Thermoplastic Injection Molding

Inox Casting – Your Irreplaceable Partner For Thermoplastic Injection Molding

Giving the best solution for your exact thermoplastic injection molding is our main goal. And since 1997, our line of work is focusing on supplying and manufacturing thermoplastic injection molding solutions. We became more professional in handling different needs of customers regarding thermoplastic injection molding as time goes by.

You can trust Inox Cast due to its rich experience in the field and capability in providing cost-effective and durable thermoplastic injection molding solutions. We offer wide selections of thermoplastic injection molding products available in different capacities, styles, and sizes to suit your required applications.

However, the thermoplastic injection molding by Inox Cast is a production process that makes completely functional components by injecting plastic resin into the pre-made mold.

Developers commonly prefer utilizing the thermoplastic injection molding process for several applications. This process is effective in producing cell phone cases for car door panels with superior finish and good accuracy. This process also offers many advantages. Here are some:

• Good accuracy,
• Pristine surface finishes,
• Fast speed, and
• Predictor of manufacturability

Inox Cast thermoplastic injection molding can be accomplished while using engineering-grade materials, especially plastic resin. This material is utilized to produce final prototypes before the production.

We always intend to satisfy the desires and needs of our valued customers. We made our thermoplastic injection molding more efficient and superior in functions. With this type of injection molding, we can create a lot of designs and styles based on your specific demands.

Our company, Inox Cast is employed with hardworking and skillful engineering personnel. We also have a broad area of manufacturing plants for different types of thermoplastic injection molding operations.

Here at Inox Cast, you can rest assured about fast delivery and the safest packaging services. Contact us now! We are always online to discuss more details with you.

Thermoplastic Injection Molding | A Useful FAQ Guide

The Thermoplastic Injection Molding FAQ Guide is a concise resource specifically written and compiled by experienced professionals with years of experience.

It provides valuable insight into how injection moulding works and the most important factors to consider while ordering, selecting material, and pricing.

The Thermoplastic Injection Molding FAQ Guide gives you an inside look at what it takes to get your project off the ground.

1.  What Is Thermoplastic Injection Molding?

Thermoplastic injection molding is a manufacturing process in which polymers are heated and injected into moulds, allowing easier shaping and design.

The process involves heating plastic and injecting it into a mould to create a new object.

This process is carried out at temperatures as high as 400° C (750° F), so it is essential to take safety precautions when using this moulding.

This manufacturing process creates strong, sometimes complex shapes with great detail.

This process creates substantial, lightweight parts and has been used to create everything from computer cases, dashboards, car doors, electronic gadgets, complex parts in the medical industry, and console housings to golf clubs.

Thermoplastic Injection Molding

2.  Applications Of Thermoplastic Injection Molding

Thermoplastic Injection Molding is used in plastics manufacturing to produce custom, low-volume parts.

Thermoplastic Injection Molding, or TIM, utilizes a semi-automated (or fully automatic) screw injection extruder.

It mixes and melts thermoplastic pellets at high temperatures inside a heated barrel.

This process has broad applications, but we have gathered widely used some of the most common industries.

Thermoplastic Injection Molding Products

        i.            Automotive Industry

Thermoplastic Injection Molding is a process used in the automotive industry to make plastic parts.

The properties of the materials allow a wide range of products, from engine blocks and transmissions to seat covers and bumpers.

The uses are many and varied: dashboards, wheel covers, Switches, gears, pump parts, screws, cams, gears, fuses, radiator grills, seat shells, and window frames.

      ii.            Packaging

Thermoplastic materials have a variety of properties that allow them to be produced in different forms and functions.

For example, polypropylene plastic can be formed into films and then used as packaging material.

It is an economical and biodegradable packaging alternative; polyurethane plastics are biodegradable.

    iii.            Medical

Thermoplastic Injection Molding is used a lot in the medical industry due to its unbreakable, lightweight, and corrosion-resistant properties.

It is also used in healthcare products that require frequent cleanings, such as syringes, Pippet tubing, trays for sterilization, medical devices, blood bags, and medical supply containers.

    iv.            Electronic Industry

Thermoplastic injection molding has many uses in the electronic industry.

