part ejection, wall thickness, material flow characteristics, cycle, hot runner feasibility, gating location and assembly at high rates.
One area that is often overlooked during product design is multi-cavitation. Product features which appear simple in design may not be simple to produce in production tooling. Some very complex designs require a host of tool actions, such as, side-action, automatic unscrewing and collapsible core, all within the same tool. It must be kept in mind these actions require large areas of space and can limit mold cavitation.
New products are routinely developed utilizing hand or semi-automatic tooling to test part function, provide marketing samples for consumer testing or aid in assembly equipment design. Although this development stage may provide useful information it most likely will not uncover production tooling problems.
A proven approach to reduce risk or delays for a complex production tool is to construct a representative single cavity, fully automatic tool of the intended production design. This ensures the new design concept will perform under production conditions. Cycle time, shrinkage, venting, cooling, steel selection, and most importantly the tool's mechanical reliability are proven. The benefits are pre-production sample parts that meet customer specification and delivery of the production tool on time without start-up delays. This process also benefits the mold maker by furnishing insight into the manufacturing of multi-cavity components. Special fixtures, tooling, or equipment can be preplanned or purchased with this knowledge.
Determining cavitation of production tooling is driven by quantity and cost. Quality, complexity and handling of molded parts are to be considered next.
Capabilities of the injection-molding machine to be used requires thorough investigation. High cavitation tools can be extremely heavy and require molding machines, which have a rigid clamp design and well supported platens. Platen deflection during mold injection or platen tipping during mold opening or closing will have a tremendous effect on part quality and mold maintenance costs. Mold damage can occur rapidly when these guidelines are not adhered to. Another critical area is plastizing of the resin. Melt quality and shot to shot consistency will greatly impact part quality and cycle time. Injection molding technology of new machines today can overcome many issues related to processing.
Hot runner technology for certain dispensing closure designs may provide cost and manufacturing advantages over a cold runner. However, not all dispensing closures lend themselves to full direct hot tip gating due to part design constraints. Cavity spacing, mold action and gate location can dictate what runner/gating option can be realistically used. In cases where complete elimination of the cold runner is not possible, a hot/cold combination system may be the practical and technical answer. It may also provide most of the available savings of a full hot runner and offers a lower cost solution.
In tool construction today, the evolution of CNC controlled machining has enabled precision tooling to be built at an affordable cost, even in the most sophisticated tools. However, the quality of the person operating the machine tool still requires skills developed over many years. The time savings in manufacturing quality and consistent, repetitive parts has been shorted considerably.
High production tooling requires the highest quality of workmanship and materials. Hardened, stainless steel mold bases and total interchangeability of components have increased production reliability. Today, millions of cycles are possible without major maintenance. This has evolved due to better tool steels, injection molding machine technology and manufacturing methods. Molders today are more conscious of purchasing higher quality tooling and implementing preventative maintenance programs.
Mold tryout and debugging by the mold maker are strongly recommended when purchasing highly complex dispensing closure tooling. This ensures that the tool function and part quality have met design objectives. A thoroughly tested tool will be production ready when it arrives on the production floor.
Open communication links between the end user, molder and mold maker will cut down on errors and clarify delivery expectations.
When making that all important purchasing decision keep in mind that production tooling is as good as the tool design which is as good as the product design. A well-engineered and developed product and tool design combination will guarantee success and greater profitability.
Ivanhoe molds are put into production without delay!