Also known as test mode debugging mold, mold manufacturing process it is the three procedures (ie design, manufacture, test mode), the last and critical processes. It is the mold design, mold making the total auditing.
Preparation of test mode
Mold preparation
After spotting the mold after the installation must be carried out through the water (the application of specialized test equipment with a supercharger), electricity (mainly with electric rods and hot runner mold, this time to be resistant to high voltage safety test) safety testing and mold activity part of the action test, for example, ejection, hydraulic and mechanical pulling mechanism, etc., and the product thickness measurements (available in different thickness of wire placed in a soft cavity between the core mode after collision measurement, or into a special wax to measure). Also, check hook, locking mechanism and other safety devices. http://www.prmindustry.com/
Abstract...Articles section Tryout material preparation
Tryout material and finished products should be used to test the same plastic mold.
Tryout machine (injection molding machine) is selected
Of the injection mold, injection molded parts according to the size of the first, to determine the shape of the injection molding machine specifications, ie the direction of injection molded parts in the projection area S and the selected average injection mold cavity pressure P, the calculation process products clamping force P2.
P2 = S ‧ P ‧ η/1000
P2-products of the process of clamping force (KN)S-products in the mold direction of the projection area and flow projection area (mm2) of the sum of theThe average P-mold injection pressure (MPa), according to the plastic viscosity and flow length ratio may be. Plastic viscosity of the resin properties include temperature, flow shear rate, etc., such as PE, PS, PP and other materials, low viscosity, PC material viscosity coefficient is more than double the three materials. Longer than the plastic melt flow from the gate to the most remote of the length of the plastic parts and plastic parts than the average thickness. Flow is required greater than long-mold pressure P higher, generally preferable to 20-40.η-characteristic coefficient, and generally 1.2.
Constant injection molding machine clamping force should be equal to or greater than the clamping force of the process of plastic products. Secondly, we should review the injection volume, the quality of parts (including products and outlets) should be used in the injection machine maximum injection volume of between 30-75% is appropriate.
Constant clamping force injection machine and injection quantity to meet the above two conditions, in order to test for mold or processed products. Injection machine nozzle hole diameter should be higher than the mainstream mold casting system crossing small diameter (0.5-1mm). Should also consider the installation of die size, mold shut height, daylight opening, positioning ring size, the top methods.
Tryout process conditions selected
Injection pressure
Should not use the test mode start too, should gradually increase in test mode, especially tendons more mold, or mold cavity deep, but also to pay attention to avoid a lot of flash and expansion mode, resulting in stripping difficulties or mold damage. Pressure setting can refer to Table 1.Table 1 Characteristics of plastic injection pressure and the relationship
Preparation of test mode
Mold preparation
After spotting the mold after the installation must be carried out through the water (the application of specialized test equipment with a supercharger), electricity (mainly with electric rods and hot runner mold, this time to be resistant to high voltage safety test) safety testing and mold activity part of the action test, for example, ejection, hydraulic and mechanical pulling mechanism, etc., and the product thickness measurements (available in different thickness of wire placed in a soft cavity between the core mode after collision measurement, or into a special wax to measure). Also, check hook, locking mechanism and other safety devices. http://www.prmindustry.com/
Abstract...Articles section Tryout material preparation
Tryout material and finished products should be used to test the same plastic mold.
Tryout machine (injection molding machine) is selected
Of the injection mold, injection molded parts according to the size of the first, to determine the shape of the injection molding machine specifications, ie the direction of injection molded parts in the projection area S and the selected average injection mold cavity pressure P, the calculation process products clamping force P2.
P2 = S ‧ P ‧ η/1000
P2-products of the process of clamping force (KN)S-products in the mold direction of the projection area and flow projection area (mm2) of the sum of theThe average P-mold injection pressure (MPa), according to the plastic viscosity and flow length ratio may be. Plastic viscosity of the resin properties include temperature, flow shear rate, etc., such as PE, PS, PP and other materials, low viscosity, PC material viscosity coefficient is more than double the three materials. Longer than the plastic melt flow from the gate to the most remote of the length of the plastic parts and plastic parts than the average thickness. Flow is required greater than long-mold pressure P higher, generally preferable to 20-40.η-characteristic coefficient, and generally 1.2.
