Cindre

Our 25-Day Mold Making Timeline – Mold for Injection Molding Machines

Summary

Elevate your manufacturing process and leverage our efficient, high-quality molds and plastic injected parts.

Our moldmaking program is the very fiber of our company and uses a meticulous timeline, ensuring precision from client consultation to final approval and mass producing that’s within the customer’s budget, which of course is in the customer’s best interest.

Let’s talk about the logical steps of the mold-making process of metal molds [or a die] we use:

The phases in the manufacture of a plastic mold for injecting plastic generally can be roughly summed up in steps below:

  • Order confirmation
  • Project kick-off
  • Learn of the customers’ standard specifications and needs
  • Manufacturability analysis
  • Engineering of mold
  • Customer mold design solution approval
  • Mold production, including etching or laser texturing 
  • Inspection and reports for quality control and quality assurance
  • Send sample parts to customer
  • Feedback from customer
  • Bring about adjustments to mold if necessary
  • Approval from customers to ship mold or start production of parts

In this article, we will detail how we reconcile the mold production with our commitment to use our 25 Day Mold Production Timeline to take a product from desktop to market. 

Day 1-2: Initiating Precision

A manufacturing master plan is essential for outlining the expectations, development timeline, and budget of a project, so the journey begins with a thorough consultation to confirm part specifications and to confirm any special issues identified match our capabilities.

Whether you are creating a custom model prototype or planning to mass-produce thousands of the same item using a multi-cavity mold will determine the steps to a successful outcome. The development criteria  are specific to each item, but typically include aspects such as part configuration, size, material, quality, tolerances, timeline, production volume, and cost constraints.

The initial analysis and the resulting mold-design delineates the dimensions, and specifications of your plastic molded part. Knowing the size of the steel block is crucial so that the supplier can order and ship the steel in time for the completion of the tool design. In this step, we also decide how the item will be oriented when it’s being molded.

Using CAD software on Day 2, a preliminary mold layout takes shape. Specialized flow software predicts potential issues during the plastic molding process.

Day 3: Fine-Tuning Design

The design for manufacturing (DFM) stage plays a crucial role in the traditional moldmaking process. In this phase, an injection molding specialist collaborates with your team and product designers as needed, to ensure the product is ready for manufacturing. Expertise in understanding potential risks, product appearance, and user interaction is essential in professional mold design. 

Any identified issues are discussed with the client, adjustments are effected, and the mold design is finalized.

If there are changes to the product, and your plastic product is complex, it may be useful to prototype it using 3d printing [again] to be sure the product continues to be developed correctly.  In this situation, it is advisable to seek advice from the manufacturer. They are experts in the manufacturing process, and can help you choose the appropriate option and suppliers for prototyping. 

Day 4: Materialization

The mold material is carefully chosen based on the part’s requirements.

Once the mold development is completed and the CNC programming is advancing, it is now necessary to begin prepping other materials. If you are collaborating with Cindre, by this stage, the steel orders required for the core and cavity inserts of the mold base would have already been placed and usually arrive within a few days.

The appropriate manufacturing method and material for a specific component or series of components heavily relies on the item’s specifications. There are instances where various manufacturing techniques can be employed to fabricate a particular design. Generally, we opt for the method that can yield the desired part quality, at the most cost-effective rate, that meets the performance needs.

Material selection and product volume are likely also key influencers in determining the choice on how to make the best investment and achieve innovation. 

Day 5: Material Procurement

Selected materials are procured from trusted suppliers.

Every plastic molded component needs a custom mold or tool, typically constructed of aluminum or steel, specifically tailored for your product. It is essential to choose the appropriate mold to ensure the success of your project in both the short and long term.

Upon the steel’s arrival, the initial process involves preparing the steel for machining the form. The steel blocks must be squared off to ensure all edges are perpendicular and have a smooth surface before CNC equipment machining can commence. This preparation stage can span 2-3 days and is a important step before moving forward with the manufacturing process by our skilled machinists.

Your mold is what goes inside the injection molding machine to create your part. It is one of the largest upfront costs in the plastic molding process.

