Tuesday, December 27, 2016

Thermoplastic Molding

Injection Molding with Thermoplastic Resins
Thermoplastic molding refers to the process of injection molding thermoplastic resins.  Thermoplastics is a type of polymer that melts and becomes pliable when reaching a certain temperature, allowing it to be molded into various forms.  This type of polymer can also be ground up and reused after hardening, as opposed to thermoset polymers, which cannot be melted and used again.  The third type of polymer is elastomer, which can also be thermoplastic, in which case this type of material is referred to as thermoplastic elastomers.  Thermoplastic resins are the most common type of material used in the injection molding process.
The Molding Process
The equipment required for thermoplastic molding is the same: a press, a steel mold, and plastic resin.  The resin is poured into a hopper on top of the press, and is then drawn into the press where it is heated in a barrel and injected into a steel mold where cavities carved out by journeyman mold makers form the molten plastic into the shape desired.  The steel mold is usually equipped with water lines running through it to cool the parts before the mold opens and parts are ejected.  Each time the mold opens, molds parts, and ejects them is called a cycle.  The typical injection molding cycle is measured in seconds.  Decreasing the cycle time can lead to improvements in efficiency and the bottom line, as long as it does not jeopardize the functionality of the part.
The Mold
The mold is the steel frame that contains the carved out cavities to actually form the part.  Every injection molding job requires a steel mold to form the molten material into a usable functional part.  There are different types of molds for different applications, but the most common is a class A hardened steel mold, capable of producing hundreds of thousands or millions of parts without wearing out. 
For the typical thermoplastic molding process, a steel mold will run in a horizontal molding press, meaning the mold will open and close on a horizontal plane.  In this case, when the mold opens and ejects the parts, the runner is also ejected.  The runner is the residual molten plastic that hardened in the channel getting the plastic to the cavity in the mold.  This is true of a cold runner mold, which is the most common injection mold.  A hot runner mold, in contrast, injects plastic directly into the cavity from a nozzle, and therefore has no runner.  A hot runner mold can assist with automation, but it is more costly than the more common cold runner mold. 
Equipment Required for Automation
While the necessary equipment is the same, a molder can invest in auxiliary equipment to automate the process and run parts without an operator, and sometimes even in a ‘lights out’ environment.  A vacuum conveying system sucks the plastic resin while in pellet form from a drum or gaylord into the hopper on the press.  As long as enough resin material is in the drum the conveying system will automatically supply a steady stream of thermoplastic resin into the press.  There are ways to regulate the amount of pellets drawn into the hopper at a time.  Some molders even have ways to measure the moisture content of material, and dry it accordingly before it enters the press.  Some molders use a moisture analyzer when required. 
Sprue Pickers Assist with Automation
When a cold runner mold is used in a horizontal press, the runner will eject with the parts and either drop to a bin below, or be grabbed by a robotic arm called a sprue picker.  A sprue is another term for a runner.  Sprue pickers assist in the automation process because it separates the parts from the runners, allowing the parts to collect in a tub by themselves and not need to be sorted or separated from the runners. 
Process Monitoring Adds Consistency and Reliability
A Process Monitoring System should be utilized for automated molding as it will monitor, as the name implies, the process as it is happening.  If something began to run out of spec, such as temperature or pressure, an alarm would sound to alert a technician.  These monitoring systems also function as material resource planning software, allowing the user to input specific job information and schedule production. 
These are some of the ways a molder can automate the injection molding process. If precision parts manufacturing is required, automation could assist to provide to a consistent and reliable process. 

Contact Michiana Global Mold today to see how we can reduce costs on your plastic part requirements.  

Tuesday, December 20, 2016

Resin Injection Molding

Molding With Plastic Resin

Resin injection molding is the manufacturing process of molding raw plastic pellet into usable parts.   Thermoplastic resin is the most common type of plastic used in the polymer molding process.  The resin, or plastic pellets, is used by injection molders to make parts for a wide variety of industries. 

