06 8月 Five Issues Your Contract Manufacturer Should Address in Tool Design
From a medical device manufacturer’s standpoint, tooling is often the least focused upon element in a product development process. Yet, tool design often has significant impact on product quality and cost; production scalability; and on-time delivery. A contract manufacturer’s ability to educate its customers on tooling options and trade-offs associated with each option helps ensure optimal decisions are made in product development.
Forefront Medical Technology, a specialty contract manufacturer with a focus in disposable diagnostic, drug delivery systems and medical device systems, routinely helps its customers understand the impact of their tool design choices and sees five areas that require strong focus in the tool design process:
- Tooling ownership
- Alignment with overall product development strategy
- Manufacturability considerations
- Alignment with cost constraints
- Maintenance and tool life considerations
While it would seem that tooling ownership is an obvious “first-step” discussion that should be addressed in the quoting process, that is not always the case. Non- recurring tooling cost can be a large number. Some contract manufacturers amortize tooling cost into unit pricing to address this concern. There is nothing wrong with amortization if there is a clear understanding of the cost of the tool and how long it will be amortized. The issue is that not every contract manufacturer is transparent in this area. In some cases, tooling is presented as included in the price without the disclosure that the contract manufacturer owns the tool. If the product stays at the contract manufacturer for the life of the project, that isn’t an issue. However, if the customer decides to move the project to another supplier due to quality or services issues, there is an ugly surprise. The contract manufacturer owns the too. In some cases, the contract manufacturer may also own the design of critical parts used in the product as well. In those situations, moving the project requires a redesign and retooling effort. In addition, not surprisingly, contract manufacturers who are deliberately vague about who owns tooling often have service and quality issues.
Forefront addresses tooling ownership as part of the product development process. Typically, tooling cost is a non-recurring charge at the beginning of the process and the customer owns the tool and the product design. Customers are kept completely in the loop on the cost of their choices and potential options/tradeoffs that can lower cost.
Alignment with Overall Product Development Strategy
Product design choices drive tooling options. Often there are multiple choices to be considered. For example, a complex mold can eliminate secondary production operations and the higher production costs that can come with those operations. However, complex molds are higher cost and often have higher maintenance costs over time. Having an integrated product design and tooling design team can speed the process of costing out and analyzing the best choice.
Forefront Medical utilizes a vertically integrated business model, which includes tooling design and fabrication, in addition to product design. Forefront’s engineering team uses a standardized process in which customer requirements are assessed and a Design Development Plan (DDP) is created. A customer specification is then developed and market inputs are collected. Once the customer specification is approved, 3D CAD models are developed and analyzed. Design reviews which include functional analysis and risk evaluation are completed. After a customer’s team approves the design, prototyping and verification begins.
When tooling design and fabrication are integrated into the product development process, tooling options, costs and constraints can be evaluated concurrently with product design decisions. Communication is streamlined, which minimizes time and cost. Forefront Medical enhances this by having standardized software tools in its US Technical Center, Singapore Design Center and China full-scale commercial tool room. Cimatron or NX-Siemens software is used for tool, hot runner and cooling system designs. Mold-flow software is used for mold-flow analysis and to support Design of Experiments (DoEs) to optimize the design and molding parameters when those parameters are not resident in their existing library. Moldex3D software is utilized for molding process simulations to test assumptions prior to tool fabrication. This standardized approach enables tool designers to easily demonstrate the likely performance of the tool under review to the customer’s team during the product development process.
In single-use medical device manufacturing, the quality of the tooling design and fabrication process dictates the amount of the secondary processing options needed for the product, the contractor’s ability to control key parameters in the process likely to affect product quality, production throughput and the life of the tool. The earlier manufacturability issues are analyzed in tooling development, the less expensive the tooling design modifications will be. Working with a design team that is analyzing design for manufacturability early in the product development process eliminates added design spins, enhances quality, and optimizes cycle time while producing higher yields, which reduces cost.
Forefront uses a gated design process that enables tooling development to begin as early in the design process as possible. The Company has taken a vertically integrated approach to tooling fabrication and use of its in-house resources often cuts 2-3 months off of product development time. The tooling design process includes a design for manufacturability (DFM) phase, followed by the development of the mold specification, As mentioned earlier, mold-flow analysis tools are used to ensure efficient molding with minimal scrap and minimization of secondary finishing processes. This computer analysis minimizes design iterations on tooling.