Constant injection molding machine clamping force should be equal to or greater than the clamping force of the process of plastic products. Secondly, we should review the injection volume, the quality of parts (including products and outlets) should be used in the injection machine maximum injection volume of between 30-75% is appropriate.
Constant clamping force injection machine and injection quantity to meet the above two conditions, in order to test for mold or processed products. Injection machine nozzle hole diameter should be higher than the mainstream mold casting system crossing small diameter (0.5-1mm). Should also consider the installation of die size, mold shut height, daylight opening, positioning ring size, the top methods.
Tryout process conditions selected
Injection pressure
Should not use the test mode start too, should gradually increase in test mode, especially tendons more mold, or mold cavity deep, but also to pay attention to avoid a lot of flash and expansion mode, resulting in stripping difficulties or mold damage. Pressure setting can refer to Table 1.Table 1 Characteristics of plastic injection pressure and the relationship
Injection volume
Injection volume generally melt injection volume (cm3) said, because the quality of the plastic due to the density varies, but the density subject to the injection time, pressure, temperature and other effects. Tryout before a test or standard parts should be calculated by the maximum value obtained, when the test mode from small to large and gradually increase until you get the complete product.
The formula is:
Product quality = injection volume * ρInjection volume = m / ρ = l * Screw cross-sectional areaInjection stroke = injection volume / screw cross-sectional area= Injection volume / 0.785D2= (M/0.785D2ρ) * 1000
D-Screw diameter (mm) ρ-density (typically whichever value is 1) m-product mass (g) l-injection stroke (mm)
Injection rate and injection rate
Injection speed is screw or plunger injection unit time at the speed of advance (cm / s), injection rate of melt per unit time from the injection nozzle melt volume (cm3 / s). General order does not melt in the mold was quickly cooled, the product does not appear on the weld, for greater injection rate. However, injection rate, the melt flow due to shear heat generated at high speed leaving the melt fracture, or kinetic energy is high due to air flow of melt over the heat generated by the rapid compression materials, heat of decomposition, while the so-called trapped gas-burning Jiao. Tryout time to take a more general first high-speed injection, found burnt again when reduced until eliminated.
Injection of the material temperature
Injection temperature is mainly made of plastic resin performance parameters to determine, for ease of injection molding, and generally the upper limit to be reduced after the injection setting the appropriate value. Because the material will appear on the air temperature is too high marks, burning and other defects. Conclusion: The test mode starting material should be selected high-temperature, low pressure, high speed and suitable storage weight (injection volume) of the process conditions. Mold according to the actual situation, through the test mode step by step, until the right, and the entire tryout process make records.
Tryout product defect analysis
Fin
Common flash in the sub-surface, forming surface core-pulling the slider, the top of the body surface, etc.. Preferred to adjust the tryout process conditions, for example, injection fluxes are too large, the injection pressure is too great or insufficient clamping force (measured with a dial indicator whether the expansion mode). Tryout process factors, mainly mold machining accuracy or spotting accuracy, sub-surface and cavity of the junction with a small arc and other causes, may take appropriate measures to solve. For example, sub-surface flash, the surface should be spotting the tough cases, reducing the sub-surface clearance; and if parting with a small cavity at the junction of the arc, as only 0.03-0.06mm or less, and in wall thickness within the tolerance range can be rubbed off the parting of some small arc (this will thinning products thickness).
Top of the white-Indian, and even through parts.
The reason is the top white plastic top and efforts beyond the elastic limit. First, check the stripping slope is too small, or even a negative angle (upside down). Second, check the core parts of the polishing is related to the required surface roughness. Should also check with the parts is too loose, or parts where the wall thickness is too thin, or mold designed with insufficient strength. Main can not be ignored mold temperature, mold temperature exceeds 40 ℃ general is often the white plastic top of the main factors. In the injection molding mold deformation is also possible causes. Before checking the mold deformation, but also first adjustment tryout process conditions, injection pressure can be reduced to small enough, the injection pressure is too much white printing produces one of the reasons.
