Technical Inquiry-Injection

A：
PC plastic is more serious than ABS because of its higher viscosity index (thicker). This is also the reason for the "shadow". When the plastic flow is blocked by the rectangular column, the colder plastic flow (thicker) at the front end is easier to block and form a shadow than the higher temperature plastic flow (thinner) at the back end. The reasons for the thicker plastic flow at the front end include the low temperature of the material head, the long contact time with relatively cold air, and the difference in physical effects of thick and thin viscosity on the obstruction of injection energy. Usually, the problem can be improved by improving the low temperature of the material head, increasing the overall material temperature, and reducing the injection energy (injection speed x injection pressure). However, in more serious cases, the effect is usually not significant. At this time, we need to explore the relationship between injection energy and liquid damping coefficient. Injection is the process of ejecting plastic flow with high energy. The higher the energy, the more obvious the above phenomenon is. The injection energy will be increased because it must overcome a series of heavy-layer blockages from the material tube nozzle, mold sprue, runner, product gate, etc. According to fluid mechanics, as long as there are two series, the flow will be blocked (one blockage will not, the fluid will only accelerate through without reducing the flow rate, and of course one blockage cannot be too serious). Therefore, the volume of these gates must be increased to effectively reduce the plastic flow blockage, and the injection energy can be lowered, which can reduce or even eliminate the shadow. The above four runners are the least likely to cause obstruction (usually the mold runners are too large). It is necessary to check and calculate the product gate and the mold sprue. If necessary, the diameter of the material tube gate must be increased. Due to these improvements, the injection energy can be lowered, and the physical effect when the front plastic flow contacts the obstruction will be slowed down, which can naturally improve or eliminate the shadow. To give a more extreme example, if it is liquid silicone or plastic with a low viscosity index, this problem usually does not occur. It is because the process focuses more on filling and less on injection components. Without injection energy, it will not happen. Therefore, minimizing the injection component in the process is the key to fundamental change.

The principle of injection compression is to complete the clamping action in stages, using a professional injection molding machine to complete the following actions: increase the transfer force, reduce the internal stress of the product, produce thinner products, produce thicker products, and enhance the exhaust function of the mold. In actual operation, it can be divided into two situations: full compression and local compression. It is necessary to design a radial cut-in groove with the mold. Some, such as increasing the exhaust function, can also be done with a general mold. The local compressor is combined with the design of the double-layer support plate of the mold to perform local compression, which is a good choice.

The compression of injection molding machines is currently widely used in thin light guide plates. The advantage is that it can effectively reduce the clamping force specifications of the injection molding machine. The important thing is that the injection compression action must be started and the speed must be very fast to match the high-speed injection. The injection can be completed in about 0.2 seconds. For fast start, it is recommended to use electronic ruler positioning. In addition, the pressure detector can be used to increase the accuracy of the injection molding machine start timing.

What Is Micro Injection Molding?

Micro injection molding is a precision technology. Any product whose size, functional features, or tolerances are measured in millimeters or even microns can be classified as micro injection molding. The micro-scale features of micro injection molding require specialized molding machines and auxiliary equipment to complete various production operations.

• Lightweight products with injection weights of 1g or below 0.1g
• Products of any weight that contain some micro-scale (micron-level) structural features

How Does Micro Injection Molding Differ from Conventional Injection Molding?

Due to the extremely small injection volumes and highly precise structures, both the physical properties and processing methods have changed. Micro injection molding cannot be achieved by simply scaling down a conventional product or by using a smaller general-purpose injection molding machine. To successfully manufacture micro injection molded products, the product design and precision requirements must be carefully analyzed, combined with the overall mold design. Using suitable precision micro injection molding machines enables efficient production of highly precise micro molded parts.


〈Further FAQ: What are some actual injection cases of EdeX micro injection machines? Can they prove superiority over other brands?〉
〈Further FAQ: What is the difference between parting-line micro injection machines and general micro injection machines? How should we cooperate?〉

The EDEX Atom series micro-injection machine took a year to develop and undergo complex testing steps, and was tested around the clock for three months before it was launched on the market. Currently, there are actual production cases in nano products, thin light guide plates, precision terminals, fiber optic products, micro fans, medical micro products, optical lenses, etc., and the smallest product can be as small as one thousandth of a gram.

