Key Questions to Ask When Ordering precision mold parts

What questions should I ask before buying injection molds?

1. What is the molder&#;s expertise?
2. What standards do they follow?
3. How long will it take to build?
4. How much will the initial mold build cost?
5. Where am I in product development?
6. What is the part&#;s geometry, material, and size like?
7. How many plastic parts does it need to make?
8. Do they guarantee the molds for the life of the project?

You&#;re finally satisfied with your plastic part design, it&#;s now time to consider mold selection so you can start production. But, picking the right mold maker and designing the right mold is less straightforward than you expect &#; you might even find yourself presented with a laundry list of new decisions to make.

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Even more confusing, you might have molding project proposals from several injection molders, all with varying designs, costs, and more. So how do you make the right selection for your project?

To help you, here are the best questions to ask before buying molds in the US:

What is the molder&#;s expertise?

Most of the injection molders that you can find in the US will have their areas of expertise. It&#;s important to ask prospective parts what they are &#; their answer will help you determine whether they have the experience and know-how they need to make the best mold for your application.

You could also check their website or ask them directly for their portfolio, equipment list, and reputation. What you will see is a testimony of the quality and stability of their services and products. Try also asking for a few of their client references, specifically those who work in the same field as you do. Doing this will help you see if this injection molding partner can meet the specific requirements of your industry.

What standards do they follow?

Ideally, the injection molding partner you choose should follow industry standards.

The most important ones include ISO : for product quality and consistency and ISO : for environmental impact. Another industry standard to look out for is IATF, which shows that the injection molding company works on continual improvement, defect prevention, and reduction of errors in its services.

If your injection molder is adhering to all of the above standards &#; like Richfields does &#; then you can rest assured that the mold maker will go above and beyond the necessary quality requirements.

How long will it take to build?

Building a new mold is one of the longest tasks in any production project. While some molds can take just a couple of weeks to design and make, some may take several months. It&#;s important to present your part design and ask your potential partner what the lead time will be for your mold so you can adjust your production schedule accordingly.

If your part design still needs some tweaking, you can ask for a prototype mold to be made instead, which usually takes around 3 to 6 weeks to make. If you&#;re ready for full production, then your mold may take upwards of 12 weeks to make.

What&#;s important here is that your molding partner has a clear idea of what to make and how much time they need to make it. If they can offer intermediary solutions to help with long lead times, then this is a benefit to your production.

How much will the initial mold build cost?

With mold-making services in the US ranging in the thousands, you must get a quote early on to see if it aligns with your production budget. Several factors impact the cost of your mold, including mold classification, design complexity, mold cavitation, and specialty molding designs.

For example, prototype molds tend to be much cheaper than a final mold. And, having a specialized design, such as a multi-cavity mold, can also increase initial build costs.

Be upfront about what you want and need for your molds, so your potential partners will know what goes into your mold building price. And great mold maker, like Richfields, will help you find ways to make your design more cost-effective &#; getting you the most bang for your buck.

Where am I in product development?

Where you are in your product development process is a critical factor in how your mold is made. In the early stages of prototyping and pre-production, you can typically expect a lower construction quality mold &#; because they are made to make short runs of your prototype, and make it more cost-effective for several design iterations.

If you&#;re later in the development stages, then you can request a better-built, sturdier mold that is production-ready. Be careful about selecting your molds &#; make sure it&#;s suitable for where you are in your product development process to avoid spending more money on new molds and mold repairs over time.

What is the part&#;s geometry, material, and size like?

Depending on what geometries, features, and size you need for your plastic parts, your potential mold-making partners may need to use different mold-making approaches. Some designs will need molds made using hardened steel, or steel inserts, rather than softer metals like aluminum.

The material you&#;re planning to use for your plastic parts will also play a role in how the mold is designed and made. Some resins are incompatible with certain mold materials. For example, plastics like nylon will need a higher quality mold to fit part specifications.

Richfield&#;s molding engineers can help you examine all your part&#;s specifications to determine what kind of mold best suits your needs. Our team will also examine overall functionality to help in the mold design process &#; taking into consideration other features like snap fits, breakaways, and more to design the right mold.

How many plastic parts does it need to make?

You&#;ll also want to consider the minimum production requirements. How many parts does your mold need to make? Will you have a short production run of only a few hundred parts, or are you aiming for mass production that creates up to a million of them?

If you only need a few parts, then you could probably go for a cheaper mold made from less sturdy materials, like aluminum. But, large volume runs will probably necessitate the use of things like hardened steel inserts, which cost more but helps in meeting your production needs.

Do they guarantee the molds for the life of the project?

For more information, please visit Yihua Mould.

Finally, ask if your mold-making partner guarantees the lifespan of their molds. If they do, then your molds should be able to meet your production requirements with minimal risk of error or breakage. If the molder seems confident that their molds can stand up to your strict requirements, it&#;s a good sign that they will be fit for your application &#; and less likely to need adjustments or repairs.

Key Takeaway

If you are considering which plastic mold maker to work with, then use these eight questions to ask before buying molds in the US to help guide you to the right partner.

At Richfields, we can help you create the best molds for your application &#; no matter how complex or detailed your designs may be. Contact us today to learn more about how we can assist you with your next plastic project.