Weld
Weld is molten plastic resin in the mold filling in through the barrier, gate or two cold feed forward flow of material when they meet, poor welding formed. Weld can often improve the melt temperature, mold temperature, etc. to improve to improve or enhance the melt flow rate of injection solutions. When products require no welding of certain parts, you should change the location of the gate, or change some of the gate and the size of cavity size, that is to change the material flow of the encounter site, the weld to a low light-sensitive area, the stress is not sensitive area. In the weld site, increase the vent or open the "garbage sales", can also reduce the weld.
Sink mark
Plastic products can be seen in some parts of the cooling contraction marks, especially in parts of the surface at the intersection with the tendon is more obvious. This is because the thickness of the material here, over there around the first condensate, where condensation has been unable to obtain from the surrounding melt caused by complement. Improved methods, one in the product design will be reinforced thinning, the thickness of normal muscle wall thickness should be at the intersection below the junction depth of no more than three times the wall thickness. Or gas-assisted injection method to increase the gas flow channel. Second, injection, increasing the injection pressure, due to lower melt temperature, packing pressure to improve. One best way is to use gas-assisted.
Silver mark
The surface of the silver filaments in parts commonly referred to as silver scar scar. Causes, mainly in the melt in the mold compound or mixed with moisture, mold can advance the material and drying solution. Some scars may be expected when the temperature is too high or melt in the barrel to stay too long, the decomposition of the melt injection gases, you can use lower melt temperature, melt in the barrel as far as possible to shorten the time to resolve, but also appropriate control injection speed solution.
Char
Performance of the products have burnt some parts, mainly die poor exhaust, material flow too fast and other causes, to take appropriate measures to resolve.
Workpiece surface is not shiny (not for surface rot before melting)
Test mode can be adjusted injection rate, melt temperature, mold temperature and other process parameters to solve. For the mold can be further polished to increase the exhaust trim.
Parts warping
This is due to uneven cooling and forming parts caused by the strain. Test mode can be increased when the injection pressure, lower mold temperature and melt temperature increase to solve. If still not resolved, you should repair mode. Can change the location of the gate, gate form (better fan than the straight gate), part of the cooling flow, cooling the temperature uniformity of addressing. Also useful to just the mold fixture of plastic products for fixed and solve warping.
Injection of less than
Some parts of the specimen defect. Mainly by the lack of injection volume, poor exhaust, injection pressure is low, the material temperature is low, low injection rate of cause, can be adjusted one by one in the tryout process parameters in the solution.
Such as repair mode should still difficult to solve. Repair mode should be considered in the mold flow is smooth, exhaust is unobstructed, products where the wall thickness is too thin, cold feed hole is too small, etc., and then take appropriate measures to resolve.
Injection volume generally melt injection volume (cm3) said, because the quality of the plastic due to the density varies, but the density subject to the injection time, pressure, temperature and other effects. Tryout before a test or standard parts should be calculated by the maximum value obtained, when the test mode from small to large and gradually increase until you get the complete product.
The formula is:
Product quality = injection volume * ρInjection volume = m / ρ = l * Screw cross-sectional areaInjection stroke = injection volume / screw cross-sectional area= Injection volume / 0.785D2= (M/0.785D2ρ) * 1000
D-Screw diameter (mm) ρ-density (typically whichever value is 1) m-product mass (g) l-injection stroke (mm)
Injection rate and injection rate
Injection speed is screw or plunger injection unit time at the speed of advance (cm / s), injection rate of melt per unit time from the injection nozzle melt volume (cm3 / s). General order does not melt in the mold was quickly cooled, the product does not appear on the weld, for greater injection rate. However, injection rate, the melt flow due to shear heat generated at high speed leaving the melt fracture, or kinetic energy is high due to air flow of melt over the heat generated by the rapid compression materials, heat of decomposition, while the so-called trapped gas-burning Jiao. Tryout time to take a more general first high-speed injection, found burnt again when reduced until eliminated.
Injection of the material temperature
Injection temperature is mainly made of plastic resin performance parameters to determine, for ease of injection molding, and generally the upper limit to be reduced after the injection setting the appropriate value. Because the material will appear on the air temperature is too high marks, burning and other defects. Conclusion: The test mode starting material should be selected high-temperature, low pressure, high speed and suitable storage weight (injection volume) of the process conditions. Mold according to the actual situation, through the test mode step by step, until the right, and the entire tryout process make records.
