Due to the persistence of some undetected faults, the working life of the Daily Necessities Mould(FURNITUREMOULD) itself may be greatly shortened, or its working efficiency is permanently damaged. Over time, such faults will be seriously deteriorated until a major fault occurs and some Some important daily necessities mould cause irreparable damage to members.
Therefore, ignoring simple basic maintenance attention can lead to serious consequences and result in considerable investment losses, which will be shown in the final profit account of the daily necessities mould.
It is known that simple faults that are neglected in the daily necessities mould mechanism ultimately lead to complete failure and the tool is completely destroyed as a production unit.
There have been cases where an order for manufacturing a large number of moulded articles has occurred, and before the total number of productions, the daily necessities mould have been worn out or destroyed as a result of some neglected malfunction or damage. This can and should be observed at an early stage, and is expected to be effective by skilled and focused daily necessities mould maintenance services.
In this case, another daily necessities mould must be made to complete the order quantity, and of course, the moulding manufacturer cannot pass this increased tool cost to the customer. Therefore, daily necessities mould buyers not only have to worry about production time concerns and losses, but the additional financial expenses of new tools may not be recovered.
Properly organized and applied maintenance services necessarily involve frequent supervision of all Crate Mould(FURNITUREMOULD) at the time of use or in the store to meet such normal requirements from time to time. These maintenance includes replacing worn, damaged or damaged mould parts, correcting errors due to deformation or wear, adjusting and restoring routes, modifying the structure and design of the mould mechanism, cleaning, lubrication and general overhaul.
However, all of these basic activities are almost entirely related to the correction of certain identified defects in the operation of the crates and can be used for correction. A certain degree of severity has been reached after this. This is generally consistent with a significant decrease in the quality of the moulded article or the inability to effectively operate the crate mould.
However, the main goal behind any planned maintenance program should be not only to provide effective service for rapid maintenance, etc. but also to ensure that such failures that need to be corrected are eliminated as much as possible.
Therefore, any plan should be highlighted by combining the inspection features of the regular intervals and the outstanding features of the mould test to find the minimum deviation from the smooth working or detrimental effects of the moulded parts. Therefore, the necessary adjustments can be made while the fault is still in a negligible phase, and on the other hand, protection measures designed to prevent the failure from progressing to a more serious proportion are allowed.
In combination with this important activity line, a high degree of intelligent expectations or proactive predictions of development issues should be developed before an opportunity is reached to achieve the basic dimensions that may result in failure of the final crates.
Such a solution also requires some simple clerical methods, in which all maintenance work, maintenance, etc., the results of routine inspections, etc. can be recorded and carefully documented. As a result, the correct cost sharing can be made while establishing a series of reliable information about the details and experience of each crate mould.
The mold indentation is a hollow region contained inside the Crate Mould(FURNITUREMOULD) into which the molten polymer is injected and allowed to cool. When a mold tool contains more than one stamp, it is called a multi-die tool.
The core forms the interior of the molded part and can be identified as a convex part that constitutes the stamp. The core is held or located in a plate called a core plate, and the mold half containing the core assembly is referred to as the core half of the mold. Due to the shrinkage characteristics encountered when the polymer is melt cooled, the cooling mold tends to shrink onto the core and away from the cavity wall once solidified. This characteristic contraction behavior allows the mold to remain on the core during the mold opening process for ejection purposes. Since the machine ejector system is located behind the moving platen of the forming machine, the half core of the mold is typically clamped to the moving platen of the machine during use.
The cavity forms the outer or display surface of the molded part and can be identified as a concave part that constitutes the stamp. Like the core, the cavity is held or located in its own template, the name of which is the cavity plate. The remaining half of the mold containing the cavity is referred to as the cavity half and is typically clamped to the stationary platen of the molding machine in front of the injection unit. The mold feed system is usually located in the half cavity of the mold because it is close to the machine injection unit.
Since the tool designer tends to position the ejection system in the half core and position the feed system in the half cavity, it is easy to understand the effect of the tool design on the chosen configuration of the molding machine. Therefore, the most commonly encountered machine design is the online 'configuration.
