Precision Injection Molds Meet Customer Specifications

Injection mold designs today must meet tough customer specifications, calling for critical fill areas with precision mold designs.   Careful planning must be taken when designing complex molds for critical applications, ensuring consistent packing and filling to tight geometric tolerances.  A qualified mold design engineer has several important considerations when beginning a complex injection mold construction, beginning with a carefully planned mold design.

CAD/CAM for Mold Design

Computer aided design and manufacturing is a valuable tool for injection mold designers, providing accurate 2D drawings and designs to meet customer specifications.  The use of CAD/CAM is beneficial when constructing molds for any industry, especially when designing and constructing injection molds for the automotive industry.  

Unigraphics and SolidWorks are two of the most technologically advanced software design programs used to satisfy the complex demands of the automotive industry.   Mold Flow Analysis is another valuable tool to identify potentially challenging fill areas, especially when using a specialty resin that may be unfamiliar to the molder.

These computer simulations are part of a thorough Advanced Product Quality Planning (APQP) set of procedures which ensure a successful mold launch.  APQP procedures are critical to the planning phase as following a detailed set of procedures identifies any issues with resin, geometric challenges such as a thin wall or critical dimensions that must remain within +/-.001” for proper functionality.  

Michiana Global Mold utilizes CAD/CAM software as part of our thorough APQP procedures, to ensure a quality constructed mold for even the most complex of mold designs.  As an ISO registered injection mold making shop, we are experienced with providing a quality mold made to customer specifications, on time and within budget.  We work closely with our customers to develop a successful mold launch to meet even the strictest of specifications.

Contact us today to speak with a knowledgeable design engineer, and Download our FREE Book on Design Considerations for Different Molds.  

Michiana Global Mold is an injection mold design and mold making company, constructing precision molds to various industries since 1964.  We are an ISO registered injection mold making facility satisfying the strict requirements of the Automotive industry with high quality precision molds.  Contact us today for a FREE design consultation.  

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Choose the Proper Gate Location in Injection Molds

The gate is the mechanism that allows the plastic resin to flow into the mold, and every plastic part design must take careful consideration of the type and the location of gates.  There are various styles of gating mechanisms typically used in injection molding, and each style will have an effect on the finished product.  The style of gating chosen can affect the visual appearance of the part, the likelihood of warping or sink marks, and proper packing to meet dimensional tolerances.

 

Avoid Defects from Gate Location

 

To avoid defects when processing, place your gate location at the heaviest cross section for maximum fill and packing to avoid sinks and voids.  Experienced mold designers will also know when to consider adding a second gate location, which may be necessary in complex geometrical shapes to obtain proper fill throughout the part.  

 

The location of the gate should allow for automatic or manual de-gating, designed with the minimal length of flow path to minimize visual flow marks.   In cold runner molds, the part is usually ejected attached to the runner and gate, de-gating removes the part from the runner system.  Some processes include automatic de-gating with robotic arms that grab the runner out of the mold separating it from the part or parts.  

 

Gates in Hot-Runner Tools

 

There are basically two types of gating systems used in hot-runner tools, where the plastic is injected directly into the cavity to avoid runners altogether.  In a hot-runner tool, the gate may be either a thermal (or hot-tip) gate, or a valve gate.  The hot-tip gate solidifies the resin at the tip nozzle immediately upon high pressure injection into the cavity, stopping the flow of plastic to the cavity.  

 

A valve gate is used when the plastic may not solidify completely upon injection, and therefore a valve slides over to cover the nozzle tip and stop the flow of resin.  Either type is effective and cost efficient when used properly in a hot-runner system mold.  

 

Michiana Global Mold is experienced with constructing cold and hot-runner tools, with various styles of gating mechanisms involved.  We are skilled with determining the optimum gate location for precision molds required to produce complex geometrical parts.

 

Michiana Global Mold has been exceeding customer expectation with high performing injection molds since 1964.  We have vast experience with all types of molds and mold base components. Contact us today for a FREE design consultation and to speak with one of our knowledgeable design engineers.  

 

Plastic Injection Part Design with Ribs and Bosses

Ribs are often used to add strength and stiffness to plastic parts in critical areas or geometric designs where thin walls exist.  This makes the part stronger with added support but can also cause sink marks on the exterior side of the part, where the rib comes together to meet the main wall in the part design.  When using ribs to add support, remember the general rule that the rib should not be more than 60% of the wall thickness.  Adding ribs to an injection mold design will increase costs, and may require EDM processes.  

