injection mold manufacturer Archives

Injection Molding Runner Design in China

The Advantages Of Good Runner Designs To Help Injection Molding

10/21/2019Klarm Mould

The plastic injection molding process in China is possible because any thermoplastic material can be melted to a predetermined size and the Injection molding machinery is designed such that it can then be injected into a mold or cavity where it can be formed. The parts of the mold which are in the shape of the parts to be manufactured are the cavities. The formed part is then ejected from the injection mold.

The sprue is a part of the runner which injects molten liquid plastic material into the die or Chinese mold through the injection machine’s nozzle. The runner system, as well as the sprue, is the passage that connects the nozzle of the machine to the mold cavities. Runner connects the sprue with the cavity through the gate. The nozzle of the machine is connected to the runner by the sprue and come in designs of hot sprue or cold sprue.

The Injection molding runner design comes in three basic types – hot runner, insulated runner, and cold runner. The runner has to ensure that the liquid material is distributed so that it fills all the China molds under the same conditions and the same pressure at the same time. This will help to prevent flashing of the china injection mold and also helps in producing parts of a uniform and improved quality. Hot runner technology, which is externally heated is more practical and feasible since the plastic is maintained in a liquid state and most China mold makers use this technology.

The usage of hot runners in injection molding machinery is useful since it ensures better quality parts. They are particularly beneficial with uneven-shaped parts which might result in improper cooling or uneven flow. Hot runners also help in reducing plastic wastage. They are designed to reduce cycle time, thus helping to maximize manufacturing productivity. The challenge in design is to maintain the liquid plastic which is molten at an optimum temperature while the china injection mold cavity is being cooled at the same time. Internal as well as external heating methods are used generally in injection molding machinery. Thus the hot runner technology, which was introduced almost 50 years before in the plastic industry, has revolutionized the china plastic injection molding technology and its processing capabilities by enhancing the efficiency of operation, improving the quality of the parts, reducing wastage and scrap and thus in effect saving money.

A very critical consideration for injection molding runner design as well as the china injection molding process is to maintain a uniform temperature in the hot-runner manifold and the sprue bar so as to ensure consistency in quality. Another consideration to be taken by China mold manufacturers is regarding the runner system. The injection mold china cavities will not be filled properly if the runner is too small. If the runner is too large, then cooling time will be increased and the cycle time will be decreased. Proper design for runners for injection molding china is most essential to reduce the effect of sink, stress, and weld marks.

A good and efficient runner design is most essential for plastic injection molding machinery as it helps in producing better quality parts at a very reasonable and affordable rate due to higher efficiency and lower wastage. Currently there are many suppliers who provide injection molding systems from China at very good quality.

Resource box: This article is originally posted in https://www.injectionmouldchina.com.

How to calculate the exact gate and runner during mold design?

10/12/2019Klarm Mould

Gates and runners

An injection feeding model of injection molding china consists of various parts including the sprue which connects to the runner. The runner connects to the gate which is the smallest part in the radius, and then the gate finally joins the cavity of the mold. The proper gate and runner calculation of these parts are very important to keep the friction where the shear rate low. Balancing the pressure and temperature for proper flow of the plastic or resin is also essential.

Calculating the runner size

The runner is part of the injection molding unit of a plastic mold manufacturers factory which connects the sprue and the gate. It is a cavity-like portion which holds the liquid plastic before it passes through the gate and fills the mold in the right way. Therefore, the size of the runner must be calibrated and optimized by all means. This is because a proper sized runner will keep the balance of the flow properly and the pressure will be optimized. The pressure plays a very important role to fill the mold and the runner. To keep a balance of the pressure among the two cavities, the runner pressure should be 25 percent or less of the total pressure to fill the mold. A good runner from injection mold maker china will also make sure that the fluid is heated to reduce the excessive pressure push.

Calculating and determining the right size of a runner is very crucial for plastic tooling china industry. Because it will determine whether the mold is filled properly or not. There are two major points to keep in mind. These are the thickness of the runner and morphology of the material to be passed. For Semi-crystalline materials, smaller runners are workable in injection molding tooling china. But there is a need for larger runners to facilitate temperature rise and reduction of pressure for the amorphous materials.

Calculating the gate size

Gate size is important for filling the part cavity properly since it is the section between the cavity and the runner. Proper pressure is important, which will determine whether the cavity will be filled uniformly or not. The two important things in injection mold tooling china about choosing the right gate size are to minimize the pressure drop and to have balanced control over the packing stage of the gate. There is a different type of gates that can be found in the double color mold parts like a ring, edge, pinpoint, disk and submarine. You have to keep in mind their sizes as well.

