Chair Moulds Solution2

8/2/2019 Chair Moulds Solution2

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Sino Mould is the leading chair mould manufacturer in china.

Annually manufacturing over than 80 sets of chair moulds.

Interchangeable inserts block for different chair backrest versions.

Backrest inserts can be easily changed on the machine, we are also

familiar with PC transparent chair with gas injection, variousmonoblock chair moulds with armrest or without


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Mould running cycle time

Mould service life guarantee

Parting Line finishing

Wall thickness How to make chair moulds with less weight but strong enough

Stack ability

Air venting on the backrest

How to keep chair mould finishing long lasting.


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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 thecooling channel is one according with the chair shape?


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Many people will say that they will have one millions

guaranteed. But God now how can they guarantee. The

guarantee for a mould run 1 million shorts without any

flashes? Because if you accept to cut the flash by your workers

heavy labor, I think you can use this mould for 10 millionsshorts. 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.


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Sharp edge on the chair is dangerous, in order to avoid the sharp edge, wehave to do many points during the mould manufacturing.

Chair mould parting design is correct or not.

The cavity and core thickness is enough or not.

How you make the CNC milling the cavity and core? One stage finishing orseveral stage finishing? Normally, we need 3 stages finishing. From rough millingto steel hardened, after hardening, take the 2nd stage milling, we call it half precisemilling, normally we leave 0.3mm, Then make the steel stress releasing, after thiswe do final precise milling. When in this time, the machining operation is veryimportant. we have to use cooling on the milling area, we have to be sure that each

cutting, the depth will not bigger then 0.08mm. All these are because of the steelwill be deformed when milling and after the hardening. The deforming will causethe cavity and cores 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.


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Hand working on the parting line also be one of the reason 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. Sometimes, we need tomake some area a little thicker to be sure that the chair is

strong enough. But we have to consider seriously when it is

need. As because the uneven thick will caused the injection not

balanced and also will caused the cooling time not even. Thiswill effect the injection speed slow down and also will caused

the shrinkage marks. If the CNC milling is too rough, you can

never get a chair with thickness even.


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When the chair plastic design are doing, we have to check its

stackability. And you also need to consider the deform

possibility of the chair moulding.


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When starting make 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 areain order to make alight chair strong enough, 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 you are using a material with MFI 4 or Max. 6.


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For some chair backrest design is very complex, there is a lot

of material jointing line, and some air can not 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 mould.


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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 needto make the polishing from time to time.


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Sino Mould Co. ,Ltd

Wendy Lu :Sales Engineer

E-Mail: [email protected]

[email protected]

[email protected]

Skype: sino.holdings.group-007

MSN:[email protected]

Tel:+8615068622586

Sino Mould is the leading chairmould manufacturer in china, we

has developed more than 500 sets

chair moulds during these years. If

you need a high speed, long time and

nice finishing chair mould, please

come to us. We are sure you will be

satisfied.

For more plastic products moulds

information, please kindly refer to

our website:

www.cnmould.com

And Sino People always warmlywelcome your visit to review our

factory.

Looking forward to start our long

term business cooperation now!!
mailto:[email protected]:[email protected]:[email protected]://MSN:[email protected]/http://www.cnmould.com/http://www.cnmould.com/http://MSN:[email protected]/mailto:[email protected]:[email protected]:[email protected]:[email protected]:[email protected]


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DAKUMAR Machinery is one of our Sino Holdings Groupbranch company, which is one of the Chinese leadinginnovator for plastic injection molding machine researchingand developing.

DAKUMAR has established service center in Brazil, Mexico,South Africa, Turkey, Israel, Russia...in order to make betterservice, we are negotiating with many oversea professionalteam to establish more and more service centers andpartnership in different countries

For more information, please kindly visit our website orcontact with me.

Welcome your down visiting !!!!!!!!!!

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Chair Moulds Solution2