The actual case of micro injection is that it can produce 0.02mm screens, successfully produce laser aspheric lenses that have been verified to be unqualified by Japanese micro injection molding machines, produce precision terminals 35% faster than Japanese machines, and produce a certain optical fiber product 50% faster than German machines. The defective rate of a certain micro-structure product has been reduced from 22% by Japanese machines to zero. After our evaluation of mold integration, the production of micro components has been reduced from 23 seconds per mold by Japanese machines to 4.5 seconds, which is 5 times faster. The above are just some representative examples. If you have any needs for micro injection technology, please contact us for testing and jointly improve more technologies in the field of micro injection.

The parting line injection machine is an injection method that injects from the top or side of the joint surface of the male and female molds. The main feature is that the mold does not have a sprue, but instead a straight cross runner is milled on the parting surface. This can not only reduce plastic loss, but also greatly shorten the molding cycle because there is no need to consider the extra cooling time of the sprue. The sprue is usually thicker because it needs a slope of at least 1°, so it requires more cooling time. The continuity of production is often affected by the breakage of the sprue. The severity of this problem is more prominent in the field of micro-injection. The parting line injection method can be said to be the ultimate solution for micro-injection.

We will have professional personnel to evaluate and only need to make minor modifications to the mold to prepare for production. Why do you only realize now that you have not been able to promote it? Even in Japan, there is only one company, JUKEN, that produces this type of injection machine. The main reason is that the applicable molds are not uniform. The specialized injection machine equipment means that when the product volume is small, the machine is idle, resulting in waste and increased costs. The Atos series precision parting line micro injection machine launched by Ides can overcome these problems. We use precision module design, and if you need to restore the horizontal injection machine in the future, you can easily modify it. There is no need to weld, drill holes, tap, etc. on the machine. It is the best solution to solve problems and save costs for the benefit of customers. We are committed to guiding micro injection into a more challenging and fine field.

• Designed with L/22 = P, both large and small diameter barrels are designed with 22 segments to ensure the raw material achieves the most uniform mixing effect inside the barrel.
• Accurate tolerances reduce backflow and improve efficiency. The backflow ring has a tolerance of 0.1%, and the screw section 0.2%, achieving high standards of material transfer and heat conduction efficiency, minimizing reflux volume and thus maximizing transmission efficiency.
• The gap between the screw and backflow ring is precisely designed to control the shot end position within 0.5 mm; using more precise injection modes can control it within 0.1 mm.
• At the contact between the screw and drive shaft, a unique groove-free design is applied, providing maximum strength and reducing the chance of screw breakage, bending, or twisting.
• Barrel assembly linearity is critical. Besides precise tolerances on barrel outer diameter and injection seat bore, the injection seat uses a force-free mechanism design to ensure linearity and true roundness during injection and material loading, maximizing barrel performance and reducing wear to extend service life.
• All screws use an integral design to increase strength and reduce breakage risks, and also prevent contamination issues caused by high-temperature materials like PC penetrating the gaps between the triangular screw threads.

• The diameters of small and medium nozzles differ, and their heater band power is also different. Controlling their temperatures together can cause the small nozzle to be underheated, which affects injection quality.
• Because the small nozzle is in contact with the mold for a longer time, it tends to overheat more easily and has better heat dissipation characteristics. Its temperature is usually lower and less stable, so it requires independent temperature control to maintain stability. It is recommended to use a hook-type thermocouple to get the closest and most accurate temperature reading near the nozzle tip.

• Because the plunger-type injection machine rotates in place without retracting, the plastic passes evenly through all screw threads, achieving optimal mixing and greatly improving injection quality.
• Since the screw no longer requires a check ring or other backflow prevention function, smaller diameter screws such as 14mm can be designed. If used with smaller plastic pellets, screws of 10mm or 12mm diameter can also be made, greatly benefiting micro-injection applications.
• The injection plunger is cylindrical and easy to manufacture with high precision. Unlike screw injection which requires the check ring to seal the screw to prevent backflow, the plunger system completely avoids inconsistent backflow and inaccurate metering. The injection endpoint is always maintained within a highly precise range, making it the top choice for producing ultra-precision products.
• Because the injection plunger is independently separated, its diameter does not have to equal that of the screw. This advantage can improve injection pressure and speed, and allows flexible design to reduce injection volume as needed, making control easier and more precise in micro-injection production.
• EdeX’s plunger-type injection machine mechanism uses the patented IPIS (Interchangeable Plunger Injection System), allowing plunger modules to be swapped anytime. This achieves the ultimate goal of an all-in-one injection machine, helping operators control equipment costs and enhance customer investment value.