 

Working with an experienced injection mold manufacturer will give you the best value for your investment.  Skilled journeyman mold makers and experienced injection mold design engineers will have the best knowledge of where to place ribs for added support and how this will affect the tool design, and the cost.

 

Mold making companies today can provide you with a two-dimensional computer aided design to show you exactly how your injection mold will produce the required plastic part, and alert you to any problematic areas ahead of time.  

 

Bosses are a very common feature in many plastic parts, and comes from the word emboss, which means a raised stamp or design, standing out on the surface.   Bosses that are designed with too thick dimensions can cause sink marks similar to the use of ribs.  Utilizing the proper ratio of ribs to bosses a molder can reduce or eliminate unsightly sink marks caused by either feature.  

 

Ribs used to connect boss areas to a side wall can add strength while avoiding sink marks.  Sharp corners are another area where excessive stress can concentrate and adding small radii feature in this area can strengthen the corner and reduce excessive stress.

 

Michiana Global Mold is a full-service mold design and construction company, with vast experience in all types of molds.  We offer an ISO registered Quality System, state-of-the-art domestic mold building facility with off-shore partner, and decades of experience with precision, complex tooling.  Contact us today for a FREE design consultation and to speak with one of our highly skilled design engineers.

Plastic Part Design to Avoid Sink and Warp

Plastic injection mold designers must consider the resin chosen for the part manufacturing when designing the mold as this plays a very important role in meeting part specifications.  One characteristic of the plastic material that requires careful consideration is the cooling rate compared to the geometry of the part.

 

What is Sink

This plays an important role in the likelihood of parts developing sinks or warps, and can have significant consequences on successfully molding parts with consistent results.  The cooling rate is extremely important because as the part begins to cool it will always begin at the mold surface and move inward, toward the center.  If the geometry of the part is such that the part is too thick, the center area of the part will not solidify quickly enough.  This center stays molten long enough for it to cause stress on the area already solidified, pulling downward towards the center and leaving a sink mark on the outer surface.  

 

Avoid Sink in Plastic Parts with This Rule of Thumb

 

Ribs are used to add strength to plastic parts in thin wall or critical areas, but can also cause sink marks on the exterior side of the part.  When designing plastic parts to avoid sink marks, remember the basic rule to keep the thickness of the rib somewhere around 60% the thickness of the wall.  Following this rule of thumb should help to avoid sink marks during the cooling process.  

 

What is Warp

 

If a plastic part design includes areas of uneven wall thickness, stress can develop during the cooling and solidifying stage.  If this stress is excessive, warps will occur where thinner sections solidify faster than thicker sections.  

 

Avoid Warp in Plastic Part Design

 

When undue stresses due to transitions in wall thickness occur, plastic part designers can combat this by using a ramp.  Designers also use gussets in corners of some geometric areas to help prevent warping.  

 

Michiana Global Mold is an injection mold design and construction company with extensive experience in designing precision tools for complex injection molded parts.  Our skilled designers have vast knowledge of injection molding with various resins, and designing a mold to avoid common pitfalls in manufacturing.  Contact us today for a FREE design consultation and to speak with one of our knowledgeable engineers.

Determine Proper Ejection Method for Injection Mold Design

Injection mold design includes design of the optimum ejection system to meet part specification.  While ejector pins are most commonly used, there are other methods of ejection systems that are required in specific situations.

Ejector pins are round, and used to extend into the cavity to push the part out during mold opening so that the parts fall out or are pulled out by a robot.  Pins are adequate in most situations, although some part designs require pins along with an alternative method, or a different method altogether.

 

Ejector blades can also be used for ejection if the part design requires it, and these have more of a rectangular geometry.  Ejector blades are often used in designs where a thin wall exists, thus an ejector pin may damage the part with force or pressure applied in a critical area.

 

Ejection sleeves are tubular, and are ideal in areas of raised surfaces.  These raised surfaces are designed to assist with assembly in some designs, for example a raised hole at the end of a vertical part would be referred to as a boss.  Ejection sleeves provide 360° surface around the boss for easy part ejection with these types of part designs.

 

A stripper plate is another type of ejection system that consists of an entirely separate moving plate, that is designed to strip the part or parts from the core of the mold.  These are ideal in situations where you need to keep parts and runners separate, and are utilized in three-plate tool.  

