What are the characteristics of automatic sandblasting machine in processing medical supplies?

Automatic sandblasting machine processes medical supplies, centering on the strict requirements of sterility, high precision, high compatibility and compliance of medical industry, and combining the advantages of automation and standardization of sandblasting machine, it has formed the exclusive characteristics of precise and controllable process, medical adaptation of surface treatment, clean and pollution-free whole process, and traceability of processing compliance. At the same time, it is aimed at the materials (titanium alloy, stainless steel, medical plastic, etc.) and structures (precision minimally invasive parts, special-shaped implants) of medical supplies. The following are the core features of actual production, covering the dimensions of process, material, cleanliness, compliance and equipment adaptation, and defining the exclusive requirements of medical sandblasting:

1. Process characteristics: high precision, standardization, adapting to the surface performance requirements of medical supplies.

The sandblasting treatment of medical supplies is not only about rust removal/deburring, but to achieve specific medical surface properties (such as roughness, hydrophilicity and biocompatibility). The automatic characteristics of the automatic sandblasting machine enable these requirements to land accurately, which is the core advantage of medical processing:

The surface parameters are accurate and controllable, and the consistency is extremely high.

The automatic sandblasting machine can control the surface roughness of medical supplies within the medical precision range of Ra0.1~1.6μm by accurately setting the parameters such as sandblasting pressure, medium flow, spray gun trajectory and conveying speed (for example, Ra0.4~0.8μm is required for implantable prosthesis to ensure tissue adhesion, and Ra0.1~0.2μm is required around the cutting edge of minimally invasive instruments to prevent tissue scratch), and the automation operation can realize that the surface parameter deviation of the same batch of workpieces is ≤ 0.05 μ m.

Targeted treatment, realizing medical exclusive surface function.

The sandblasting purpose of different medical supplies is highly customized, and the automatic sandblasting machine can realize precise adaptation by changing the medium and adjusting the process, which is different from the single derusting function of ordinary industrial sandblasting:

Medical metal parts (316L stainless steel and titanium alloy implants/surgical instruments): the surface is descaled and the rough surface is homogenized by sandblasting, which improves the adhesion of subsequent coating and passivation, and the micro-rough surface formed at the same time can enhance the osseointegration/soft tissue fit between implants and human tissues and avoid prosthesis loosening;

Medical plastic parts (PEEK, medical-grade PC/PP, such as infusion set, catheter and prosthesis shell): sandblasting with flexible media (nylon sand and glass beads) to realize deburring and matte surface, so as to avoid sharp burrs from scratching human tissues, and at the same time, the matte surface can prevent optical reflection from affecting surgical operation;

Precision minimally invasive instruments (such as laparoscopic instruments and puncture needles): Clean the machining residue around the cutting edge by micro-pressure low-speed sandblasting (pressure 0.1~0.3MPa), and ensure that the sharpness of the cutting edge is not damaged, so as to meet the precision requirements of minimally invasive operation.

Non-contact machining can avoid the secondary damage and deformation of the workpiece.

The automatic sandblasting machine adopts the non-contact processing mode of high-pressure medium injection, and is matched with special flexible positioning tooling to avoid mechanical extrusion and collision deformation of the precise structures of medical supplies (such as small-diameter catheters, micro gears and threads/slots of implants); At the same time, for thin-walled medical parts (such as titanium alloy sternum plate and medical plastic catheter), surface treatment can be realized by micro-pressure sandblasting (≤0.2MPa), so as to prevent the depression and cracking of the workpiece caused by sandblasting and meet the structural integrity requirements of medical supplies.

Second, material and medium characteristics: medical grade adaptation, ensuring biocompatibility from the source.

Medical supplies are in direct contact with human tissues/body fluids, and harmful substances precipitation, metal ion pollution and foreign body residue should be avoided in sandblasting media and processing. This is the core difference between medical sandblasting and ordinary industrial sandblasting, and all consumables should meet medical-grade requirements:

The sandblasting medium is medical special grade, and there is no impurity or harmful precipitation.

Abandon ordinary industrial sand blasting quartz sand and ordinary steel shot, and adopt medical-grade high-purity sand blasting medium, and the medium is strictly adapted to the workpiece material to avoid pollution and damage;

Medical metal parts: high-purity stainless steel pills, titanium pills and high-purity glass beads (purity ≥99.9%) are preferred, and there are no iron ions and heavy metal impurities, so as to avoid the allergy and inflammation of human tissues caused by medium residue after sandblasting;

Medical plastic/soft metal parts (such as aluminum medical fittings): medical grade nylon sand, walnut sand and corncob sand are selected, and the flexible medium will not cause pits on the surface of the workpiece, and it is easy to clean without residue;

All media must undergo aseptic treatment, with uniform particle size (usually fine particle size of 100~300 mesh), without caking and slag, so as to prevent coarse particles from scratching the workpiece or remaining in the gap of the workpiece.