Our factory has reliable suppliers to ensure the latest and most reliable materials available to ensure a durable tool for the long term.  To complete the list of mold materials, the next task is to acquire all necessary standardized components, such as screws, nuts, and bolts, as well as any other items  that are still needed.

This is also the moment to purchase the plastic material

Day 6 and 7: Raw Material Preparation

Preparation of raw material involves meticulous cleaning, pre-treatment, and defect checks.

At this stage, it is wise to be sure core and cavity inserts are the precise sizes required, as opposed to the alternative of grinding them down to fit correctly, which can be time-consuming. Doing adjustments like these can be time-consuming and may cause delays, especially if you are working on a tight development schedule.

After completing the CNC programming, it is necessary to procure the copper material needed for any electrical discharge machining (EDM) as per the design specifications. This copper will be used to create the electrodes for sinker EDM elements.

Day 8: Mold Base preparing

This component surrounds the core and cavity sections of the mold and serves to withstand the pressure during the molding process. Typically, the mold base is crafted from a less durable steel compared to the core and cavity parts, as it is more cost-effective than the harder steel utilized for those components.

Additionally, speaking of mold bases, let’s discuss the interchangeable type. Mold bases are often manufactured in standard dimensions that can accommodate various mold cores and cavities. Using a mold base from previous projects can save time and labor that would have been spent creating a new one.  While some minor adjustments may be necessary, using an interchangeable base ultimately results in significant time savings.

Day 8-9: Precision Machining

CNC machines sculpt the mold’s cavity, core, and other components with precision.

The prepared steel blocks are used to machine the core and cavity, beginning with rough CNC machining using larger cutting tools to create a general shape. In the past, some manufacturers used cheaper, less precise machines for this initial rough machining before transferring the inserts to a high-precision machine.
However, with advancements in CNC technology, machines have become more accurate and cost-effective, rendering the cost savings of using separate machines for rough and finishing cuts negligible in recent years.
Our manufacturing partners streamline the process by combining rough and fine machining in a single step on the same machine, allowing them to produce the cavity, core, and lifter/sliders within just a few days.
Following CNC machining to refine the mold components, additional adjustments are done to the geometry using electrical discharge machining (EDM) to achieve specific shapes that are unattainable with a CNC mill. Wire EDM, for example, is utilized for cutting gear teeth with sharp internal corners and square holes. The cavity, core, lifters, sliders, and inserts then undergo sinker EDM which uses machined copper electrodes to create extremely fine details such as text or internal features that are challenging or impossible to achieve with a CNC machine.
The copper blocks are machined concurrently with the steel blocks to ensure that the EDM electrodes are ready for use as soon as the mold is completed.

Day 10: Seamless Assembly

Lastly, it is time to assemble the mold by combining the mold core and cavity, along with any sliders, lifters, or inserts, and securing them with nuts and bolts.

The assembly process typically takes place within the same 24-hour time frame as precision grinding, mold fitting, and polishing. The core and cavity, the two halves of the mold, are assembled with precision to ensure perfect alignment and prevent flash or mismatched parting lines.

Additionally, If necessary,  precision grinding is performed on the mold components to guarantee a proper fit and meet the strict tolerances necessary.

Various mold components are assembled with a keen eye on perfect alignment

Once the components fit correctly, the next step is to apply the appropriate finish to the mold. This often involves buffing it to a specified level of smoothness or incorporating different textures as needed. Regardless of whether a polished surface is the desired outcome, some polishing is always necessary to eliminate machining marks and create a smooth surface for texture application.

Once the mold cavity, core, and other parts have been machined, it’s time to move onto the final touches, so we can actually manufacture some parts!

 

Day 11: Efficient Cooling Implementation

Cooling systems, like water channels, are integrated for uniform cooling during injection molding.

The cooling system is essential not only for maintaining low temperatures but also for maximizing cooling efficiency across the entire manufacturing process.
 Effective cooling promotes consistent solidification and reduces the risk of distortion, warping, and internal stress in the different molded plastic components.

