How Reaction Injection Molding Can Reduce Manufacturing Costs

VanDerLande product from Reaction injection molding

Companies continually strive to improve production costs. Whether you need a large, lightweight, or complex, 3-D part, or a limited tooling budget, RIM can be the solution you’re looking for.

Reaction Injection Molding (RIM)  is an example of an innovative manufacturing process that lends to high-quality polyurethane parts.

What Is Reaction Injection Molding (RIM)?

RIM creates end-use products or parts by combining two liquid polyurethane chemicals – an isocyanate and a polyol. These chemicals are isolated as they re-circulate through a sophisticated dispensing machine until a part is produced. 

Parts are produced when the chemicals enter the mixing chamber of the mix-head, which is attached to a machined aluminum mold with heated water lines.  The chemicals impinge at high-pressure (3000 psi) and flow into the mold at low pressure (150 psi).  An exothermic reaction occurs within the mold as the temperature reaches 350℉.  The mold’s water lines quickly wick away the heat and allow the molder to quickly withdraw parts by hand.

Tooling Cost Advantages of Reaction Injection Molding

By using aluminum molds, instead of steel molds, your overall capital expenditure can be dramatically lower – especially for larger parts.  We still use aluminum molds manufactured over 30 years ago!

Injection molding requires high pressures, high temperatures, and highly viscous materials.  All of these elements place tremendous stress on the mold, which is why steel is required to produce conforming parts and minimize mold maintenance. 

Comparatively, more affordable aluminum molds are perfect for the RIM process and its integration of low pressures, low temperatures, and non-viscous materials.

Additional Benefits of RIM Molding

  • RIM is best suited for larger parts and lower volumes.  However, RIM Manufacturing produces smaller parts by the thousands too. 
  • RIM offers tight tolerances with more cosmetic freedom in part design, variable wall thickness, geometric complexities, and the ability to combine multiple parts into one single, seamless part. 
  • Parts can be solid, elastomeric, structural foam, or flexible foam.
  • RIM parts can be pigmented, in-mold painted, or post-painted to provide the required cosmetic finish at the right price point.

Work with RIM Manufacturing for Your Next Custom Project

Partnering with RIM Manufacturing for custom Reaction Injection Molded parts and products can yield high-quality parts that perform well, are durable, and uniquely designed.

Learn more about reaction injection molding and how it can help your business. Contact RIM Manufacturing today.

4 Cost Benefits of Reaction Injection Molding for Manufacturing

Theranos medical device from reaction injection molding

Manufacturing firms are always looking to lower their overall production costs. Especially now that we’re in the middle of a global economic recession, companies strive to minimize their expenses and maximize their cash reserves.

One of the solutions that can help cut your production costs is reaction injection molding or RIM. Compared to the standard or thermoplastic injection molding, RIM is a more economical plastic manufacturing method. It offers plenty of cost benefits, helping manufacturing firms save on assembly expenditures. 

What is Reaction Injection Molding?

RIM uses thermoset polyurethane liquid chemicals instead of standard thermoplastic resin pellets. The process starts by mixing two base polymers, causing a chemical reaction that thickens and expands the polymers. The polymers are then injected into the mold, where they are heated until they harden.

The polymers used in RIM have a lower viscosity than the ones used in standard plastic injection molding. It’s easy to achieve your desired density, weight, thickness, and hardness with RIM. 

Here are some of the cost benefits you get with reaction injection molding.

1. Lower Machine Costs

RIM features low injection pressures and low processing temperatures, unlike the more intensive plastic injection molding process. The mold also requires less clamping force to form the thermoset plastic materials. There’s little need for external force or pressure in RIM since the polymers used rely on chemical reactions and low processing pressures.

For these reasons, RIM has more economical processing machines than other manufacturing processes of plastic parts. Plastic injection molding, for example, needs high-grade steel machinery to support high pressure and temperature. 

2. Lower Tooling Costs

RIM also offers lower tooling costs. The thermoset polymers expand on their own exerting less stress on the machined aluminum tools.  These are more affordable than the high-grade steel tooling required in thermoplastic injection molding. 

RIM tooling experiences little or no wear because of the non-viscous chemicals used to produce parts.  Therefore, tool maintenance, if any, is minimal thereby eliminating or significantly reducing mold maintenance costs over the life of a project.

