Press Trimming

The press trim tool is in two parts and each half is bolted on either the upper or lower platen on one of our Hare presses. The trim press has typically 15 to 20 tons of closing pressure. The press raises and lowers as the worker actuates the press guard. The die casting part fits perfectly in the trim die bottom, the trim die top half closes on the part and uses a cutting edge to cut the excess metal (flash) away from the part.

A casting shot is placed on the lower half seating of the press tool. The operator shuts the safety gate which operates the top tool to come down onto the die casting shot and cuts away the runner feed. The top tool returns automatically which releases the safety guard.

The operator removes the castings and places them in a works container. The operator removes and discards the runner feed to a scrap container.

We then return the runner feed to the foundry where it is remelted and reused in the die casting process. The process is reliable and repeatable and can be repeated 200 to 600 times per hour depending on each casting product and the exact process we use with cleaning the tool etc.

Firstly, you must understand the process. The Zinc die casting manufacturing process is where molten metal is injected into the tool under extreme pressure, it is under that much pressure the metal “flashes” out around the edges of the part inside the die casting tool. This excess metal is also called “flash”. This flash is typically very thin, sometimes paper thin, wall of metal. The flash is frequently sharp and can cut fingers if not handled carefully. After the part cools sufficiently, the flash must be removed before we can dispatch the components to our customer. This is where a press trim operation comes in, the press trim tool will remove the excess flash reliably and repeatably and is the most cost-effective way to remove the flash.

A press too, comprises of two halves, a top tool and a bottom tool. The bottom tool is designed to seat the casting shot on so it does not move. The press tool is made from tooling steel and hardened and pre-treated. commonly known as a die set.

The life of a press tool is expected to cover 1000 000 strokes plus. We use simple cleaning and lubricating after each run where the tool condition is checked for wear.

The cutting edges need to be sharpened periodically; A simple cost-effective task. Wear parts such as punches and ejectors may need replacing after 250000 plus depending on each press tool as an average.

Press tools are reliable and very cost effective to separate castings from the die casting shot.

The press trim machines we use are Hydraulic and operates between 5 Tons and 15 Tons.

The size of the die casting shot will determine which machine the press tool is designed to fit. The press is designed to take a tool in two halves. The bottom half is fixed to the lower platen. The top tool is fitted to the dolly in the top position.

When the press tool is set on the press. it is aligned by pillars to ensure the tool is set squarely and will operate squarely throughout the production run. Only the top tool lowers and returns in the pressing operation. Presses operate reliably and repeatably with great accuracy.

Yes. It is the fastest and more consistent way to remove flash. The only other way to remove flash would be by using a file or sander – This is far more labour intensive and not always consistent in the process.