It is used to mould electronic parts and housings, such as wire connectors, Electrical cooker knobs, cameras, cable insulations, Lenses, plugs, housings for all kinds of devices, etc.

3.  Thermoplastic Injection Molding Process

The step by step process of thermoplastic injection molding is given as follows:

        i.            Required Material Selection

The material selection process is critical for a successful manufacturing operation for thermoplastic injection molding.

Each part must meet stringent quality control requirements to ensure that parts are manufactured correctly and consistently.

The mould and the tool steel used must be designed, engineered, and tested to meet each customer’s requirements.

Some of the commonly used materials are given as follows:

1. Acrylonitrile Butadiene Styrene (ABS.)
2. Polycarbonate
3. Nylons
4. Polypropylene

      ii.            Mould Creation

The mold creation process in thermoplastic injection molding is different from that of other plastic processing types.

The first step is to create a detailed model of the part you want to create.

It can be done with a computer-aided design (CAD) program, or you may want to hand-sketch the parts.

After this has been completed and approved, the CAD files must be used to create a solid model that includes any core parts or inserts needed.

    iii.            Clamping

The first step in any injection molding manufacturing process is to clamp the mould halves together. It creates mould, which will soon be filled with molten plastic.

    iv.            Feeding

Feeding the material is one of the most critical steps in injection molding. The method of feeding can be gravity-based or mechanical.

A gravity feeder uses very little in the way of complicated mechanisms.

It can also accommodate materials with lower viscosity, like PP and PE.

A screw with a slight pitch is also utilized to keep the material flowing and flowing evenly throughout the injection molding process.

In this step, molten plastic material is injected into the mold cavity through the gate

      v.            Thermoplastic Melting

In thermoplastic injection molding, pellets of thermoplastic resins are fed through a hopper into the barrel of an injection molding machine.

The temperature in the barrel is typically set to the melting temperature of the resin being used, which causes it to melt and flow through a heated nozzle.

The melted plastic then passes through the gate into the cavity of the mould

    vi.            Hold And Cooling

The resin flows through a heated barrel.

It is softened and mixed with an additive package that may include colourants, antioxidants, impact modifiers, and flame retardants to control flow characteristics, impact strength, and melt-flow rate.

  vii.            Ejection

The Ejection Process in Thermoplastic Injection Molding occurs when the molten liquid plastic is injected into the mould cavity, cooled down, and solidified.

The solidified part is then ejected from the mold and removed.

It can be done by pulling out or pushing out the finished part. However, in some instances, such as thermoplastic injection molding, pulling out is preferred.

Thermoplastic Injection Molding Process

4.  Benefits Of Rapid Injection Molding Thermoplastic

The various benefits of rapid injection molding thermoplastic are given as follows:

        i.            Less Cost Of Design Modifications And Geometry

The Thermoplastic Injection Molding process offers you a reduced cost of design modifications and geometry.

Thermoplastics are suited to short runs, making them ideal for prototypes, while it also offers quick delivery times and low tooling costs.

      ii.            Recommended Method For Prototypes

Thermoplastic injection molding is the most affordable, reliable, and fastest method for creating your prototypes.

It gives great strength to the product and could be used in all materials like thermoplastic polyurethanes.

    iii.            Resistant To Harsh Conditions

Rapid Injection Molding thermoplastic resin is more resistant to heat and abrasion than other kinds of plastic.

As a result, the products used to create are durable and designed to last.

    iv.            Long-Lasting And Durable

The biggest reason why this process is so popular is that it is durable, easy to use, and can be applied to many different materials.

Thermoplastic is long-lasting and durable because it doesn’t rust, chip, or peel like metal.

      v.            Quick Time Of Production

The rapid Injection Molding thermoplastic process has a Quick Time Of Production and high-speed cycle times 15 to 30% faster than conventional injection molding processes.

    vi.            Large Volume Production

Rapid Injection Molding (RIC) is a thermoplastic process used by many companies to produce large plastic parts.

The injection molding machine fills the mould cavity quickly and allows between 10 and 60 tons of pressure to be applied with each shot, depending on application requirements.

