After filling you must pressurize the mold to get a good imprint of the cavity to minimize the effects of cooling. Short shots, sinks, voids and dimensional variations in parts are caused because of insufficient packing pressure in the mold cavities. […]
As part of a rigorous mold tryout, it is essential to instrument a mold to see what is going on inside the mold. […]
With the proper temperatures set, the mold must be filled as fast as consistently possible. This means that the mold should be able to be filled to at least 90 percent of the injection rate of the production molding machine without adverse effects. […]
It starts out with the temperatures of the plastic. The temperature of the plastic coming out of the molding machine should be right down the middle of the manufacturer’s spec. If you can run a mold here, […]
How do you get a ready-to-go mold? Obviously, it starts with good design with no broken rules. It must be cut properly. It must be assembled properly. Checks must be made to ensure that all items function as designed, clearances are proper and water lines are correct based on flow. […]
The unitized system offers considerable improvements in quality and addresses the cost of repair favorably. Since the integrated system is based upon using the unitized prewired design for installation in the mold, the chance for pinched or severed heater and thermocouple wires is eliminated during assembly. […]
On unitized systems, the nozzles and manifold block constitute a single drop-in unit. The melt channel runs from the manifold block directly to the nozzle without any potential misalignment or dead spots. Any potential for plastic leakage between the nozzles and the manifold block is eliminated since the nozzles are inserted within the manifold by [...]
When choosing plating for your mold or mold components, you must first identify the problem to be solved or the problem to be prevented. The first question you should ask is “What is the cause of this problem? Is this problem the result of corrosion or wear?” If the component has previously been plated, this [...]
There are two basic types of plating – electrolytic and electroless. Electrolytic plating requires electricity to make the process occur. There is a positive and negative charge. The positive is called the anode and the negative is the cathode. The part to be plated gets the negative charge so it becomes the cathode. The anode [...]
The most common problem associated with polishing aluminum is the deep scratches that plague the finishes. Three things primarily cause deep scratches in aluminum: 1) The wrong type of abrasive being used. 2) Too much downward pressure from the polisher's hand. 3) Using too long a stroke while stoning. Aluminum is primarily stoned by hand [...]