Introduction
In the competitive realm of manufacturing, finding ways to reduce costs in injection molding is crucial to maintaining profitability. While maintaining quality as a manufacturer, you can implement several strategies to cut expenses and optimize the injection moulding process. It involves an examination of each step of the moulding process, from design to final production,
Cost savings in injection molding are not just about cutting costs – it’s about smart manufacturing. It requires a strategic approach to efficiently utilize resources, optimize production cycles and minimize waste. By identifying critical areas for cost reduction, you can significantly reduce your overall expenses while producing high-quality products. In this post, we have highlighted 10 critical tips that can help you significantly reduce your manufacturing. So, if you’re excited to find out more about how to stay within your manufacturing budget, then come along on this expository journey with us.
Tip 1: Simplify Part Design
Preparing an elaborate and fully dimensioned drawing for the mould project is not always imperative. Simplifying the process can be achieved through a basic sketch accompanied by textual descriptions of each component, together with an impression of the part. This simplified approach is an initial step towards cost reduction, effectively reducing the workload and expenses associated with CAD processes.
The geometric complexity of your part is an essential factor that influences the costs of injection moulded parts. Complex geometries require greater design effort and longer production times. Furthermore, expenses related to tools and moulds increase due to their complex nature.
Furthermore, parts characterized by thicker walls imply greater material consumption, increasing their overall cost.
Optimize the manufacture of drilling templates used to shape holes in sheet metal parts through glass-reinforced plastic (GRP) laminates. Typically, a representative part is created after drilling all holes in their exact locations. This tool can be accompanied by a variety of instructions, from freehand sketches to written guidelines that specify part dimensions and quantities of drill dowels required.
Tip 2: Eliminate Unnecessary Features
Selecting the right auxiliary equipment is essential. However, it should not only meet the project requirements but it should also not be too expensive to significantly affect the production budget. It’s also important to optimize how the main machine and peripheral equipment work together so as to ensure production excellence and precision. You’ll have to ensure they operate in the right sequence, with precision, and specification. Additionally, position the peripheral equipment as close to the main machine as possible without affecting operations adversely.
Luckily, some auxiliary equipment manufacturers offer power supply systems tailored to your needs helping you meet your peculiar project needs and solving your manufacturing challenges. These systems can save a lot of energy. Another way to improve efficiency is by using quick mould change equipment. This reduces the waiting time for product changes during production.
Tip 3: Optimize Cosmetics for Functionality
It’s a known fact that the beauty and aesthetics of products are the first things that attract a potential buyer or end user. However, improving the aesthetic characteristics of moulded parts often means resorting to embossing, EDM or high mould polishing in order to achieve the desired level of finish.
This leads to an inevitable increase in processing costs which can often be significant depending on the level of finish desired by the client. For example, finishes higher than PM-F0 (milled) require a certain degree of manual processing, with an amount that gradually increases up to the SPI-A2 to get a mirror finish. It is therefore better to avoid complex finishes like these if they are not strictly necessary especially where part function is more critical for the end user than the aesthetics. Still, when referring to aesthetics, it is advisable to communicate with your injection moulding partner whether you wish to subject the entire piece to polishing or just a small part. In fact, it is possible to reduce processing costs by limiting polishing to the desired area instead of applying it to the entire surface of the mould.
In most cases, you only need to send a colour-coded image in your request to your moulding partner for a custom finish. This request often clearly indicates critical areas and the desired level of finish for each part.
Tip 4: Consider Mould Modifications Carefully
Removing metal from a metal mould is quite easy. However, adding metal can be difficult or, for all intents and purposes, impossible with rapid injection moulding. Let’s consider the question from the point of view of the piece: it is possible to add plastic but it is impossible to remove it. Projects created taking this principle into account are described as averse to metal tools.
Some injection moulded parts require several iterations before the final design is achieved. But instead of purchasing a new mould to use for each change, a little smart planning and modifications to the old mould will allow you to reuse the same mould multiple times.
Start with the smallest, most basic piece and produce it in the quantities you need. Then, create a new mould to introduce the desired details or a larger or taller version of the same piece. While continuing with this iteration, you can proceed to mould further higher and bigger units without having to break the banks. This is certainly not an exact science. But, if employed correctly, this approach will allow you to reduce mould production costs.
Tip 5: Conduct Moldability-DFM (Design for Manufacturability) Analysis
Every injection moulding service should come with a Moldability-DFM (Design for Manufacturability) Analysis. This analysis allows you to highlight any problem areas alongside possible opportunities for improving the project.
For instance, insufficient draft angles, difficult details, or impossible geometries are just a few examples of things that can and should be corrected before giving the final approval before embarking on the production.
Thankfully, moldability gives the assurance required to proceed with manufacturing as it ensures that all parameters that can impact the production have been scrutinized and confirmed satisfactory. We recommend that you review these suggestions carefully and contact your injection moulding partner for assistance during the design.
Tip 6: Optimize Part Size and Weight
Consideration of the maximum dimensions of a piece is crucial in the moulding process. It involves ensuring that the piece’s size is appropriate for the mould, taking into account elements like cones, casting channels, ejector pins, and others essential for proper functionality. Some manufacturers allow a maximum dimension for injection moulding at 480mm x 751mm, with a maximum depth of 101mm. However, creating larger parts necessitates larger moulds, potentially impacting manufacturing costs.
