The use of Table Mould(FURNITUREMOULD) is now very extensive. In order to improve the manufacturing process performance of table mould, the heat treatment process is usually carried out for the moulds. The common defects in heat treatment of the moulds are: quenching, deformation, poor hardness, electric machining cracking, grinding cracks, Early damage to the mould, etc. It can be seen that insufficient hardness of the table mould is one of the common types of defects.
What are the reasons for the lack of defects in the table mould and the preventive measures?
There are four main aspects:
1. The quenching temperature is too low. Mainly due to improper process setting temperature, temperature control system error, improper furnace installation or improper entry into the cooling tank, etc., the process temperature should be corrected, and the temperature control system should be repaired. When the furnace is installed, the workpiece spacing should be placed evenly and evenly. Slots are not allowed to be stacked or bundled into the trough for cooling.
2. The quenching temperature is too high. This is caused by improper process temperature setting or temperature control system error. The process temperature should be corrected and the photoelectric control shaft of the temperature control system should be overhauled.
3, over the temper. This is caused by the tempering temperature setting being too high, the temperature control system failure error or the furnace temperature is too high, and the furnace temperature should be corrected, and the inspection and temperature control system should be repaired.
4. Improper cooling. The reason is that the pre-cooling time is too long, the cooling medium is improperly selected, the quenching medium temperature is gradually increased, the cooling performance is lowered, the stirring is poor, or the bathing temperature is too high. Measures: quick release, slotting, etc.; master the cooling characteristics of quenching medium; oil temperature 60~80°C, water temperature below 30°C, when the table mould is quenched and the cooling medium is warmed, cooling quenching medium should be added or other The cooling bath is cooled; the agitation of the coolant is enhanced; the threaded grinding insert is taken out at Ms + 50 °C.
Due to the high precision of the manufacturing and processing precision of the Chair Mould(FURNITUREMOULD), the production and processing technology is also complicated, so the processing and production cost of the general plastic manufacturing chair mould is high. Plastic mould manufacturers hope that the service life of the mould is longer, and the requirements for the use, maintenance and maintenance of the mould are higher, so as to maintain the working precision and prolong the service life. Whether the choice of chair mould material is reasonable or not is also an important condition for extending the service life of the chair mould.
Chair mould manufacturing materials must meet the following requirements:
1. The chair mould steel should have better processing performance, and the deformation should be small when working in a high-temperature environment and heat treatment.
2. The working surface of the melt channel in the cavity of the chair mould should be small in the flow of the material. Therefore, the surface roughness of the working surface should be reduced. The steel should have good polishing performance and no impurities in the material. No pores.
3. Excellent wear resistance. In order to maintain the dimensional accuracy of the chair mould structure for a long time, it is necessary to wear the chair mould working surface after processing. In particular, when the raw material of the processed product contains a glass fibre-based hard filler, it is easy to accelerate the wear of the working face of the mould. For such a chair mould, it must have sufficient hardness and wear resistance.
4. Corrosion performance is good. In the plastic melt moulding production process, the plastic raw materials and some auxiliary materials should be in contact with the steel, which has a certain chemical corrosion effect on the steel. In order to maintain the chair mould has good corrosion resistance, it is necessary to choose corrosion-resistant alloy steel or high-quality carbon steel, if necessary, the surface should also be chrome-plated or nickel-plated.
5. Steel should have sufficient working strength. In addition to a certain hardness after surface heat treatment, the selected steel should have sufficient core strength. Because the injection mould is subjected to large injection pressure and clamping force, the core of the steel for the chair mould must be considered. strength.
Plastic chairs have become essential household goods in the current life, of which plastic rattan chairs are works of art in life, and their processing technology is beyond the reach of wooden chairs. How are these Chair Mould(FURNITUREMOULD) made? Mainly grasp the following points:
First of all: 1. The steel material of the chair mould is generally P20 or 718. 2. Gate method: 90% of chair mould generally use edge gates, and some use hot runner large gates. 3. molding method: the ejector pin is pushed on the rib. if the manipulator takes it out, it will be pushed up. if it is automatically pulled off, it will be turned over and pushed down. 4. Surface treatment: polishing, dermatoglyphics, and regional dermatoglyphics. Swapping of flower boards: generally, oblique rods are used for tapping and exchanging, and screw rotation and exchange are more advanced. 5. The waterway design of the chair mould shall not exceed 1m. After the chair mould is finished, it needs to be tested: Haff line: no rowing. Fringe: Fringe is easy to occur at the foot of the chair and the fusion joint due to poor exhaust. Overlay: more than 10 chairs cannot be tilted when stacked; When stacking, the distance between the two chair legs shall not exceed 60mm;; It is easy to separate after stacking (stacking ribs are generally located under the cushion) 6. Lighting: brightness. Intensity: Top White: Due to poor lighting.