There are two conventional cooling methods: air cooling and water cooling:

• Air-cooled molds are not frequently used due to the lengthy process of dissipating heat from the mold to the surrounding air, resulting in slow cooling. Keeping the injection molding machine and mold environment cold can increase the amount of heat released into the air, potentially leading to higher operational costs for cooling.
• Fluid cooling molds is the predominant method of cooling, commonly using mixtures of glycol and water. Water effectively removes heat from the mold as it circulates through it, while glycol helps prevent corrosion in the mold’s cooling system and maintains a consistent temperature during production.

The amount of time it takes to cool directly affects the overall cycle time, with a shorter cooling period being more beneficial. Engineers focus on achieving the ideal equilibrium between cooling time and cycle time to enhance productivity while upholding quality standards.

Day 12: Preliminary Testing

A preliminary test ensures functionality and alignment.

The mold trial phase is crucial to guarantee that a mold is capable of generating approved products, functioning effectively in typical production scenarios, and fulfilling the designated longevity and production standards. It establishes benchmarks for product excellence, mold design, and molding process necessities.

Familiarity with these benchmarks enables evaluation of the mold’s quality, and education in the mold trial phase and its essential factors is gained through training.

Other important factors that should be measured and considered are:

It is crucial for a mold trial and production to have efficient and reliable mechanisms for ejecting the mold, resetting, pulling the core, and retrieving the part.
The gate system is crucial during mold trials, directing molten material accurately into mold cavities. A well-designed gate system is key for high-quality products, less waste, and faster production cycles. 
It is essential to maintain accuracy and quality in the molding components, parting surface, and exhaust grooves to achieve a clean mold trial. These components play a key role in determining the quality, appearance, and functionality of the final product.

Day 13-15: Surface Treatment

Polishing and treatment enhance part release, aesthetics, and mold durability.

To enhance the attractiveness and functionality of an injection molded part, it may be necessary to apply some surface finishing techniques. The two most commonly used surfaces in the industry are SPI and VDI, however, laser texturing can greatly enhance a product by creating all kinds of textures..

The majority of molds are crafted from aluminum and/or steel, and any imperfection in the mold surfaces will be replicated in the molded part. The marks created by the end mills during machining will show up on the molded part unless they are eliminated through bead blasting or polishing. Oftentimes, the tooling marks can be left on the mold, especially on the inner surface that is not visible, without affecting the function or appearance of the part.

Most molds are completed to some extent, however, the greater the need for polishing, the more expensive the mold tooling will be and the longer it will take to complete the mold.

The appearance of molded parts is greatly influenced by the color and hardness of the material used.

For instance, tougher materials tend to highlight textures more than softer ones. In the case of polycarbonate, the difference between an F1 surface finish and a B1 is more noticeable compared to a part created of TPV. Dark colors tend to accentuate textures more than lighter colors, regardless of the hardness of the part.

The presence of fillers also affects the overall texture of a part.

Day 16-18: Quality Assurance & Refinements

Stringent tests identify defects, misalignments, or issues. Necessary refinements are done, culminating in a final quality check.

Ensuring quality in the plastics manufacturing industry requires efficient inspection processes. Inspecting can be challenging and consume time, underscoring the need for a well-thought-out approach. It is the job of your plastic molding partner to consider each aspect before green-lighting the mold for the next steps. The following list are some key elements to consider in this step:
  • Injection Pressure
  • Stability And Repeatability
  • Injection Speed
  • Holding Pressure
  • Clamping Force
  • Product And Sprue Removal
  • Inserted Parts In Molds

During this phase, the manufacturer oversees the production process to guarantee compliance with the established quality goals.

Quality control and Refinements includes the following tasks:

a. Supervising the production process to confirm adherence to the quality criteria established at the planning phase.
b. Gathering information to assess the quality of the products and the efficiency of the production process.
c. Examining the data to detect patterns and trends in the production process.
d. Pinpointing areas of the production process that need enhancement.
e. Enacting corrective measures to enhance the production process.
f. Recognizing aspects of the manufacturing process that need enhancement.
g. Creating plans for improvement that detail the necessary actions to solve the identified issues.
h. Putting the improvement plans into action.
i. Assessing the efficacy of the improvement plans.
j. Consistently overseeing and enhancing the production process.

