What Are Sponge Forceps?

Sponge forceps are also called holding forceps. It is divided into two types: toothed and non-toothed. The toothed is mainly used to hold and transfer sterilized instruments, sutures, needles, dressings, drainage tubes, etc.

Chinese name: Sponge pliers
Foreign name: Ring forceps

Management category: Class I medical devices
Category Name: Basic surgical forceps

Application range of sponge pliers

It is used for clamping human internal cavity tissues and dressings.

Classification of sponge pliers

1. Toothed. It is mainly used to hold and transfer sterilized instruments, sutures, needles, dressings, drainage tubes, etc. It is also used to clamp gauze dipped in disinfectant to disinfect the skin of the surgical field or to wipe blood deep in the surgical field.

2. No tooth marks. Used to hold organs and assist in exposure. Dressing clamps are usually placed in sterile large-mouth measuring cups or large-mouth bottles in the dressing room and the operating room, and the knife-shearing solution is contained inside. ^[1]

Notes on the use of sponge pliers

1. Do not point the head end (that is, the end immersed in the disinfectant solution) upwards. This will contaminate the head end when the disinfectant solution is returned to the bacterial area on the handle end. The normal holding head should always face down.

2. It is designed for gripping sterile items and cannot be used for dressing change.

3. The head should be closed when removing or returning. Do not touch the mouth of the container or touch the instrument table.

4. The container opening of the holding forceps should be covered with a plastic cover. ^[1]

Manufacturing materials, processes and production status of sponge pliers

The sponge pliers are made of hot-rolled stainless steel rods with a diameter of 12mm. The manufacturing process is to cut the punch into short rods-high-frequency heating to stretch into the original billet-the oil furnace is heated to forge the blank (the fuel nozzle is placed on the box furnace, the temperature is determined by the color of the workpiece, there is no temperature measuring device) × 2 h high temperature tempering, cooling with the furnace to room temperaturecut edge1000 quenching, 250 300 tempering (quenching and tempering holding time is determined by the amount of furnace installed) surface electrolytic descalingrivetingcorrection Grinding and polishing. According to the production tracking and feedback on the quality, it was found that the spray nozzle of the oil furnace was uneven, and there was often a problem that the heating oil could not be burned enough to collect carbon black, and black spots were formed on the surface of the forging. Sometimes in order to increase the output, the production is often overloaded, causing the heating temperature to be too high, causing overburning on the surface of the forging to produce black spots. ^[2]

Analysis of black spots, cracks and ultra-high temperature carburization of sponge pliers

1. Analysis of the cause of dark spots. According to production experience and analysis, it is believed that the reason for the occurrence of dark spots is that the heating oil in the oil furnace does not burn enough, and the carbon black droplets generated are agglomerated on the steel surface. Oil furnace nozzles are non-uniform, and large particles of oil droplets are easy to appear. Due to their large size, they cannot be completely burned and produce free carbon and tar (similar to asphalt) large molecular weight organic matter. Under the action of its own gravity, such viscous particles containing free carbon and tar macromolecules will drip on the surface of the forging. During subsequent heating, part of the carbon will be converted to CO2 and run away, and the rest will be decomposed due to anoxia due to tar blocking oxygen, forming free carbon and tightly binding to the steel surface, eventually forming carbon black.

2. Analysis of the causes of cracks. The formation of carburized layer is the cause of correction cracking, riveting cracking and surface cracking. It is well known that the carburized layer can improve the surface hardness, wear resistance and fatigue resistance of parts, but it is not resistant to bending and impact. The correction should make the metal withstand bending and impact forces, and it is easy to break when there is a hard and brittle carburized layer on the steel surface. Riveting causes the steel to withstand impact forces and lateral expansion forces. The presence of a surface carburized layer makes the steel easily crack along the edges of the holes, eventually causing the steel to fracture. In particular, the amount of carbides in the white mouth layer is large and the shape is extremely poor, which exacerbates the brittleness of the surface layer of steel.

3. Analysis of ultra-high temperature carburization. From the perspective of the preform heating method, the atmosphere in the furnace should be mainly air, carbon dioxide, water vapor and other small amounts of gas, without carburizing conditions. There is only one possible cause of carburization, that is, the insufficient combustion of heating oil to form carbon black. In previous books, publications, and other technical materials, the case of carburizing caused by oil furnace heating has not been mentioned, because this phenomenon does not occur in ordinary carbon steel and alloy steel heating. Because ordinary carbon steel and alloy steel heat surface oxidize quickly, the carbon black produced by combustion will be blocked by thick oxide scale even if it drops on the surface of the steel. Activated carbon atoms have no chance to contact the metal surface to cause carburization. Even if carburizing, because carburizing speed is far less than the surface oxidation speed, carburizing cannot be achieved in the end. However, stainless steel is different. The surface oxidation rate is slow. Even at 1200 ° C, the oxidation rate is much slower than ordinary carbon steel and alloy steel. Therefore, once carbon black is agglomerated on the surface of the steel, carbon black contains tar-like components to prevent it. The action of air, so that anoxic decomposition will occur at the interface with the steel to form activated carbon atoms, which will penetrate the surface of the steel through cracks and pores on the scale. When there is a large amount of backlog in the oil furnace, the temperature of the forgings often exceeds 1200 , and the highest can reach the melting temperature, that is above 1300 . At this time, the carburizing speed is extremely fast, which may exceed several times the ordinary carburizing speed. Therefore, a very thick carburized layer is formed in a short time. ^[2]