Why injection molds use hot runners?

Why injection molds use hot runners?

After years of development, injection molds have become one of the preferred molds for manufacturing in all walks of life around the world, especially in the developed countries of Europe and The United States, which have advanced in the industry. The most important thing to mention is the use of hot runner technology in injection molds.

1, hot runner technology shortens the injection molding cycle

Because there is no limitation of the cooling time of the main channel and the secondary flow channel, the injection mold can be ejected in time after being solidified. Many thin-walled product molding cycles produced with hot runner molds can be completed in less than 8 seconds.

2, eliminating subsequent processes is conducive to production automation.

After the workpiece is formed by the hot runner mold, it is the finished product, and there is no need to trim the gate and recycle the cold glue lane. Conducive to production automation. Many foreign manufacturers have combined hot runners with automation to significantly increase production efficiency.

3, hot runner technology saves plastic raw materials

In the traditional mold injection, the nozzle material is produced. The high plastic product is not allowed to use the water material (recycled secondary material). Because the reuse of the nozzle material will degrade the structure and performance of the plastic part, the reuse will affect the product quality. There is no cold runner in the hot runner mold, so no nozzle material is produced (fees are required). This is especially significant for applications where the price of plastics is expensive. In fact, the major hot runner manufacturers in the world have experienced rapid development in the world when oil and plastic raw materials are expensive because hot runner technology is reducing materials and reducing materials. Fees, an effective way to save costs.

Expand the application of injection molding process

Many advanced plastic molding processes have been developed based on hot runner technology. Such as PET preforming, multi-color co-injection in the mold, a variety of materials co-injection process

4, reduce the defective products of injection molds and improves product quality

During the hot runner mold forming process, the plastic melt temperature is accurately controlled in the runner system. The plastic can flow into the cavities in a more uniform state, resulting in a consistent quality plastic part. The hot runner molding plastic parts have good quality, low residual stress after demolding, small deformation of plastic parts, and greatly improved surface appearance of injection molded products. Therefore, many high-quality products on the market are produced by hot runner molds. Many familiar plastic parts, such as telephone casings, mobile phone cases, printer cases, computers, and automobiles are produced using hot runner molds.

Design points for injection molding parts

Design points for injection molding parts

In the injection molding process, due to the uneven cooling and uneven shrinkage of the plastic in the cavity and the unreasonable structural design of the injection molded part, it is easy to cause various defects of the product:

Shrinkage, weld marks, pores, deformation, napping, top injury, flash.

  

In order to obtain high-quality injection molding products, we must fully consider the structural processability when designing the products. The following is a combination of the main structural characteristics of the injection molding products to analyze the methods to avoid injection defects. Design points for injection molding parts

1 mold opening direction and parting line

Each injection molding product must first determine its mold opening direction and parting line at the beginning of the design to ensure that the core pulling mechanism is minimized and the influence of the parting line on the appearance is eliminated.

  1.1 After the mold opening direction is determined, the reinforcement ribs, snaps, protrusions, and other structures of the product are designed to be consistent with the mold opening direction as much as possible to avoid the core pulling to reduce the seam line and prolong the life of the mold.

1.2, For example, the direction of the mold opening of the bumper is generally the direction of the body coordinate,. If the mold opening direction is designed to be inconsistent with the χ axis, the angle must be indicated in the product drawing.

  

1.3 After the mold opening direction is determined, the appropriate parting line can be selected to improve the appearance and performance.

2 draft angle

2.1 Appropriate draft angle can avoid product pulling. The smooth surface should have a draft angle greater than 0.5 degrees, a fine grain surface greater than 1 degree, and a rough grain surface greater than 1.5 degrees.

2.2 Appropriate draft angle can avoid product top injury.

  

2.3 Deep cavity structure product design When the outer surface slope is required to be smaller than the inner surface slope, to ensure that the mold core is not biased during injection, to obtain a uniform product wall thickness, and to ensure the material density strength of the product opening.

3 product wall thickness

   3.1 All kinds of plastics have a certain wall thickness range, generally 0.5 ~ 4mm, when the wall thickness exceeds 4mm, it will cause the cooling time is too long, resulting in shrinkage and other issues should consider changing the product structure.