5.  Thermoplastic Material Selection For Injection Molding

We have compiled a list of thermoplastic injection molding materials that are used in various industries are given as follows:

For Commodity

Materials Used In Thermoplastic Injection molding

        I.            Polypropylene (PP.)

It has good hot strength, cold strength, and modulus of elasticity.

It is often used to blend Nylon, EPDM, and other elastomers to improve their properties and make more suitable materials for different applications.

      II.            Polyethene

Polyethene is a polymer with many different applications in manufacturing different parts and is used in Thermoplastic Injection Molding.

For example, when a plastic part needs to be formed repeatedly, Polyethylene can be used to make this part.

    III.            HDPE and LDPE

HDPE stands for High-Density Polyethylene, and it is a rigid, impact-resistant material that maintains its strength through hot or cold temperatures.

LDPE stands for Low-Density Polyethylene, which means it can be thin and light.

   IV.            Polyvinylchloride (PVC)

Thermoplastic Injection Molding uses PVC (Polyvinylchloride) as the primary material due to its excellent processing performance, low cost, and easy mould construction.

     V.            High impact polystyrene (HIPS)

HIPS is a synthetic polymer and is considered the most versatile material, which offers high impact toughness and excellent strength and stiffness.

The ability to provide a good surface finish without sacrificing strength gives HIPS the advantage of handling intricate designs.

For Engineering

   VI.            Acrylonitrile Butadiene Styrene (ABS)

The polymer is used in injection-moulded plastic parts that see rugged use in the automotive, appliance, and electronics industries.

 VII.            Acrylic

The transparent nature of acrylic makes it an ideal choice for picture frames, protective cases for electronics, and sunglasses.

VIII.            Polycarbonate (PC)

The Polycarbonate (PC) product contains 25% of recycled and renewable material content.

It can be moulded with a processing temperature of 130 degrees C and moulded in various colours.

    IX.            Polyoxymethylene (POM)

The POM material usage in Thermoplastic Injection Molding is plastic that offers good mechanical properties and high resistance to wear and tear.

      X.            Polyamide (Nylons)

The applications of nylon in injection moulding are wide-ranging, including automotive parts (door sill plates), sports equipment (tennis racket frames), consumer goods (cutlery handles), military applications (radio housings), and even musical instruments (bass drum rims).

    XI.            Polybenzimidazole (PBI)

Polybenzimidazole (PBI) is one of the most common engineering thermoplastics.

It has high strength and stiffness at elevated temperatures, superior chemical and electrochemical resistance, good thermal stability, and a low coefficient of friction.

6.  Choosing Thermoplastic Injection Molding Machine

The process of choosing a thermoplastic injection molding machine depends on various factors, which are given as follows:

        i.            Machine Capacity

Machine capacity is a critical factor because it is a deciding factor for choosing the most suitable injection molding machine for your production requirements.

      ii.            Material Understanding

Understanding your materials is essential when choosing a TIM machine that best suits your needs.

This is especially with the various plastics used in the aerospace, automotive, consumer goods, and mechanical industries.

    iii.            Mould Dimensions

The mould dimensions must suit the type of material being injected.

If the dimension of the mould is not suitable, there will be leaks and undercuts when it comes to manufacturing prototypes or a mass production run.

    iv.            Time Of Cycle

Generally, the time of the cycle of a thermoplastic injection molding machine is the most critical factor to be considered to get the required output from a particular machine.

      v.            Speed Of Injection

The speed of injection largely depends on the size of your product.

The larger the product, the greater its diameter and thus lesser the mold time if the machine uses the same amperage.

    vi.            Core Pullers

The number of motions controlled by the injection molding machine depends on core pullers.