Larger gates corresponds to lower pressure increase. Packing stage is longer in this case and vice versa for the smaller gates. The gate is the place where the molten plastic goes through the shearing and has the most shear rate due to smaller cross-section area. Shear rate is influenced by the cross-sectional radius and flow of the material. It is crucial in china mold-building services to keep the shear lower while filling the gate to cause smaller injection damage. This is the reason why shear sensitive materials like heavily filled resins, fiber-reinforced resins, amorphous resins and gates should be larger according to the injection mold makers in china. This will keep the lower the rise in pressure and temperature.

When you choose the china fundamental of plastic mold design or the oem/odm medical injection mold factory, you should keep in mind the size factor. This will make sure that you end up with a high precision plastic making mould china that can be effective in the prototype production.

Resource box: This article is originally posted in https://www.injectionmouldchina.com.

How to eliminate injection molding defects?

05/28/2019Klarm Mould

Injection molding is an art, which involves science as well. Actually, injection molding requires great attention to detail as minor mistakes can cause a lot of financial loss to a company. In this article, we are going to discuss how you can eliminate common injection molding defects.

Flow Lines

Flow lines may include lines, patterns, and streaks that appear on the prototype part because of the cooling profile or physical path of the molten plastic while it moves into the cavity.

Fix:

One way to fix the issue is to increase the pressure and injection speed, which will make sure that the mold will fill the cavities.
Another way is to round the locations and corners where the thickness of the wall changes.

Sink Marks

These are minor depressions or craters that form in the thicker areas when shrinkage happens in the internal areas of the end product.

Fix:

Reduce the mold temperature, increase the holding pressure and time for better curing and cooling.
Reduce the thickness of the wall sections that are the thickest. This will allow faster cooling and prevent the sink marks.

Vacuum Voids

Vacuum voids refer to the air pockets inside or near the prototype surface. They occur because of the uneven solidification amidst the inner sections and the surface.

Fix:

Find the gate at the mold’s thickest part
Opt for the plastic that is less viscous, which will reduce the amount of gas trapped.
Increase the holding time and pressure
Try to keep the mold parts aligned

Surface Delamination

Surface delamination happens when thin layers of the surface show up on the part because of a contaminant. Actually, these layers look like coats that can be peeled off.

Fix:

Before molding, make sure you dry the plastic properly
Raise the degree of mold temperature
There should no sharp turns and corners in the mold design

Weld Lines

Weld lines show up on an area where the liquid plastics mixes while they flow from different injection mold parts.

Fix

Increase the temperature of molten plastic or mold
Raise the injection speed
Make adjustments to the design to ensure that the flow pattern is only one source flow

Short Shot

Short shot refers to a situation that happens when a molding shot tends to fall short. In other words, the molten plastic won’t fill the cavity of the mold for some reason. As a result, it leaves a portion where you can see plastic.

Fix

Opt for a plastic that features higher flow and less viscosity
Raise the mold temperature for better flow
Get a machine that features more material feed

To cut a long story short, you may have to face a lot of defects during the process of injection molding in China. What you need to do is follow the tips given in this article to fix or eliminate these issues to make the process error free. Hopefully, you will find these tips helpful.

Resource box: This article is originally posted in https://www.injectionmouldchina.com.

Difficulties of molding different plastics on injection molding

05/18/2019Klarm Mould

When it comes to plastic injection molding, manufacturers have a lot of problems and difficulties to deal with. Manufacturers use plastic for many reasons, such as design flexibility, affordability, and lightweight, just to name a few. Making parts and designs with injection molding has some difficulties. Let’s take a look at them.

During the injection molding process, you may have problems, such as parts deformation, structural weakness, surface blemishes, warpage, shrinkage, parting lines, voids, and air traps, to name a few.

All these problems may add to the cost of manufacturing. For streamlining the process, you have to use the trial-and-error prototyping process in a virtual environment.

Making tools that can help make high-quality injection-molded parts requires you to consider a lot of variables. For instance, it includes the optimal temperatures of the plastic, cooling channels, and the configuration of these systems, to name a few. Aside from this, you also need to consider pressure, flow rate, thermoplastic material type, solidification time, and so on.

