Find the answers to frequently asked questions about our services and products.
Injection molding is a casting procedure that is particularly used for plastics processing. Tanner Formenbau is your professional partner in this field.
‘Casting’ refers to a certain group of production processes, specifically those where a solid object with a geometrically defined shape is manufactured from a previously shapeless material (in liquid, gas, malleable, granular or powder form).
An injection mold is a permanent mold used to manufacture components. It is inserted into an injection molding machine. Most injection molds are made of metal. They have a hollow that determines the shape and surface properties of the part to be manufactured.
Injection molds for the plastics processing industry are usually made of steel. Depending on the number of planned injection processes, more wear-resistant materials such as hardened or tempered tool steel or hard metal can also be used. Let us advise you. The wealth of expertise and practical experience that we have gained over the years perfectly positions us to develop the optimum solution for you.
During this procedure, the injection mold is pressure-filled with plasticized plastic, which then cools and hardens. Finally, the mold is opened and the molded part is removed.
These kinds of molds are used to produce the widest range of components—with weights ranging from just a few tenths of a gram to over 100 kilograms. We will gladly advise you on your options, for which we are always happy to push the boundaries of what is technically feasible.
This procedure enables highly economical and efficient series production—making it greatly valued in the plastics processing industry. We can gladly provide you with a list of reference customers.
Injection molds are typically made up of two halves. One half of the mold is called the nozzle side, and the other is the ejector side. Each half is further composed of multiple plates, each with different functions.
The nozzle side is the stationary half of the mold during production. In most cases, the nozzle-side mold plate of two-plate molds contains the cavity halves—also known as mold inserts or mold nests. It also consists of a clamping plate, a mold plate, a cooling system, a sprue bushing, as well as a centering ring and guide elements.
The sprue bushing—usually in combination with a cold runner distribution system—is located on the nozzle-side mold plate, as is the hot runner manifold with hot runner nozzles. The mold is attached to the machine’s clamping plate, which has an interchangeable centering ring. The nozzle tip enters the mold through the centering ring and presses against the sprue bushing. In the case of an injection mold with higher mold temperatures, an insulating plate is additionally mounted in front of the clamping plate. This prevents heat transfer to the machine-side clamping plate.
The ejector side also consists of a clamping plate and a mold plate, plus ejector pins, ejector plates, support rails, an intermediate plate, and cavities.
The injector side is the side of the mold that does not move (i.e. remains static) during injection molding. It contains the gate system components and the cavity half shells (known as mold inserts). The injector side of the mold usually also features a distribution system for the coolant. This plays an important role in the heat dissipation process once the molten material has been injected.
The injection molds are attached to the tooling plate. They have a replaceable centering ring, which enables the nozzle to be centered as it is inserted. The nozzle is inserted into the mold until it reaches the gate bushing. When injection molding at high temperatures, an insulating plate is usually also inserted before the tooling plate. This prevents too much heat being transferred to the tooling plate.
The ejector side of an injection mold can be identified from the ejection elements. Once the injection molded component has cooled down and hardened, the tool halves are opened. The component is initially located in the ejector side. The ejection system removes the finished part from the mold. It can now be further processed and quality inspected.
A differentiation is made between standard molds, sliding core molds and quick-change molds. Standard molds are suitable for an incredibly diverse range of applications. Sliding core molds, on the other hand, come equipped with a slide, making them particularly ideal for components with large undercuts. The third type—quick-change molds—are primarily used for prototypes and small-scale production as the mold structure remains on the machine and only the quick-change inserts on the injector and ejector sides have to be changed.
Which is the best mold for your project? Click to determine the answer together.
The ejector side contains shape-defining cores and inserts, also known as cavities. When the mold is opened, the injection molded part usually remains on the ejector side. Several ejector mechanisms are used depending how hard it is to demold the part. The following are possible:
- Injection molded parts without an undercut: these can be slipped or pulled off or demolded using ejector pins.
- Injection molded parts with an undercut: these are demolded using slides or sliding cores.
- Injection molded parts with internal or external threads: these can be pressure demolded, unscrewed with rotating cores or even demolded using collapsible cores.
As both mold halves have their own temperature control system, the optimum temperature can be ensured. Different mold temperatures are required depending on the plastic being processed.
Tanner Formenbau’s many years of experience ensure the best results for your project. Discuss it with us.
Yes, all injection molds can be divided into three basic modules and their respective subgroups. These are the demolding methods, the gate technology and the temperature control. A fourth criterion—the special design—is also possible.
The development of an injection mold involves several steps. Not only is the mold tailored to the plastic to be used but the injection process is also optimized using calculations and simulations. The following steps are required from the initial sketch to the finished injection molded part:
- Creation of a schematic sketch
- Definition of the mold technology
- Definition of the mold’s dimensions and technical design
- Alignment of the mold to the plastic material
- Development of the gate system
- Production of the mold elements
- Simulation of the filling process
- Analysis
- Production
Interested in realizing your project with us? Then we look forward to hearing from you. Together, we will make your vision a reality.
The short answer is that yes, it is. In many cases, unscrewing cores get jammed when producing medical syringe barrels with Luer-lock threads. This is costly, causing expensive machine and production downtime as well as wear to the unscrewing mechanism. The cause of the problem in molds for syringe barrels with Luer-lock threads is well-known: a poorly designed unscrewing mechanism. If insufficient consideration is given to the thermal expansion of the part, this quickly leads to warping and tension when the system is in continuous operation, resulting in the unscrewing cores jamming.
The solution is an unscrewing mechanism that has been engineered for tension-free operation. Tanner Formenbau has specialized in molds for edge-gated parts with Luer-lock threads for decades. Experience often makes the difference. So choose Tanner right from the outset.
The question of whether the cycle time for a new mold can be further shortened can be answered with a “yes”. This is where Tanner Formenbau comes in: if the new mold has to fit the existing system while producing parts with the same outstanding level of quality yet at a higher rate of production, Tanner Formenbau’s expertise is required.
One solution that worked well for one of our customers was an optimized cooling system. Thanks to the latest production technologies, we have succeeded in enhancing cooling in the area of the core tip. The newly designed cooling channel reduced the cycle time by around 0.5 seconds, leading to a 10% increase in production without compromising on the part quality. Sometimes, victory comes down to mere tenths of a second. Count on us when your goal is to finish in first place in your sector.
High injection pressure of up to 2,000 bar can often cause slide cracks and therefore flash development on the products. To durably withstand a high injection pressure, we developed a mold concept with a nozzle-side slide arrangement for one of our customers. The heavy-duty construction enables an extremely rigid and durable closing mechanism. The mold passed the test: production-process reliability, no need for repairs and consistently high product quality. Our customer replaced its entire line of molds in this product series with new Tanner molds. It pays to invest. Place your trust in Tanner’s innovative strengths—for profitable and sustainable production.
Still Got Questions?
If you still have further questions, please don’t hesitate to contact us. Our team will gladly assist you—quickly and efficiently.