Because it uses low-cost tooling, RIM significantly reduces capital costs associated with new projects and is ideal for large productions that require a large number of molds.

3. Shorter Lead Times

Lead time is an important consideration in manufacturing. The shorter your build cycle, the quicker you can get your product to the market.  Because aluminum machines faster than steel, RIM tools require shorter lead times than injection molding tools, which saves you money and time.

You can enjoy shorter tooling lead times with reaction injection molding. The typical build cycle of complex molds is four to six weeks.

4. Lower Finishing Costs

Finally, RIM allows in-mold painting. You can produce aesthetically pleasing finishes, such as high or low glosses or color variety. In-mold painting saves you time, manpower, and even production floor space during the finishing process. It can also reduce the costs that usually come with secondary finishing.

Cost-Efficient Reaction Injection Molding Processes

RIM Manufacturing specializes in custom reaction injection molding. ISO 9001:2015 and 13485:2016-certified, we’re one of the largest and most trusted independently owned manufacturing plants in the country. We help our clients optimize reaction injection molding processes unique for their business needs and goals.

Connect with us today to learn more about reaction injection molding.

Understanding the ‘Reaction’ Process in Reaction Injection Molding

Injection Molding machine for RIM process

Some people assume that the difference between traditional injection molding and reaction injection molding (RIM) is purely superficial. But the two processes are considerably different and provide distinctive results. Although both inject raw materials into a mold, RIM is more complex as it uses chemical reactions to create parts.

Educate yourself on RIM’s “reaction” process to understand how it differs from traditional injection molding. Apart from this, you will discover how chemical reactions create stronger, more durable, and more customizable parts.

The Reaction Process

RIM uses low-viscosity liquid polymers, specifically isocyanate and polyol, which are lightweight and cost-efficient. These liquids are stored in large tanks before high-pressure industrial pumps dispense them into the appropriate molds. The injected liquids slowly expand and thicken through a chemical reaction. Once this is complete, the materials harden into the finished parts.

RIM differs from traditional injection molding in its design process. It is highly customizable, making it easier to select which raw materials and molding techniques to use. It results in finished parts that have custom weight, strength, and density characteristics. The RIM process also allows for more intricate designs.

The Advantages of RIM

The chemical reaction utilized in this process has several advantages, including better structural integrity at a low cost. Learn more about it to understand why many businesses prefer the RIM process.

Build Larger Parts

The traditional injection molding process is more expensive, making it difficult to use in manufacturing larger parts. The RIM process for parts molding offers clients a cost-efficient alternative. Additionally, liquid polyurethane is better at filling molds for larger pieces without compromising on its finer details.

Experience Better Durability

The materials used in the RIM process offer better design flexibility, allowing you to design and build parts with varying thicknesses to suit the final product better. Parts created through RIM exhibit better dimensional stability and chemical resistance, letting them withstand internal stress during processing. Polymer-made products are also known for their corrosion resistance, making them ideal for moisture-prone applications and environments.

Enjoy Superior Flexibility

Polymer materials used in RIM are known for their flexibility, especially compared to aluminum and sheet molding compound. Quickly form parts with intricate details without compromising their durability with these materials.

Create In-mold Paintings

RIM provides aesthetic benefits, including in-mold painting. This is achieved by painting the cavity of the mold before it is filled with polymer materials. The paint adheres to the liquid through a chemical bonding process, coating the finished part as it dries. It results in a paint job that is resistant to cracking, flaking, and chipping.

Experience the Advantages of RIM Processes When You Work with RIM Manufacturing

For over four decades, we have worked with businesses across industries, providing them with high-quality parts for their products. We take a hands-on approach to each project, allowing us to create custom parts for any product.

Get in touch with us for more information about our services.

The Applications & Advantages of Reaction Injection Molding (RIM) over Thermoforming

Spacelabs - Akron Thermoforming product

Plastics play a huge role in manufacturing. They are present in virtually every industry. From automotive to medicine, plastic materials are utilized as end products and components for assembling a more complex product.

However, these plastic products are not readily available in the market, and they have to undergo a manufacturing process within a plant dedicated to designing and molding plastics.

RIM Manufacturing is an example, and helping to design and molding plastic end products or components is something we do exceptionally well. To give you a clear picture of what we do, we’ll compare the process we use, Reaction Injection Molding (RIM), with another popular plastic manufacturing method – thermoforming.

What Thermosetting & Thermoforming?

