Mainly three factors that influence the cost of plastic injection molding – design of the part to be molded, material used in the molding tools and the cost of the unit. But the cost of plastic mold tool depends only on the material used in making it. These tools are made with a focus on their long lasting production benefits. In order to save mold tool cost you will have to go through this write-up.
Saving the cost by selecting right material
Plastic mold tools are normally made of different materials without compromising on their quality including aluminum, aluminum alloy and steel. Though the plastic mold tools made of aluminum and aluminum alloy can save the cost of entire project due to their resale value and stronger structure but the tools made of steel are considered the best one due to various reasons.
Though the initial cost of steel plastic mold tools is a bit higher than aluminum or aluminum alloy tools but still they can save mold tool cost for entire project due to their durability and least wearing properties. They can mould 100 thousands of pieces without any repair or replacement.
Some of the steels you can use for making injection mold tools may include Alumec, Corrax, Elmax, Holdax, Impax Supreme, Mirrax ESR and Moldmax HH etc.
Mold design for hot runner system
Though both, cold runner and hot runner molds, are used for plastic injection molding but hot runner system can help in reducing the cost of mold tools by increasing their productivity. Both the molding systems have their own pros and cons. In this write-up you will read the benefits of mold design for hot runner system to save mold tool cost more effectively.
Benefits of hot runner system
Removal of the runner: The cost of regrinding the runners of cold runner system can be reduced by using hot runner system in injection plastic molding as they can be reused in various types of molding operations.
Lower cycle time: Smaller shots in hot runner system save cycle time in comparison to cold runner system as cooling time of molded part depends on its thickness.
Improve efficiency of molding system: It is easier to start hot runner molds as they are not removed after each use like cold runner molds. The molding starts automatically in hot runner system after getting heated to the temperature required. Molding can be done with low pressure than cold runner system. It will increase the efficiency of the machine.
Best production quality: The filling and packing conditions can be better by using hot runner molds as its constant temperature offer you balanced flow of melted plastic from the nozzle of the machine to fill and pack the cavities completely. It is not possible with cold runner molds.
Automatic molding: Hot runner system allows you to automate your production system to produce flash free and more accurate plastic parts.
Flexibility of designing parts: Hot runners allow you to place the gate of the mold in most suitable position to fill it completely or partially more accurately. In this way you can aesthetically design the parts of your final object more flexibly.
Balanced flow of molten plastic: The users of hot runners have the advantage of consistent flow of melted material. The material is heated various times externally with the help of well insulated heaters surrounding the flow channel of the machine to fill each cavity through its nozzle with same heat and pressure.
Cost of mold produced in China is down for every customer in this world
The cost of mold tools depends on various factors including the location where it is designed and built along with complexity of the part and number and size of the cavities. The cost of these tools will be higher if you are going to use them for moulding bigger and more complex parts like dashboard of a car.
Addition of moving parts in the tool like unscrew able molds or sliders can also increase its cost as it goes bigger with every addition. Improving the finish of the surface of the part can also increase the cost of mold tool to some extent. In other words it can be said that the cost of plastic mold tools can be higher with the use of superior materials and larger volume of the part.
So, in order to save mold tool cost for their plastic molding units, many businesses prefer to get their tools manufactured in China as they can cost nearly 40% less than manufacturing them in the USA or the Europe. These tools will cost your cheaper because less capital expenditure in China. But you will have to visit the manufacturer’s factory frequently to ensure the production of your tools which can increase their cost to some extent.
Improve production efficiency of molded products
In order to improve the production efficiency of your plastic molding unit you should first of all find out its present efficiency level. The production efficiency of your unit depends on two things- how long you have used the machinery i.e. efficiency of the machinery and how efficiently the mold worked.
The efficiency of the machine can be calculated simply by calculating run time against available time to run it. For instance the efficiency of your machine can be 75% if it is used two hours less in the shift of 8 hours.
On the contrary, the calculation of the efficiency of the mold is a bit complicated. It depends upon the performance of the molding machine during its run time. The efficiency of mold also depends on various factors like cycle time, scrap and number of cavities to be filled.
Using the information collected
You can use the information collected by calculating the efficiency of the machine and the mold for improving the production efficiency of your plastic molding unit and save mold tool cost. This information can help you in finding out the basis of the problems so that you can know the main reason of less production. After knowing the basic reason of fall in production you can easily try to resolve the problem by changing the things accordingly.