Description
Medical Ejector Pin Mold Parts are ejector system components designed specifically for medical injection molds. These include straight, angled, flat, and sleeve types. They work in conjunction with the mold’s ejector plate, angled guide pins, and other components to eject the product from the mold cavity after injection molding. Their materials must comply with USP Class VI or ISO 10993 biocompatibility standards, and their surface treatment must pass corrosion resistance tests (such as a salt spray test for ≥500 hours) to ensure they release no harmful substances when in contact with pharmaceuticals or body fluids.
Product Features
1. High-Precision Machining
Manufactured using a high-precision Swiss TORNOS CNC lathe, the ejector pin’s outer diameter tolerance is controlled within ±0.002mm, with a coaxiality of ≤0.003mm. This prevents eccentricity during ejection, which can cause product whitening and mold core wear.
2. Biocompatible Materials
The main body is made of 316L stainless steel (carbon content ≤ 0.03%) or PEEK (polyetheretherketone), FDA 510(k) certified, and sterilization-resistant (e.g., 121°C autoclave sterilization with no deformation for 1000 cycles).
3. Ultra-Smooth Surface
After electropolishing, the ejector pin achieves a surface roughness of Ra ≤ 0.05μm, reducing the coefficient of friction with the product (μ ≤ 0.1) and ejection resistance by over 20%.
4. Corrosion-Resistant Coating
DLC (diamond-like carbon) or TiN (titanium nitride) coating, 2-5μm thick, with a hardness of HV 2000-3000, is resistant to corrosion from medical cleaning agents such as hydrochloric acid and alcohol.
5. Customized Design
We can manufacture custom-shaped ejector pins (such as stepped ejector pins and ejector pins with cooling channels) according to customer drawings. Our minimum diameter is 0.2mm (suitable for microfluidic chip molds) and our maximum length is 500mm (suitable for large medical device housing molds).
Applications
1. Disposable Medical Consumables
Ejector pins for syringe pistons, blood collection tube caps, and infusion pump dropper molds. Syringe mold ejector pins are made of 316L stainless steel. After EDM machining, the piston sealing surface has a roughness of Ra ≤ 0.08μm, ensuring no leakage of medication.
2. Surgical Instrument Housings
Ejector pins for ultrasonic scalpel handles, electrocoagulation forceps housings, and laparoscopic lens holder molds. Ejector pins for minimally invasive surgical instrument molds must pass the IPX7 waterproof test, and the clearance between the ejector pin and the core must be ≤ 0.005mm to prevent body fluids from seeping into the mold.
3. Implantable Medical Devices
Ejector pins for artificial joint trial molds, cardiac stent delivery system housings, and bone screw packaging box molds. Ejectors for artificial joint trial molds are made of PEEK, which is resistant to gamma ray sterilization and prevents metal pins from interfering with MRI imaging.
4. Medical Electronic Equipment
Ejectors for blood glucose meter housings, oxygen concentrator panels, and portable ultrasound device buttons. These ejectors must pass ESD protection testing to prevent static electricity from damaging electronic components.
5. Diagnostic Reagent Packaging
Ejectors for PCR tubes, ELISA plates, and virus sampling tubes. These ejectors feature a flat design to minimize deformation of the tube wall during ejection, ensuring a reagent volume accuracy of ±0.5μL.
6. Rehabilitation Assistive Devices
Ejectors for prosthetic sockets, orthotic brackets, and walker housings. These ejectors must pass fatigue testing to ensure long-term reliability.
7. Oral Medical Products
Ejectors for invisible braces, implant guides, and dental trays. These ejectors feature a miniature design to avoid leaving marks on the brace surface during ejection.
Maintenance and Cleaning
1. Daily Cleaning
After each production cycle, wipe the ejector pin surface with a dust-free cloth dipped in isopropyl alcohol to remove any plastic residue and lubricant mixture, and to avoid any corrosive residue. Blow the ejector pin hole weekly with compressed air (0.5 MPa) to prevent clogging and poor ejection.
2. Regular Lubrication
After every 5,000 injection cycles, apply medical-grade silicone grease to the ejector pin surface to reduce friction and wear. Avoid using lubricants containing graphite or molybdenum disulfide to prevent particle contamination of medical products.
3. Wear Inspection
After every 10,000 cycles, measure the ejector pin diameter with a micrometer. If wear exceeds 0.01 mm, replace it immediately. Use an optical projector to check the ejector pin’s straightness. If deflection exceeds 0.005 mm/100 mm, calibrate or replace it.
4. Storage Instructions
Ejectors that are not used for an extended period should be coated with anti-rust oil and stored in a dry cabinet (humidity <40%) to avoid contact with gases such as chlorine and hydrogen sulfide. The ejector hole should be sealed with a dedicated plug to prevent the entry of dust and insects.
