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When the Chair Mould(FURNITUREMOULD) is operated at high hardness, the mould steel has high yield strength and low fracture toughness. High yield strength is beneficial to delay the generation of fatigue cracks, but low fracture toughness accelerates the expansion rate of fatigue cracks, reduces the critical length, and greatly shortens the fatigue crack growth cycle. Therefore, the fatigue life of the cold work dies mainly depends on the fatigue crack initiation time.

Hot work dies are typically used for medium or low hardness conditions, and chair mould fracture toughness is much higher than cold work dies. Therefore, in the hot work die, the fatigue crack growth rate is lower than that of the cold work die, and the critical length is greater than the cold work. The subcritical expansion period of the hot mould fatigue crack is much longer than that of the cold mould. However, the surface of the hot work die is susceptible to rapid cooling and rapid heating. The fatigue crack initiation time of hot work die is much shorter than that of cold work die. Therefore, the fatigue fracture life of many hot moulds mainly depends on the time of fatigue crack growth.

Common forms of fracture failure are: fragmentation, caries, splitting, fracture, cracking, etc. The driving force for different mould fractures is different. Cold working dies are mainly subjected to mechanical forces (impact pressure). In addition to mechanical forces, hot moulds also have thermal stresses and microstructure stresses. Many hot working dies have higher operating temperatures and forced cooling. Internal stresses can far exceed mechanical stresses. Therefore, the fracture of many hot moulds is mainly related to excessive internal stress.

There are two types of chair mould fracture processes: one-time fracture and fatigue fracture. A one-time break is a mould that sometimes breaks suddenly during the stamping process, and once cracks begin, it becomes unstable and expands. The main reason for this is the severe overload or severe embrittlement of the mould material (eg overheating, insufficient tempering, severe stress setting and severe metallurgical defects).

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The design of the gate is related to the size of the plastic part, the shape and the mould structure of the Crate Mould(FURNITUREMOULD), the conditions of the injection moulding process and the performance of the plastic part. However, in terms of basic functions, the gate portion should be small and the length should be short, as this is the only way to increase flow rate, rapid cooling and sealing, separation of plastic parts and minimal residual marking.

Regardless of whether the product is filled or not, the flow length determines the injection pressure, and the clamping force and shortening of the entire flow length reduce the injection pressure and clamping force.

The gate position will affect the pressure holding pressure, the pressure holding pressure and the pressure maintaining pressure balance. Keep the gate away from the stress position of the product (eg bearing position) to avoid residual stresses. Exhaust gas must be considered at the gate location to avoid wind accumulation.

If there is no balanced runner system, the following gate balancing method can be used to achieve the goal of uniform injection moulding. This method is suitable for crates moulds with a large number of holes.

There are two ways to balance the gate: change the length of the gate trench and change the cross-sectional area of the gate. In another case, the balancing door is also required when the chambers have different projected areas.

At this point, in order to determine the size of the gate, it is necessary to determine the size of one of the gates, find the ratio of its gate volume to the corresponding cavity volume, and apply the ratio to the gate and the corresponding gate comparison cavity, and then calculate The size of each door.

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For crate mould, we pay more attention to Crate Mould(FURNITUREMOULD) design in order to obtain crate mould in a sufficient cooling system. This will allow the box mould to avoid zone hot pots and achieve uniform cooling for rapid cycle moulding. In addition, we offer a good slat ventilation solution design for the crate handling area and the crates strength points.

Through the processing of crates, the Chinese team values ??the size control of the crates, so that each part is in good working condition. It keeps the mould within the tolerances of the tool and does not cause any scratches. With these, we keep our crate mould faster than our competitors. In addition, we are confident to run our crate mould and mass production simulation process, confirm the cycle time and then ship it to you.

Taizhou Huangyan Rongwei Plastic Mould Co., Ltd.is located in Huangyan, which is the mould town in China. Our company has more than 20 years of professional experience in mould field. We have the most advanced equipment for mould manufacturing as well as the most qualified trained employees. We have made full use of high techniques as CAD/CAM/ CAE for a long time and summarized a set of specific experience. Our mould is mainly exported to the countries in Europe, Mid-East, Africa and so on.

