Rubber Products in Different Sizes and Diverse Molding Capabilities
Do you need rubber products in different sizes? Maybe you need a choice of rubber molding methods instead. The Rubber Group of Rochester, New Hampshire (USA) uses injection, compression, and transfer molding to produce molded rubber parts in sizes large and small. We can also help you to choose the best rubber molding process for your application. Whether you need standard or custom molded rubber products, contact us for value-added manufacturing that includes design assistance, rapid prototyping, process selection, and more.
Molded Rubber Parts in a Range of Sizes
Does your company buy custom molded rubber parts in a range of sizes? Instead of sourcing them from multiple vendors, you can simplify your procurement activities and order everything from us. In the transportation industry, for example, manufacturers ask us for molded rubber parts that range in size from large railcar suspension components to small valve body seals. They need rubber-to-metal bonded assemblies, too. In the power generation industry, customers ask us to supply them with everything from large insulators for power transformers to small rubber grommets.
For these and many other types of molded parts, Our recent technology investments underscore our commitment to meeting all of your rubber molding needs. Earlier this year, we invested in a new DESMA 968.400 Benchmark (S2) injection molding machine for rubber parts. This new equipment complements our injection, compression, and transfer molding capabilities for smaller molded rubber components such as grommets, seals, and O-rings. To provide our customers with additional value, we’ve also added new laser marking capabilities.
Rubber Molding Capabilities and Process Selection
Whether you’re a designer, an engineer, or an industrial buyer, The Rubber Group can recommend the right rubber molding method for your application. Many customers are familiar with rubber injection molding, but transfer molding or compression molding could be a better choice for what you need. By learning how each process works and understanding the advantages and tradeoffs, you can make an informed decision that covers considerations such as part volumes and per-part costs, tooling costs and turnaround times, part tolerances and complexity, and available rubber materials.
For example, rubber injection molding is usually the right choice for high volumes of parts that require medium-to-high levels of precision. If you need tight control of dimensional tolerances, then transfer molding may be a fit. For flashless molding, both injection molding and transfer molding are options. For high value materials, The Rubber Group can incorporate wasteless molding that combines the speed and precision of transfer and injection molding with the low material waste of compression molding. Typically, compression molding is used for large parts and low volumes. For each of these molding methods, The Rubber Group’s ability to provide you with a cost-effective mold frame means that you can use the same rubber molding method for both rapid prototyping and parts production.
The Molded Rubber Products That You Need
Do you need molded rubber products in different sizes that are produced with different molding methods? You can reduce your vendor list and select the right rubber molding process by partnering with us.
Reduce Tooling Costs with Better Designs for Molded Rubber Products
MOLDING SERVICES, VALUE-ADDED MANUFACTURING
Do you need to reduce tooling costs for molded rubber products? Then it may be time to review your part designs and find some areas for improvement. After all, design for manufacturing (DFM) isn’t just about material selection or the rubber molding process. DFM also means finding ways to improve part designs so that your molds are less expensive to produce.
Contact us for design aid that’s backed by expert molding services and high-quality tooling. When you work with us, we’ll share cost-saving ideas like the ones you’ll read about in this article. Whether you need standard molded rubber parts or custom molded rubber parts, we can help.
Use Correct Tolerances
Tolerances are allowable variations in size for molded rubber parts. The Association for Rubber Products Manufacturers (ARPM) organizes these variations into drawing designations with alphanumeric classes. Because higher-precision parts require molds that are more expensive to produce, you’ll have greater capital outlays for tooling if you specify a drawing designation of A2 (precision) or A1 (high precision). Unless you need this level of precision, a less expensive commercial tolerance (A3) or even a basic tolerance (A4) may be appropriate to help limit tooling costs.
Avoid Excessive Undercuts
Undercuts are protrusions or indentations that can complicate the release of molded products. Because rubber is more flexible than plastic, designers don’t face the same challenges as with injection molded plastic, which is more rigid and less forgiving. Yet, excessive undercuts in molded rubber products may require the use of side actions, features that are designed into the mold to help facilitate part ejection but that also increase tooling costs and can add complexity to mold maintenance.
Consider Part Size and Mold Size
Larger parts require larger, more expensive molds. If you can reduce the size of your part, you’ll probably reduce your tooling costs. Remember, however, that there’s more to the mold than just the core and the cavity. With rubber injection molding, your part needs to fit inside the mold while leaving enough space for sprues, runners, tear trims, overflows, and alignment pins. All of these features are important, so consider the size of the part that you need and the size of the mold to produce it.
Account for Part Appearance
Molded rubber parts with a superior appearance are usually more expensive to produce. That’s because processes like bead blasting, electrical discharge machining (EDM), and mold polishing add costs. Some finer mold finishes even require hand labor. Unless your molded rubber part requires a special cosmetic appearance, avoid specifying a fine finish for the machined mold. Textured part surfaces and features such as logos also add costs to projects.
Define Flash Requirements
Flash is excess rubber on injection, compression, or transfer molded products. It is a normal part of the molding process that needs to be controlled for your individual application. When defining your flash requirements, there are two measurements to consider. Flash extension projects from the part along the mold’s parting line. Flash thickness is measured perpendicular to the parting line instead.
Consider the amount of flash your application will tolerate because reducing the allowable flash extension and thickness can dramatically increase both mold cost and part cost. If your flash removal requirements are strict, you can specify a flash-less mold so that your rubber parts do not have excess material in the first place. Flash-less molds can double or even triple your mold costs, so define your flash requirements carefully. A rubber molder can also hand trim your parts or use cryogenic deflashing, a batch process.
Evaluate Family Molds
Family molds produce different rubber parts that are made of the same elastomer. They have more than one cavity and effectively reduce tooling costs by improving productivity. For example, let’s say you need to mold two silicone parts for an assembly. Producing a separate single-cavity mold for each part would add 30% to 60% to your capital investment. Moreover, these molded parts would be priced based on running them in a single cavity.
If you use a family mold instead, your tooling costs will be less and your parts will be priced as if they were produced in two-cavity mold. This cost savings is attractive, but there are some other considerations as well. For example, family molds add complexity if the different parts in the mold have different quantities or are so close in design or size that there’s a risk of mixed parts packaging. The rubber parts in a family mold must also be made of the same material and have similar sizes and processing times.
Calculate the Number of Cavities
Multi-cavity molds have multiple cavities that all produce the same part. The benefits include increased cycle time efficiency and higher production volumes. To determine the optimum number of cavities for your molding project, it’s important to balance the capital outlay from your tooling costs against your per-part costs. Sharing the projected annual demand and product life expectancy with The Rubber Group will enable us to calculate the return on investment (ROI) for a larger mold with a higher number of cavities.
Contact us to Learn More
Are you looking for ways to reduce tooling costs for molded rubber products? Improving your part designs could hold the key to savings. This article describes just some of the ways that we can help. Whether you need standard or custom molded rubber parts, we add value to molding projects and are committed to quality in all that we do. Contact us to learn more.