One other key strategy to reduce the size and volume of your part is minimizing its wall thickness. This not only conserves material but also significantly accelerates the injection moulding cycle. For instance, reducing wall thickness from 3 mm to 2 mm can cut cycle time by 50% to 75%.
Essentially, thinner walls enable quicker mould filling, and more importantly, they cool and harden faster. Considering that almost half of the injection moulding cycle involves waiting for the part to solidify, this time-saving aspect is crucial to making significant cost savings. However, striking a balance is essential- you don’t want to compromise the part’s rigidity, which could affect its mechanical performance. To maintain rigidity, consider strategically adding ribs in specific areas.
Tip 7: Select the Right Material
Different plastic resins have distinct attributes that significantly influence the potential for reducing injection moulding expenses. Some resins are designed for high-volume applications, while others respond to low-volume manufacturing needs. Another way to reduce costs involves incorporating recycled plastics into your moulds, which can bring more financial benefits.
The key to reducing injection moulding costs is the careful choice of materials that have lower energy consumption during the melting and cooling phases. This is especially pertinent when dealing with multi-colour processes or complex mould structures.
For example, if you are using rigid PVC material characterized by thick walls – resulting in higher energy consumption, consider transitioning to alternative materials such as ABS or PP (polypropylene). Both options have thinner walls, thus minimizing energy needs during the heating and cooling phases.
Still, using the wrong material can lead to anomalies and defects that constitute reworks and associated costs. These costs can be significant especially if the parts affected are many.
Tip 8: Use Multi-Cavity Moulds
To minimize waste and save money in the long run, it is often advisable to design durable products and streamline production processes. For instance, if multiple identical parts are needed, you should consider using a multi-cavity mould instead of a single-cavity mould as this reduces the loading and unloading time of moulds when switching between parts.
It’s also common practice to use a single mould for multiple parts. Usually, you can accommodate six to eight small identical parts in one mould, which slashes production time by about 80%. Moreover, you can place parts with different shapes in the same mould, like those in model aeroplane kits. This approach helps lower assembly costs and increase the volume of production in a short time, especially in large-volume production.
In some cases, two assembly parts share the same main body. By incorporating a creative design element, you can establish interlocking points or hinges at symmetrical positions, essentially creating a mirrored piece. This enables you to utilize one mould for both parts, effectively halving tooling expenses.
Tip 9: Automate Where Possible
With the 4.0 industrial revolution gradually taking over the injection moulding industry, enhancing the production process with things like automation can help make significant cost savings. Automating the injection moulding process can provide cost savings in several ways. Firstly, it allows you to produce more parts with less labour – which means lower personnel and salary costs. This allows manufacturers to channel their best hands to do more intelligent and productive work leaving repetitive tasks to robotic tools to perform automatically.
Additionally, automation increases efficiency by reducing cycle times. This means less downtime between cycles, saving on labour and materials where more can be done in very short periods. Also, it reduces the possibility of errors that are often associated with human-supervised activities which often lead to reworks or more post-production cleaning that slows down the work significantly. These reworks often come at a cost.
Ultimately, automation reduces the risk of employee injuries due to repetitive tasks. Although initially expensive, automation can improve the bottom line in the long run especially where high-volume production is involved.
Tip 10: Maintain Moulds Properly
Mould maintenance plays a crucial role in cutting down injection moulding costs. Moreover, keeping moulds well-maintained helps minimize defects and enhance part quality.
Additionally, it’s essential to ensure that equipment undergoes proper maintenance to keep it in good working order. Especially when there are auxiliary attachments that are appended to the machine, ensuring that these attached elements remain functional through periodic maintenance routines. Faulty auxiliary equipment can lead to unstable production or even lower part quality, which ultimately increases energy consumption.
Some tips for mould maintenance involve regular cleaning, inspecting for wear, and promptly repairing any damages. Also, replace any worn-out parts as quickly as possible to avoid any delay in production. This delay often costs a lot of money in unproductive time, machines, and personnel.
Again, you want to ensure that other parts that need periodic calibration are calibrated as of when due. This activity is crucial to maintaining quality as well as keeping the connection between components error-free. This way, you’ll be able to avoid downtime resulting in unforeseen breakdowns as a result of lack of maintenance of error from uncalibrated elements.
Conclusion
You will need to understand the intricacies involved in successfully managing the multifaceted cost elements often encountered in injection moulding to have success with manufacturing. As exemplified in this post, we’ve not been hesitant about sharing the cost components that accompany the injection moulding process ranging from material selection to mould manufacturing.
However, it is evident that the mould itself is a major component of expense management in this injection moulding journey, especially with its design and manufacturing costs influenced by complexity and size. Nevertheless, selecting your material judiciously can prove crucial including balancing the cost and performance as a key objective of the project. Still, you need to consider the efficient use of the equipment and labour. Their roles in cost management are equally essential.
In the end, a comprehensive grasp of the injection moulding cost element is crucial for cost-effective and efficient manufacturing. This is realistic considering that a meticulous analysis of each cost element often leads to significant cost savings.
