Plastic production has become commonplace in our society. Every year, tons of plastic products are produced to meet rising demands. In 2021, Statista placed the global plastic production volume at 390.7 million metric tons and projected a four percent growth in plastic market value between 2023 and 2033. While several product owners are raking in massive profits from the production and sale of plastic products, many continue to record demoralizing losses.
We can attribute the losses to several factors, but the most prominent is poor planning and execution. We’ve all heard the dreary consequences of recklessly committing funds to a project without performing due diligence. As such, taking a proactive step to understand how to plan and execute a plastic manufacturing project for maximum returns is non-negotiable.
In this article, you’ll discover answers to the following:
● How much does injection molding cost?
● Is injection molding expensive?
● Is injection molding cheaper than 3D printing
● Key areas determining the cost of an injection molding project
● Types of injection molding techniques
● How to build a checklist for an injection molding project
How Much Does Injection Molding Cost?
Plastic injection molded parts cost as low as $0.5 and as high as $1,000, depending on the material type, grade of the machine, the expertise of the manufacturer, the volume of production, the complexity of mold, and much more. To finance a simple injection molding project, you may need at least a couple thousand dollars. Most small projects may require between $1,000 and $100,000.
A cheap hydraulic or electric injection molding machine usually ranges between $500 and $900,000 on Alibaba. Injection molding machines can be vertical or horizontal, depending on the size of products and ease of machine operation. State-of-the-art injection molding machines may even cost as much as $4,000,000 or $70,000,000. On eBay, you can purchase used molding machines for as low as $1,000.
Is Injection Molding Expensive?
Injection molding can be both cheap and expensive, depending on the details of your project. If you’re a first-timer, the start-up costs might be expensive as you’ll have to cover the mold cavities, molding machine, plastic materials, post-production equipment and machines, manpower hiring, and training costs. However, in subsequent productions, you’ll benefit from economies of scale.
Injection molds may need to be constantly changed or adjusted for different use cases. Complex molds typically cost more. Also, the type of plastic materials you work with causes increased wear and tear in your machine, so the budget for maintaining the machine regularly should be accounted for.
Is Injection Molding Cheaper
than 3D Printing?
Injection molding startup costs are more than 3D printing, but it’s only because it relies heavily on mass production even on the first trial. 3D printers, which
can cost as little as a few hundred dollars, support the procurement of single units of plastic products, hence making it easier to manage resources. However,
mass-producing 3D-printed plastic parts is expensive, particularly since the process is not as efficient as with injection molding.
On average, DIY 3D printer kits cost as low as $110 and as high as $800. State-of-the-art Industrial 3D printers may cost as much as $1,000,000. Nevertheless, many manufacturers prefer injection-molded parts as they’re stronger than 3D-printed parts because of their production process. Several manufacturers use 3D printers for rapid prototyping and injection molding machines for mass-producing the final parts.
Key Areas to Determine Cost of an Injection Molded Project
Mold Cost
A plastic mold is fabricated from a combining metal such as stainless steel, aluminum, and beryllium copper alloys using one or a combination of processes such as 3D printing CNC machining, and electric discharge (EDM). The mold is then inserted into the injection molding machine for plastic production. The price of molds depends on the size of the mold base, the number of mold cavities, and the complexity of the mold design.
Molds with two cavities and smaller part sizes cost less and vice versa. According to FocusEconomics, steel price per metric ton in the United States averaged $711 in the last quarter of 2023. Outsourcing the mold design and engineering also contributes to the cost of the project. The mold design affects the overall success of the project as such it must be designed for high tolerance and performance.
Injection Machine Cost
Injection molding machines range between a few hundred dollars and several millions of dollars, depending on the level of sophistication of the machine. Depending on the use case and volume of production, you might want to consider the types of machines available. Currently, manufacturers can choose from hydraulic, electric, or hybrid injection molding machines.
Hydraulic machines rely on a hydraulic pump to regulate pressure and temperature. They are also cheaper than the electric machines. Electric injection molding machines use high-speed servo motors to control the pressure and temperature of the machine. The size of the machine can be measured in tons. The higher the tonnage, the higher the capacity of the machine to produce larger plastic parts in size and volume. Of course, larger machines cost more.