 

Michiana Global Mold is a leading global injection mold design and construction company, with extensive experience in all types of ejection systems.  Our skilled mold designers and journeyman mold makers have extensive knowledge and experience with various types of mold construction.  We construct prototype molds with sample parts, cold runner or hot runner tools, shuttle molds, insert cavities and all aspects of injection mold design including engineering changes.

 

Michiana Global Mold was established in Indiana in 1964, serving various industries and specializing in complex, precision tools for the Automotive industry.  We offer a partner company in China with offshore mold making capabilities.  Both facilities are registered to ISO 9001 and follow strict quality management systems.  Contact us today for a FREE design consultation and to speak with a skilled design engineer.  

Molded Part Surface Finish and Ejection Methods

Injection mold designers must always take into consideration the surface finish required of the finished molded part.  The ejection system in the mold that removes the solidified parts out of the mold cavity or cavities has great impact on the part’s surface finish.  The most common ejection system uses ejector pins which can leave marks on the part, often referred to as witness lines.  

 

An experienced mold designer will position ejector pins in order to place witness lines in an area acceptable to the part print.  The ejection system and ejector pins are housed in the B side of the mold, extending into the cavity during ejection then retracting back into the mold.   Restrictions on ejection must be apparent prior to mold design, if ejector pins cannot be used without damaging the part, lifters can be utilized for proper ejection.  

 

The injection mold design must correspond to the ejection pattern and stroke of the press.  Michiana Global Mold is an experienced injection mold maker with in-depth knowledge of designing various ejection systems to meet customer specifications.  We use CAD/CAM Unigraphics software to design and develop a layout for the ejection system prior to cutting steel.   

 

In some cases, ejection systems must be designed around robotic arms that reach into grab the parts upon ejection.  These robotic systems are called ‘sprue pickers’, as sprue is another term for the runner that is also ejected with the part.  Some ejection systems automatically separate parts and runners, so that they do not need to be separated later.  

 

Whatever your part design, surface finish, or ejection system is required, Michiana Global Mold will design and construct a superior mold with flawless ejection for the specified part surface finish.  We are an ISO registered mold making company with an offshore mold making partner in China.  Contact us today for a FREE design consultation and to speak with a skilled mold engineer.

What are the Differences of ISO 9001:2015 and 9001:2008

ISO 9001 is a set of internationally recognized standards that provides a uniform way of measuring a company’s internal quality systems.  ISO was first introduced in 1987, and is administered by the International Organization for Standardization (ISO) headquartered in Geneva, Switzerland.  

The latest version of ISO9001:2015 is replacing the prior version from 2008, as a new standard is introduced about every seven years.  When first introduced in 1987, the standards focused on documentation, saying what you do, and how you do it.  Defining job descriptions, work instructions, and quality checks and balances was a big part of the initial introduction of ISO standards.  

The updated version that came next in 1994 enhanced upon “say what you do”, and added “say what you do, and do what you say” (and prove it).   Further documentation was required to show that you are actually doing what you say you are doing.  Internal audits are emphasized with honest findings, and corrective actions.  

The ISO updates in 2000 turned focus to “continual improvement” and “customer satisfaction”.  Continual improvement projects must be identified, and customer satisfaction must be measured.   The ISO9001:2008 version went into greater depth of all prior versions, emphasizing processes, process owners, measurable goals and how they impact continual improvement and total customer satisfaction.  

With the most recent updates of ISO9001:2015, there is even greater emphasis on business management and leadership, and top-down management involvement.  Each employee should be aware of the organization’s mission statement, quality policy, and what their role is in achieving these goals.  Top management should be involved with communicating the quality management system, and the importance of each employee’s role to the organization.

ISO9001:2015 puts more emphasis on risk based thinking, and having contingency plans in place.  The bottom line is that businesses that adhere to an ISO compliant quality system are poised for the future, with quality systems in place that focus on total customer satisfaction.

Total customer satisfaction reaps many benefits in customer retention, increased volume of business, and new business referrals.  The efficiencies recognized when implementing ISO leads to cost-efficient improvements, thus saving time and money.  

Michiana Global Mold is a superior plastic injection mold designer registered to ISO9001:2015 in the United States, and ISO9001:2008 in China.  We offer offshore mold making options, rebate programs and high-volume discounts.  Contact us today for a FREE injection mold design consultation.