If you have the required mold-filling simulation, you can easily balance the design against manufacturability. Moreover, mold makers can choose to optimize tools without the need for prototype molds. This way the manufacturers can also reduce run cycles, which results in better quality, reduced costs, and less time consumption.

Actually, the primary factor that you need to keep in mind in order to avoid the traditional problems associated with plastic injection molding is the accuracy of simulations.

Evaluating Manufacturability

With plastic injection molding simulation, designers can get answers to common questions related to part filling, air traps, voids, and gate locations, to name a few. With the help of these analyses, designers can perform the simulation of the mold-filling stage in order to understand whether it can speed up the tooling design and production process.

Optimization of the Mold Design

The primary goal of a Chinese mold maker is to develop injection molding tooling that can produce quality parts without costing a lot of money. Moreover, this simulation offers extra tools to optimize tooling designers of different complexity levels. And this helps mold makers simulate different phases like filling and packing.

Improving Cycle Times

It’s really important to reduce cycle times by ejecting quality parts in the shortest time span possible. If advanced capabilities are used, plastic injection molding can help specialists hit the best balance between quality production and short cycle times.

All of this helps the designing and simulating of the cooling line layouts, processing parameter optimization and the making of conformal cooling systems.

Improving Mold-Filling Simulations

Nowadays, manufacturers can enjoy a lot of benefits by molding plastic parts instead of using the traditionally machined parts. For instance, they can reduce costs, scrap, weight and increase the design flexibility via the production of design and shape geometries that are more complex.

However, they can only enjoy these benefits if they boost the design and the productivity of the tooling. Nowadays, manufacturers can improve the performance and efficiency of their operations if they choose to replace or improve the conventional mold using the mold-filling simulations.

So, this was a description of some of the difficulties that manufacturers face during the plastic injection molding process and how these problems can be fixed.

Resource box: This article is originally posted in https://www.injectionmouldchina.com.

How to design injection mold gate?

01/17/2019Klarm Mould

An injection mold gate is a small hole that allows the molted stuff into another mold chamber. For a successful design, designers have to consider a lot of factors, such as mold pate types, materials, location, dimensions, gate type, and many economic factors, just to name a few. Let’s find out how an injection mold gate is designed by a Chinese injection mold making factory.

Gate design carries a lot of importance if you want to get high-quality mold parts. Given below are a few factors that should be considered when designing the injection mold gate with injection mold design services in China. Read on.

Material

First off, choosing the right material is really important for the design process. Use the wrong material and be ready to suffer a loss. Based on the type of machine, the right material should be used.

Keep in mind that castings are strong enough to withstand the stress. For stronger parts, the cast material should be machined first. If you need to work on sharp corners, know that it can create difficulties during the molding process.

Size

The size of the gate also depends upon the resin and the part that you are going to mold. It’s important to note that small gates offer a better look but they take higher pressure or longer mold time for proper fill.

Also, high pressures in the cavity cause more stress, which can result in a structural failure.

On the other hand, bigger gates allow smoother resin flow and reduced mold time. Now, if the size of the gate is not right, it may restrict the molten resin. As a result, the material won’t be able to reach the next cavity. In another scenario, this restriction may slow down the filling rate, which may reduce the process efficiency significantly.

In the worst case scenario, if the size is not right, you may end up with gate defects, such as black streaks and mold warpage, just to name a few. So, the size of the gate is of great importance.

Location

Just like size, the location of the gate can have an impact on different factors. And these factors are extremely important for the whole process. Given below are some of those factors.

Aesthetics (flow lines, voids, sink marks, gate marks)
Operational considerations
Wrong flatness or roundness
Mold warpage
Part shrinkage
Wrong structure or strength of the part
Molecule orientation

At times, multiple gates are required in order to enjoy the best results. However, for using multiple gates, designers may want to take into account the meeting area of the flows, as this can cause many issues related to aesthetic and component weakness.

Defects

Now, let’s talk about the defects. Know that whether it’s the wrong position or size, any defect may cost a great deal of time and money. To correct the issues, the location of the gate may need to be changed. In some cases, the entire mold has to be re-configured.

So, these are a few things that can help you find out how you can design an injection mold gate by an injection mold maker in China.

Resource box: This article is originally posted in https://www.injectionmouldchina.com.

What Are The Purposes Of Hot Runner In Making Plastic Injection Molds?