Material Cost
Several factors affect the cost of plastic resins. According to IBISWorld, the price of plastic resins is expected to grow by 3.2% in 2023, a trend that should
continue in 2024. The average price of plastic resins in 2023 is $372 per metric ton. Since plastic resins are derived from crude oil, a surge in the price of oil will boost the prices of conventional plastic resins.
Polyethylene (PE), polypropylene (PP), styrene, Polyethylene Terephthalate (PET), and Polyvinyl Chloride (PVC) are some of the most used plastic resins for production. According to Statista, polyvinyl chloride (PVC) costs $1,115 per metric ton in 2022. As of February of 2022, the average price of polypropylene (PP) stood at $1208 per metric ton.
Plastic resins with higher properties—higher tensile strength, heat resistance, impact resistance, durability, flexibility—and are more expensive and rare to procure. Other factors such as the availability, shrinkage level, adhesive compatibility, and biocompatibility also determine their price.
Expertise
If you’re expecting your manufacturer to help you extract, refine, and convert plastic pellets into finished parts, you’re going to need a lot more than a few hundred dollars. Experienced polymer manufacturers, designers, and engineers play a huge role in boosting the success of any molding project. At every stage of the injection molding process, knowledge and competence are required.
From choosing the right resins compatible with your idea and machine capacity to designing the mold for the project to even assembling the parts, different techniques must be implemented. Although most of the steps are automated, areas such as setting up industrial machines, operating machines, maintaining or repairing industrial machines, and controlling quality attract additional costs.
Post-Production Concerns
To achieve maximum control over the product, you may need to apply post-processing and finishing touches. Post-processing and finishing touches can both boost the appearance, safety, and functionality of the plastic components. Post-processing and applying finishing touches to molded parts also hike the costs of injection molding.
Activities such as removing the parts from the machine, trimming the parts, assembling the parts, adding final designs, packaging, installing, and transporting the parts from the manufacturer to final consumers involve additional costs.
What are the Types of Plastic Injection Molding Techniques?
- Low-Pressure/Reaction Injection Molding: low-pressure or reaction injection molding involves loading the electronic parts into the cavity and injecting molten materials into the machine at a low pressure, below 240oC, before transferring it to the cooling unit to solidify under a few seconds. The type of material used and the purpose of the process are the major factors to consider here. Eco-friendly materials such as polyamides and polyolefins have high melting points and good viscosity and adhesion, as such they’re the molding compounds used for this method. Overmolding under low pressure protects the electronic parts loaded into the precision
mold from moisture, dirt, and vibration. - Micro-Injection Molding: Micro-injection molding allows you to manufacture tiny geometric plastic parts with shot weights of less than
one gram and tolerances of less than 100 microns. The process can be completed in a few steps. First, the small mold cavities are fabricated to achieve an inverse geometric pattern. Then, the liquid thermoplastic is injected into the machine to the cavity to take on the desired shape of the mold, before being transferred to the curing unit to solidify. - Gas-Assisted Injection Molding: The gas-assisted injection molding process involves injecting the melted polymer material into the
hollow-shaped mold cavity to fill the volume up to 80%. Once the liquid has covered the walls of the cavity, the nitrogen gas is injected
strategically into the mold cavity, under lower pressure than conventional molding, to fill the remaining volume and push the molten material against the walls of the cavity so they can form hollow plastic parts with unique geometries. - Water-Assisted Injection Molding: Water-assisted injection molding process is a variation of the gas-assisted injection molding process. This process involves replacing the inert gas with water. In water-assisted injection molding, when the water mixes with the molten polymer material, it creates thinner wall sections than in gas-assisted injection molding. It also has a 50% faster cooling time than gas-assisted injection molding as the thermal conductivity of water is 40 times greater than that of gas. This process leads to lesser material and tool costs.
