Welches Metallgussverfahren ist dem Kunststoffspritzguss am ähnlichsten?

Plastic injection molding is one of the most common and versatile manufacturing processes used today. From toys and household goods to medical devices and car parts, injection molded plastic components are everywhere.

Given how ubiquitous and useful injection molding is for plastics, it’s natural to wonder – is there an equivalent process for metal parts? As it turns out, there is one metal casting process that works very similarly to plastic injection molding: die casting.

In dieser Stelle, als Fachmann Hersteller von Kunststoff-Spritzgussteilen, we’ll take an in-depth look at how die casting stacks up against injection molding to see why it can be considered the metal version of this popular manufacturing technique.

Welches Metallgussverfahren ist dem Kunststoffspritzguss am ähnlichsten?

The metal casting process that works most similarly to plastic injection molding is die casting. Die casting injects molten metal alloy into steel molds under high pressure, allowing complex, high tolerance metal parts to be mass produced. This mirrors several key stages and capabilities of the injection molding process, qualifying die casting as the closest metal equivalent.

How Plastic Injection Molding Works

Before we can properly compare it to die casting, let’s quickly review how conventional injection molding works. Here is the standard injection molding process:

The plastic raw material is melted inside the injection molding machine barrel. Common plastics used include ABS, PVC, nylon, HDPE, and polycarbonate. The plastic is melted by heat and pressure from a rotating screw.

The now liquid plastic gets injected into a steel mold. The mold is clamped shut and has been lubricated and cooled by water lines. The plastic fills the cavity, taking the shape of the mold.

The molded part cools inside the mold until rigid enough to be ejected. Cooling times depend on the plastic used and wall thickness but typically range from 20 seconds to 2 minutes.

The mold opens, and the completed plastic part gets ejected. Some minor trimming of the parts is required to remove excess plastic and mold lines.

This quick 4 stage process allows intricate plastic parts to be mass produced with precision, efficiency, and repeatability. But is there a metal equivalent?

How Die Casting Compares to Injection Molding

Die casting is a manufacturing process where a molten metal gets injected under high pressure into a steel mold, called a die. The most commonly die cast metals are non-ferrous alloys of zinc, aluminum, magnesium, and copper.

This may already sound very similar to plastic injection molding, but let’s look closer at each key stage:

Mold Preparation

This step is nearly identical between the two processes. The metal dies or steel injection molds get sprayed with a lubricant and then clamped shut. This aids with temperature control and part ejection.

Filling the Mold

Here is where we start to see the similarities shine through. With die casting, a molten metal gets injected into the die mold through a gooseneck. The pressure, temperature, and speed are carefully controlled to fill the die cavity.

Just like injection molding, thin, complex, high tolerance metal parts can be created via the high pressure die casting process.

Abkühlung und Erstarrung

After the mold fills, the molten metal starts to rapidly cool and solidify, taking the shape of the metal die. Cooling times depend on the alloy used and wall thickness but are typically faster than plastic injection molding.

Part Ejection

Finally, the die separates, and the solidified metal part gets ejected. Some minor trimming is also performed to remove excess metal and flash.

As you can see from this comparison, die casting works remarkably similar to plastic injection molding, just with molten metal instead of plastic. This qualifies it as the most equivalent metal fabrication process.

Unique Benefits of Die Casting

Beyond just process similarities, die casting provides some unique advantages, much like injection molding does for plastics:

• Ability to produce complex, high tolerance metal parts at mass scale
• Very fast production cycle times
• Low per unit cost at higher volumes
• Wide material selection of castable alloys
• High degree of automation possible

These beneficial characteristics have made die casting the process of choice for metal part production across many industries, including automotive, aerospace, electronics, and consumer products.

Die casting is able to create durable metal components with tighter dimensional accuracies versus other metal fabrication techniques. This allows small but intricate metal parts to be manufactured at scale, much like injection molding does with plastics.

Key Differences Between Die Casting and Injection Molding

While the die casting process shares many commonalities with plastic injection molding, there are some notable differences as well:

Materials Used: The core difference is that injection molding uses plastic polymers, while die casting works exclusively with molten metal alloys. Each process is tailored for its respective material type.

Mold Cost: Due to high temperatures and pressures, die casting molds are more complex and expensive than plastic injection molds. However, they also tend to last for over 1 million shots.

Post-Processing: Die cast parts require little finishing since they eject with smooth surfaces. Injection molded plastics usually need some degating, texturing, or decorating secondary operations.

Lead Time: Die casting generally has faster cycle times than injection molding, especially for small, thin-walled parts. But plastic injection prototyping is easier with lower-cost aluminum molds.

So in summary, the two main differences come down to materials used and mold complexity/cost. The actual formation process is otherwise quite similar.

Which Process is Right For Your Application?

Wir haben viel über den Vergleich zwischen Druckguss und Kunststoffspritzguss gesprochen. Lassen Sie uns die wichtigsten Erkenntnisse zusammenfassen:

• Das Druckgießen funktioniert ähnlich wie das Spritzgießen, jedoch mit geschmolzenem Metall anstelle von Kunststoffpolymeren.
• Beide können komplexe, hochtolerante Teile in Massenproduktion herstellen
• Druckguss bietet einzigartige Vorteile wie Festigkeit, Hitzebeständigkeit und schnellere Zyklen
• Kunststoff-Spritzgießen bietet niedrigere Kosten und Materialflexibilität

Welche ist also für Ihr spezielles Produkt oder Ihre Anwendung sinnvoll?

Hier sind einige Leitlinien:

Kunststoff-Spritzgießen funktioniert in der Regel besser, wenn Sie es brauchen:

• Niedrige Stückkosten, insbesondere bei sehr hohen Stückzahlen
• Leichte Teile mit Korrosionsbeständigkeit
• Geringe Anlauf- und Prototyping-Kosten
• Kreative Freiheit bei Farben, Texturen und Materialien

Druckgießen funktioniert in der Regel besser, wenn Sie dies wünschen:

• Hochfeste und hitzebeständige/abriebfeste Metallteile
• Komplizierte Bauteile mit sehr engen Toleranzen
• Glattere Oberflächen, die nicht nachbearbeitet werden müssen
• Schnelle Produktionszykluszeiten

Für manche Anwendungen können beide oder sogar eine Kombination sinnvoll sein. Aber die Bewertung Ihrer spezifischen Anforderungen und Prioritäten wird Ihnen bei der Auswahl des besten Verfahrens helfen.

Die Vielseitigkeit des Kunststoffspritzgießens hat es zum bevorzugten Herstellungsverfahren für die Massenproduktion von Kunststoffteilen in unzähligen Branchen gemacht. Der Druckguss bietet dieselbe Fähigkeit, Effizienz und Präzision, allerdings für kostengünstige Metallteile.

Wenn Sie also schon immer über ein Metallherstellungsverfahren nachgedacht haben, das ähnliche Vorteile wie das Spritzgießen bietet, dann sind Sie beim Druckguss genau richtig - er kommt einer Metallversion dieser allgegenwärtigen Produktionstechnik am nächsten.