Custom injection molding is the process used by custom molders to make parts that are designed by others, typically engineers in the Automotive, Aerospace, Consumer Electronics, or Medical field.  Injection molding is also used for the Furniture, Construction, and Toy industries, although precision molding is required for the former mentioned industries requiring a high level of quality with tight tolerances.

Each resin has a melt temperature when it becomes pliable, which allows it to flow through an injection molding press, into a barrel and screw, where it is injected with pressure into a steel mold forming the desired parts.  After forming, the mold ejects the parts and closes again to prepare for another cycle. 

Characteristics of Thermoplastic Resins

Thermoplastic resins have a unique ability to be strong and durable, yet also lightweight which makes is a desirable material for several functional parts. They can be reinforced with glass filled polymers, or they can have a rubber like appearance, and several variations in between.  They can be made into virtually any color, size or shape.  This flexibility is the main reason that plastic resins are the material of choice for supplying various industries with necessary functional parts.  Some examples:

·         Polycarbonate
·         Polyethylene (low or high density)
·         Polyethylene Terephthalate (PET)
·         Polypropylene (Acetal)
·         Polyphenylene Ether (PPE)

The experienced molder has all procedures in place to provide full traceability throughout the resin injection molding process up to and including shipment of quality parts that meet or exceed customer specifications, along with proper documentation.  Contact Michiana Global Mold today to see how we can help you with your injection molding needs.



Friday, December 16, 2016

Precision Parts Manufacturing



Industries That Require Precision Parts Manufacturing
Precision Parts Manufacturing supplies several industries with critical components.  Aerospace, Automotive, Military / Ordnance, Medical and Consumer Electronics are just a few of the areas where a precision parts molder is a valuable supplier.  
The majority of molded critical components are made by the precision injection molding process, using thermoplastic resins.  Engineering Resins are a group of thermoplastic materials that combine great strength with light weight to be a desirable material in a wide range of conditions, and still be economical.
Precision Molding Process
The quality of a final critical component from the precision parts manufacturing process depends on several parameters.  Three factors that greatly impact the quality of a precision part are the manufacturing parameters, the material characteristics, and the mold design. 
Manufacturing Parameters
When a precision injection molder is presented with a part print, they must determine the best size press to run the parts in taking the press attributes including tonnage, and clamping pressure into consideration.  They must also consider the type of tool to build, and the molding conditions that would yield the most optimum processing conditions. 
Auxiliary equipment must also be considered.   When a precision molder can use automation such as sprue pickers and conveyors, they can maintain a consistent process and reliably produce quality accepted parts. 
Determining the optimal parameters for the molding process is necessary to ensure consistency and reliable product quality. 
Material Characteristics
When choosing the best material for an application, engineers must consider all characteristics of several different thermoplastic resins to choose the most appropriate resin that will meet the strength and durability demands of the functionality of the part.
It is also important to maintain a strong relationship with your resin suppliers.  Most polymer supply companies have material experts on hand ready and willing to assist with new information, suggestions and/or simulations.
Mold Design
A quality precision injection molded part requires a quality precision injection mold.  A flawless mold is the key to reliably and consistently producing parts to customers’ specification.
In most cases, the injection molder will design the mold based on the part print received by the customer.  Molds for manufacturing precision parts can be complex and require the skills of a journeyman mold maker.  It is helpful to have journeyman mold makers in-house that will lead the tool design and communicate with the customer’s engineers during the design phase. 
CAD software and mold flow analysis is used, which is an indispensable tool for any plastic injection molded part.  Mold flow analysis is an indispensable component of any plastic injection molding design project. 
Quality Procedures of Precision Parts Molders
Precision Injection Molding for demanding industries requires the molder to follow necessary quality procedures.  Meeting ISO9001:2008, and compliant to TS/ISO16949, and AS9100 standards standards and practicing them daily is necessary for success with precision parts manufacturing.

Monday, November 28, 2016

Finding a Chinese Injection Mold Provider Consideration List


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.

