Category Archives: injection mold design

Mold Design and Automated Injection Molding

When an injection mold designer begins a development of the mold design, they must be aware of the environment in which the mold will run.  This includes the size and type of press the mold will run in, the material used for molding, and any auxiliary equipment used for automation as the location of tie bars and cooling lines must not interfere with setting and running the mold.

 

Vacuum Conveying System

 

A vacuum conveying system is an automated way to get the material into the press, with the right suction and force.  Vacuum conveying systems suck the material while still in pellet from the gaylord or drum into the hopper of the press, providing a steady flow of material for continuous production.   Vacuum conveying systems pull in a steady flow of material, and control the amount of material in flow to the press, and are also helpful with controlling the moisture content in the material.  

 

Sprue Pickers Aid Automation

 

Sprue pickers are robotic arms that reach into the press and grab the runner when the mold ejects, instantly separating from it the parts which can then fall into a bucket or onto a conveyor belt.  Some robotic sprue pickers reach in and pick up the runner then drop it either into a separate bin, or directly into a grinder where it can be ground up and reused as regrind material.  

 

Process Monitoring

 

Injection molders use process monitoring systems to constantly monitor the press settings such as temperature and pressure, alerting an operator if the job begins to run out of specification.  Some monitoring systems also provide material resource planning functions, tracking job due dates and material inventory for scheduling of jobs.  

 

All of the additional auxiliary equipment must function properly and work in conjunction with the mold when it opens and closes and operates on the tie bar.

 

Michiana Global Mold has vast experience designing and manufacturing molds adhering to customer specifications and each unique environment.  Contact us today for a FREE design consultation and to learn how we can assist.  

Mold Design Considerations for Thermoplastic Resins

The most common type of polymer used in injection molding is thermoplastic resins.  There are many different types of resins with various properties to meet part specifications for functionality.  When designing injection molds, the engineer must take into consideration all properties of the resin specified for the produce including adhesion, elasticity, resistance to high temperatures, shrink rate, resistance to corrosives, and desired finish whether matte or polished.

 

The cooling and shrink rate are of the utmost importance, as some parts with a high shrink rate will need the cavity designed accordingly so the finished product will cool and shrink within specifications.  Cooling rate is also important for ejection, as the resin must completely solidify prior to mold ejection.

When an injection molded part has a critical functionality, mold flow analysis may be helpful in determining resin flow into tight geometric areas.  Mold flow analysis clearly shows with computer aided simulation how the resin will flow as determined from its properties.  Predicting how thermoplastic resin will flow in the mold and cavities prior to cutting steel can be a valuable tool in avoiding costly mistakes.  Conducting the proper advanced quality planning with mold flow analysis can greatly improve lead times.  

Most journeyman mold makers will already possess the knowledge of hos particular resins flow just from experience.  A skilled design engineer with experience in manufacturing molds will have the knowledge to design the tool to produce a part to print specifications, with the chosen resin properties playing a huge role in tool design.

At Michiana Global Mold, we have been providing high quality precision molds for over 60 years, possessing more than 500 years of combined experience.  Our staff of highly skilled design engineers and journeymen mold makers are the best in the business with vast experience in various thermoplastic resins.

Contact Michiana Global Mold today to speak with one of our skilled and experienced mold designers to learn how we can assist you with your injection mold requirement.  We are an ISO9001:2015 Registered mold making company with vast experience constructing custom, precision injection molds for various industries.

Press Considerations for Injection Mold Design

 

 

When constructing plastic or rubber injection molds, in addition to the part design the molding environment that the tool will run in is of the utmost importance.  A mold designer must be aware of the injection molding process that the tool is designed for, the press it will run in including the clamping system and whether or not it is a vertical or horizontal clamping press.

 

Each injection molding press will have a particular clamping pressure that is either delivered in an electric or hydraulic system.  Some molders prefer to use all hydraulic presses, while some have a mix of hydraulic and electric, while other molders use only electric machines.  There are some benefits to both, but the mold designer must be well aware of the power and pressure utilized in the press of choice prior to designing and constructing the injection molds.

