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| Hot runner system application technical survey |
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Hot runner system application technical survey
1 The advantage of HRS mold:
Hot runner system mold is widely used on the modern industrial-developed countries and areas. The main reason is that the hot runner mold includes the below obvious features:
1. shortening the part cycle time
As there is no limit of the runner system cooling time, the part can be timely ejected after forming and solidification. The cycle time of many thin-wall parts produced by Hot runner system can be under 5 seconds.
2. Saving plastic materials
In the pure hot runner system without cold runner, there is no waste material produced, which has the application project meaning for the plastic in expensive cost. Actually, The main international HRS manufacturer are speedily developed the time the oil and plastic all around the world are very expensive, as the HRS technology is the main route for reducing the wasting plastic cost.
3. reducing the waste, and advancing the product quality
During the hot runner mold forming process, the plastic melt temperature can be exactly controlled in the hot runner system. The plastic can flew into each cavity in the more even status, which will produce the parts in the same quality.
The part gate by Hot runner forming is in good quality, and the residual stress after mold unloading is very low, so the part is under small deforming, which cause the parts on the market with high-quality request are produced by Hot runner mold, such as the plastic parts of the MOTOROLA mobile phone , HP printer, DELL notebook which are familiar with people.
4. Canceling the subsequent handling is benefit for automatic production
The part is the finish part after forming by the hot runner mold, there is no need of pruning of the gate and regrinding and processing the cold runner etc., which is good for automatic production.
Now many manufacturers abroad combine the hot runner system and automatic production to advance the production effect widely-range.
5. Enlarging the range of plastic forming crafts application.
There are many advanced plastic forming skills are developed on the basis of hot runner system technology, such as the pre-forming of PET, the multiple color injection mold, there are many kinds of materials mold injection craft, STACK MOLD etc..
2. The disadvantage of hot runner mold:
Comparing with the cold runner mold, there are many obvious merit of hot runner system, but the customers also needs to know the demerit of hot runner system , the concluded points are showed as below:
1.The mold cost is increased.
The hot runner parts are more expensive, so the cost of the hot runner mold is increased in wide-range. Economically, the mold tooling cost is comparatively high. As to many mold customers in developing countries, the high cost is the main reason influences the widely application of hot runner mold.
2.The craft equipment of hot runner mold making is in high requirement
The hot runner mold needs the processing machine as warranty. There is strict requirement on the integration and match of the hot runner system and the mould, otherwise there will be many serious problems during the production.
If the plastic sealing is incorrect causing the plastic leakage and damaging the parts in the hot runner, it will cause the production interruption, and the sprue insert had not matched with the correct position of the gate, which will cause the parts in bad quality.
3.The operation and repairing are very complex
Comparing with cold runner mold, the hot runner mold operation is very complicated. If the operation is not correct, the runner spare parts will be easily damaged, which cause large economic lost.
For the new user of hot runner system, they need to accumulate the using experiences by longer times
3. The composition of hot runner system
Although there are many hot runner system manufacturers and many hot runner system serials all around the world, but the typical hot runner system is made of the below several parts:
1MANIFOLD
2. NOZZLE
3.temperature controller
4.other spare parts
We will provide the categories and application of these spare parts in future articles.
4. The technical key for hot runner system use
There are guarantee on many links for a successful use of hot runner system, among which, there are two critical technical factors: firstly, it is the temperature control of plastic; secondly, it is the control of plastic flow.
1. The temperature control of plastic
It is very important of the plastic temperature control in the hot runner system application. There are many processing and part quality problems during the production come from directly the improper control of the hot runner system temperature, such as the part gate in bad quality problem by using hot pin gate for mold injection, the difficulty of closing pin in valve pin gate system, the time and quality are not same for the part filling in the multiple cavity mold, etc. If possible, pls. try to choose the hot runner system in several areas by temperature control separately, to advance the flexibility of use.
2. The control of plastic flow
There needs the balanced flow of the plastic in the hot runner system. The gates should be opened in the same time for plastic filling each cavity synchronically. There is not the design of the runner size in balanced for the FAMILY MOLD, for which the part weight is different greatly, otherwise, there will be some parts with less pressure when filling the cavity, and some others with over pressure, causing the flashing quality problems. Then the size of the hot runner should be designed reasonable, as the size is smaller causing the filling cavity pressure loosing, and the size is larger causing the runner size is large, and the plastic retained on the runner for longer time, then finally damaging the materials and making the part unsatisfied the use after forming. All around the world, there are the software of designing for the best runner, such as MOLDCAE.
5. The application scope of hot runner system
1. The sort of plastic material
The hot runner system now is used for each kind of plastic processing, such as PP, PE, PS, ABS, PBT, PA, PSU, PC, POM, LCP, PVC, PET, PMMA, PEI, ABS / PC etc. Any materials using the cold runner system for processing can use the hot runner system for processing.
2.part size and weight
The weight of the smallest part made by hot runner mold is less than 0.1g, the weight of the largest one is more than 30kgs, so the application scope of hot runner system is very wide.
3.Industrial Area
There is widely use of hot runner system in electronics, car, health care, daily necessity, tools, packaging, construction, office equipment, etc.
6. The brief of the international hot runner mold production
Globally the hot runner mold production is very active in the industry-developed countries and areas. The use percentage of the hot runner mold is increased gradually. There are many factories less than 10 people are producing hot runner mold. By and large, the time of using hot runner technology is long in North America and Europe, which had accumulated rich experience. In Asia, except Japan, Singapore, South Korea, Taiwan, Hong Kong are the pioneers.
Although the mold making level is high in North America and Europe, their price is comparatively high and the delivery time is longer. The Asian hot runner mold manufacturer has more competitive ability on the price and delivery time.
7. Globally main hot runner manufacturers and the headquarter place
The competition is very intense in the hot runner technology domain, so many companies had invested many resources on the product development. On each main plastic & mold exhibition, we always can see the new hot runner system. Now we collect the global main hot runner manufacturer names and their headquarters showed as below:
1. North America
MOLD-MASTERS Canada HUSKY America
SYNVENTIVE America CACO America INCOE America FASTHEAT America D-M-E America HASCO America
2. Europe EWIKON Germany GUNTHER Germany SPEAR Germany PLASTHING United Kingdom UNITEMP Sweden THERMOPLY Italy
3.Asia
SEIKI Japan YUDO South Korea
4.Australia MASTIP New Zealand
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