Friday, November 25, 2016

The Right Choice for Chinese Injection Mold Makers - Domestic Versus Offshore



Finding the right China plastic injection molding provider is a difficult decision. With a number of different considerations to make, you want to get it right the first time. You will also need to be prepared to negotiate.
Research
Research is essential to avoid making the wrong decision, which can cost you not only money but a lot of time, and potentially customers. There are three sourcing options:
  • Direct sourcing
  • Broker sourcing
  • Domestic sourcing
Each of these options has their own appeal. To help you determine which is right for you, consider the following three points:
Finding the Right Material
The material used for the China plastic injection molding is one of the most important aspects because it determines the durability of your final product. If you do not specify what materials you want used at the beginning, you may end up with a product that does not meet your expectations.
Materials Originating in China
Many Chinese mold makers have their own material providers. This means without specifying the type of material, you are almost guaranteed to have a final product made that uses steel produced in China.
The Chinese regulations and standards are typically lower than steels made in Europe and North America. As a result, your final product may wear down faster, be more fragile, and require more frequent replacements.
Materials Originating in Europe
This is easily the most cost effective material. European standards are comparable to the standards of North America, but the product has a much shorter distance to travel.
Testing
Mold testing often requires the use of a representative to conduct a review at the facility to check the functionality and quality of the product. If you have tune-ins built into the contract, you will have a better product by the time you send your representative to conduct the review.
Lead Times
The shipping lead times are important because the different sourcing options handle shipping differently. Having excessively long lead times could end up negating cost savings. The following are important to know before you sign anything:
  • Time zone difference for communicating and shipping
  • Chinese holidays
  • The receipt of sample shots from T-0
  • Import duties
You need to know how each of these are handled so that you can plan accordingly.



Wednesday, November 23, 2016

Choose the Right China Injection Mold Supplier





Finding the right China injection molding supplier can be a very time consuming endeavor. You have three different channels to consider:
  • Find a direct Chinese mold maker
  • Hire a broker
  • Work with a domestic provider
Each option has its own advantages and disadvantages.
Direct Chinese Mold Maker
Initially, this will seem like the most cost effective method of getting a reliable China injection molding supplier. You won’t have to pay for a middleman, substantially reducing the initial cost.
However, it can end up being the most costly. The biggest issues are the language barrier and additional QA efforts. It will be much more difficult to negotiate if you do not have a native speaker who can work with the supplier. While they will surely have an English speaker, you will need someone who speaks their language as well. This can be very costly. You will also need to manage more of the QA to ensure the product meets your needs.
China Injection Molding Broker
The issues you could encounter with a direct provider can be largely avoided by using a broker. It will also look a bit more expensive up front. This is because they have established connections to help you find the right provider, as well as managing the monetary conversions.
Do keep in mind that they are only brokers. You will not be able to discuss specifics with them, only the people at the companies they recommend. This can also create lag time in getting your questions answered.
Domestic Providers
Domestic providers will appear to be the least cost effective China injection molding provider, but ultimately, they can save you a lot of time. Not only will you avoid having to research companies, they have the necessary experts to answer your questions. This substantially speeds up the design and development process, reducing the amount of time required to complete the project. They also manage the QA aspects, so that you can focus on other projects.
Initially, they are the most expensive option. However, cost is the only major drawback, and it usually ends up being far less costly than it appears at first. Because you save time and have the necessary experts to answer your questions, the final cost for domestic providers is a lot more competitive than you may initially believe.



