ProMed’s Approach to Low Volume Production

Many silicone injection molding companies focus on high volume production runs, and often do not give enough attention to prototyping or low volume runs. In fact, some manufacturers avoid low volume production all together, requiring customers to commit to a minimum number of molded parts before agreeing to a new project. That is not ProMed’s approach! The ProMed team offers cost effective solutions for low volumes, and does not shy away from low volume production for silicone injection molding. Regardless of the volume, ProMed views each project as an opportunity to build a long-term relationship with a customer!

Cost-Effective Prototyping

When it comes to silicone injection molding, the initial tooling cost can be pricey! Thus, companies often utilize the prototyping phase to fine-tune the design and work out any potential manufacturability issues prior to investing in the tooling that will be utilized for high volume production. Prototyping lowers risk and costs for injection molding projects.

Experienced injection molders, like ProMed, offer different materials and methods for creating prototypes, as well as molds for low volume runs. Below are 4 of the most common techniques.

  • RTV Molding – Most companies are familiar with LSR and HCR but RTV (Room Temperature Vulcanization) may be lesser known. RTV is a silicone casting for prototyping, testing, and lower volume production. Making parts out of these materials requires a mold, which can be made of almost any metal or plastic material. This technique is actually an indirect molding process, or casting, where the molds are first created and then the actual parts are made. A cost-effective way to produce small volumes of parts, RTV casting reproduces surface textures and other fine details. Furthermore, since silicones feature great chemical and heat resistance, RTV molds can be used to cast materials like low melting point metals, epoxies, waxes, and gypsum—all without needing a mold release agent.
    • Pros: The use of RTV is attractive because of the low capital equipment requirements and the availability of raw materials. Once the mold is made, making parts is a simple fill-and-wait process, and a skilled technician can make the first part within a day.
    • Cons: RTV molding is a slow process with cure times extending from 20 minutes to hours, and ovens are often used to accelerate the curing process. Production rates and cost per piece are both largely determined by the processing time.
  • 3D printing – 3D printing in silicone is now an option for prototypes, thanks to new elastomeric materials specially formulated for 3D printing. As additive manufacturing technologies continue to advance, part fabrication speed and resolution continue to improve while capital equipment costs quickly drop.
    • Pros: 3D printing doesn’t require machining a mold and runs unattended. Very small batches of parts can be manufactured in hours.
    • Cons: The elastomeric material options are not true silicone rubber. The mechanical properties and method of manufacture do not approximate production LSR. Precision can be a challenge for fine featured parts and thin-walled part designs. Large batches of parts (>100) are not practical due to high unit cost.
  • HCR – Transfer molding is used to make parts out of HCR, and is a simple manufacturing process. HCR (“gum stock”) material is placed in a heated cavity to cure and form a part. HCR is a natural fit for transfer molding since gum stock is much more viscous than LSR.
    • Pros: Simple tools with little or no process development.
    • Cons: Complex geometries may not be possible and cycle times are longer than LSR.
  • LSR – Production equivalent injection molding press and production grade materials are molded in soft metal tooling.
    • Pros: Tooling can be made quickly and the production of parts is fast. The resulting prototypes are very close approximations of production parts.
    • Cons: Can result in a higher cost per part for small runs of parts, since the initial tool cost can’t be amortized over a large number of parts.

ProMed Prototyping Expertise

ProMed Prototypes fills a market void by offering customers real molded parts, made from a wide variety of materials. Our team of prototyping experts offers complete in-house mold design, mold build, and prototype component manufacturing. Allowing ProMed to serve its customers throughout a product’s lifecycle decreases production development time, development cost, and production piece part price due to critical manufacturing information learned through prototyping. Click here for a comparison of the speed, cost, and likeness to production for different prototype materials.

ProMed Prototypes offers quick turn prototypes that include tool design, tool manufacturing, prototype manufacturing, cleaning, packaging, and shipment. ProMed provides customers a distinct advantage because, in the world of product development, time is money, and getting a product to market before the competition is a key to the success of the long-term business strategy. When your device is ready for full scale production, ProMed Prototypes’ manufacturing knowledge will be transferred to the New Product Development department of ProMed Molded Products for pre-production runs, validation, and ongoing production runs. We focus on prototypes for the following industries:

  • Medical: Dedicated quality system, facilities and personnel support the activities necessary to develop and manufacture these drug eluting components. Working with both established and early-stage medical device and pharmaceutical companies, we develop robust manufacturing processes and platforms for the controlled release of drugs from a variety of materials. Our medical prototypes are offered in a variety of materials including LSR, HCR, and RTV.
  • Aerospace and Defense: ProMed also has more than ten years of experience in serving the aerospace and defense markets. We offer quick turn silicone molded prototypes of nearly any geometry and material type, along with complex assembly and over-molding prototypes for the aerospace market. ProMed Prototypes has leveraged its experience to become a leader in providing precision quick turn silicone prototypes to the aerospace and defense markets, along with ProMed Molded Products taking many aerospace and defense products into full production.
  • Pharmaceuticals: ProMed Pharma, offers quick turn pharmaceutical prototypes for drug eluting and drug delivery components, among other pharmaceutical, medical device, and combination products. ProMed Pharma focuses on silicone and plastic pharmaceutical prototypes but has extensive experience in final product assembly and packaging as well.

Contact ProMed today at 763-331-3800 to discuss your next prototype or low volume project or click here to request a quote.

Cost Effective Prototypes and Low Volume Production
Article Name
Cost Effective Prototypes and Low Volume Production
Cost effective options for prototypes and low volume production such as RTV molding, 3D printing, and LSR and HCR molding options.
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ProMed Molding
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