Gate placement can playa big part on quality, appearance, and cycle time. It affects the flowcharacteristics of the plastics
as it fills the mold, which is directly relatedto the shrinkage and the resulting part dimensions. It must also allow foradequate plastic flow distribution to ensure optimum form and strength of thepart. Gate placement and type can dramatically affect cycle time for theprocess. Since
manufacturing cost is directly related to cycle time—the fasterthe cycle, the lower the manufacturing cost—gating placement must ensure efficientand effective manufactureHowever, the reason that many molds see
significant delays in achieving aproduction process is often overlooked by the product designer. These problemsrelate to the mold construction and how it functions. Specifically, there arethree main areas of concern:·Parting lines (where the mold opens) ·The type and location of gate(s) (opening through which plastic isforced into the part) ·How the part is ejected from the mold All three of these mold design and construction features have a directrelationship to each other and to the overall look and quality of the moldedpart.The product designer must have an intimate knowledge of mold design andconstruction techniques or must use the services of a manufacturing engineerearly in the design cycle in Gates can also have a significant impact on the cosmetics of a part, creating ablemish where the plastic enters the part. On every part, there inevitably hasto be a gate and therefore a gate mark so the placement must be strategic.A mold maker might decide to put a gate on a certain part of a mold for theirconvenience but this new location may be detrimental to the use of the part. Gateplacement changes will affect the entire mold, which can mean much time andmoney wasted. A designdefect that can create the biggest manufacturing problem is arguably whenejection doesn’t work and/or potentially damages the part. Ejection problems(failure of the part to eject cleanly and completely from the mold withoutwarpage or other damage) can cause significant delays in startup production andaffect the cycle time for the process. Ejection also affects the cosmetics ofthe part due to the witness lines that arise from the use of ejector pins, etc.In some cases, ejection design problems can be fixed easier than moving thegates, but sometimes, it can affect other design issues and result in new moldsbeing necessary. With certain parts, ejection can be more complicated andrequire activation from both sides of the mold. A designerwho takes into account individual potential pitfalls can still err if therelationship between design factors is not considered since many designprincipals are interconnected. Gating, parting lines, and ejection are allrelated to each other, and a device manufacture may have used up their budgetby the time they realize it, which is often at the point when they expect to gointo full production.Designers often design the parts and take them to a manufacturing facility latein the game expecting production to go off without a hitch. In reality,manufacturing design should be included throughout the design process so thatinteractions can be taken into account in the earliest part of the designphase. Choose a manufacturing vendor or experienced consultant early on andhave them do a detailed review of the interconnected factors that affectmanufacture. Serious delays and expense can result from molds not working, andthis can be avoided with careful planning and expertise.A heating solution can be a tricky, yet necessary,component in a variety of medical devices. As such, manufacturers want toensure they can rely on the experience and expertise of a leader in this area. This month’s ‘View From The Top’ discusses thistechnology area with a leader in the marketplace.As manufacturers are well aware, healthcare professionals and their patientsalike demand that the medical devices they are using be made smaller,convenient, and discrete, while retaining complete efficiency andeffectiveness. For most areas of medicine, this is a challenge for thecompanies serving this industry. It is an even greater obstacle to the successof a product when working with a technology that requires extensive experienceto deliver optimal results. Fortunately for medical device manufacturers, PeterDesloge—Watlow’s president, CEO, and chairman of the board—recognizes this andhas continued to move the company to a position that enables it to be relied onas a source of expertise for the full range of heating solutions required inmany medical devices.