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Standard Crate Mould(FURNITUREMOULD) temperatures help ensure uniform heat exchange on each wall surface. This may put the components in equilibrium and the wall thickness of the supply is uniform. The basic elements of management. Crate mould should be developed to adequately manage temperatures from the range required for material processing. This not only reduces the amount of residual tension but also reduces cycle time.

Technologies to get the right core cooling to include:

Baffle

Spherical cooling channel for cavity and core insert

Extremely conductive alloy

Foaming

Any of these techniques are suitable to provide a heat removal capability sufficient to maintain a uniform temperature along the length of the core. Even if proper core cooling can have an impact on crate mould manufacturing costs, as long as the crates are put into production, it can reduce cycle times and improve part quality.

Baffles and bubblers are two of the most typical techniques used to provide core cooling. With this configuration, a thin blade is inserted from the hole along the length. This divides the bore into two semi-circular flow channels. Water moves from inside the core of one side of the baffle blade and then slightly lower from the other side of the blade.

The bubbler is very similar to the baffle except that water passes from the core with the bubble tube towards the finisher. Water returns from the core through the annular space between the bubbler tube OD and the core ID.

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Design parts to ensure that the Crate Mould(FURNITUREMOULD) is properly cooled, and you can reduce cycle times and high-quality parts while reducing the price. Good cooling is critical when proposing crates.

Some results of poor cooling:

Increased cycle time

Uneven cooling between parts or parts

High residual tension

Increased warpage

Adhesives and problems in ejection

Even though all of the above problems can be serious problems, the most typical difficulties may be stay and ejection problems. We are unable to fully pay attention to the importance of crate mould cooling, especially in cores. By following the powerful core cooling principles, you can significantly improve the processing window and achieve good results in terms of overall component performance.

An effective and critical cooling method is to ensure that there is turbulent water flow in the cooling circuit. When the water stream is laminar, the heating from the crate mould only enters the outer layer from the water as it flows through the channels. The outer water does not mix with the cooler inner layer and does not fully utilize cooling.

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The temperature of the Crate Mould(FURNITUREMOULD) affects the overall cycle, shrinkage, warpage and different characteristics of the cast components. Copolyesters require cooler moulds than many different plastics, so predicting cooling requirements in advance (ie, through injection mould blueprints) pays off in terms of reduced cycle time and processability. Higher crate mould temperatures can cause adhesion. Uniform local hot spots where adhesion may occur increase the cycle.

In order to reduce the entrance blush, unfolding or all, the filling speed for the copolyester is reduced compared to many different plastics. A machine with filling speed programming capability is recommended.

The screw should be operated at the lowest speed so that it can recover 3-6 seconds before the crate mould opens. This reduces viscous heat generation, which has a tendency to standardize the melt and reduces dead time.

A typical problem with direct gate assemblies is usually to reduce the gap on the basis of the runner. A long hold time of 8.1-12.1 seconds and a minimum holding pressure of 276-551 bar (4,000-8,000 psi) (nozzle polymer tension) will supply the polymer to the injection port at a rate at which voids are removed, but will not an over-inject package. In general, if the cooling timer is reduced by the amount of increase in the hold timer, there is no need to extend the cycle time. At the junction of the runner and the suction pin, the standard runner can also form a constricted void; this can be eliminated by utilizing the aforementioned method.

Cushion size

The buffer size should be large enough to ensure that the screws do not touch the base and that the packaging and holding pressure is transmitted to the part. Depending on the machine size and injection speed, the mat remaining after the cycle of packaging and holding is typically 3-13 mm (0.125-0.5 inches). Larger mats increase the residence time in the barrel and cause deterioration. After the shooting, the screw continues to move forward to indicate the drip check valve. The drip check valve will be retained to avoid cushioning and may result in random fast shots and shot changes.

Back tension

A typical back tension is 7 -4 -10 C column (100-150 psi), although it may be a minimum of 3.5 bar (50 psi). To increase melt uniformity, increase melt heat or eliminate air retention (air expansion), backside tension can be increased to 28 bar (400 psi). Excessive back pressure can cause the drool to be directly exacerbated into the crate mold because the decompression is usually kept to a minimum.

Usually, a small decompression is used. Decompression may pull the back of the air directly into the nozzle, causing the spray in the spray. A small amount of reduced pressure can be used to reduce drooling.