Sensors and molds

Five questions to answer before you instrument a mold:

1. What do you want the sensor to do for you?

This is the most critical question to ask yourself before installing sensors in your mold. But most people stall right here because they&#;re not sure what functions a sensor can perform. A lot of people just want to instrument a tool because they&#;ve heard they should run DECOUPLED MOLDING® processes, or they want to try out process control software. Others are curious about the ability to collect data, track a part to a molding cycle, resolve ongoing challenges, or create a template to maintain or transfer processes. Whatever the answer, this single question needs one before proceeding so you can make decisions to work toward your goal moving forward.

Once you answer that question, you can begin to explore the many different functions sensors can serve if used correctly. Some examples are: monitoring pressure at a specific area in the cavity, transferring the injection portion of the cycle to hold via pressure or temperature, detecting mold defection, sequencing valves gates, sorting, and the list goes on. Once you know what you want the sensor to achieve, you have some important decisions to make.

2. Where do you want to install the sensor?

Now to install it. Conventional installation techniques to consider include post gate, mid-cavity, and end of fill, but there are more less common locations in addition to these. You may need one or a combination of these techniques, depending on your particular project. In some cases, it&#;s not necessary to sensor every cavity.

The Benefits of Each Sensor Location

Post gate sensors allow you to know the moment plastic enters the cavity and at what pressure. With this information, you can perform various studies, including pressure loss (from the nozzle to the gate), pack rate, and gate seal (pressure lost when the hold pressure is released). Also, post gate sensors are often the location of choice when transferring off cavity pressure. Still, other locations can work as well, depending on your machine and percentage of barrel usage.

Mid-cavity sensors can also aid in performing calculations like determining pressure lost through the cavity and cavity deflection. Also, they can help with timing the firing pattern of valve gates on larger parts, like car panels, where manifolds are being implemented. Used in this application, sensors can help with moving knit lines or reducing the flow length ratio. Mid-cavity sensors are also a good option for very small parts, as they can typically represent an average pressure in the cavity.

End-of-fill sensors can also be used in calculations but add an additional beneficial attribute: monitoring the pressure required to fill your part. Short shots have always been an issue in the injection molding industry. If used in conjunction with a post gate sensor, you can see the pressure lost through the cavity and observe the cooling behavior of the plastic, which is critical in semi-crystalline polymers.

Temperature sensors can be used to detect the time at which the flow front passes over a particular area in the cavity and the surface temperature of the plastic or steel. You can then use this telemetry to fire valve pins or adjust accordingly.

Knowing some of the different functions of instrumenting a tool will significantly aid in deciding what sensor type and location you&#;ll need to achieve your goal.

3. What Type of Sensor Technology Do You Need?

Once you determine what you want to achieve and where you need to place your sensors, then the next step is to determine what type of sensor technology to use. There are several factors to take into consideration, including available real-estate in the tool and cost. The two pressure sensor options we offer are Strain Gage and Piezoelectric. Strain Gage sensors generally are more cost-effective, require less maintenance, and have less noise but require more space.

4. How Should You Install the Sensor?

The most common installation styles for pressure sensors are direct and in-direct. Direct is when the sensor comes in contact with the plastic, sometimes called flush mount. In-direct is when the sensor is mounted away from the area of interest, and the pressure is transferred to the sensor via transfer pin, static pin, or ejector sleeve.

After decades of sensor installs, customer feedback, and testing, we firmly believe that mounting the sensor in the clamping plate and utilizing a transfer pin to transfer the pressure is the most robust configuration. Some of the benefits include:

• Mitigating the chances of damaging the sensor due to the tool&#;s action or while it is serviced on the bench
• Ease of accessibility
• Minimizing heat exposer to the sensor
• Improving the sensor&#;s life by removing it from the movement and shock of the ejector plate

5. What Load Capacity Do You Need?

Next, we move towards determining the load capacity of the sensor. The load capacity is determined by the predicted force that will be exerted on the sensor. You can make this determination in several ways, the preferred method being a flow simulation with predictions of the pressure in your chosen area. If this is not available, you can resort to the material datasheet, which frequently gives a pressure or tonnage factor. This gives you the recommended pressure per square inch required within the cavity to mold that particular resin properly.

If the tool under consideration for sensoring is already built and simulations are not a luxury you have, you can perform a Short Shot Study. To do this, you fill the part gradually at your preferred linear speed or volumetric flow rate and observe the filling pattern. Determining Post Gate (PG) is fairly straight forward, however determining Mid-Cavity and End of Fill (EOF) can be a little trickier depending on the material, flow rate, and geometry. The key is to not make too many assumptions without supporting your decisions with actual data.

A Real-World Example

Let&#;s imagine for a minute that you want a cavity pressure sensor for your tool. Let&#;s run through each question to create an implementation plan.

1. What do you want the sensor to do for you? The goal is to ensure you hit a particular cavity pressure on each cycle, eliminate part variation, and sort out suspect parts.

2. Where do you want to install the sensor? Your parts are very small in size, so a mid-cavity sensor would be sufficient in representing the average cavity pressure.

3. What type of sensor technology do you need? Because there is limited real estate, you opt for the piezo option.

4. How should you install the sensor? You choose to go with a flush-mount installation because the simplicity and minimal hardware requirements offer a small footprint in your limited space.

5. What load capacity do you need? The plastic flow simulation software provided data showing where the plastic would flow and that the recommended sensor capacity in your mold is ppsi.

The Key Takeaway

Putting a sensor anywhere in a tool can give you some form of data, but it may not be value-added. The key is knowing upfront what you want the sensor to do for you.

For more precision mold partsinformation, please contact us. We will provide professional answers.