Plastic Chair Mould
Plastic Chair Mould is needed every where on the world, but how ti purchase a good quality plastic chair mould from China mold companies is not easy thing, normally all of China Mold Makers can make Chair mould, but you need ti need to very carefully to select your supplier,Please ask below questions to the mould company to see if they are good or not.
Quality points we need to take careful during Chair Mould Making
1, Can you tell your chair mould running cycle time?
If the cooling water temperature is from 8 to 12 centigrade degree, if the chair weight from 1700g to 2400g, the cycle time should be 35s to 50s. If the machine plastic melt and injection is with accumulators. Please check how they make the cooling channel? If the cooling channel is extra in and out? If the cooling channel is one according with the chair shape?
2, How you guarantee your chair mould run shorts?
The guarantee for a mould runs 1 million shorts without any flashes? Because if you accept to cut the flash by your workers, I think you can use this mould for 10 millions shorts. So you need to check the steel hardness, and in the mould if there is any parting area were welded. Normally the steel hardness should be HRC33.
3, How you make the parting line finishing is good, if there is any sharp edges?
Sharp edge on the chair is dangerous, in order to avoid the sharp edge, we have to do many points during the chair mould manufacturing.
– Chair mould parting design is correct or not.
– The chair mould cavity and core thickness is enough or not.
– How you make the CNC milling the cavity and core? Normally, we need 3 stages finishing. From rough milling to steel hardened, after hardening, take the 2nd stage milling, we call it half precise milling, normally we leave 0.3mm, Then make the steel stress releasing, after this we do final precise milling. When in this time, the machining operation is very important.
1). we have to use cooling on the milling area. 2). we have to be sure that each cutting, the depth will not bigger then 0.08mm. All these are because of the steel will be deformed when milling and after the hardening. The deforming will cause the cavity and core’s fitting are not accurate, there will be a lot of hand works on it. By hand works on the parting area, you can never work out a perfect parting line.
4, the wall thickness is even or not.
Hand working on the parting line also be one of the reasons for wall thickness is not even. Of course, most of the reason is from the plastic chair 3D design and poor polishing on the cavities and cores. So when we start a plastic chair design, we have to consider the wall thickness. Some time, we need to make some area a little thicker to be sure that the chair is strong enough. But we have to consider seriously when it is need. because the uneven thickness will caused the injection not balanced and also will caused the cooling time not even. This will affect the injection speed slow down and also will cause the shrinkage marks. If the CNC milling is too rough, you can never get a chair with thickness even.
5, how about the stackable?
When the chair plastic designs are doing, we have to check its stack ability. And you also need to consider the deform possibility of the chair molding.
6, how you can make the Plastic chair mould with less weight but strong enough?
When starting makes the plastic chair design, we have to consider the weight and the strength. You can make the bottom area be strong enough by add more ribs. But how about the leg, backrest and armrest area? For this reason, you need to calculate or analyze the force of each area…in order to make a light chair strong, you can choose a very low MFI PP material. But in this way, you need to make the mould very strong and also you need to be sure the injection filling are available, as because you are using a material with MFI 4 or Max. 6.
7, How to make the air venting on the chair mould backrest?
For some chair backrest design is very complex, there is a lot of material jointing line, and some air cannot venting out when material filling and flowing. For this reason, you need to analyze by mold-flow maybe, and there are a lot of area need air venting built in the chair mould.
8, how to keep your chair mould finishing long lasting?
In order to make your chair mould cavity and core will not be rust by the plastic material, you need to be sure that the steel are high chrome and also the hardness are bigger then HRC33. If you will use some recycled material for injection, you need your chair mould be hard chrome plated. Otherwise, you need to make the polishing from time to time.
HYX is the leading plastic chair mould manufacturer in china, we has developed more than 300 sets chair moulds during these years. We are also professional in PC transparent chair mould gas injection. If you need a high speed, long time and nice finishing chair mould, please come to us. We are sure you will be satisfied.