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Unless an alternative surface treatment is required, all of the Crate Mould(FURNITUREMOULD) surfaces should be highly polished in terms of drawing for cavity and punching. Gate bushings and runners should also be highly polished by flow to aid in the streamlined flow of the polymer and prevent these trends from "bounce."

Chrome plating can be used to improve hardness and corrosion resistance and to improve the release of moulded parts. The degree of finishing depends to a large extent on the amount of polishing before placement. Plating will never improve the surface, it will only add to the bad surface.

Use very corrosive materials such as PVC and certain types of thermoplastic rubber. Stainless steel is often used to combat corrosion. Unfortunately, even the best stainless steel alloys contain impurities and localized iron (iron) regions. These will soon be corroded by corrosive materials, causing pitting on the surface of the steel. With long-running tools, it is recommended to use a cavity area made of stainless steel to prevent this possibility. If a lion stainless steel mould is to be used to mould the corrosive material, the moulding surface must be chrome-plated and the remainder of the tool chrome-plated to protect it.

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Daily inspection

Check out some maintenance items for the Crate Mould(FURNITUREMOULD) of the crates every day..: hydraulic oil level, lubrication, leaks on the pressure line, hose connections, crates and wires, including thermocouple leads. Clean the machine weekly and check the cleanliness of the oil. Less often, the thermocouple should be inspected by inserting the tip into boiling water and ensuring that it indicates 100 °C. The timer can occasionally be checked by the stopwatch and check for leaks in the screw check valve.

Report error

You should be aware of any reports of failures and provide the first convenient opportunity. Items that should be checked regularly (but not necessarily often) include tie rods, tie rod bushings, frame rails and bushings, toggle link bushings and lever pins. The hydraulic cylinder should be checked for leaks in the seal. If any undue wear and tear occur, you can save time by solving the problem at the critical moment by taking the first opportunity. If this procedure is followed, there is no need to plan maintenance and replace worn parts of the stripping equipment every six or twelve months. However, checking every working part of the machine every three hours usually brings benefits to ensure stable production.

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A good reason why Daily Necessities Mould(FURNITUREMOULD) makers should insist on choosing the least amount of tool steel is to stay away from many heat treatment specifications, which are usually different for various metals. By doing so, developers and heat treatment businesses are equally Familiar with specific steels and know what to expect.

Almost all daily necessities mould manufacturers use outsourced suppliers for heat treatment because it is actually a professional practice and costs are required for any other situation due to the required plants and equipment. Sometimes two sheets of steel, although the same number of AISIs, may require considerable heat treatment (as evidenced by the metal supplier's specifications) to achieve the desired properties of the metal. The daily necessities mould manufacturer only needs to specify the required hardness on the part because the developer does not need a good understanding of the heat treatment practice. However, it is attractive that basic treatments are recognized to ensure that developers are aware of the various outcomes.

Specifically, by using the option hardening technique to achieve the same level of hardness, the daily necessities mould manufacturer should determine which method is needed because these methods can affect wear, strength, and mechanized robustness.

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If a fairly wet fabric is injection moulded, the finished injection moulded part will show splashes, splashes or spots as the melt moves over the entire Daily Necessities Mould(FURNITUREMOULD) due to cracking of the vapor bubbles and other volatiles.

Some examples are polycarbonate or ABS, which can be subjected to extreme embrittlement if it is treated with even surprisingly low water content and is not sufficient to present any splash marks. Therefore, after the daily necessities mould is ready, these materials should be completely dry before moulding.

In the case of undesired conditions (ie if the material is extremely immersed, or the dewatering machine is not particularly effective), the injection moulding plant in China should strengthen the dewatering time. Preferably, the nylon material should be dewatered in a vacuum oven to prevent the risk of degradation, resulting in discoloration and possibly embrittlement due to reaction with oxygen in the surrounding environment.

When using an air circulating oven or dryer, it is recommended to pre-dry the air circulating through the dehumidifier.

It should be considered that some fabrics that may theoretically require pre-drying can be used directly in the container. However, when they buy a complete sealed container from a professional company, this is true, and they are supplied quickly and the moisture in the moulded store is small enough. If you have a suspected dehydration requirement, ask the material manufacturer for advice on professional guidance.

Many fill level polymers generally do not absorb moisture and in some cases require dewatering prior to moulding.

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