Alignment with Cost Constraints
Typically, medical device manufacturers have defined cost target for their products. In single use medical devices, these unit price cost targets have little margin for deviation. Consequently, both the product development and tooling design strategy must align within these cost constraints. Additionally, tooling cost can be a significant factor when a company is introducing a new product that is expected to take months or a year to increase to high volume. Having a contract manufacturer able to understand these constraints and recommend tooling strategies that address them can be critical.
Forefront Medical maintains a detailed library of injection parameters related to the best mix of injection pressure, speed and other variables based on materials used. With standard molds and resins, developing optimal injection parameters utilizing this library typically takes two hours. This knowledge base also makes it easier to validate assumptions on most efficient tool design relative product cost targets.
The team also looks at tradeoffs between mold complexity and preferred machine size. For example, on one high volume part, Forefront’s team determined that a 64-cavity mold was needed to support the anticipated second year volumes. As originally designed, the mold was too large for a 220-ton injection molding machine. Utilizing a higher tonnage machine would increase cost since the machine consumes more space and energy, so the team need to change the mold assembly layout to reduce the size of the mold. A key challenge was that this part was small and formed by the core, cavity and sliders.
The team needed to develop a design that had sufficient space between cavitation, runners and a comfortable ejection system. They designed a mold without thin steel, positioned the layout accordingly, so that a single hot runner tip would inject the plastic to two parts and designed a hot runner system that met those requirements. This reduced the space required enough to utilize the lower tonnage 220-ton machine.
Another area of focus involved optimizing the process to ensure a 22-second cycle time was achievable. One key constraint in achieving that cycle time was cooling requirements. The parts needed sufficient time to cool during the mold opening and closing process. Providing sufficient cooling time required optimization and synchronization of the mold opening, cavity release and part ejection process. The design team estimated cycle times during mold flow analysis and then work with production time to fine tune process to the targeted 22-second cycle time.
Maintenance Cost and Tool Life Considerations
Tool Maintenance and tool life are two other considerations that should be considered in tool design. The more complex the tool, the more preventive maintenance the tool is likely to need. Similarly, tool composition metal or “hardness” is determined by the projected product volumes. In some cases, a lower cost “soft” tool may be utilized during a lengthy product introduction phase if volumes are relatively low or the design is expected to be modified as volumes grow.
The maintenance strategy should be carefully considered. Does the contract manufacturer have an in-house tool room or will the mold need to be sent out for preventive maintenance? How much downtime will offsite maintenance typically require ? Will that impact production capacity to the point where an additional mold is needed?Complex tools may have more frequent maintenance and repair requirements than less complex tools, but any tool that doesn’t have routine preventive maintenance will wear inappropriately and develop quality issues over time.
Forefront Medical operates a full scale commercial tool room. This provides the resources necessary to maintain tooling on-site. A robust preventive maintenance program that extends the life of each tool., helps minimize unscheduled downtime and contributes to high product quality. Plus, an in-house tool room minimizes the downtime and cost associated with tool maintenance and repair since the tool can stay in the factory instead of being shipped to a third-party tool repair facility.
Tooling cost can often be a large investment. Working with a contract manufacturer who is able to discuss options and trade-offs in tooling design choices helps minimize cost and time. The ability to sue simulation software to optimize tool performance is also key in reducing cost, and enduring quality and manufacturability. Working with a contract manufacturerwith in-house tool design and a tool room reduces tool design and fabrication time, and reduces downtime in production.
About Forefront Medical Technology
Forefront Medical Technology is a global medical device contract manufacturer with five locations. Singapore is Forefront’s headquarters, as well as home to our Design Engineering Center and specialty manufacturing. JiangSu and Xiamen, China, are additional manufacturing locations and are also China FDA Registered. Shanghai, China, Farmington, CT USA are regional Business Development offices which assure our technical sales teams are close to our customers for local, responsive assistance.
We have developed extensive capabilities with laryngeal mask airways, diagnostic devices, drug delivery systems, enteral feeding catheters, infusion sets, wire reinforced tubes, optically clear components, patient monitoring devices and other specialty products. Each of our locations has state of the art manufacturing capabilities that include class 100K clean rooms for extrusion and injection molding, complimented by class 10K clean rooms for assembly and packaging. Forefront Medical’s integrated technical approach provides customers the total manufacturing solution and global supply chain. Our facilities are TUV ISO 13485:2016, ISO 9001 and FDA Registered. Forefront is a wholly owned subsidiary of VicPlas International Ltd, who is listed on the SGX Main Board, Singapore stock exchange.