7.  Thermoset Injection Molding Vs. Thermoplastic Injection Molding

Thermoset Injection Molding Vs. Thermoplastic Injection Molding

8.  Advantages Of Injection Molding Thermoplastics

There are numerous advantages of this method; some of them are given below:

        i.            Maximum Production Rate

The Thermoplastic Injection Molding process allows for maximum production rates, with flexibility in short and long runs.

      ii.            Cost-Effective

Thermoplastic materials are easy to process and have excellent flow properties so that design cycles can be reduced and tooling costs can be minimized.

    iii.            Flexible Design

The process can handle any design, whether a simple part or one with complex geometries.

    iv.            Lightweight And Extreme Strength

Because the moulds are made from resin, which is lightweight and easy to work with, it is possible to create powerful parts while remaining lightweight at the same time.

      v.            Efficient Method With Maximum Precision

The process offers high material efficiency and repeatability, giving your business a competitive advantage.

    vi.            Environmentally Friendly With Minimum Waste Material

This type of injection molding over other plastic parts production methods includes minimal waste material and low tooling costs.

  vii.            Recycling Ability Without Any Damage

The recycled scrap and waste material can be remoulded, unlike other injection moulding processes where the material is melted off to make a new part. Stress Resistant And Chemically Retardant

9.  Design Consideration For Injection Molding Thermoplastic

Injection-moulded thermoplastic parts are typically more robust, stiffer, and more dimensionally stable than moulded thermoset products.

It is because of their ability to withstand higher thermal loads and extreme moulding pressures.

Thus for design considerations, you must keep in mind the following factors:

        i.            Material Of Plastic

An engineer should consider all angles when creating or designing a product, including the type of plastic used to fill the mould and other project parts.

      ii.            Dimensions

Without the proper dimensions, everything from the surface finish to the product’s functionality may not be at its full potential.

    iii.            Important Tolerances

Tolerance is the amount of variation allowed for parts to fit together or for a component within its design.

In injection moulding, tolerances are typically between +/- 0.005″ and 0.010″ on all features.

Except snap fits and one-piece moulds where smaller tolerances can be held at +/-0.001″ or less.

    iv.            Weight

The weight of the plastic piece can affect many aspects of your design.

If the part is too heavy, it could affect how well it can be moulded and whether or not you need to add fillers to make up for its density.

      v.            Location Of Gate

The gate position affects the ejection force requirements, part wall thickness, product strength, surface finish, and appearance.

    vi.            Required Quality

According to injection moulding, the required quality has an essential function in design consideration of it. It can save so much time, cost, and energy.

  vii.            Quantity Requirements

It is an essential factor because the quantities required for thermoplastic injection are high. Still, at the same time, a slight difference in the cost may result in significant changes.

viii.            Shut-off Angles

The shut-off angle is the maximum relationship between the parting line of the core and the gate at which filling will occur.

If this angle is too large, it may result in incomplete filling or even air voids.

10.  Defects In Thermoplastic Moulding

Several defects in thermoplastic injection molding can occur during this process due to several reasons, which are given as follows:

        i.            Sink Marks

This defect commonly occurs due to inadequate resin density or vacuum void created due to large wall thickness.

To overcome this defect must increase injection and backpressure. And also enlarge the gate size with an increment of cylinder and mould temperatures.

      ii.            Ejection Defects

This defect occurs due to overfilling and low angle of draft taper with unsuitable injection pin. It can be avoided by increasing cooling time and decreasing injection pressure with the balanced placement of the injection pin.

    iii.            Short Shot

This defect is also known as short filling of resin or low-temperature resin.

It creates a defect in the finished products, which affects the appearance and quality of products.

These problems can be reduced by calculating how much injection pressure is needed for each mold.

    iv.            Jetting

This problem can be due to the wrong position of the gate and low mold temperature.

Jetting can be avoided by increasing slug well size with the precise placement of the gate to change its position rapidly.

      v.            Internal Cracks

Due to excessive stress, sudden cooling, and unnecessary wall thickness, internal cracks occur. To ensure this defect does not happen, reduce wall thickness with temperature adjustment and injector pin balancing.

11.  Thermoplastic Injection Molding Technologies

        I.            Hot And Cold Runner Technology

Hot and cold runner technology is the most commonly used production process, which uses two or more heated and cooled runners to deliver plastics to the cavity.

Hot Runner machines can provide a much faster cycle time and higher production capacity, with improved consistency in part size and shape than Cold Runner systems.