  

3.2 Uneven wall thickness will cause surface shrinkage.

3.3 Uneven wall thickness can cause pores and weld lines.

4 stiffeners

4.1 Reasonable application of ribs can increase product rigidity and reduce deformation.

 4.2 The thickness of the ribs must be less than 1/3 of the wall thickness of the product, otherwise the surface will be reduced.

New purchasing strategies in the global economic slowdown

What will happen to the world economy in 2019? A large number of uncertain factors have left the world economy in a fog, and overall, anxiety and optimism coexist. Basically, the global economy will slow down in 2019. Since the beginning of 2018, emerging market economies have suffered from capital outflows, weakening the economies of emerging countries, leading to currency depreciation, rising inflation, and reduced household purchasing power. In the second half of the year, some emerging markets broke out in a currency crisis, geopolitical situations were once again tense, trade frictions escalated, and the risk of a resurgence of the crisis was reshaping new growth patterns through different forms.

In the global economic downturn in 2019, companies have become increasingly difficult to survive. Especially for large and medium-sized enterprises, faced with high labor costs, rental pressures, and rising raw material prices. How to find the right supplier, reduce the procurement cost and ensure the quality?

1, how to reduce procurement costs

Currently, companies are in a highly competitive and rapidly changing environment, and competition has caused the industry's average profit to fall. It is increasingly difficult for companies to establish or maintain sustainable competitive advantage through sales and production; there is still room for development in the procurement field that has been neglected for many years.

Effectively reducing the overall cost of procurement and integrating supplier capabilities through strategic procurement will become an important source for leading companies to continuously reduce procurement costs and enhance their competitive advantage. Therefore, the focus of procurement is on how to choose suppliers, especially the supplier price comparison that pays more attention to the transaction process. Through the competition of suppliers, choose the lower price as the partner. Perhaps the blind pursuit of low prices may lead to a decline in quality. If you cooperate with CN-MOULDING, you don't have to worry about this problem. CN-MOULDING is a typical small and medium-sized enterprise in China. The company is not too large. It is a real manufacturing enterprise. CN-MOULDING can supply customers directly, eliminating all the difference in the middle and reducing costs. The company coordinates Shanghai has geographical advantages, convenient import and export, familiar with business operations, saving time and cost.

2, how to choose low-cost high-quality suppliers

Taking CN-MOULDING as an example, an injection mold company was established in 1997 and has been a small and medium-sized private enterprise for 20 years. Since its establishment, it has been focusing on mold manufacturing and injection molding. Since 2001, it has been engaged in the foreign trade business. It has a large customer base and recognition in Europe and America. With its exquisite technology and rich experience, it has been provided to customers in more than ten countries and regions. solution:

1. Help customers to properly adjust the wall thickness of the product and find the best balance between product quality and production cost.

2, predicting the appearance of weld defects, gas marks, trapped gas, and other defects,

3, predict and control on the mold. Predict product distortion,

4, Help customers to improve the product assembly structure, the front design to avoid deformation.

5, rationally arrange the glue and cooling system to achieve the best process and the most economical investment.

6, to provide optimized production process parameters to help customers solve the problem of product injection production.

The following mold is produced by CN-MOULDING for American customers. It is bulky, thin wall, complex in structure, high in precision, and more difficult to de-mold the gas roof unit. At that time, CN-MOULDING was not the first choice partner of customers, but more inclined to have large companies on a large scale. In the eyes of customers, big companies mean high quality, high standard, on-time delivery, after-sales service and so on. But ignoring an important issue is the cost of procurement, the quality of the mold is excellent, is the price equally satisfactory?

After the customer revealed that the original mold price was 680,000 RMB, far exceeding their budget. Then the friends around me came to Shanghai CN-MOULDING company to visit and inspect, and offered the quotation on the spot, the total price was 476,000 RMB. They said that it is hard to believe, after all, the price is only 70% of the previous company. It is also doubtful that such a low price can really be achieved? Can you really guarantee the quality of the mold? Is the after-sales service guaranteed? Wait for a series of questions. CN-MOULDING has shown that the larger and more difficult mold cases that have been done before have been shown to customers. Although CN-MOULDING is a small and medium-sized enterprise, it has 20 years of experience in mold manufacturing, and the cooperative companies have many world-class companies. The business has also spread to more than ten countries and regions. Numerous successful cooperation cases have enabled customers to have confidence that CN-MOULDING is a professional, experienced and trustworthy mold manufacturing company.