12/14/201812/14/2018Klarm Mould

Basically, the injection molding process has been used the traditional way, which is known as the cold runner system. Nowadays, another method is getting popular. It’s known as the hot runner system. In this process, liquid substrate is put into the mold via a nozzle. So, the runner is kind of a passage through which the material travels. During the process, the substrate doesn’t cool down or get hard. Let’s find out why most people go for the hot runner for their plastic injection molds.

During a hot runner process, the mold is heated up and then cooled down once all of the cavity is full. Remember: the hot runner process may use many ways to heat up the injection mold, such as hot oil, hot water, induction/steam heating for quick heating. Unlike the cold runner system, this system cause fewer issues.

Now, let’s discuss why people go for the hot runner system in the injection molding process.

Less waste: This is an important point. In the hot runner system, the substance that passes through the chambers remains hot even when it reaches the last stage. In the cold molding, on the other hand, the runner is either discarded (waste) or recycled/reground. This is a disadvantage.

Quick cycle: As said earlier, the runner process requires time and may cause a loss of resource if enough time is not given. By fixing these problems, the hot runner system can boost the cycle times.

Keep in mind that the cooling and heating mold takes more time. Often, the time is offset through the savings from the elimination of the runner. However, it’s better to discuss the topic with your service provider.

Quality output: the removal of runners from the cold molded components requires a mechanical process. The product may get rejected if it is not up to the mark. In other words, the look and function of the product should be acceptable.

On the other hand, the hot molding can help resolve many issues, such as surface irregularities and burn marks, just to name a few.

Lower costs: cost is an importance consideration when opting for a cold or hot molding for a long-term. The initial cost of cold molding is less but the hot the hot runner system is a cost effective option as far as the long-term use is concerned.

Range of material: Actually, the inherent chemical composition of most of injection molding substance makes them a bit too “allergic” to temperature changes. The impact is stronger in extreme temperatures. So, for lower temperatures, the hot runner system is the way to go.

Colorant options: The hot runner system allows you to benefit from colorant mixtures in the process. So, this is another reason people opt for the hot runner process.

Long story short, these are the reasons the hot runner is an ideal choice for the majority of plastic injection mold projects. If you are looking to increase production in an efficient manner, we suggest that you give a go to this process. Hope this helps.

When it comes to hot runner injection mold, china plastic injection molding is the best choice.

Resource box: This article is originally posted in https://www.injectionmouldchina.com.

How to calculate production costs of making an injection mold

10/10/2018Klarm Mould

With the coming of the modern age, there have been a lot of new techniques that have been developed, but one can safely say that not all of them have been adopted by the industry. There are many reasons for it like they are not eco-friendly, or they can’t be easily automated, but the major reason that leads the way is they are not economically viable. There is no point in appointing a technique to produce something which is not worth the cost that one spent on creating it.

Injection molding is one such technique that has gained the attention of various industries and everyone is talking about it, but the same question still worries everyone, that what is the cost associated with it. In this article, we will try to describe how one can get a rough estimate of how much cost it will be on them once they start implementing the method.

Production rate: – One must have an idea about the product that they are going to make and how many cavities will be in there as it plays an important role in deciding the amount of material required which directly controls the total cost. Another thing that they need to aim for is the number of parts that will be produced in each cycle and the number of cycles in an hour. The larger the number of products produced in each cycle and the number of cycles in an hour, lower the cost of production.
The injection molding material used in each cycle: – It is not a good idea to simply measure the weight of the end product and then decide on how much material do you want. A substantial quantity of material is also scraped and wasted here and there and must be considered as well while calculating the material cost. An idea about the number of cavities that you will be having will also help with this
Other costs: – Other costs include the number of workers that you will be needing to carry out the different manual or automated operations. Workers doing manual work have low wages, but they will be needed in a large number while the workers working on the automated machine are skilled and will have a higher wage as compared to the workers doing manual work. Factors like the idle time of the different machines, post-processing time and the cost associated with giving final touches to the product must also be taken into consideration.

These are just some of the factors that go on deciding what the total cost will look like as they cover the core operations associated. Even the smallest of changes can go on to affect the total amount by a good amount and that’s why one should always aim to find the optimum method so as to balance all the cost involved resulting in the maximum profit that is the main goal.

Since China is the best place for any company to set up their factory, it is important to know about the China injection mold cost and on what factors does this amount depend on.

Resource box: This article is originally posted from https://www.injectionmouldchina.com.

What are the Worldwide standards of plastic injection molds?

