"Electric Injection Molding Machines" At the Height of Injection Molding Machines,       

LS Mtron captivates customers with energy savings and precision!

Electric injection molding machines, which have reached the last peak in the development process of injection molding machines, have shown a steady sales increase in the industry due to the advantages of cost reduction and product quality improvement. With this trend, LS Mtron Injection & Molding Machine Division is making headlines by providing electric injection molding machines with higher cleanliness, low energy consumption, excellent reproducibility and precision, and fast speed. We would like to introduce the products of LS Mtron Injection & Molding Machine Division that will keep trying to improve product quality and save cost through constant technical development and investment in electric injection molding machines.

1. What is an electric injection molding machine?

The electric injection molding machine is a model at the last heights in the development process of injection molding machines. Injection molding machines have been developed from a hydraulic to a hybrid type, and the purchase of electric injection molding machines has recently been increasing. Due to a recent rise in electricity bills in the industry, the purchase of electric injection is on the increase because it can save electricity costs, leading to cost reduction.

Unlike traditional hydraulic injection molding machines which use energy even while idle, electric injection molding machines consume energy only when required for a given action, and motor output is matched to meet requirements.

Instead of being driven by a hydraulic system, electric injection molding machines are digitally controlled with high-speed and highly-efficient servo motors to drive the whole process. Each axis is controlled by an independent motor for injection, extrusion, clamping and ejection.

The outcome brings about a faster, cleaner, more repeatable and energy efficient injection molding process. Energy consumption for electric injection molding machines can be reduced by 50 to 75% compared to a hydraulic type.

2. Electric injection molding machines vs. hydraulic injection molding machines

As shown in the table below, electric injection molding machines are characterized by all motor parts and hydraulic parts that are electrically driven, as compared with hydraulic injection molding machines. Conventional hydraulic and hybrid injection molding machines have a disadvantage in that electricity is continuously consumed even when the equipment is not operated. But an electric injection molding machine has a completely different configuration of main parts, so when not in operation, it dramatically reduces energy consumption. In addition, since the electric injection molding machine does not use hydraulic fluid used in hydraulic injection molding machines, it can maintain a cleaner environment.

3. Application of electric injection molding machines

There are many products that can be manufactured using an electric injection molding machine.

In the past, the motor power of electric injection molding machines was insufficient to produce a limited number of products. But recently, with the growing sales of electric injection molding machines, the motor power has increased along with technical development. Accordingly, its application is expanded, and precision injection machines specialized for specific products are also being developed and sold. Besides, the rising sales of electric injection molding machines have led to high-volume purchases of parts, thereby lowering the prices gradually.

Electric injection molding machines are currently being applied to various industries such as automobile parts, medical supplies, medical equipment, electronic parts, household appliances, lens molding, and daily necessities.

4. Market forecast of electric injection molding machines

In future injection molding machines, energy saving and precision are expected to become key factors that determine the purchase. Since electric injection molding machines satisfy these two factors, their growth potential is much higher than that of general hydraulic or hybrid injection molding machines.

In particular, the manufacturing industry must solve two challenges: product quality and cost reduction. Electric injection molding machines can meet all of these requirements, and the sales volume of electric injection molding machines are expected to increase steadily due to recent environmental regulations in the world.

The table below shows the sales trends of electric injection molding machines.

5. Feature of electric injection molding machines - LS Mtron Injection & Molding Machine Division  

Electric injection molding machines have been on the market for decades, and there are many benefits of using them. Although hydraulic and hybrid injection molding machines are still applied a lot, many of the major injection molding machine manufacturers are primarily focused on manufacturing electric injection molding machines. Especially, as technology is constantly advancing and it is too expensive to build larger tonnage, electric injection molding machines are becoming more and more common. It is clear that the future of the industry lies in electric injection molding machines.

There are key five reasons why it makes sense to mold with electric injection molding machines.

(1) Cleanliness(No hydraulic oil, no oil leaks and spills on the floor)

No Oil Equals No Mess

Injection molding machine types are categorized into hydraulic, hybrid, and electric injection molding machines. Typical hydraulic and hybrid injection molding machines require hydraulic oil to actuate the clamping motion and injection unit of a molding machine. Electric injection molding machines use servo electric motors to actuate all of the machine motions without hydraulic oil.

Electric injection molding machines have no risk of oil leaks because they don’t use oil. Your manufacturing site will be free of dirty and slippery oil leaks which are a huge safety hazard during mold changes. Not to mention you will no longer have to replace hydraulic oil after 2 to 5-year lifecycle of oil. The lifecycle of oil depends on whether you run 24/7 and whether you keep oil temperature hot, which accelerates degradation. Using hydraulic oil is significantly different from not using it. You never want to have oil contamination and damage your production site, but this may become a serious problem in the case of food packaging, medical molding or clean room required industries.

