Injection Molding Blog

March 06, 2022

Where have all the machines gone?

Used machines are in high demand! Elite Machinery Systems is currently searching for the machines below. Any Electric Machines – All Tonnage Ranges Needed - Prefer 2005 or newer - Will Consider Older Well Maintained Machines Any FNX-Model, NEX-Model, FN-Model, and FV-Model Nissei machines – Several Machines Required Any machines 2005 or newer – All Brands Considered – Will Consider Older Well Maintained Machines Any Large Tonnage Machines 1000 ton to 3500 ton – 2000 or Newer Preferred - Will Consider Older Well Maintained Machines 1000 ton to 1100 ton – 2010 or Newer Preferred - Will Consider Older Machines...

November 20, 2015

Injection Molding Troubleshooting

Injection Molding Screw and Barrel Cleaning Cleaning a screw and barrel can be a full day's job, even when conducted by two or more operators. It can be done by removing parts or injecting a purging compound. It is not always necessary to remove the screw and barrel from the machine, however it may be more cost effective than using a purging compound. The following will guide you in either method of cleaning. Read More Urethane Release Agents and Coatings If you're an injection molder, you probably know how sticky urethane can be and how difficult it is to remove...

November 20, 2015

Injection Molding Defects Glossary

Molding Defects Alternative Name Description Causes Blister Blistering Raised or layered area on surface of the piece Tool is not properly cooled and/or has a faulty heater, leaving the material hotter than it should be. Burn Marks Air burn/gas burn/dieseling Black or brown marks from where the air is trapped Tool is not properly vented, or injection speed is too fast. Color Streaks Localized color change The plastic additive Masterbatch does not properly mix or the material runs out and is pushed through naturally; material from a previous run is dragging in the nozzle of valve. Delamination Thin mica like...

October 07, 2014

Choosing the Right Cooling Method is the Key to Cycle Time Reduction

An always important factor of injection molding production is the total cycle time. One segment of the process is the cooling time of the machine tools and molds. Cooling happens to take the majority of the processing, so to optimize this process would heavily impact the overall production rate. Cooling systems are also imperative to reducing wear and tear on an injection molding machine. The cooling process is the middle portion of the plastic running cycle. It comes after injection and before the ejection of the plastic. The goal of the cooling phase is to bring the running temperature of...

March 17, 2014

Cleaning a Screw and Barrel of an Injection Molding Machine

Cleaning a screw and barrel can be a full day's job, even when conducted by two or more operators. It can be done by removing parts or injecting a purging compound. It is not always necessary to remove the screw and barrel from the machine, however it may be more cost effective than using a purging compound. The following will guide you in either method of cleaning.Using a Purging CompoundWhen using a purging compound, the first step you want to take is closing off the flow of the resin that's being processed by pushing the slide gate at the bottom...

March 04, 2014

How To Prevent Bubbles in Plastic Injection Molding

Time is money and one small issue that can be costly in injection molding is bubbling. Bubbles have two primary causes: gas pockets or vacuum voids. Both of these are essentially air-flow related issues.In order to remedy the situation you need to examine which type of bubble you are dealing with specifically because the quicker you can identify they type of bubble, the faster you can diagnose and repair the issues slowing production.To be able to differentiate between gas pockets or vacuum voids you can use a simple heat test. By using a hot air gun or small lighter, warm...

October 03, 2013

Urethane Release Agents and Coatings

If you're an injection molder, you probably know how sticky urethane can be and how difficult it is to remove from the steel cavities and cores of molds in the injection molding machine you're working with. Using a release agent on the steel surfaces will loosen the urethane in order to remove it. A surface treatment that works well for this is Nano Mould Release Coating. This is actually a line of products that advocates using nanotechnology in their "mesh-like" microstructure of the solution to absorb and removed any remnants of surface debris, including urethane. Another method for surface upkeep...

September 10, 2013

Calculating Residence Time and Machine Shot Capacity

Injection molding is the most common way to manufacture plastic products in high volume. Injection molding machines operate horizontally or vertically to fasten and employ molds. Most machines today are horizontally-oriented, however vertical machines are primarily used for insert molding in order for the process to utilize gravity. A mold may be designed for either a cold runner system or a hot runner system. With a cold runner system, the plastic is injected through a carved channel and cools from the mold. The plastic from the carved channel forms a sprue, which is later removed. The more complex hot runner...

August 06, 2013

Plastic Injection Molding Defects and Solutions

These plastic molding defects articles are intended to help facilities managers, machine operators and all the like. We developed these articles in an effort to produce content to help you. We hope you will find these articles to be informative. Injection Molding Defects GlossaryThis content outlines various common injection molding defects, alternative names, descriptions and causes. Blister, Blistering: Raised or layered area on surface of the piece. Tool is not properly cooled and/or has a faulty heater, leaving the material hotter than it should be. Burn marks, air burn/gas burn/dieseling: Black or brown markes from where air is trapped. Tool...

November 20, 2012

Plastic Injection Molding Machines

In 1868, John Wesley Hyatt became the first person to inject hot celluloid into a mold, producing billiard balls. In 1872 John and his brother Isaiah patented an injection molding machine that used a plunger, and the process remained more or less the same until 1946. In 1946 James Hendry built the first screw plastic injection molding machine, which revolutionized the plastics industry. Roughly 95% of all plastic injection molding machines now use screws to efficiently heat, mix, and inject plastic into molds. Injection molding machines consist of two basic parts, an injection unit and a clamping unit. Injection molding...

December 15, 2010

How Do Plastic Injection Molding Machines Work?

There are horizontal injection molding machines and vertical injection molding machines. While horizontal injection molding machines are very popular, vertical injection molding machines are very versatile and can save valuable floor space. A horizontal injection molding machine is pictured to the right. Hopper This serves as a funnel into the barrel. The hopper is where the plastics resin is placed for injection. Plastic resin can be compromised of flakes, shavings or pellets. The plastic resin can be fed manually, automatically or via vacuum. Barrel, Injection Molding Screw, Heater Bands The injection molding screw has dual purpose in the function of...