Day 19-21: Machine Integration (Mounting the Mold)

The mold is installed, machine settings are calibrated, and test cycles are run without injecting plastic. Ensuring that a machine performs at its best and lasts a long time is crucial for its success and longevity. When setting up your machine, it is important to prioritize having a clean, well-ventilated, and well-lit area – these are critical factors that will help you make informed choices to get the most out of it!
Some factors to consider before installing a mold include:
  • Choosing an Ideal Location: Cleanliness and Ventilation
  • Sufficient Space for Machine, Materials, and Products
  • Ensuring Floor Stability
  • Prioritizing Electrical Safety
  • Hydraulic Systems and Additional Needs
  • Thorough Cleaning for Impeccable Results
  • Safety precautions

To ensure smooth integration into the machine’s tie bar spacing and to withstand clamping force effectively, it is essential to have a high level of strength. For optimal performance, it is crucial to have efficient and timely mold design and installation of high quality. After being placed into the machine it is meant for, it is important to be sure it is properly secured and aligned for maximum efficiency in production.

Before starting the actual production process, operators need to run multiple test cycles on their machines. This will allow them to evaluate performance against expected standards and identify any issues with parameters that may hinder optimal performance.

Day 22: Sample Production

Sample parts are produced, setting the stage for meticulous inspection.

Even the smallest imperfection can lead to significant ramifications. Additionally, most projects span across multiple years. To prevent defects over time, it is essential to catalog and keep all tools for their designated usage period. This involves saving parts from each production run to guarantee they match the quality of the initial batch.

The production process typically begins with a trial run of around 100 parts, which are sent to customers for final approval. This crucial step helps to minimize risks before moving on to higher volume production. If any issues with quality or defects are identified, they can be promptly resolved. In order to maintain uniformity over time, the approved samples are stored with the mold.

This way, when a customer requests more parts from the same tool, the press operator can refer to an approved sample to adjust the molding parameters accurately.

Day 23: Rigorous Inspection

Parts are scrutinized for accuracy, dimensions, aesthetics, and functionality.

Day 24: Adjustment and Perfection

Necessary adjustments to machine settings or the mold are made based on the sample review.

Aside from evaluating the size and appearance of the sample, it is crucial to conduct a comprehensive verification of the entire assembly. Prior to conducting a mold trial, be sure all assembly components are present. This thorough assembly inspection provides valuable information on any assembly problems with the trial product. It also helps in identifying and addressing current assembly issues, ultimately streamlining the process and saving time.

Before proceeding with large-scale production, be sure that:

  • All issues that were identified have been resolved, and the mold is now capable of producing a specified quantity (e.g., 5000 units) without any problems on the designated machine.
  • Identify the components of the mold that are prone to wear and request spare parts from the mold workshop to prevent any interruptions in production.
  • Apply anti-rust paint to the exposed parts of the mold and properly label it.
  • Ensure that the product’s surface is defect-free, with no issues such as short shots, burns, whitening, flow marks, burrs, bubbles, weld lines, shrinkage, or snake-like patterns.

Day 25: Client Approval & Production Green Light

Once everything is in place, you can now proceed with the manufacturing of your component. Your mold will be set up in an injection molding machine to begin producing the parts. Following the production of the parts, you will collaborate with your designated manufacturer to address any assembly, packaging, and shipping parameters.

At this phase, you will also receive detailed quality specifications for your component, such as first inspection reports (which include the dimensions and details of the initial manufactured parts) and additional quality criteria tailored to your specific needs. Depending on the quantity of parts required, you can expect shipments to commence shortly after your production process begins.

Sample parts are presented to the client for review and approval. Upon the client’s nod, the mold is primed for full-scale production.

This logical timeline offers a glimpse into the precision and dedication that define our mold production process. Note: Timelines may vary based on project complexity and material specifics.

Tips for when creating a mold for plastic moulding

To achieve the shortest production time, keep in mind these three important tactics:

  • Obtain design for manufacturability (DFM) advice from your supplier earlier at the beginning
  • Make sure your supplier simultaneously works on different aspects of the mold in parallel
  • Use interchangeable mold bases, they’re time and money savers

Additional aspects to consider

A standard delivery time for a prototype mold with a single cavity usually ranges from 3 to 4 weeks.

