Plastic injection molds: 5 key aspects

In past articles, we talked about the relevance of plastic injection in San Antonio in processes, both from industries and final users around the world. 

All industries find plastic as an ally for over a century because of the optimization and quality that it provides. 

That is why it is important to contemplate both aspects for the increasingly responsible use of plastic as keys to optimized molds used in plastic injection in San Antonio.

Do you know which are the 5 key aspects of a mold in plastic injection? Today we will be talking about it so you can make a better decision in the production or purchase of your plastic products.  

Why is mold important in plastic injection? 

The main goal of plastic injection molding is to produce as quickly as possible the largest number of serial parts to satisfy the needs of all types of industries.

In this way, the plastic resins are melted at high temperatures and then injected under pressure into the mold, generating the part, which once cooled takes the desired shape.

There are many aspects that we have to take care of to control our plastic injection process, and one of the main ones will be the mold. A mold with good qualities as we will see below, as well as with an elaboration that meets the objectives of the piece, has exceptional durability and a fully certified quality control.

1.- Engineering Design

A good mold is the result of a good design. To begin with, it will be necessary to define the drawing of the piece, specifying it from the start:

• Split lines 
• Entry zone 
• Location of ejector pins

On the other hand, if you are searching for the development of strong pieces and optimal appearance, you must pay attention to the wall thickness, making sure that it is as uniform as possible throughout the design.

At the same time, the right thickness will help you to eliminate possible imperfections generated in the process. So define this point for sure.

Remember that figures show that a 10% increase in wall thickness provides an increase of up to 33% in the stiffness of most materials. In this aspect, it is advisable to take advantage of elements that help as reinforcement or support and that, with less thickness, provide a stiffness equivalent to the one you are looking for.

Think of your mold and the design of your plastic injection molding process, eliminating the required thicknesses, whether for plastic injection parts for the medical industry or any other type of company.

2.- Perfect engineering 

A reliable plastic injection provider will help you make better decisions about the engineering of your molds and how to optimize your future production. 

It must have the capacity to provide, and manage molding techniques, whether they are standards or specialized, according to your piece or production requirements. 

Seek that it has a specialized and fully trained team to fix, as well as perfect the engineering and the results you can achieve with it and your mold.

With the professional help of the services of a plastic injection supplier, you will define basic aspects of your mold such as the draft or angle of inclination of the part to facilitate a correct ejection of the plastic, the minimum necessary being 0.5°. 

3.- Correct choice of material

Each plastic has different physical behaviors, associated with the chemical nature of each resin, so it will be necessary to have complete knowledge of the quality and expected results according to the plastic polymer used.

Many plastic resins are used for plastic injection, such as the range of thermoplastics, some thermosets, and elastomers.

In the case of thermoplastics, a decisive factor will be their shrinkage, abrasion, and flow characteristics, as well as their heating and cooling conditions.

The nature of your final piece, together with the desired finish, as well as the behavior of your mold plastic and the machinery used, will guide your production process decisions.

This way, the 5 materials most used in plastic injection are the following: 

1. Nylon 
2. Acrylic (PMMA)
3. Acetal resin (POM) 
4. Polyvinyl chloride (PVC) 

4.- Mold maintenance 

The mold resistance in plastic injection must be optimal to tolerate hundreds of thousands of cycles, especially with the high pressure under which these processes are carried out.

Depending on the use and nature of the mold, there are 3 types of maintenance: preventive, corrective, and predictive. The sum of the 3 will make your molds work as close to perfection as possible.

There are many maintenance tasks that we can highlight and classify according to their importance, as well as schedule them according to their daily, monthly, or even annual frequency:

• Checking and revision of screws and bolts.
• Cleaning with solvent and compressed air.
• Greasing and cleaning of guides.
• Greasing of moving parts.
• Checking the absence of oil leaks and humidity.
• Checking of fastening.
• Gasket replacement.

5.- Customization and detail

Injection molding provides solutions for a wide variety of requirements, meeting demands as competitive as those for the production of aeronautical and automotive parts.

In this way, with the quality certifications of plastic injection, it is achieved to homologate the international standard, providing the customized solution for the industry and its parts, with specialized machinery for it.

At Precision Group we work side by side with our customers, through an automated production control, producing molds through innovative techniques such as EDM or 4 and 5 axis CNC machining to always provide the best solution in injection molding.

Do you already know where to start to manage the production of your plastic injection molds? Contact us or leave us your comments, we will advise you at all times and from start to finish. For more information visit our blog.