 

A mold designer, and mold builder will need to know the tonnage of the press, the clamping orientation and clamping pressure whether it is electric or hydraulic, and they will also need to know the barrel capacity of the press.  This will determine how much material will be able to flow into the mold, and based on cycle times and cavitation, will determine whether or not the tool is designed to meet projected production volume requirements.

 

Each injection molding press will also have a certain type of mounting system to secure the mold in the press.  A toe-clamping system is most common, although a skilled mold designer can adapt the tool to fit even a custom designed mounting system.  The platen must be large enough to hold the mold but it must also allow enough room to pass through the tie-bars when loading or unloading the mold.  The tie bars hold the mounting platens in place which securely hold the mold in the press, and also contain the ejection system allowing opening and closing of the mold.

 

Michiana Global Mold has vast experience designing complex, precision molds for various industries, meeting all requirements of our customers molding environment.  We are valuable addition to any supply chain, providing proven solutions with high performing quality steel molds.  Contact us today for a free design consultation, and to learn more about our discount and rebate programs.  

Expert Injection Molds from Concept to Completion

 

Choosing the right injection mold supplier for your project is an important decision.  Every injection molding project begins with a quality constructed injection mold.  You need to choose a supplier that can handle your project, no matter the complexity or precision tooling required.  

At Michiana Global Mold, we are experienced in constructing quality precision molds, taking into account all necessary design considerations from the beginning resulting in a perfect mold for your application.  Michiana Global Mold employs expert mold designers, utilizing the latest in technological advancements with CAD/CAM (Computer Aided Design / Computer Aided Manufacturing) Software.   Download our FREE Book on Design Considerations for Various Molds.  

Michiana Global Mold will partner with your business from the beginning, providing you with options that will give you the best value for your mold construction project.  We use CAD/CAM along with mold flow analysis when necessary, to pinpoint any critical dimensions before cutting steel.  

We have full in-house design capabilities with expert experience in all facets of design construction and machining.  We can construct fully functional molds, mold inserts, over molds for insert molding, mold compositions, and adaptations including engineering changes.  

We have the skill and experience to produce best in class automotive injection molds, satisfying even the most stringent of quality requirements.   As an ISO Registered tool shop, we are familiar with following documented guidelines, providing excellent workmanship to meet precision tolerances.  We will identify problem areas before they would become a problem.

Our staff includes journeyman moldmakers that have vast experience with tool construction for a wide array of industries.  We have the knowledge required to provide precise, technical tools for various applications including those required in the automotive industry, consumer electronics, medical, and military / ordnance requirements.  

Contact Michiana Global Mold today to learn how our vast experience, knowledge, and technical capabilities will add value to your supply chain.  We partner with our customers from the beginning, providing quality, precision molds for a wide array of applications over various industries.  Michiana Global Mold is an ISO Registered injection mold construction supplier, providing quality class A steel molds since 1952.  

Injection Mold Designs for Various Molding Environments

 

When designing plastic injection molds, there are several factors to take into consideration including the molding environment in which the tool will run.  Of the utmost importance in mold design is the injection molding press specified for the production operation.  

Some presses have either a vertical or horizontal clamping system.  A vertical clamping system is typically used for shuttle molds, also referred to as insert molds, and is used for molding plastic around an insert usually made of plastic or steel.  The clamping system will open, allowing an operator to place an insert in the bottom half of the mold, prior to closing allowing plastic to flow around the insert.  This process is used to put a plastic or rubber like coating around an object such as knives for example, or electrical wiring harnesses requiring a housing to fit around a wire assembly.  Shuttle molds for vertical clamping presses will have at least two bottom (B) halves so that the molding is occurring on one side of the press while an operator is loading inserts on the open side.  This allows for maximum production even when an operator is required.

The typical injection mold will have a horizontal clamping system, opening on a horizontal plane and allowing parts to fall below into a bin or straight onto a conveyor belt when ejected.  Some horizontal molding operations are fully automatic and do not require an operator, once the mold is set in the press and proper parameters are set.  This is a very efficient method of molding, and several molders utilize this type of operation in a lights out automatic environment.  This, of course, requires a quality crafted precision tool to ensure a consistent molding process.  

The placement of water fitting and hoses is also of equal importance, as these lines cannot be in the way of the mold operating in the press.  The tonnage and clamping pressure of the press is needed when designing the mold, and the barrel capacity is required to ensure production requirements can be met.  Download a FREE copy of our book “Design Considerations for Different Molds” for more information.