Monday, October 10, 2016

Injection Mold Types: Production Molds



As their name suggests, production molds are used in the final stages by the injection mold makers. Unlike prototype molds, production molds are meant to be used repeatedly for long periods of time, so they must be durable and able to handle harsher conditions. Since it is the final stage of the process, the end product is meant to meet all of the project requirements and specifications.
Custom mold makers will skip the prototype mold if customers request that a project only goes through to production instead of working with a prototype. While the prototype can save money, it can also require more time as the production of the first few parts is meant to be a test run. Custom injection molds that go straight into production molds are given a much longer duration for the design process to ensure the first product is nearly perfect.
Production molds are not meant to be modified or changed. If the first product is too far off of the necessary requirements, you may need to start from the beginning. However, without the additional time for modifications, these injection molds can actually save time as long as the design process goes smoothly.
If you want to avoid using prototype molds, you need to find expert injection mold makers. New companies do not have the knowledge or experience required to create a final product that is nearly perfect on the first round. A number of things can go wrong and many considerations can be missed in the design stages. These are problems that expert injection mold makers have already encountered and learned to fix before moving to the production mold. In the event that there is a problem with the production mold, the experts can make modifications to avoid starting over again.




Injection Mold Types: Shuttle molds



Shuttle molds are made through the shuttle injection molding process. It is one of the more complicated types of molds and requires injection mold makers who understand more than just the basics of that process. Where injection molds usually produce a single product at the end, shuttle molds typically produces two bottom halves with a single top half.
The shuttle mold process creates a single unit – the top half and the first bottom half are made simultaneously. At the same time a second bottom half is being processed to include all of the additional aspects, such as inserts. Once the process is complete, the completed mold is moved further down the assembly line. The lower half with the added inserts is then worked with the top half to ensure it fits like the first one did.
Custom mold makers then begin the process again, closing the mold so that the bottom can be adjusted to align with the top as the second lower half is assembled.
The primary purpose of shuttle molds is to reduce the amount of time required to process each mold. Because the more complex portion of the mold is done at the same time as the top and bottom half are aligned, the custom mold makers do not have to wait for the inserts and other additions to be completed before completing another one. Since the top half does not require additions, it only needs to be included in the first round of the process.




Injection Mold Types: Insert Molds



Insert molds are one of the more difficult types of injection mold types. Injection mold makers have to consider several different areas to complete the final mold. Insert molds can combine plastics and metals (and some other types of materials) so that the final part can connect to different parts of the final product. Custom mold makers typically have to ensure the insert mold is wear resistant, has a reduced weight, conductivity, and tensile strength.
Insert mold makers must create parts that can be molded into other plastic components. There are a wide range of applications for insert molds, such as screws, studs, pins, rivets, tubes, bushings, and surface mount pads. The custom injection molds have to be able to create parts that are more durable and sturdy than other molds because they will be used with metal, which can be very harsh on plastics.
The purpose of insert molds is to reinforce the final product. They reduce the amount of time required to assemble parts, the cost of labor, and improve the strength of the final product. As they are meant to be made of durable plastics, they also help to reduce the weight of the part.
This particular mold type follows the same process as other injection molds. The primary differences are the design and QA processes. The design has to meet strict requirements to ensure the insert will be able to function as intended. The following are the two most common considerations during the design process:
                Determine the means for holding the insert during the custom injection mold process
                Any required undercuts or bosses required to strengthen the final product
Insert molds also tend to have a more rigorous QA process to ensure the final part provides the necessary durability and strength.




Custom Injection Molds



Custom injection molds provide manufacturers with a way to utilize one of the quickest processes to mass produce a product. While most plastic injection molds are customized, it is possible to use existing designs to quickly create molds that are basically recycled instead of customized.
The reason that most plastic molds are customized is because of the requirements and standards that every part and product must meet. If you already have a mold for a 1.25” screw, but you need one that fits a 1” screw, you have to create a new mold to produce the different size. Seldom can a manufacturer work with existing mold designs without having a custom injection mold made to complete the project.
Custom plastic molds offer more than just a way to meet specifications though. If you aren’t sure what method of assembly a product will be best for, or if a tolerance can be met with a particular type of rib, a custom injection mold can be a way of testing different designs to see which product is best for the intended purposes.
Custom injection molds can also be used to test out different plastics to see which ones work best under various conditions. For example, if you have been working with a metal mold that now needs to be replaced, a custom injection mold can be made to see if a plastic mold will be able to tolerate the harsh conditions that the metal mold had undergone. If the custom injection mold can handle the temperatures and other harsh conditions, you can save a considerable amount of money by making the change.
Custom injection molds are sometimes compared to 3D printing as well. There are times when 3D is more cost effective, but on the whole, plastic molds tend to be better for longer term projects as the process tends to be much faster and the final product more durable. Custom plastic molds can typically produce much larger parts than 3D printing.
Experienced custom injection mold makers can help you determine what mold type is best for your current project by reviewing your specifications and the final requirements for the finished product.