 

This time frame is appropriate for a low quantity of 450 to 1000 samples, with a basic cooling system, and a few simple ejector pins.

 

In contrast, molds with multiple cavities or more intricate designs may require between 1 to 6 months for completion. These advanced molds are typically used for high production volumes ranging from 100,000 to 1,000,000 plastic molded parts. They also feature multiple cooling channels, various actions such as slide cams and lifters, and a sophisticated ejection mechanism.

 

Additional delays may also be caused by factors such as the type of feed system, which includes features like multiple nozzle hot manifold, high surface finish, and strict dimensional requirements. Acquiring specialized components like hot runner systems and imported accessories can further extend the project timeline.

 

It is important to consider that molds for low-volume production typically employ softer metals (unless specified otherwise by the client) that can be cast before undergoing CNC milling. In contrast, molds for high-volume production require the use of extremely hard steels, which are machined using CNC machining and spark erosion techniques. Spark erosion involves using electric sparks to shape steel inserts, which can be a costly and time-consuming process.

 

Although injection molding is known for being highly efficient and economical for creating plastic parts, it does require a certain amount of time. The duration of each step in the process can vary, so it is important to collaborate with your manufacturer to establish a timeline that aligns with your requirements and helps manage expectations.

8 hours – 70 hours

Irrespective of the design of your product, a certain level of design for manufacturing must be undertaken before a mold can be constructed to produce it. This process may involve a minimal amount of design and engineering work, or it could require more than 60 hours of design revisions, depending on the complexity of the design and its intended use.

2 weeks – 10+ weeks

The main factors that affect the time it takes to build your tool are the complexity of the part, the number of cavities in the mold, and the type of material used for the mold.

Less complex molds made of aluminum with a single cavity can be completed in as little as two weeks, whereas highly intricate molds made of hardened steel with multiple cavities can take several months to complete.

Asking about the cost of injection molding is like inquiring about the price of purchasing a home – it varies.

There are different cost factors to consider to help you budget for the expense. These costs will differ based on the specific details of your part and project, so collaborating with a reliable contract manufacturer can give you a clearer picture of your overall expenses.

$180 – $270 / hour

The costs for this stage of product development can vary significantly depending on when you involve your manufacturer and how advanced you are in the design process. It is crucial to budget at least $1,000 for this phase before moving on to mold production, but expenses could potentially reach tens of thousands of dollars.

$2,000 – $100,000s

The most surprising expense for scouting entrepreneurs and business owners is typically the cost of creating a mold.
Each mold is specifically designed and crafted for your particular part, using either aluminum or steel. This expense is often the most significant initial cost for many business owners, so it is crucial to be ready for it.

Basic aluminum molds for small parts start at a minimum of $5,000 and the cost increases with the size and complexity of the part. Aluminum molds are often used as initial tools in production to quickly produce a small volume of parts. However, they have a shorter lifespan and cannot produce as many parts as higher-quality molds.

On the other hand, more intricate molds made of higher-quality materials with more cavities can cost hundreds of thousands of dollars. Despite the higher cost, these molds can produce a larger quantity of parts at faster rate and can last for decades, producing millions of parts.

$0.01 – $15.00+/part

Injection molding offers significant cost advantages for startups and entrepreneurs, especially in terms of the price per piece.
When producing the same part in large quantities, the piece price is typically lower compared to other manufacturing methods. The more parts you manufacture, the lower the piece price is likely to be.

For starting businesses producing a small quantity of parts (less than 100), the initial piece price may start at around $15.00 per part due to startup costs, mold installation, and material purchases.

However, as production volume increases, the piece price decreases, potentially leading to costs as low as a few pennies per part.

Is your project ready for injection molding?

Although injection molding is the predominant method for manufacturing plastic parts, it may not be suitable for every situation. Factors that might lead a startup to opt out of injection molding include the high initial costs for tooling, limitations in part design, or the impracticality of producing small quantities.

Nevertheless, for projects requiring thousands or millions of parts to be made consistently and efficiently, and for those willing to invest in creating a high-quality mold, injection molding is the ideal choice.