More production processes 
https://www.youtube.com/watch?v=b3lB0wqWYB0  

China's small businesses are fundamental to the vitality of production

There are tens of thousands of small and medium-sized enterprises in China. SMEs are the most dynamic and innovative enterprise groups in China. At the same time, SMEs provide more than 50% of tax revenue, create more than 60% of GDP, and complete more than 70% of invention patents, providing 80%. More than % of urban jobs. SMEs have a pivotal position and have unique advantages. With reasonable prices, rich experience and reliable quality, they are gradually replacing the original large enterprises.

CN-MOULDING is a small and medium-sized enterprise in China that is dynamic, innovative, and professional, and directly supplied to foreign countries. In 2015, we obtained ISO9001:2000 quality certification! With 20 years of integrity, 20 years of experience, and 20 years of quality assurance and after-sales protection.

Injection operator processing requirements

1, plastic product quality requirements 
1, the injection forming of the product, must ensure that the product structure is complete, there is no less material, more material phenomena.

2, product surface bright, uniform chromaticity, full.
3, the product surface is not filled with flowers, impurities, defects such as black spots.

4, the product shape neat, there is no deformation, warpage, and the internal products are obvious bubble phenomenon.

5, the product can cooperate with relevant parts is normal, without external force cannot be separated.

6, the assembled product to need, after assembling the operator's need to introspection, to ensure that products meet quality requirements. There is no
Not installed in place, packing, and have a fracture phenomenon.

2, the plastic products trimming 
1, the product of the inlet with trimming knife cutting, cutting mouth who can not have an express white appearance.

2, when trimming knife trimming, forcibly when repairing products shall repair products outside introversion, resistance force direction is not allowed to have another hand

3, product trim on the handle of the strength should be uniform, can guarantee a hard cut product as much as possible, long group of the front, middle
Not stagnation, a fix to the end, to ensure that after trimming the edges of the beautiful appearance.

4, the surface of the product by trimming does not allow defects wavy lines and uneven.
5, to remove the inlet area, trimming should level off, allow the phi 10 from minor scratches, trimming to improper Other parts are not allowed to have should be trimming undeserved cause scratch defect.

6, to put front height is greater than 0.2 mm should be handled for trimming (unless adjusting injection parameters to solve), especially in the production
The product outline on the edge of the phi front must be removed.

7, for different products, it is suggested that should use different types of trimming knife, to ensure product quality, improve the efficiency of trimming. 8, don't allow should trim other qualified on the surface of the damage caused by improper operation (such as good surface scratch, cut, etc.).

3, product storage and handling 
1, product stacked on the pallet height should not exceed 1.2 mm, the number of the same specifications each building products must be the same, with winding mode finally. For small products in the turnover box, the bottom in turnover box height should be 10 cm, the turnover box the loading weight of not more than 25 kg.

mold life what is factor affect

 mold life what is factor affect

No matter what kind of object has a certain service life, the injection mold is no exception. When the mold is used to a certain extent, the injection mold will be invalid. It is necessary to open the mold to produce a new mold. The service life of the injection mold is affected by many factors, only An injection mold factory that fully understands these factors can produce molds with longer life.
The first factor affecting the life of an injection mold is dissolution failure. The injection molding alloys commonly used in injection mold factories are zinc alloys, aluminum alloys, magnesium alloys, and copper alloys, as well as pure aluminum injection molding. Zn, Al, and Mg are more active metal elements, and they have a better affinity with mold materials, especially Al is easy to bite. When the hardness of the mold is high, the corrosion resistance is good, and if the molding surface has a soft point, the corrosion resistance is disadvantageous.

The second reason that affects the life of injection molds is thermal fatigue, which leads to failure of crack damage. During injection molding, the mold is repeatedly subjected to the action of stimulating heat, and the forming surface and its interior are deformed, causing repeated cyclic thermal stresses. The damage of the structure and the loss of toughness lead to the appearance of microcracks and continue to expand. Once the cracks are enlarged, the molten metal liquid is squeezed in, and the repeated mechanical stress causes the cracks to accelerate and expand. For this purpose, on the one hand, the mould must be sufficiently preheated at the beginning of the injection. In addition, the mold must be kept in a certain operating temperature range during the injection molding process to avoid early crack failure. At the same time, it is necessary to ensure that the internal factors before and during the production of the mold are not problematic. Due to actual production, most mold failures are a crack failure.