      II.            Narrow Wall Moulding

Thin wall moulding allows us to produce parts with minimum diameter while maintaining the robustness needed in applications.

It’s ideal for today’s “thin-is-in” marketplace, where design demands slimmed-down products with maximum functionality.

    III.            Injection Molding Through Metal

It has the advantage of being able to achieve a high strength-to-weight ratio, as well as being able to perform complex shapes that are required by modern manufacturing.

   IV.            Gas Supported Injection Molding

By using a helium-based injection gas, stress is relieved from the mold. It reduces cycle times and improves part quality compared to traditional sprue gas systems.

     V.            3D Printing

The technology was initially developed to produce complex plastic prototypes.

But it has grown in popularity in other areas, including highly customized products and low-volume manufacturing.

12.  Choosing Thermoplastic Injection Molding Tooling System

The type of tooling system you choose is critical to the success of your plastic product.

That is why there are some factors which you should consider in the tooling system.

        i.            Must-Know Parts Of Plastic Need To Mold

The most common plastic parts to be moulded through thermoplastic injection molding are low pressure, small batch production, and low mass-production costs.

The main reason is that its properties make it easy to process in the mold to reduce tooling costs.

      ii.            Machine Type Selection

Machine type selection and system design depend on various factors such as the product and process type, production volume, essential quality characteristics, equipment sourcing options and other factors.

    iii.            Selection Of Tooling Material

The material, surface finish, and hardness of plastic products greatly influence the choice of injection molding tooling, so for some familiar with it after the tip.

    iv.            Injection Unit Size Calculation

The size of the injection unit will be based on two things, the melt flow of your material and how much material you need to inject per cycle.

The system’s injection unit must be tailored to handle the volume and material type specified by the part designer.

To know this, you must know the required parts

1. Cycle Duration
2. Material of plastic
3. Rate Of Injection
4. Cooling time
5. holding time With pressure
6. Weight of shot
7. Screw Diameter

13.  Choosing Mold For Thermoplastic Injection Molding

There are a lot of factors to consider when choosing your mould for thermoplastic injection molding.

The first step is to determine the material you want to produce.

Many companies opt for polypropylene or nylon because these engineering plastics are inexpensive and easy to process in an injection moulding machine.

Choosing the right tool steel grade is the next step, followed by choosing a material supplier who can help guide you through the process while offering competitive rates on custom thermoplastic parts.

14.  How To Reduce Cost Of Injection Molding Thermoplastic

There are multiple factors involved in the cost reduction process. Some of them are given as follows:

        i.            Number Of Cavities

If you have complex parts, it’s better to split the design into a few different components.

Of course, that can be manufactured using less expensive tooling and a shorter cycle time than moulding one solid part from one cavity.

      ii.            Use Of Aluminium Mold

Using aluminium mould will reduce certain costs compared to its steel counterpart.

A steel mould is more expensive than an aluminium one, and there are extra costs related to the maintenance and repairs of steel moulds.

    iii.            Must-Have Quicker Cycle Time

The Thermoplastic Injection Molding Process is costly due to the cost of molding and the amount of raw material required.

The Quicker Cycle Time was developed to reduce these costs, which requires 10-15% less thermoplastic by weight, which lowers the cost by 3-5%.

    iv.            Undercuts Elimination

Undercuts are eliminated by designing the part to accommodate them, as they can cause stress that leads to cracking and other issues with injection molded parts.

      v.            Reusing And Modifying Molds

Reusing the same molds reduces the cost of Injection Molding Thermoplastic.

This is because it reduces tooling costs and avoids mechanical stress that leads to deterioration and eventually a need for replacement.

    vi.            More Care Required For DFM Analysis

The purpose of design for molding (DFM) analysis is to minimize the costs of an injection moulded part.

That is by reducing the time and labour required while maintaining production rates, quality standards, and cost-effectiveness.

  vii.            Increase Multi-Cavity Usage

One way to increase multi-cavity usage is through tool consolidation. Combining multiple tools into one mould can lower the overall number and cost of tools used per job.

For questions or inquiry on thermoplastic injection molding, contact us now.