Michiana Global Mold has over 500 years of combined experience designing and building precision custom molds for various industries. Contact us today to speak with one of our knowledgeable engineers for a free quotation on your mold building requirements.  We can custom design molds for your applications, regardless of your molding environment.

Plastic Injection Mold Designs Requiring Cam Action and Lifters

Engineers have many factors to consider when it comes to plastic injection mold designs, including cam action and the ejection system.    Once a mold designer has evaluated all geometric tolerances on the part print, they will typically create a CAD (Computer Aided Design) drawing of the part to aid in the design of the tool.  While reviewing part requirements and the tooling necessary to mold the part, it will become apparent if any Cam Action, or specialized ejection system is necessary.

What is Cam Action

Cam action refers to the mechanics necessary to create an undercut feature, a hole in a part would be an example.   Cam action occurs on sliding plates that would slide in when the plastic is molding around it to create the feature such as a hole, then it must slide back out in order for the part to eject properly.  If the pins or mechanics that molded the feature like a hole did not slide out of the way, the part would be lodged on that pin and would not fall out.  A cam device will pull the side-action mold surface out of the way to allow ejection from the mold.

cam-action-1-minPictured is an example of cam action; the sliding plates have barrel like rods attached to move in during the molding process creating holes in the part.  They slide back out when finished for proper ejection.

cam-action-2-minThis photo shows cams in a closed position, while molding the hollow geometrical shape of the part.

Lifters and the Ejection System

The ejection system is what pushes the part out of the mold after a fully formed plastic part has been molded.  In some instances, some help might be required for proper ejection.  This is where lifters would be included as a mechanism in the ejector system.  A lifter is an angled feature that is part of the ejector plate system, and is activated upon ejection.

The ejection system has several considerations during the injection mold design.  The ejection pattern and stroke of the press must correspond with the mold design.  Proper location of ejection pics is crucial to properly eject the mold without damaging the finished part.  In some instances, lifters are the only option to ensure proper ejection.

lifter-example-iso-view-cut-away-1An example of lifters assisting with ejection

 

Michiana Global Mold is an ISO9001:2015 Registered injection mold designing and building company.  We have been supplying custom precision injection molds to various industries including automotive, medical, electronics and defense for over 52 years.  Contact us today to see how we can assist you with your plastic injection mold designs.  

 

Finding a Chinese Injection Mold Provider Consideration List

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Searching for a China injection mold provider can be incredibly difficult and time consuming. There are plenty of blogs and articles that cover different aspects of what you need to consider, but you”ll need a list. This ensures that you look at all of your potential China injection mold source options and the range of questions you need to ask.

Remember, the cost is not your only consideration. Things like shipping time, communication, and QA process play very important roles in determining if a particular China injection mold provider is cost effective.

Your Sourcing Options

You have three options for finding a provider in China:

  • Direct Chinese source
  • Broker who recommend and negotiates with a Chinese source on your behalf
  • Domestic provider with a Chinese partner

Initially, this list appears to reflect the cost in ascending order. A direct source will often appear to be the most cost effective source and a domestic partner will appear to be the least cost effective.

However, when you take the following considerations into account, you will see the initial cost for the domestic provider has some distinct advantages, including easier negotiations, design time, and predictable delivery times.

Considerations and Questions

When you talk to each of your potential sourcing options, the following considerations and questions will help you determine if the source is likely to meet your needs.

Communication

This is one of the biggest potential issues, particularly during the design phase. You need to be able to talk to the people who are responsible for the designs. There are several potential communication issues to consider:

  • Time zones can pose a problem if you work directly with someone in China
  • Designs can be more difficult to finalize when you cannot speak directly to one of the professionals working on the design
  • Shipping times may be off because of holidays, so you need to know the production schedule for the entire time your product is being processed

Planning

Planning is one of the most important aspects as it sets the tone for the entire project. Here are the things to consider for the planning phase:

  • Materials
  • Design time
  • Production time frame

Quality Assurance and Shipping

Make sure that you discuss your QA needs and shipping expectations. If you are working on a tight deadline, you need to make sure that the product is high quality and can be turned around quickly.