The third reason that affects the life of the injection mold is the failure of the fracture. Under the action of the injection force, the mold will crack at the weakest point, especially the trace marks or electro machining marks on the molding surface are not polished, or Fine cracks appear first at the clear corners of the molding. When there is a brittle phase or coarse grain in the grain boundary, it is easy to break. The crack propagates rapidly during brittle fracture, which is a dangerous factor for the failure of the mold. For this reason, on the one hand, scratches, electric machining marks, etc. on the mold surface must be polished, even if it is in the casting system, it must be polished. In addition, the mold material used is required to have high strength, good plasticity, impact toughness, and fracture toughness.
 
      After understanding the three factors that affect the service life of injection molds, CNMOULDING injection mold factory can adjust these problems in the process of manufacturing, avoiding the influence of these factors in advance, and making better quality molds. It not only greatly improves the efficiency of production, but also saves the production cost of the enterprise.

There are also some reasons that affect the precision of the mold.

Sensors on the car

Sensors on the car

Now the car is more and more intelligent, many functions on the car are controlled by the computer to complete, such as engine systems, transmission systems, suspension systems, brake systems, air conditioning systems, body control systems and so on. The computer has to control the system, must obtain the correct information to confirm the state of the system, and then issue the correct instructions to control the system action, so the implementation of the driver's intention, the correct control of the car. The information on these reaction system states is done by a component called a sensor. Even a very common car, up to dozens of sensors, and up to hundreds of cars. So what are the effects of these sensors?

What is a car sensor?

We are in the daily maintenance of the car, often hear a variety of sensors, then in the end what is the car sensor?

In the operation of the car, the system will be in different working conditions, such as water temperature, oil temperature, intake pressure, speed, throttle position, stalls, etc., these information car computers can not read directly, must be translated into the computer can recognize the electrical signal. Car sensor is the implementation of this task, it is running the car light, electricity, temperature, pressure, time and other information into electrical signals, and then enter the car the computer system, and then by the computer in advance of the stored procedures for the calculation and analysis, thus Determine the running status of the car. Now the car on the sensor is very much, here we talk about the car system in the name of the sensor and the role.

Injection molding is equally important for medical products

1, the intake pressure sensor

Intake manifold pressure sensor (MAP)

The function of the intake manifold pressure sensor (MAP) is to detect the degree of vacuum of the intake manifold and to convert the pressure signal into an electronic signal to the engine control computer. It is the main reference signal for controlling the pulse width and ignition timing

Divided into two types of semiconductor varistor and capacitive intake manifold pressure sensor.

Ingress manifold pressure sensor failure, the engine will start difficult, performance disorders, acceleration deterioration, idle instability, fuel consumption, accelerated instability, accelerated tempering, blasting, fuel consumption, deflagration and other failures.

2, the crankshaft position sensor

Crankshaft position sensor (CKP)

Crankshaft position sensor (CKP) is one of the most important sensors in the engine centralized control system. It is an indispensable source for confirming the crank angle position and the engine speed. The engine control module (ECU) uses this signal to control the fuel injection quantity, Timing, ignition timing (ignition advance angle), ignition coil charging closure angle, idling speed and electric gasoline pump operation.

3, the camshaft position sensor (CMP)

The camshaft position sensor is used to detect the angular position of the camshaft. The engine control module (ECU) uses this signal to determine the cylinder sequence of the engine to control the injection sequence, the ignition sequence

When the camshaft position sensor fails, the engine output power will be reduced.

4, the engine coolant temperature sensor (ECT)

The engine coolant temperature sensor is used to detect the temperature of the engine coolant and convert the temperature signal into an electrical signal to the engine control module (ECU) as the primary correction signal for gasoline injection, ignition timing, idling and exhaust emission control.

5, piezoelectric knock sensor

The knock sensor is used to detect the knocking of the engine during combustion and to send the knock signal to the engine control computer as an important reference signal for correcting the ignition advance angle

Knock sensor with non-resonant and resonant type of two, generally installed in the 2-cylinder and 3-cylinder, or 1, 2 the cylinder in the middle of a 3,4-cylinder in the middle one. The connection of the general knock sensor is wrapped with shielded wire.

When the knock sensor failure, the engine will deflagration, ignition timing inaccurate, high fuel consumption, power reduction, the engine work rough

Plastic Injection Mold Assembly Process Cnmoulding® (China)