Tryout product defect analysis
Fin
Common flash in the sub-surface, forming surface core-pulling the slider, the top of the body surface, etc.. Preferred to adjust the tryout process conditions, for example, injection fluxes are too large, the injection pressure is too great or insufficient clamping force (measured with a dial indicator whether the expansion mode). Tryout process factors, mainly mold machining accuracy or spotting accuracy, sub-surface and cavity of the junction with a small arc and other causes, may take appropriate measures to solve. For example, sub-surface flash, the surface should be spotting the tough cases, reducing the sub-surface clearance; and if parting with a small cavity at the junction of the arc, as only 0.03-0.06mm or less, and in wall thickness within the tolerance range can be rubbed off the parting of some small arc (this will thinning products thickness).
Top of the white-Indian, and even through parts.
The reason is the top white plastic top and efforts beyond the elastic limit. First, check the stripping slope is too small, or even a negative angle (upside down). Second, check the core parts of the polishing is related to the required surface roughness. Should also check with the parts is too loose, or parts where the wall thickness is too thin, or mold designed with insufficient strength. Main can not be ignored mold temperature, mold temperature exceeds 40 ℃ general is often the white plastic top of the main factors. In the injection molding mold deformation is also possible causes. Before checking the mold deformation, but also first adjustment tryout process conditions, injection pressure can be reduced to small enough, the injection pressure is too much white printing produces one of the reasons.
Weld
Weld is molten plastic resin in the mold filling in through the barrier, gate or two cold feed forward flow of material when they meet, poor welding formed. Weld can often improve the melt temperature, mold temperature, etc. to improve to improve or enhance the melt flow rate of injection solutions. When products require no welding of certain parts, you should change the location of the gate, or change some of the gate and the size of cavity size, that is to change the material flow of the encounter site, the weld to a low light-sensitive area, the stress is not sensitive area. In the weld site, increase the vent or open the "garbage sales", can also reduce the weld.
Sink mark
Plastic products can be seen in some parts of the cooling contraction marks, especially in parts of the surface at the intersection with the tendon is more obvious. This is because the thickness of the material here, over there around the first condensate, where condensation has been unable to obtain from the surrounding melt caused by complement. Improved methods, one in the product design will be reinforced thinning, the thickness of normal muscle wall thickness should be at the intersection below the junction depth of no more than three times the wall thickness. Or gas-assisted injection method to increase the gas flow channel. Second, injection, increasing the injection pressure, due to lower melt temperature, packing pressure to improve. One best way is to use gas-assisted.
Silver mark
The surface of the silver filaments in parts commonly referred to as silver scar scar. Causes, mainly in the melt in the mold compound or mixed with moisture, mold can advance the material and drying solution. Some scars may be expected when the temperature is too high or melt in the barrel to stay too long, the decomposition of the melt injection gases, you can use lower melt temperature, melt in the barrel as far as possible to shorten the time to resolve, but also appropriate control injection speed solution.
Char
Performance of the products have burnt some parts, mainly die poor exhaust, material flow too fast and other causes, to take appropriate measures to resolve.
Workpiece surface is not shiny (not for surface rot before melting)
Test mode can be adjusted injection rate, melt temperature, mold temperature and other process parameters to solve. For the mold can be further polished to increase the exhaust trim.
Parts warping
This is due to uneven cooling and forming parts caused by the strain. Test mode can be increased when the injection pressure, lower mold temperature and melt temperature increase to solve. If still not resolved, you should repair mode. Can change the location of the gate, gate form (better fan than the straight gate), part of the cooling flow, cooling the temperature uniformity of addressing. Also useful to just the mold fixture of plastic products for fixed and solve warping.
Injection of less than
Some parts of the specimen defect. Mainly by the lack of injection volume, poor exhaust, injection pressure is low, the material temperature is low, low injection rate of cause, can be adjusted one by one in the tryout process parameters in the solution.
Such as repair mode should still difficult to solve. Repair mode should be considered in the mold flow is smooth, exhaust is unobstructed, products where the wall thickness is too thin, cold feed hole is too small, etc., and then take appropriate measures to resolve.
Peter Huang
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