Selection of models to be used for chair mould: length = height of chair +140 (distance from the top of chair back to edge) +220 (distance from the end of chair foot to edge) width = chair width +140÷2. Height: depending on the demoulding slope, the height in the vertical direction when the cushion is tilted is generally +100 (upper) +120 (lower) on the premise that the cushion can be smoothly demounted. The size of the machine is determined by the gram weight of the product. If the weight is less than 2500g, 650 tons of machine can be generally used. Larger, 780 tons. Armchairs and chairs with U-shaped slots or triangular slots at the back require 1,000 tons of elongated nozzles.
During the Crate Mould(FURNITUREMOULD) process, the plastic in the gate sticks into the sprue bushing and is not easily removed. When the mould is opened, cracks are broken in the plastic product. In addition, the operator pulls out the entire hot runner with a ejector, and then repairs the runner and illuminates it. If it continues, it will seriously affect production efficiency.
The reasons for these problems are: the smoothness of the taper hole is not enough, the inner hole has the knife mark not polished, the second is that the material is too soft, the small end of the tapered hole is deformed or damaged after a period of use, and the spherical curvature of the nozzle is too small, resulting in the gate material A rivet head is produced here. The taper hole of the sprue sleeve is difficult to process. Standard parts should be used as much as possible. If you need to process it yourself, you should also make a special reamer. The taper hole needs to be ground to Ra0.4 or higher; in addition, the gate pull rod or the gate ejecting mechanism must be provided.
2. It is difficult to remove the gate
Large-scale crate mould have different moving and fixed-mode offsets due to different filling rates and the influence of the mould's own weight during mould loading. In the above cases, the lateral offset force will be applied to the guide post during injection. When the mould is opened, the surface of the guide post is pulled and damaged. In severe cases, the guide post is bent or cut, and even the mould cannot be opened.
In order to solve the above problems, a high-strength positioning key is added on the parting surface of the crate mould, and one of the four sides is used. The most convenient and effective one is to use a cylindrical key. The perpendicularity of the guide post hole to the parting surface is critical. During processing, after clamping with the movable and fixed mould alignment positions, the boring is completed once on the trampoline, which ensures the concentricity of the moving and fixed hole and minimizes the vertical error. In addition, the heat treatment hardness of the guide post and the guide sleeve must meet the design requirements.
The moulding shrinkage of the prefabricated integral moulding compound is very small, and the shrinkage and warpage of the product are not serious. For some products, if the above phenomenon occurs, it can be put into an oven for slow cooling to eliminate it.
(2) Product finishing
Because prefabricated integrally moulded products often have some burrs attached to them, they need to be removed. The maximum thickness of burrs shall be limited to 0.1 mm. If the thickness of burrs is too large, it will not only be difficult to remove, but also the material waste will be too large and the cost will be greatly increased. If time permits, the operator can clean burrs and holes on the product using tools such as cutting blades, embossing belts and press-in rods during the time interval between the closing and curing of the Crate Mould(FURNITUREMOULD). Smaller products usually use roller edges to remove burrs.
(3) Cleaning the crate mould
After taking out the product, carefully clean the crate mould. First of all, the residual prefabricated integral moulding plastic chips, flash and other chips in the crate mold should be completely removed, especially the materials that have penetrated into the gap of the joint surface of the cavity should be completely removed, otherwise, not only the surface quality of the product will be affected, but also the opening and closing and exhaust of the crate mould may be affected.
Compressed air, brushes and copper non-ferrous metal tools are usually used to clean the crate mould to prevent damage to the cavity surface during cleaning. After cleaning the crate mould, apply a certain amount of release agent to the area where adhesion may occur, and then carefully check whether there are other foreign matters in the cavity. After completing the above work, you can proceed to the next process.
Consumers are familiar with plastic products in our daily life. Everyone is familiar with them. Here is a summary of how to make plastic products during processing.
According to different products, plastic products processing plants will also produce different Dustbin Mould(FURNITUREMOULD) models. These different injection moulding models can easily produce different types of products for consumers to use. However, the sizes of these models will not have any problems in production. We need to measure and clean the size of the dustbin mould at any time during the production process to ensure that the used grooves can work normally. If there are impurities in the groove, the surface of the produced product is very rough, affecting the beauty of the product. Therefore, special attention must be paid when using the dustbin mould.
The quality of processed plastic products is not only light and portable, but also some large plastic products can be easily moved without wasting too much time for consumers. Therefore, the product must be strictly made of plastic material before using the dustbin mould to manufacture the product. Check to ensure that these plastics will not undergo qualitative changes under any circumstances and will not harm the physical and mental health of consumers. It is necessary to choose some high temperature resistant materials. The better the heat resistance of the material, the less problems and time it takes to use the dustbin mould.