Prototype Injection Molding
Before the actual injection molding process starts, you must make samples products called prototype. Usually, this is the first stage where we convert ideas to actual products in injection molding process.
All the process in prototype injection molding are exactly the same during the mass production process. The best part, prototype injection molding helps you understand viability of the production process in terms of quality control, cost and viability.
Steps in Prototype Injection Molding Process
The prototype injection molding process involves the following steps:
Mold Design – The first step is to design a mould that you are to use for the production process. The perfect design should consider the weight and dimensions of your product.
Clamping – Clamping involves using a clamping unit to hold the halves of your mould into position. You then attach the moulds to the injection machine allowing one side to open.
Injection – Injection involves feeding the molding machine with plastic pellets through the hopper. Feeding allows the pellets to move to the molding unit.
Heating takes place at the molding unit, which melts the pellets. The melting process is complete once all the pellets melt, which varies depending on the type of pellets.
Melting allows the pellets to take the shape of the mould under pressure. The mould formation
Cooling – Cooling takes place inside the molding unit by passing cool air through it. The cooling rate depends on the nature of the metal part you want and the type of pellets you are using during the melting stage.
Cooling gives strength to your product part since it hardens.
EjectionOnce cooling takes place, the product part is now ready. Ejection from the mould involves removing the clamps to open up the mould.
This process should be automatic to ensure product quality and minimize damage.
Prototype Injection Molding Machine
There are three types of prototype injection molding machines which include, hydraulic, electric and hybrid prototype injection molding machines.
Electric prototype injection machines have a high initial cost and require regular maintenance. However, the electric prototype injection machines have a high quality and volume of product parts.
A hybrid prototype injection machine utilizes both electric motors and hydraulics. This machine is relatively cheaper than the others and is ideal for producing thicker parts.
However, it has a high operational cost due to electricity and hydraulics. The main limitation of this type is the likelihood of lacking product uniformity.
The hydraulic prototype injection molding machine operates on hydraulics. It is cheaper than the electric one but has a lower production output.
The hydraulic machine is the best option in the small-scale production of parts.
When to Adopt Prototype Injection Mold
Prototype injection mould is an ideal process for the mass production of your product. This is due to uniformity and quality consistent with this process.
However, always check on your product design. It should be compatible with the mould design.
Prototype injection mould is an ideal option for market research. This will allow your customers to give valid feedback for the product before considering the next step.
If you want your product to undergo various tests before final production, you need to consider prototype molding. Ma production of the product allows you to test the different parameters you want before production.
Reduces Production Risks – Several risks are present due to the use of hot plastic materials. These risks include human risks and improper manufacturing processes.
It reduces this risk by ensuring the smooth flow of hot plastics. The hot plastic flows into the moulds creating the part you want.
Accelerates the Production Process – Prototyping allows you to understand the parameters needed for an accurate production process. This reduces both production time and resources.
Reduces Production Cost – The reuse of the moulds during the production process ensures you minimize cost. It also allows for product uniformity, ensuring exact raw materials are used.
Prototype injection molding produces various parts for different functions. The use of these parts ranges from household items to industrial items.
Such items include bottle caps, plastic bottles, furniture, kitchenware, toilet seats and flower pots. Other items include medical devices, computers and electronic accessories.
Usually prototype injection molded parts act as samples. They for a benchmark for other injection molding processes.
It would help if you considered the following before selecting injection molding prototypes:
Mold Classes – Mould determines the operating temperature for manufacturing your part. We have different materials that can withstand different temperatures during the molding process.
However, classes 104 and 105 o, mild steel or aluminum, offer the best material for your mould. Selecting the mould materials enhances the quality of your parts while increasing the mold’s durability.
Gating Method – The gating method for your injection molding process helps determine the final product’s quality. Common gating methods include a sub gate, edge gate, sprue gate and hot tip gate.
An ideal gating method should withstand high shear pressure and hot operating runners. This maximizes the efficiency and durability of your mould.
Mold Polishing and Texturing – Due to their operating environment, mold finishes, and texturing tend to wear out over time. However, you can select a durable texturing or polishing procedure, enhancing the mold’s visual appeal.
Such finishes range between B and D SPI mould finishes.
Tool Durability – The durability o your tools is essential in maximizing the output o your injection molding prototype. Materials you use to manufacture these tools should be durable and tough for quality processes.
Steel is the main material for the manufacturing of molding tools.
Type of Injection Molding Prototype Machine
We have three main types of injection molding prototype machines. Each of these machines has different production quality, which affects the price of your molding.
The price of a hybrid injection molding is relatively low than that of an electric injection molding. This is due to the quality inconsistency that a hybrid machine offers.
Design of the Molding Part
The design of your molding part affects its cost significantly. This is due to the molding process’s nature and the mould type to use.
Complex parts are usually more costly than simple ones. This is because of the varying number of cavities present, which affect the type o mould and quantity of materials to use.
Type of Molding Materials
Plastic pellets are the main materials for the production of injection moulds. These materials differ due to the different melting points.
Different mould thickness also affects the type and quantity of your plastic pellets. This influences the cost of your molding part.
Applicable Finishing
Simple surface finishes are cheaper than complex surface finishing on your injection molding prototype. This can either increase or reduce the final purchasing price.
Surface finishing has the advantage of increasing the aesthetic appeal of your final product.
Rapid injection molding technique allows for faster production of your prototypes using modern technology. This includes rapid cooling and cutting of the part.
The best material for your prototype injection mold is aluminum or stainless steel. This is due to their strength and ability to withstand high temperatures.
Prototype injection molding uses plastic pellets as the main material in the molding process. However, you can include other materials like coloring additives and stabilizers.
The main classifications are low, high and medium fidelity prototypes. This classification helps in understanding the quality of your product part.