08/23/201810/10/2018Klarm Mould

In the modern age, there are more and more upcoming manufacturing methods coming up that are allowing the industry to move in the forward direction at a great pace without compromising on the quality of the material being produced. Injection method is one such manufacturing process that has dynamically changed the whole industry and is being used by most of the major companies.

Injection molding method is the process of making or manufacturing any parts that are being required by injecting the molten material into a mold which is in the shape of the desired material. This technique is usually used with polymers and plastic, but can also be extended to different metals as well. Since this method is now being used by a large number of industries, there should be some standard that must be set at a global level so that the parts can be used all across the world without any tension of it malfunctioning or breaking down in between. There are specific technical specifications of the injection mold standards that need to be attained in order to make your product qualify as being usable. We will be discussing some of the most basic and elementary standards that need to be followed and one can look for a more detailed explanation on the internet afterwards.

Eco-Friendly: – the major reason to devise new techniques for everything these days is to save the environment and that goes for this technique as well. Polymers and plastics have long been ridiculed for their non-biodegradable nature and that’s why their usage has always been debated. Since this method aims to produce parts that will be used in the other industries, it is important to make sure that there is no major cause of pollution that will impact the environment in the long term as well as short term.
Durability: – Since the parts or the products made from injection molds will be used in the industries, they should be durable and long lasting. There is no point in manufacturing something that will break after only some days of use or will fall apart by the application of a small force.
Economical: – One of the major reasons people are trying to find more means and methods to use plastic components in an effective manner is that they are pretty cheap. The product that is being manufactured should be cheap in comparison with the other alternative products that are available in the market.
Automated: – Since we are dealing with molten materials, the automated process should be preferred because of many reasons. First of all is that it will largely reduce the accidents caused while handling molten materials, increase the work rate and save the cost of the workforce as well.

These are only some of the things that are standardized. There are a lot more things like the type of plastics that can be used, minimal smoothness that a product needs to have and many more. One should make sure that they comply with every rule so that they don’t face any difficulty in the near future.

China, having such a large workforce, is an ideal place for the companies to set up their factory and that’s why can find a large number of mold company China that are operating in the region successfully and have created a name for themselves.

Resource box: This article is originally posted from https://www.injectionmouldchina.com.

How to calculate injection molding cost

07/02/2018Klarm Mould

The question is a straightforward one, but there are various things to consider while calculating the cost. Factors like the durability of the mold, shipping cost, material selection, maintenance costs, etc. affects the final cost. The cost differs for every purchaser in different situations. You can go from the lowest to the highest depends on your choice and budget.

The durability of the mold – The injection mold you are choosing for should last for the entire program; if it loses its shape or characteristics then buying it will be just a waste of money. Also making a purchase from a trusted source is better to avoid future complications if the product turns out defective.

Shipping cost – It is a matter of concern for those who are buying mold on a foreign land. Getting it shipped to your workplace could be costly. It can cost a good share of the final price you pay for the product.

Maintenance cost – If you are making purchase offshore then its maintenance is your responsibility and getting it home with safety and looking after requires more money. If something misshapen during shipping then it may affect the product’s productivity. In such conditions, you will be obliged to make another purchase. And precaution is better than cure. It is better to invest a little more in its safety than buying altogether a new one.

Material selection – It is an important factor to keep in mind while selecting. Your payment rate depends upon the type of material you choose. The material should be strong enough to endure all the mechanical pressure it is about to go through.

Roughly the cost of the injection molding is the price finalized on the RFO but apart from this the cost of the mold also includes many factors that cannot be measured. That is the experience of the builder and what technique he is using. If the builder is good at his job and is experienced then work becomes easier and the cost of repeating the cycle again reduces bringing monetary savings. These things are not written on papers, but if you give it a thought then can cost you a good whooping amount. Plus there is always little wiggle room in the final cost of any product. It is better to keep a little sum aside for safety purposes. It will keep you ready in hard situations.

In case if you have already a fixed amount in your mind and don’t want to spend any extra buck then you should tell so to your mold builder. That way the mold will be designed with your instructions and budget in mind. If the number of cavities is higher in every per cycle then the parts will be less expensive allowing higher input. You can also opt for the basic products supplied by you rather than paying for it as part of the final product. Through these small hacks, you could save much money.

Need more insights on injection mold selection and costing then visit https://www.injectionmouldchina.com. They will not only provide you proper guidance but are also makers of best injecting mould in China. Here you will get all the details on China injection molding cost.