Why is Tool/Mold making crucial to produce accurate and precise plastic parts?
Tool/Mold making involves as much science as art. Function of a tool/mold is to shape and cool the molten plastic into solid then eject the formed plastic parts. Tool/mold is an assembly of components to incorporate all systems. Tool/mold making is not just machining steel but achieving synchronized steel movement to produce accurate and precise plastic parts.
Tool/mold making is a critical phase between part design and process engineering. Tool/mold is a capital investment, a trade-off between tool/mold price and part price can be performed at this stage. Usually higher the tool cost lower the part cost. Selection of materials used in the tool/mold limits the number of cycles the tool/mold can be used as well as the cycle time for production. Tool/mold design is a critical factor in how fast the molten plastic can be injected and how efficiently the molten plastic can be solidified.
Mostly hardened steel is used to make core and cavity blocks but material selection is not limited to steel. Depending on shape and size of the part various different types of tools/molds are available. Almost all of the tools/molds include following sub-assemblies/systems
- Mold base: Hold core, cavity and all the components and systems. Depending on tool life requirements (50 to 1,000,000 shots) mold base material is selected
- Core-cavity blocks: negative image of the designed plastic part is incorporated in the core and cavity blocks. The molten plastic is solidified in the core and cavity blocks.
- Cooling system: extracting heat from molten plastic and maintain uniform tool temp. Depending on part design (variation in thickness, rib locations, gate location) number, size and location of water lines and improvements (bubblers, baffles, heat tubes, etc.) are selected
- Ejection system: Removing solidified plastic from tool/mold. Depending on part requirement and space available type of ejectors (pins, blades, plates, manual or combination) are selected. According to tooling guidelines at least 2% of total surface area should be available for ejection.
Each of the major systems can include multiple sub systems and components. We can help in designing and supervising tool/mold construction. We can recommend several options for tool/mold based on your project requirements.
SPI Classification of injection molds
Type 101: 1,000,000 or more cycles. Highest price mold made with highest quality materials for tight tolerances and high quality parts
Type 102: up to 1,000,000 cycles. Fair price mold for high quality mostly for abrasive plastic material high quality and tight tolerance parts
Type 103: up to 500,000 cycles. Most popular for price range used in medium production requirements.
Type 104: up to 100,000 cycles. For limited production and low to moderate price range.
Type 105: less than 500 cycles. Mostly commonly known as prototype mold, used for limited quantity of parts.
This classification is only a guideline for life of a mold. Mold life depends on part design, mold design, workmanship, molding conditions and cannot be guaranteed.
We can help you!
Our tool/mold making team of experts at Simuplast Engineering LLP has more than 15 yrs of experience in plastic injection mold design for various industries including automotive, consumer, consumer electronics, medical, surgical and aviation.
- We can help with selection and design of mold to best suited for the product requirements and budget.
- We can help in designing and supervising tool/mold construction.
- We can recommend several options for tool/mold based on your project requirements.
Contact us today for an initial consultation to see how we can help you in your tool/mold making process.