Different Types of Plastic Injection Mold


Plastic injection molds are used in injection molding machines to produce plastic parts. They are made of various materials with differing degrees of hardness and wear resistance that can withstand high temperatures. Learn the best info about Horizontal injection molding machines.

Injection molding cycles involve many variables that need to be managed carefully in order to produce flawless products. Any deviation can lead to unsightly surface flaws on finished products that require additional manufacturing processes to correct.


thermoplastic injection molding offers an abundance of material options and product possibilities, from prototyping to high-volume production, due to its speed and completed component quality. Furthermore, thermoplastic injection molding allows for the use of different colors, textures, and surface treatments – ideal for creating everything from plastic toys and lab equipment to microwave ovens and medical devices.

The selection of an optimal thermoplastic resin depends on several variables, including its intended strength and functionality. Numerous engineered plastic options are available, and you can combine different materials to meet the physical/chemical properties necessary for your product, giving you greater versatility in designing parts that are both strong and economical.

ABS (acrylonitrile butadiene styrene), polyethylene (PE), and polystyrene (PS) thermoplastics are among the most popular thermoplastic materials because of their optimal balance of stiffness, impact resistance, cost, and affordability. You can even add additives such as glass fibers for additional strength and durability.

When selecting a thermoplastic material, it is crucial to consider its melting point and heat resistance. A high melting point allows manufacturers to manipulate various raw materials easily for use as raw materials for custom products requiring multiple plastics; conversely, a low melting point decreases accidental damage to molded parts during molding processes.

The viscosity of your chosen material should also be taken into account; it determines its ease of flow into the mold and pressure requirements during injection. Lower viscosities reduce energy usage and cycle times, while higher ones increase them.

After injection, melted plastic is left to cool for a short period before holding pressure (slightly lower than injection pressure) is applied to account for shrinkage while cooling and solidifying. Once sufficiently cooled, the plastic is released from its mold and ready for use.

If your business requires multiple thermoplastic resins, consolidating them to reduce waste production is worth exploring. This may save costs for purchasing raw materials and storage while cutting labor expenses.


Thermoset plastics are long-chained polymers used in injection molding. Beginning as liquid, they undergo a chemical process during curing that forms permanent links between molecular chains—in contrast to thermoplastics, which liquefy when exposed to heat. Thermoset plastics often offer greater strength, shrink resistance, and impact protection than their thermoplastic counterparts.

At the core of injection molding lies the thermoset material placed into a hot mold and injected under pressure with variable speed and temperature settings, impacting bubble size and appearance and holding pressure for material shrinkage until solidification occurs. Once the injection process is complete, valves close off the injection system while chemical precursors remain isolated from the hot mold until holding pressure can compensate for material shrinkage until the product solidifies.

Attaining quality finishes requires advanced injection molding equipment. This includes feeders for bulk material, quick-change mold systems, hydraulic fluid accumulators, and machines that remove molten plastic shear and runners during each molding cycle in order to prevent flash (a thin film of brittle plastic produced during each cycle). Depending on their application, some thermoset molded products do not require post-production finishing processes – saving costs and production times while simultaneously cutting costs and production times.

Injection molding can produce an array of products, from automotive components and electrical parts to consumer electronics and large complex parts with tight tolerances – ideal for applications that demand precision and accuracy.

Another advantage of injection molding is its ability to combine multiple materials in a single part. This allows for the production of hybrid products with differing physical properties – for instance, combining rigidity and flexibility or adding soft-touch surfaces on complex bases. Furthermore, injection molding enables designers to incorporate design elements such as threading or windows more seamlessly into the production process.

Though thermoset injection molding offers many advantages, it also has some drawbacks. One such drawback is visible lines on the finished product, known as parting lines, sprue marks, or gate marks created where melt delivery channels (sprue and runners) connect with part-forming cavities.


Thermoforming is a versatile plastic injection mold method suitable for many different uses. It involves heating plastic sheets until they become malleable and then molding them around specially designed molding tools into desired shapes. This technique works best for small to medium production runs and parts requiring colors or textures.

Thermoformed plastic is also lighter than metal or fiberglass alternatives, helping your business reduce shipping costs and fuel consumption, increasing efficiency while decreasing environmental impact. Furthermore, thermoformed plastic products tend to be more durable than injection-molded ones, making thermoformed an excellent option for products subject to rigorous use or handling.

When searching for plastic injection mold services, the provider must fit your individual project’s specific characteristics and requirements. Rydtooling offers both thermoforming and injection molding processes; before selecting one that is suitable for your needs, it’s essential that you fully comprehend their differences and choose accordingly.

Injection molding is ideal for projects requiring larger production numbers, particularly those featuring complex or intricate designs, due to its reliability in producing multiple batches in an efficient and timely fashion. On the other hand, thermoforming offers lower per-piece production costs and can better accommodate intricate details.

Thermoforming can be used for many different applications, from packaging and furniture manufacturing to automotive components. It is especially suitable for curved and shaped surfaces due to tight tolerances, making thermoforming highly versatile; for instance, vacuum forming can also be combined with thermoforming for enhanced detail and rigidity.

thermoforming plastic offers manufacturers an economical and faster method for product development and prototyping. Its molds are typically single-sided and made of inexpensive aluminum compared to steel or other heavy materials required by injection molds; this allows manufacturers to test designs quickly and adapt them efficiently before production begins. Furthermore, thermoformed plastic makes an excellent material choice when adding aesthetic features like silk screening or specialty coatings – and thermoformed plastic makes for excellent prototypes.


Casting offers several distinct advantages over injection molding for creating small components with precise specifications that require matching finishes, creating durable parts resistant to chemicals or washdown, and being cost-effective when producing large volumes of similar items.

Plastic injection molding and casting should not be treated as interchangeable processes, each offering its own set of benefits and drawbacks that must be carefully considered before selecting one as a manufacturing method. For instance, injection molding requires complex tooling, which may increase costs and lengthen delivery times, whilst casting requires no such requirements.

Injection molding creates high-quality parts that are both highly durable and versatile, suitable for use across a range of environments. Injection-molded parts often stand up better against washed-down environments, chemical exposure, extreme temperatures, and washdown conditions than other plastic parts manufactured through other processes – these features make injection-molded parts suitable for medical devices, automotive parts, and consumer goods.

As part of the injection molding process, plastic material is fed from a hopper into a screw-shaped mold. A machine controls the moving speed of the screw and injection pressure in order to control how fast molten plastic fills its cavities. Furthermore, it monitors gate position – which connects melt delivery channels (sprue and runner) to part-forming cavities – before setting dwell pressure once all cavities have been filled by melted plastic – for faster or slower filling times.

Injection molding produces parts with high-quality finishes that can be immediately used, eliminating the need for surface finishing and saving both time and money in production. Furthermore, injection molding allows the production of multiple, intricately designed products at the same time without additional processing steps such as surface finishing. Moreover, this technique requires little to no maintenance as long as proper protocols for optimal performance are adhered to; doing so will extend its life while improving accuracy. Therefore, when choosing your mold manufacturer, they must provide ongoing support.