Processing Examples
An example of ultra precision molding
JGMA Grade 0 insert gears
Application: OA-related gears
Materials: POM, elastomer
Number of molds taken: 4
Reason for development: Noise reduction
JGMA Grade 0 insert gears
Comments: In order to reduce the noise of OA related products, we were examining inner diameter insert gears. The key to good gears is coaxiality between the shaft and teeth. They cannot insert unless there is a gap between the inner diameter bracket and the mold. (If there is a gap where the metal fitting does not enter the mold, then the coaxiality of the metal fitting and gear will be out of alignment, making it impossible to achieve JGMA Class 0.) We have developed (and patented) a new molding method and have achieved gears that maintain precision even with insert molding.
Micro module gears
Application: Gear related to mobile phones
Material: PEEK
Number of molds taken: 1
Reason for development: New development
Micro module gears
Comments: We were considering micro module gears for mobile phones. The teeth are small and torque is applied, so ordinary engineering plastics cannot be used for this application. Therefore, using the unique knowledge of super engineering plastics accumulated by our company through 20 years in business, we selected and proposed materials from various perspectives, such as the purpose and atmosphere of use. Since the parts are very small, we needed know-how for the gate and ejector methods.
Micro screws
Application: Unspecified
Material: PEEK, others
Number of molds taken: 1
Reason for development: Noise reduction
Micro screws
Comments: We manufactured this mold in response to a request to make a non-metal substitute for very small screws. Because the screw is so small, screw threads made of ordinary plastics cannot provide the required strength. Therefore, we used PEEK and other super engineering plastics.
Inner diameter Φ0.5 / length 72 mm pipe
Application: Medical prototyping
Material: PES
Number of molds taken: 1
Reason for development: New development
Inner diameter Φ0.5 / length 72 mm pipe
Comments: The customer required a transparent pipe with an inner diameter of 0.5 mm and a length of 72 mm, with a funnel shape at the mouth, and burrs could not be tolerated on the opposite side. Extrusion molding and cutting methods could not be used to meet this requirement. We were asked if there was anything we could do, so we undertook this challenge with injection molding. Since the injection pressure is very high, it is extremely difficult for a Φ0.5 mm pin to stand straight during molding. Additionally, the length of 72 mm made it nearly impossible to do molding. After a series of trial and error, we were finally able to complete a molded product with satisfactory precision.
Resinous bearing with inner and outer diameter run-out tolerance of 0.005
Application: OA-related bearings
Material: POM
Number of molds taken: 4
Reason for development: New development
Resinous bearing with inner and outer diameter run-out tolerance of 0.005
Comment: At the beginning of development, the customer manufactured this part by cutting it to satisfy the required specifications, and produced it with wet polishing, but they had difficulty coming up with satisfactory specifications. So, they consulted with our company and we made a proposal for injection molding. One characteristic of crystalline resin is after-shrinkage that starts immediately after molding. Because of the characteristics of the product, it cannot be used if there is after-shrinkage. Therefore, the customer and our company each manufactured a dedicated measuring machine with the same mechanical difference in order to measure the product’s dimensions. We observed changes over time, 1 month, 3 months, 6 months, and 1 year after molding, and started mass production after confirming that there was no change in dimensions. With consideration for process capability, during mass production, we support 2μ to 3μ, with a monthly production of 4 molds, so they could handle a maximum part production number of 300,000 bearings.
Thick bearing / coaxiality tolerance 0.01
Application: OA-related bearings
Material: POM
Number of molds taken: 1
Reason for development: Replacement for cut products (quality improvement)
Thick bearing / coaxiality tolerance 0.01
Comment: At the start of development, the customer did mass-production by cutting to satisfy their specifications, but this method took time and incurred costs, and also caused quality problems. Therefore, the customer consulted with our company and made a proposal for injection molding. When the molded product is very thick, it causes a molding defect called “sink marks”, causing problems even before dimension precision. Also, molding with a coaxiality of 0.01 or less is extremely difficult. We solved all these problems and achieved mass production.
Resinous bearing / roundness 0.002, outer diameter tolerance width 0.008
Application: OA-related bearings
Material: Liquid crystal polymer
Number of molds taken: 4
Reason for development: New development (prototype)
Resinous bearing / roundness 0.002, outer diameter tolerance width 0.008
Comment: Due to stringent specifications for roundness of 0.002 and outer diameter tolerance width 0.008, it was difficult to do molding. Therefore, we proposed a unique molding method, and achieved satisfactory molded products that meet requirements for both functionality and specifications.
Various super engineering plastic parts
Application: Wide variety
Material: PEEK, PI, PAI, PBI, etc.
Number of molds taken: -
Reason for development: -
Various super engineering plastic parts
Comments: Nichiei has a track record of about 20 years with super engineering plastic molding technology, and we are working on a wide variety of production. In particular, we produce a large number of super engineering plastic precision molded products, such as PEEK, PI, PAI (Torlon), and PBI (Celazole), which are difficult to mold. Molded products are used for bearing retainers, trochoid pumps, material handling parts used in clean rooms, and parts that require sucker strength, heat resistance, and slidability. It can be used as a metal substitute, so it is expected to be used in various environmentally friendly devices in the future.