〈Further reading: What are Injection Molding Machines? What are the Types?〉

Professional Analysis of Liquid Silicone Injection Molding Machines and Injection-Grade Silicone Materials

Can a standard injection molding machine use injection-grade silicone materials? While standard injection molding machines can process silicone, the unique properties and limited hardness range of injection-grade silicone materials make them unsuitable for high-precision requirements, necessitating specialized liquid silicone injection molding machines.

Injection-grade liquid silicone rubber (LSR) is a high-purity thermosetting plastic, consisting of Part A (silicone base) and Part B (curing agent) mixed in a 1:1 ratio. It offers excellent flowability, heat resistance, and stability, making it ideal for medical, automotive, and electronics industries. For coloring, a liquid colorant (Part C) can be added. The material feeder performs "static mixing" to ensure uniformity. The mixed silicone enters a cooled barrel, undergoes "dynamic mixing" via a screw, and is injected into a heated mold. The mold is heated to the curing temperature, with curing time determined by product thickness, resulting in high-quality finished products upon demolding.

To ensure defect-free products, liquid silicone injection molding machine molds utilize low-pressure injection and emphasize venting design, often paired with a vacuum pump to remove air from the mold cavity. Only professional liquid silicone injection molding machines, combined with high-quality injection-grade silicone materials, can meet stringent quality standards!

Comparison Table of Injection-Grade Silicone Materials

EdeX Liquid Silicone Injection Machine Application Scenarios

• Medical Industry: Producing high-purity products such as syringes, test tubes, and medical seals that meet strict biocompatibility and hygiene standards.
• Automotive Industry: Manufacturing heat-resistant and oil-resistant seals, sensor housings, and wire harness clips to enhance part durability.
• Electronics Industry: Producing waterproof connectors, buttons, and precision silicone housings ensuring high precision and reliability.
• Consumer Goods Manufacturing: Suitable for silicone kitchenware, baby products, sports goods, providing soft touch and high safety.
• Special Applications: Supports composite molding, insert molding, and multi-color injection to meet customized and high value-added product needs.

EdeX liquid silicone injection machines, with their precise feeding system, low-pressure injection design, and efficient curing technology, ensure excellent product quality and production efficiency, helping customers achieve outstanding manufacturing performance across various industries〈Further reading: Understand the Differences Between Rubber Injection and Silicone Injection〉

PS plastic has nothing to do with poor mold release. Although PS plastic is brittle, it will not crack in the middle due to mold release. The cover product is very shallow and has nothing to do with the draft angle. The brittle cracking is caused by the vacuum formed between the mold core and the product during mold release. PS products are relatively brittle and are cracked by the external atmospheric pressure. The mold design is indeed not good, but it can be solved through the air intake design of four ejector pins. The small diameter can be machined for a distance of 1mm at the front end of the ejector pin, and three outer circle straight grooves can be machined at the rear end of the ejector pin. In this way, when ejecting the mold, 1~2mm of ejection will only cause the product to deform inward but not crack. At this time, the external air is connected to the space between the mold core and the product, and the atmospheric pressure offsets each other, so that the PS product will not crack and can be ejected completely. If necessary, reduce the ejection speed to ensure that the air replenishment speed is sufficient.

For example: the screw diameter is 30mm, the injection stroke is 120mm, it is more convenient to convert the weight into cm (1cm=10mm), 3x3x0.785(3.14/4)x12=84.78cm^3 or 1.5x1.5x3.14x12=84.78cm^3.
If the specific gravity of ABS is 1.06, the weight is 84.78cm^3x1.06g/cm^3=89.87g (grams).