Monday, September 26, 2016

Injection Mold Types: Stack molds



As their name suggests, stack molds include several molds attached to the machine so that multiple levels (or faces) can be produced at one time. Even if only two final products are made at a time, it will reduce the amount of time required to produce the same number of products nearly in half. This particular mold system can also be used to make assemblies with multiple components and a series of parts within a single family.

Components and Process
The machine must be set up with the stack molds all connected to the injection area. These molds almost always use the hot runner process. You can set them up to create between two and four molds at a time, although the more molds stacked, the more floor space needed for production .

Things to Consider
Consider these points :
                While it may take longer to set up these unique molds, it is not necessarily more difficult.
                The primary difference between setting up the stack molds versus traditional molds is that more side gear mechanisms are required. However, the steps to complete the setup are nearly identical.
Maintenance will take a bit longer because there are more areas to monitor. Like the setup, however, it doesn’t require many extra steps to keep the molds working properly. The steps to be remembered are:
                Ensure surfaces are clean, including being residue free.
                Ensure the stripper inserts are clean.
                Know and identify the relevant areas and ensure they are checked off during the maintenance process.


Injection Mold Types: Cold runner molds




Cold runner molds are often used for different plastic injection mold processes. Heated plastic is cooled before it passes from the nozzle to the cavity. Once it is through this part of the process, both the part and the material are  ejected from the system. Compared with the  hot runner mold process, cold runner molds area  considerably cheaper and simpler alternative for smaller projects.

Components and Process
The average cold runner system can have either two or three plate molds. In two plate systems, there is a parting line that divides the mold in two.
Systems that have three plates have two of these lines so that the mold splits into three different sections once the part is ejected. Though more difficult, three plates offer more flexibility, as well as having more gates when directed  by the final requirements.

Things to Consider
When you begin with cold runner molds, here are some additional things to consider:
                Thicker dimensions than the starting component will allow the heated plastics to be added during the cooling process.
                Round runner is the most common cold runner system design. It is a two-plate system with each plate containing exactly half of the runner’s diameter.
                Round trapezoid is another design; it allows for the milling of the cavity (or core side) of the tool.
                Gates are important to the process as a primary reason for choosing this particular system. They are removed from the part once the mold opens or once the part ejects from it.



Injection Mold Types: Hot runner molds



Hot runner molds is a generally effective method of mold making that has less scrap (sometimes the process has no scrap) due to keeping the plastic is kept above the melting temperature. Because it is more effective, it tends to be a bit more expensive than other types of molds, particularly cold runner molds. The overall savings makes up for the cost if you have large quantities to produce or if you need quick production.

Components and Process
All hot runner mold systems include two plates to complete the process quickly. It is composed of the manifold and drops. The purpose of the manifold is to convey the plastic to an area above the cavity.
Running perpendicular to the manifold are the drops, which move the plastic from the manifold to the part. Systems have some variations based on the method of heating the plastic.

Things to Consider
In addition to reducing the waste, hot runner molds have a quicker cycle time. Robotics are common in many molding processes, but you will not need as many for a hot running system. Large parts are typically best when made with hot runner molds because these molds can better accommodate the size.
However, if you have a more limited budget or fewer parts, you can save on the cost by using a cold runner system. If color is important and you are likely to need to change it frequently, hot runner systems will not be able to make the change easily.