Analysis on the Key Quality Points of Chair Mould

Judge the cycle period of the chair mould

If the cooling water temperature is between 8-12℃ and the seat weight is between 1700g to 2400g, then the cycle period should be between 35s to 50s. If the plastic melting and injection are performed under the function of an accumulator, please check  the waterway to ensure whether the waterway is straight-through or not, and whether the direction of the waterway is consistent with the shape of the chair mould.

Ensure the lifespan of the chair mould

Many manufacturers will say that they can guarantee that one pair of their moulds can produce one million products, but how they can guarantee this? Can they guarantee that a mould can run without flash after 1 million moulds? If you cut the flash by hand, you can produce 10 million molds with this mold. Therefore, you need to check the hardness of the steel material and whether this mold has welded parts. Under normal circumstances, the hardness of steel should be HRC33.

Whether the wall thickness of the chair mould is uniform

Manual work on the parting line is one of the reasons for uneven wall thickness. Of course, most of the causes are due to the poor 3D design of the plastic chair and the poor polishing of the cavity and core. Therefore, when we start designing a set of plastic chair moulds, the thickness should be considered. Sometimes, we need to thicken some parts to ensure the strength of the chair. But at the same time, we also need to carefully consider this issue. Because uneven wall thickness will cause uneven injection molding and cooling. This will slow down the injection molding speed and cause shrinkage.

Ensure that the chair mould is light and sturdy enough

When designing injection molded chairs, we need to consider their weight and strength. You can increase more reinforcing ribs to make the bottom of the chair strong enough. What about the chair legs, backrests, and seat cushions? In order to solve this issue, you need to analyze the force in each part. To make a lightweight chair with good strength, you need to select a PP material with a low melt index.

Design the exhaust system on the back of the chair mould

Some chair back designs are very complicated because there are many plastic welding points, which may cause poor exhaust when the material is filled and flow. Therefore, you need to analyze whether some areas of the mold need to be exhausted through mold flow analysis.

Ensure the durability of the chair mould polishing

To prevent the plastic from corroding the cavity and core of the mold, you need to ensure that the steel is chrome-plated and that the hardness exceeds 33. If you use some recycled materials for production, the chair mold must be chrome-plated. Otherwise, the mold will need to be polished frequently.