Let’s cover the basics.  Reaction Injection Molding is a Thermoset process whereby low-viscosity liquid polymers and isocyanates are mixed at high-pressure (2000 psi) and injected into temperature-controlled molds at low-pressure (150 psi).   An exothermic reaction occurs as the temperature of the liquids reach 350 degrees Fahrenheit before quickly cooling to become a solid polyurethane part. Thermoforming, on the other hand, draws a pliable plastic sheet stock down onto a heated mold.  A vacuum may be used to evacuate any air and accurately reproduce the details of the mold.

The key difference between the two is significant.  RIM (Thermosetting) allows for tight tolerances, unique design, and molded in ribbing and bosses.  Thermoforming, on the other hand, is good for simple design parts with limited functionality and cosmetic finish.

The Applications of Thermosets & Thermoplastics

The different qualities that thermosets and thermoplastics possess dictate where and how they may be applied.

For example, thermosets are ideal for products exposed to high temperatures because of their incredible heat resistance. For this reason, manufacturers use thermosets for the body and components of household and kitchen appliances. These machines tend to generate excess heat. If thermoplastics are used for these products, they could warp at best and melt and mess up the electricals at worst.

Thermoplastics, on the other hand, are ideal for single-use plasticware like cups, drinking bottles, food containers, and grocery bags. CDs, DVDs, children’s toys, sports equipment, and eyeglass lenses are also made from different thermoplastics.

Thermoset vs. Thermoplastic: Which Should You Choose?

Which is the better material to use for your products? The answer depends on the uses of your products. Our opinion at RIM Manufacturing, however, skews in favor of thermosets. We attest to the quality of thermoset plastic, and its heat-resistance and physical integrity are additional perks. More importantly, it’s easier for us to create intricate details like textures, irregular corners, and protrusions using reaction injection molding. Thermoforming is more acceptable for simpler designs.

Find out if thermoset plastics are compatible with your manufacturing requirements and product design. Talk to our product specialists at RIM Manufacturing. Contact us today.

RIM Parts & the Industries That Use Them

Reaction injection molding (RIM) process

Reaction Injection Molding (RIM) is a robust process used to produce polyurethane plastic parts by combining liquids (polyol and isocyanate) to form large, high-performing, lightweight parts used in manufacturing different products. Over the years, the process has become popular because of the design flexibility and cost-effectiveness when compared to other manufacturing processes.

The Advantages of the RIM Process

Apart from its affordability, the benefits of RIM Mold and Part Design are useful to our customers for the following reasons.

  • Creation of Large Parts: RIM uses low viscosity polyurethane liquids, making it easier to create uniquely designed, large plastic parts without compromising performance.
  • Highly Cosmetic Surface Finish: The process accommodates finer design details and surface finish to produce quality pigmented or in-mold painted parts.
  • Variable Wall Thickness: The chemical reaction used to form parts is highly customizable, giving designers better control to vary wall thickness and eliminate sink marks.

All of these allow for the creation of high-quality, aesthetically pleasing, and long-lasting plastic parts. In choosing the RIM process in manufacturing your product parts, you join a select group of industries.

Industries that Utilize the RIM Process

It’s difficult to beat results, making the RIM manufacturing process highly sought-after. In the last few years, more businesses across many industries have made the switch to the RIM process. It has resulted in high-quality, high functioning, finished products.

Automotive Industry

RIM is widely used in the automotive industry. Most car manufacturers use it to create large parts, including bumpers, quarter panels, decorative trims, and wheel arch liners.  The durability and flexibility of hardened polyurethane provide these parts with ample tensile strength and shock resistance. Some automotive brands also use RIM to create whole prototypes for testing purposes and show cars for their showroom displays.

Heavy Equipment Industry

The heavy equipment industry uses the RIM process in creating intricate parts, specifically for heaters, mobile generators, and light towers. The polyurethane solution is resistant to corrosion and other forms of wear and tear, resulting in tough and low-maintenance parts. The process is also used for B-side geometry, in-mold paint, and molded-in inserts. All of these give designers better control in building the final products. 

Healthcare Industry

Although the RIM process is largely known for its ability to create large parts, the healthcare industry utilizes it to design and manufacture intricate parts for medical devices (e.g., ophthalmic enclosures for eye examination equipment). In some cases, the RIM process is used to make whole devices, such as an electronic spray system, a DNA analyzer, and a full-body analysis machine. Polyurethane plastic is also resistant to bacteria growth, making it a hygienic alternative to other materials.   