Adapted to medical special materials, without corrosion and oxidation.

According to the mainstream materials of medical supplies (316L/304 medical stainless steel, TC4 titanium alloy, PEEK PEEK, medical silica gel, etc.), the sandblasting process has been adjusted:

Stainless steel/titanium alloy parts: after sandblasting, passivation and pickling processes can be directly connected, and dry and oil-free compressed air (after multistage oil-water separation and filtration) is used in the sandblasting process to avoid water stains and oil stains on the surface of the workpiece leading to later corrosion;

PEEK/medical plastic parts: low-temperature sandblasting (compressed air is cooled) is used to prevent the plastic from softening and deforming due to high temperature generated by medium friction during sandblasting, and at the same time ensure the uniform matte effect on the surface;

Medical silicone parts: only ultra-soft medium (such as ultra-fine glass beads) is used for light sandblasting to remove the mold residue on the surface and ensure the elasticity and surface integrity of silicone.

3. Processing environment and cleanliness features: aseptic and dust-free, in line with GMP production specifications.

The production of medical supplies should follow the good manufacturing practice (GMP), and the processing environment and equipment structure of automatic sandblasting machine have been reformed for medical cleaning, so as to prevent dust, foreign bodies and microbial pollution in the whole process and meet the production requirements of sterile medical supplies:

The processing environment is a medical clean area, and the whole process is dust-free and sterile.

The sandblasting processing of medical supplies needs to be carried out in a medical clean workshop with a class of 10,000/100,000. The automatic sandblasting machine has a fully enclosed negative pressure structure and is equipped with a medical-grade high-efficiency dust removal system (HEPA high-efficiency filtration). The dust removal efficiency is ≥99.97%, and the internal circulation collection of sandblasting dust is realized without dust spillage, so as to avoid polluting the clean workshop environment. At the same time, there is no sanitary dead angle inside the equipment, which is easy to clean and disinfect, and meets the clean requirements of GMP for production equipment.

The medical clean design of equipment and tooling has no residue and is easy to disinfect.

The parts of the automatic sandblasting machine in contact with the medium/workpiece (sandblasting cabin, silo, spray gun and conveying mechanism) are all made of 316L medical stainless steel, and the surface is polished (Ra≤0.8μm), without welds and grooves, so as to avoid medium and dust residue, and can withstand high-temperature and high-pressure sterilization (steam sterilization at 121℃) and alcohol/hydrogen peroxide wiping disinfection, so as to meet the requirements of medical supplies after processing.

The workpiece positioning fixture is also made of 316L stainless steel or medical-grade PTFE, and the flexible contact part is made of medical silica gel, which has no chipping and harmful precipitation, and the fixture can be disassembled and disinfected separately to prevent cross-contamination.

There is no secondary pollution in the processing process, and the workpiece can be directly connected with the subsequent aseptic process.

Dry, aseptic and oil-free compressed air (after three-stage filtration: precision filtration+activated carbon filtration+aseptic filtration) is used in the whole process of sandblasting to avoid oil pollution and microbial contamination of the workpiece in the compressed air; After sandblasting, there is no residual medium on the surface of the workpiece (the residual medium in the gap is cleaned by the high-pressure aseptic air sand blowing device that comes with the equipment), so there is no need for additional extensive cleaning, and only after pure water cleaning and aseptic drying, the subsequent processes such as coating, assembly and sterilization can be directly connected, thus reducing the pollution risk of the processing link.

IV. Features of equipment and operation: automation and intelligence, meeting the compliance and traceability of medical production.

The production of medical supplies requires full traceability, reproducible operation and controllable quality, and the automatic and intelligent characteristics of automatic sandblasting machine are perfectly adapted to this requirement. Different from the simple operation of ordinary industrial sandblasting machines, automatic sandblasting machines for medical use have added special medical control functions:

Fully automatic operation, no human intervention, to avoid human pollution.

Adopt the integrated process of automatic feeding-positioning-sandblasting-sandblasting-blanking, and some high-end equipment is equipped with robot feeding and unloading and spray gun servo positioning to realize unmanned processing and avoid hand grease and microbial pollution caused by manual contact with workpieces; At the same time, automatic operation can ensure that the processing parameters of each workpiece are completely consistent and meet the quality uniformity requirements of mass production of medical supplies.