In any part of the Table Mould(FURNITUREMOULD), when the part suddenly changes and locally increases the volume of the material, the surface will be inhaled when the material shrinks, creating a dent, or if the surface becomes hard enough, it will not sink, shrink It will occur in the body of the material that causes the void. Overcoming this problem is not simple.
One method that is often recommended by the manufacturer to reduce or prevent sink marks and voids in the literature is to increase the injection hold time (plunger residence time). This may have some impact, especially when using large gates to make thick molded parts, but there is the pressure that is not evenly distributed throughout the material in the table mould and some parts will be more stressed than others. danger. Therefore, the molding may appear to be completely flawless but will decompose in use under adverse environmental conditions. This technique requires great care to ensure that the holding pressure is not too great without causing excessive stress.
Another recommended method is to reduce the temperature of the material in the cylinder (based on less shrinkage of the cooler material). This may only have a limited impact, as it is highly unlikely to withstand a few degrees of reduction, and it should be remembered that the forming should always be carried out at the lowest possible temperature.
For a temperature change of 10 ° C, the average heating volume of the crystalline plastic varies by about 1% (about half of the amorphous material). If the reduction of 10.C can be tolerated, then when the effect of the consideration is a 14-18% change in volume, this will result in a shrinkage of only 1%.
In addition, a decrease in temperature also leads to a decrease in the ease of filling because the viscosity of the melt is slightly higher. Therefore, more pressure is required, resulting in greater residual stress.
It can be said that the damage that occurs during the use or storage of a mold for any given Crate Mould(FURNITUREMOULD) requires a certain amount of repair. The more you use it, or the longer it is stored, the more damage it will take. The damage that occurs during use includes items such as broken cores or thimbles, shot blasting lines and worn gate areas, while the most common damage during storage is in the form of rust.
It is a good idea to save the last shot in any production run and save it with the crate mould. This provides a visual example of how to produce parts for the crate mould maintenance area. Maintenance personnel can inspect the part to determine the fit of the parting line, cavity surface condition, thimble position and other relevant information.
Allowing nozzle drooling can cause material to seep out to the A side of the cavity group. This is usually a thin material that can solidify quickly and become a hardened plastic sheet. If it is allowed to stay, it will cause serious damage to the cavity when the mold is closed.
The actual pressure applied should be higher than the full chamber pressure. During the injection process, the Crate Mould(FURNITUREMOULD) pressure rises sharply and eventually peaks. This peak is the so-called injection pressure. The injection pressure is significantly higher than the full chamber pressure.
The effect of pressure on the pressure: after the cavity is filled with plastic until the gate is completely cooled and closed for a period of time, the plastic in the cavity still needs relatively high-pressure support, ie maintaining pressure, the specific role is:
The amount of material near the gate is replenished and the uncured plastic in the mold cavity is controlled to flow back to the gate material source under residual pressure before the gate condensation is closed.
Prevent parts from shrinking and reduce vacuum bubbles.
Reduce the adhesion or bending deformation caused by excessive injection pressure of parts. Therefore, the holding pressure is usually 50% to 60% of the injection pressure. If the holding pressure or time is too long, the gate may be too large. The cold material on the flow violently hits the part, adding bright spots near the gate and extending the loop without any benefit.
In production, it is often encountered that a heating coil is damaged or the heating control portion is out of control, and the temperature of the Crate Mould(FURNITUREMOULD) is drastically changed to cause chromatic aberration. The chromatic aberration caused by these causes is easy to determine. Typically, the heating ring is damaged and the chromatic aberration is accompanied by uneven plasticization, and the heating control portion is out of control and often burns due to product spots, severe discoloration or even coking. Therefore, the heating components should be inspected frequently during the production process, and the heating components are found to be damaged or out of control and replaced in time to reduce the occurrence of such chromatic aberration.