Partner with RIM Manufacturing for Your Next Reaction Injection Molding Project

Discover the advantages of using this innovative parts manufacturing for yourself. RIM Manufacturing, LLC, has over four decades of industry experience, giving us the expertise to meet different needs. Let us help you create the parts you need for your products – whatever they may be!

Get in touch with our team to learn more about our products and services.

Manufacturing Plastic Parts: Choosing the Best Process for Your Needs

medical device 3 made from reaction injection molding

There’s a need for flexible solutions in the manufacturing industry that can accommodate varying, tight tolerance requirements. It’s critical to consistently deliver the desired dimensions, weight, density, strength, and hardness characteristics that each client or market segment demands. 

Production companies look into different processes that offer the design flexibility they need to keep their customer satisfaction rates high. Two of the popular methods in producing plastic components are injection molding and reaction injection molding

RIM Manufacturing explains the difference between the two processes and how they help you meet client demands and requirements.

Injection Molding Process

In this method, plastic resin pellets are melted, at high temperatures, into a viscous homogenous, injectable liquid. The resulting molten liquid is then fed through the injection molding machine, at very high pressure, forcing the liquid to fill hardened steel mold cavities. 

Once the mold is filled, the resin is cooled by a water cooling system. The resin becomes solid again, is now in the desired shape, and is ejected from the mold.

Reaction Injection Molding Process

Reaction injection molding (RIM) is similar to plastic injection molding, but with a few key and critical differences. RIM uses polyurethane liquids instead of plastic pellets. A liquid resin and a liquid catalyst are injected at low temperature and low pressure through a RIM dispensing machine and a mix-head, which is mounted onto a machined aluminum mold.  The use of liquid polymers allows for unique and creative design features.  Because the liquid is non-viscous flows like water into the mold, the RIM process is capable of producing small plastic parts to very large plastic parts.  As the liquid enters the mold, an exothermic reaction occurs significantly increasing the temperature of the liquid.  A chemical reaction occurs and the liquid then quickly becomes hardened plastic.  Water lines within the mold accelerate the reaction and then are used to quickly cool the parts so it can be easily removed from the mold by hand. 

Advantages of Reaction Injection Molding

The differences between the two manufacturing processes may seem inconsequential, but these give RIM many advantages. Below are some benefits of using reaction injection molding:

  • Design Flexibility

The RIM process allows adherence to tight tolerances, similar to injection molding.  However, the low viscosity of the RIM polyurethane systems allows for unique creative and design features not easily afforded by injection molding.  The RIM process utilizes low pressure and low temperature, which allows the variance of wall thickness through a part, and allows larger parts to be molded without visible flow lines.  Additionally, the RIM process allows over-molding of substrates materials like metal and aluminum which can be incorporated into parts to provide hinge or other types of connection.  In other words, the RIM process provides the opportunity to combine several parts into one part.  Furthermore, circuit boards and other types of temperature and pressure sensitive material can be over-molded because of RIM’s low temperature and low pressure processing.  

  • Weight and Durability

Large lightweight plastic parts are much easier to produce using the RIM process because it combines low-viscosity materials with lower processing temperatures and lower processing pressures. Even though parts produced may be light-weight, they are highly durable.

Automotive, aerospace, and medical device manufacturers often use reaction injection molding to produce large, durable, and lightweight parts.

  • Lower Tooling Costs

RIM molds are manufactured from aluminum as compared to injection molding, which requires hardened steel molds.  Therefore, the capital requirements are significantly less for RIM than injection molding.  And, unlike injection molding, there is little to no ongoing expenditure requirements for mold maintenance. 

The low viscosity of RIM polyurethane systems used to produce parts, as well as the low temperature and processing pressures mitigate the wear on an aluminum mold.  Whereas injection molding requires hardened steel molds because of the wear associated with using highly viscous materials at high temperatures and processing pressures.  

Trusted Reaction Injection Molding Manufacturer

RIM Manufacturing is one of the largest independently owned plants in the country, specializing in custom Reaction Injection Molding. ISO 9001:2015 and 13485:2016-certified, we are recognized industry experts who help our clients optimize the RIM processes for the benefit of their product design and utilization.

Get in touch with us today to learn more about Reaction Injection Molding.