Process parameters can be recorded and traced, meeting the requirements of medical compliance.

The equipment is equipped with a medical-grade production data acquisition system (SCADA), which can record and store information such as sandblasting process parameters (pressure, time, medium type, spray gun trajectory, etc.), production time, operator, equipment number, etc. of each batch of workpieces in real time. The data storage time is ≥3 years, which supports retrieval and printing at any time, and meets the requirements of full life cycle traceability of medical device supervision. At the same time, the parameters support encryption and locking, and unauthorized personnel are forbidden to modify them, so as to avoid quality problems caused by process deviation.

The equipment has medical-grade safety and protection functions.

In addition to the safety devices of ordinary industrial sandblasting machines, automatic sandblasting machines for medical use have added exclusive medical protection, such as the emergency stop of equipment, the linkage of door-controlled interlocking devices with fire fighting and fresh air systems in clean workshops; A sterile air purge port is set in the sandblasting cabin, which will automatically purge and disinfect the cabin after shutdown; The equipment is equipped with a medium aseptic supplement device to avoid introducing microbial pollution when new media is added.

Five, processing efficiency and quality characteristics: stable batch, high yield, suitable for large-scale production of medical supplies.

The production of medical supplies should not only ensure high precision and cleanliness, but also meet the large-scale demand of the market. The automatic characteristics of automatic sandblasting machine effectively balance precision and efficiency, which is the preferred way for batch processing of medical supplies:

High processing efficiency, and is suitable for large-scale production.

The continuous operation mode of automatic sandblasting machine (such as belt conveying and rotary positioning) can handle 10~50 small medical articles (such as surgical blades, puncture needles and infusion set accessories) per minute, which is much higher than the efficiency of manual sandblasting; For large medical supplies (such as artificial joints and prostheses), multi-spray guns can be used for synchronous sandblasting, and the processing time of a single piece can be controlled within 1~5 minutes, which meets the requirements of mass production.

The product yield is extremely high, reducing rework and waste.

Because the process parameters are accurate and controllable, there is no manual error and no secondary damage, the yield of medical supplies sandblasting can reach over 99.5%, which is much higher than that of manual sandblasting. At the same time, the surface performance of the workpiece after sandblasting is stable, and there is no batch difference, which avoids the rework of the subsequent process caused by surface quality problems and reduces the waste of medical high-value materials (such as titanium alloy and PEEK).

Seamless connection with medical follow-up procedures

The processing effect of automatic sandblasting machine can accurately match the requirements of subsequent processes of medical supplies: for example, the surface roughness of metal parts after sandblasting is uniform, which can improve the adhesion of passive film and antibacterial coating and prolong the service life of coating; After sandblasting, the surface of plastic parts has no burr and even matte, which can be directly connected to aseptic packaging; Moreover, the workpiece after sandblasting does not need additional surface treatment, which reduces the processing links and improves the overall production efficiency.

6. Core exclusive requirements: the key to distinguish it from ordinary industrial sandblasting.

The automatic sandblasting machine is not a simple equipment upgrade, but a medical transformation and control of the whole process. The following exclusive requirements are the core of medical sandblasting and are indispensable:

All consumables (media, compressed air, tooling) are required to provide medical-grade test reports, which are in line with national standards such as "Quality Management Standard for Medical Device Production" and "Medical Stainless Steel Products";

The processing environment, equipment and operators must pass aseptic certification, and the operators must wear medical clean clothes and sterile gloves and follow the operating specifications of clean workshop;

The workpiece after sandblasting must pass medical-grade inspection: if there is no medium residue on the surface (the impurity content is ≤0.001% through energy spectrometer inspection), there is no microbial pollution (the number of colonies is ≤10CFU/piece), and the surface roughness and biocompatibility meet the medical design requirements;

The equipment and processing process must pass GMP certification, be included in the quality control system of medical device production, and be subject to regular inspection by the regulatory authorities.

summary

The core feature of automatic sandblasting machine in treating medical supplies is to deeply integrate the advantages of automatic and standardized sandblasting with the aseptic, high-precision and compliance requirements of medical industry. From sandblasting medium, processing environment and equipment structure to process parameters and data traceability, medical-grade exclusive design and control have been made, and finally the processing goal of accurate surface performance, cleanliness and sterility, stable quality and traceability of medical supplies has been achieved. Compared with manual sand blasting and ordinary industrial automatic sand blasting, it can better meet the strict standards of medical device production, is the mainstream way of surface treatment of medical supplies at present, and is widely used in the processing and production of various medical supplies such as surgical instruments, implantable prostheses, medical consumables, medical equipment accessories and so on.