- High-Gloss Injection Molding: In the high-gloss injection molding, the mold is heated before and during the clamping stage. Then,
the molten plastic material is injected under high temperatures and transferred into a pressurized cooling unit, which shortens the cooling time, producing glossed thermoplastic parts. This process is also known as rapid thermal cycle injection molding and is used to achieve a smooth surface on plastic products to achieve a mirror finish and boost the surface strength, hardness, and fluidity of the plastic part.
A Step-By-Step Approach to Building a Checklist for Your Next
Manufacturing Project.
Executing an injection molding project can be exciting if you’ve made a proactive step like drafting a checklist and making intentional efforts to check items off that list. If you don’t know where to start, we’ve created a checklist that eliminates the guesswork.
1. Define Project Details
Before deciding to embark on a large-scale manufacturing project, you should ascertain your ability to see the project through. Even with a brilliant product idea, you must ascertain the market viability of your idea. Ask yourself what laws support or oppose your idea. You’d be surprised to discover your answers. Find
out the short-term and long-term demand volume for your product. Injection molding projects can be worthwhile but they’re research intensive, require huge
startup funds and still come with a lot of risks.
As such, product owners must determine project details such as the proposed timeline for the project, funding options, and profit projections. Based on the outcome of the meetings with the polymer technology company, most of these details will change. However, it’s important to start with a tentative blueprint.
2. Select Plastic Material
Contact your polymer material supplier to decide on the best thermoplastic for your product use case as there are several to choose from in the market. Depending on the features you want your polymer resins to possess, you can review aspects such as tensile strength, cost per ton, ductility, impact
resistance, heat resistance, wall thickness, abrasion resistance, and durability.
Most manufacturers work with thermoplastics such as polycarbonate, polypropylene, acrylic, polyamides, polyetheretherketone, polyethylene, polystyrene, polyvinyl chloride, and polyethylene terephthalate because of their unique physical and mechanical properties.
3. Choose a Manufacturing Process
Choosing your plastic production process can be done with the help of your manufacturer. These individuals are experts in defining the grade of the injection molding machine and the process parameters for each production recycle. The type of injection molding machine you should consider should be compatible with the raw materials and mold design you’ve selected.
Other factors to consider when deciding on the plastic manufacturing process to adopt are the processing speed, dimension, energy consumption, efficiency, price, and accuracy of the mold machine. You also need to know the availability of auxiliary parts and maintenance procedures for each machine.
4. Design Mold
Tooling in injection molding refers to fabricating the mold that is used to form the plastic components during the manufacturing process. The mold is usually made from a stainless steel, aluminum, or copper metal alloy and should be classified according to the desired volume. The mold accounts for a large
percentage of the total upfront costs.
Based on the product use case, the mold must be structured to reflect the geometric properties of the product. You should consult a mold maker to establish the designs and cost implications for the mold base, mold cavities, mold core, locating rings, pins, and other auxiliary parts to achieve the desired surface
appearance, parting lines, and undercuts.
5. Adopt a Quality Management Approach
You don’t want to lose the profits on your investment because of poor quality control, do you? Adopting a proven quality management approach allows you to manufacture products that are safe, durable, and functional. Quality management bridges the gap between client specifications and final product outcomes. It allows you to reduce waste and optimize labor efficiency in production.
Quality management involves establishing and facilitating the monitoring, testing, controlling, and salvaging of the plastic parts, based on collective
principles. As such you must choose companies with quality management values that align with yours. You should work with companies that have multiple industry-standard quality certifications to prove their competence.
Final Thoughts
The best way to manage your injection molding cost is to create a detailed checklist that allows you to track your product resources and progress. Start by outsourcing your manufacturing needs to a reputable polymer technology company that offers capabilities in areas, such as research and development, prototyping, tooling, design and material engineering, product manufacturing, quality, and facilities management.
PTI.Tech offers new and experienced product owners affordable access to a competent design team, sophisticated industry molding machines and operators, an array of commodity and specialty-engineered polymer materials to select from, a holistic quality control and assurance system, and robust post-production services within a stipulated time frame to maximize your project outcome.
Stop guessing: request a quote today and bring that idea to life. We’ll provide the answers to all your questions. PTI. Tech will work with you to define your project needs and streamline the manufacturing process to allow you to cut down on unnecessary costs and production delays.