When the injection molding process parameters need to be adjusted for non-chromatic aberration reasons, the injection molding temperature, back pressure, injection cycle and masterbatch addition amount should not be changed as much as possible. Adjustments also need to observe the effect of changes in process parameters on color. If color difference is found, it should be adjusted in time.
Avoid high injection speeds, high back pressures and other injection molding processes that produce strong shear to prevent chromatic aberrations caused by local overheating or thermal decomposition. The temperature of each heated portion of the barrel is strictly controlled, particularly the nozzle and the heated portion near the nozzle.
It is also necessary to know the trend of the color of the product as a function of temperature and masterbatch before performing the color difference adjustment. The masterbatch of different colors varies with the temperature or color masterbatch of the product, and the color change law of the product is also different. The color change process can be used to determine the law of change. Unless the color change of the color masterbatch is known, it is not possible to quickly adjust the chromatic aberration, especially when using the color tone produced by the new masterbatch.
In order to clarify the design requirements of the Table Mould(FURNITUREMOULD), carefully read the parts drawing of the plastic parts, consider the feasibility and economy of the injection molding process from the aspects of plastic varieties, plastic shapes, dimensional accuracy, surface roughness, etc. If necessary, the product designer explores the table mold The possibility of material type and structural modification.
In small batch production, in order to reduce the cost, the table mould is as simple as possible. In the large-scale production, under the premise of ensuring the quality of the plastic parts, multi-cavity or high-speed automatic production is used as much as possible to shorten the production cycle and improve the production efficiency. Extrusion mechanisms for table mould, automatic mold release mechanisms for plastic parts, and flow channel assemblies must be strictly required.
Calculating the volume and quality of plastic parts is the choice of injection molding machines, increasing the utilization of the equipment and determining the number of cavities.
In addition, the selection of the injection molding machine, the structure of the mold is roughly determined according to the volume or weight of the plastic part, and the model of the injection molding machine and the technical parameters related to the design are initially determined. Injection molding machines and design molds are known, such as the diameter of the positioning ring of the injection molding machine, the nozzle front end aperture and the spherical radius, the maximum injection volume of the injection molding machine, the clamping force, the injection pressure, the fixed template and the moving template area size and the mounting screw holes. Position, injection molding rod spacing, closing thickness, mold opening stroke, ejecting stroke waiting.
The structure of the Household Product Mould(FURNITUREMOULD) can vary depending on the type and performance of the plastic, the shape and structure of the plastic product, and the type of injection molding machine, but the basic structure is uniform.
Household product mould is mainly composed of a gating system, a temperature control system, molded parts and structural parts. The gating system and molded parts are in direct contact with the plastic and vary with the plastic and product. It is the most complex and variable part of the mold and requires the highest level of smoothness and precision.
The household product mould consists of two parts: a movable mold and a fixed mold. The movable mold is mounted on the moving template of the injection molding machine, and the fixed mold is mounted on the fixed template of the injection molding machine. In injection molding, the movable mold and the fixed mold are closed to form a casting system and a cavity, and when the mold is opened, the movable mold and the fixed mold are separated to take out the plastic product. To reduce heavy mold design and manufacturing effort, most household product mould use standard mold bases.
The gating system refers to the flow path portion of the plastic before it enters the cavity from the nozzle, including the main passage, the cold feed hole, the split flow passage and the gate.
The gating system, also known as the sprue system, is a set of feed channels that direct the plastic melt from the nozzle nozzle to the cavity, typically consisting of a main flow path, a runner, a gate, and a cold feed bag. . It is directly related to the molding quality and production efficiency of plastic products.
It is a passage in the mold that connects the nozzle of the injection molding machine to the flow channel or cavity. The top of the main flow path is concave to engage the nozzle. The inlet diameter of the main flow channel should be slightly larger than the nozzle diameter (0.8 mm) to avoid flicker and to prevent both from being cut due to inaccurate connections. The diameter of the inlet depends on the size of the product and is usually 4-8 mm. The diameter of the main flow path should be increased by an angle of 3° to 5° inward to demold the flow path.