No Oil Change Equals Less Maintenance

The lifecycle of hydraulic oil in a machine depends highly on the hours of use and the quality of the machine itself. We have seen some instances where hydraulic oil was extremely contaminated in a competitor’s brand new machine in 6 months after its use. Imagine the need to replace oil every 6 to 12 months, not to mention the costs of oil which are relatively expensive with larger machines requiring over 500 gallons of hydraulic oil. With our hybrid injection molding machines, we have seen some of our customers, who periodically test the quality of hydraulic oil, use it for more than 5 years. However, please note that the manufacturer recommends that hydraulic oil be changed every 3 to 4 years depending on the hours of operation.

The clean and quiet working environment that you get with electric injection molding machines make them ideal to use for food packaging and medical molders. You won’t have to worry about oil contamination when cleaning your facility before a plant audit and about sending your customers contaminated parts.

(2) Low Energy Consumption

Contrary to its name, electric injection molding machines are extremely energy efficient. If you compare typical hydraulic injection molding machines and electric injection molding machines in terms of the same part and mold, you will see 50% to 70% energy savings in most applications of electric machines.

In a typical hydraulic injection molding machine, a hydraulic pump is constantly on when the machine is running. It has to keep running to circulate oil and is generating heat as long as the machine is running. On the other hand, an electric injection molding machine only consumes electricity as a servo motor turns to actuate movement, so much of the production cycle is spent idling, this is especially so in case of the cooling phase of cycle.

Electric Servo Motors

Typical hydraulic injection molding machines have one or more pumps that generate hydraulic pressure, and valves that direct pressure to hydraulic mechanisms to build pressure based on the necessary movements. Electric injection molding machines do not have a central electric motor, but use individual electric motors designed for each function that is needed throughout the machine, i.e. mold open/close, injection, recovery, and ejection. This means that the motors can be idle until their specific function is required. This is day/night comparison with a typical hydraulic injection molding machine that has to run its pumps continuously, even when nothing is happening. This is especially apparent during the cooling phase.

No Hydraulic Cooling Needed

Energy savings don’t end with an injection molding machine. The elimination of hydraulic pump circuit also doesn’t have a need for cooling hydraulics. Since electric injection molding machines don’t have hydraulics, they don’t require machine cooling. The only cooling that you will likely need is for your mold and feed throat. This leads to additional savings as you will not need additional water lines. Chillers also consume large amounts of electricity, and cooling towers consume water and electricity and require frequent maintenance and monthly water treatment plans.

Less Equipment Equals Less Maintenance

It is very common for customers who use only electric injection molding machines to only have chillers in their plant. This is because they no longer have a need for the high temperature circuit of cooling (85-95F) for their machines but only require the low temperature circuit of chilling (anything under 80F, usually 55F) for their molds and feed throats. Having fewer pieces of equipment obviously means, less capital invested, less upkeep and maintenance costs, less energy consumed, and lower overhead costs.

Overall Plant Energy Savings

Electric injection molding machines also run significantly cooler because there is no heat being generated by a hydraulic pump. Medical and clean room molding facilities are often climate controlled, which means that an air conditioning system does not have to work as hard to remove the heat from a molding room, if the machine is electric. This is another reason why many medical and clean room manufacturers exclusively use electric injection molding machines.

Think Long Term Savings

Based on all of the above points, when comparing a 390-ton typical hydraulic injection molding machine vs. an electric injection molding machine, there is around $17,000 of annual savings on the electric machine. This number represents the savings based on today’s factors, but it is only expected to increase as long as energy costs all across the U.S and Mexico are constantly on the rise. With proper maintenance and care, quality injection molding machines should last 20+ years.  This means that when considering a new injection molding machine, you need to think of 10 to even possibly 20 years down the road. Make sure to purchase your new machines from a reputable and established company who manufacturers their own components, such as platens, motors, sensors, breakers, contactors, cables etc. This ensures that you will always have access to replacement parts. LS Mtron is one of the billion dollar companies that manufacture all sorts of major components for their machines in house.

(3) High Repeatability and Precision(Closed loop controls and linear motions)

Accuracy

Of the 3 types of molding machines, electric injection molding machines have the highest accuracy and repeatability. This is due to the fact that these machines use electric servo motors with a 0.1mm +/- rotation to actuate their movements. This type of movement allows the process to completely negate the fluctuations and inaccuracies of movements actuated by hydraulic pressure and their unavoidable pressure curves.

Consistency In Production

Typical hydraulic injection molding machines constantly experience variations in their process throughout the year, and even throughout the day. This is because the weather is always changing and has an effect on machine temperature and humidity. As hydraulic oil gets cooler, its viscosity increases, and as hydraulic oil gets warmer, its viscosity decreases. The way hydraulic oil performs also changes as it degrades over time. This means that the way the oil in a machine moves and is lubricated will be always totally different from the 1st day. This also means that your molding machine’s process may need to be adjusted periodically throughout the day. Typical hydraulic molding machine controls are considered “open loop” because they send signals to valves to adjust pressures, but don’t actually have direct control over the physical movements of the machine, and thus cannot make all of the minor adjustments that an electric machine can make in real time. Electric injection molding machines are considered to have “closed loop” controls because they control every movement with physical gear turns of their servo motors, and have the ability to constantly monitor and control their positions and speeds to a very tight tolerance, regardless of ambient conditions. This is the difference between “closed loop” and “open loop” controls.

Electric injection molding machines are the perfect fit for manufacturing most complex, difficult, and thin walled parts. You can inject very accurate shots, while maintaining precise repeatability through the day, night, and seasons.

(4) High Speed

Simultaneous Movements

Electric injection molding machines have multiple electric servo motors. These motors are coupled to pulleys and belts that work onto ball screw mechanisms that actuate the movements of functions, i.e. platen open and close. The ability of electric machines to make compound movements(actuating multiple functions at the same time) is one of the reasons why electric machines often reduce cycle time, compared to typical and hybrid injection molding machines. You can “eject on the fly” or eject your parts before opening the mold completely, and you can start recovering the screw while opening and closing the mold. Hydraulic injection molding machines can only handle one movement at a time because they typically only have one hydraulic pressure circuit to actuate movements. This becomes a huge game changer for many molders to advance to electric injection molding machines.

Instant Torque

We all know that electric cars get their immense speed from the instant torque of their electric motors, and the same goes for our electric injection molding machines. They have instant linear motions from our AC electric servo motors, and they can achieve up to 800mm per second injection speeds and also have multi-step injection speeds with our high output and high response AC servo motors.

All that instant torque also has a need for a very rigid and robust toggle clamping mechanism. LS Mtron utilizes a very rigid 5 pin toggle mechanism to ensure that you will continue to have a fast and reliable machine. Our platens and toggles have gone through extensive FEA(Finite Element Analysis) to determine where all of the major stress points on the mechanisms are. We also utilize the highest quality steel and casting technologies via our own in-house steel forging division. All of these are done to maximize the lifetime of our electric injection molding machines.

We also utilize a very robust and precise ball screw mechanism to actuate the clamping motion. With any machine component, the range of performance and quality can range drastically, so it is important to ask what manufacturer’s ball screw you will use for the injection molding machine, to fully understand its reliability of performance.

(5) Technology Advancements

Extremely Reliable

Electric injection molding machines are most reliable among different types of injection molding machines. This is because unlike typical hydraulic and hybrid injection molding machines that were designed many decades ago and are often more geared to a lower price bracket, electric injection molding machines normally use state of the art technologies. Electric injection molding machines are also very quiet while running, and most run at or below 70db. This means that your employees are not required to wear hearing protection while operating the machines.

You will have no oil, less maintenance, more accuracy, higher repeatability, energy savings, much quieter work environment, and machine with easier maintenance to continue running production.

Automated Features

With electric injection molding machines, you will have no sticking valve issues, degrading oil quality issues, ambient temperature process fluctuations, and noisy pumps. Many of the electric injection molding machines have safety feature standards, such as mold safety to prevent crushing parts and foreign objects in the mold, and cold screw rotation prevention against the mistake of accidentally rotating injection screw when plastic is still cold and solidified from an idle machine. Most machines will have a centralized lubrication system or an automation lubrication system to automatically pump grease onto tie bars, toggle links, linear guides and other locations where greasing is necessary. So as long as grease reservoir or cartridge is full, an injection molding machine will automatically grease the areas that need lubrication based on the number of full cycles. When grease levels are low, some machines have sensors to alert your maintenance team to refill grease or change the cartridge when grease reservoir or cartridge levels are low.

Conclusion

Many of our customers prefer Electric Injection Molding Machines due to the following reasons:

• The highest degree of cleanliness                

• Very low energy consumption

• Very high repeatability and precision

• High speed molding

• Technological advancements and features

For these reasons, electric molding machines are extremely reliable for long-term production runs.

6. Lineup of electric injection molding machines - LS Mtron Injection & Molding Machine Division

LS Mtron Injection & Molding Machine Division has the lineup of electric injection molding machines as follows. (Note: http://lsinjection.com/en/product/list.html?cat1=3S)

(1) WIZ-E Series(Standard)      

The WIZ-E Series is the result of years of research and experience in the development and manufacture of injection molding machines. These exceptional machines combine the benefits of servo electric technology, an injection speed/pressure control algorithm, conformance to safety standards, a 5-point toggle clamping system designed by FEA analysis, and a high speed injection molding mechanism.

(2) WIZ-EC Series(Dissimilar)

Two Color / Dissimilar is the process of molding two or more different materials into one plastic part at one time with multiple injection units and index units. WIZ-EC Series has the benefits of performing a variety of designs, color representations, reduction of cycle time, and wide applications in various industries. LS Mtron offers you total solution for multi-component injection based on our accumulated know-how and specialized technology in control system.

(3) WIZ-E IBM Series(Injection Blow Molding)

LS IBM Series(Injection Blow Molding Machine) can be applied to cosmetic, medical, food containers and baby products. IBM Series has the benefit of energy saving and quick cycle time.

(4) WIZ-E LSR Series(Liquid Silicone Rubber)

LSR(Liquid Silicone Rubber) is a non-toxic(colorless, odorless, tasteless) material and used in a variety of industries such as medical, electronics, home-appliances, automotive with its high temperature stability, dielectrical properties, and favorable burning characteristics.