Among all silicone rubber products, in addition to the […]
Among all silicone rubber products, in addition to the most common tires, the other is the O-ring (there is also a 0-ring statement), which has the basic characteristics of shock absorption, sealing, and wear resistance. Depending on the material, it can also have oil resistance and resistance. Chemistry and other characteristics are often used in excavators, automobiles, instruments, engineering machinery and other fields.
The most basic requirement for measuring the quality of the sealing ring is: whether there is a flash (flash), because only zero flash can guarantee the sealing of the O-ring. Today we are talking about how the flash is generated and how to do it Zero-burr O-ring
The occurrence of burrs often occurs during molding and vulcanization. At this time, the rubber material will fill the entire cavity of the mold, and because the filled rubber material must have a sufficient amount, the excess rubber material will flow out along the parting surface at this time. The edges with different thicknesses of inner diameter and outer diameter, such edges are called burrs,
There are two common trimming methods: manual trimming and mechanical trimming
1. Manual trimming
This method is the most primitive and traditional, that is, manually use the cutter to remove the burrs on the inner and outer edges of the ring. The quality of this trimming method depends on the experience of the worker, the efficiency is low, and the scrap rate is high, so it is only suitable for small batches of zero Processing of raw O-ring
2. There are two types of mechanical edging: grinding wheel edging, low-temperature freezing edging
Compared with manual trimming, grinding wheel sandpaper edging has correspondingly improved efficiency and quality. The specific method is to wrap the vulcanized O-ring on the sand rod or nylon rod with the same inner diameter as the inner diameter, and use a motor to drive it. High-speed rotation, and then rub the outer circle of the O-ring through sandpaper or grinding wheel to achieve trimming, but the accuracy is not high, and the rough grinding surface is the disadvantage of this trimming method
The other is low-temperature freezing to remove the edge. This method originates from Japan and is also a type of mechanical trimming. The difference is that it works in a freezing environment and can be passed through: vibration, swing or jitter, drum, brush grinding and shot blasting. , Five different forms to achieve zero-burr O-ring,
The specific principle is that in a low-temperature freezing environment, the thin burrs of the O-ring change from elastic state to glass state (hardening and brittleness) due to freezing, but the product itself still has a certain elasticity, and then operates with vibration (or other Five forms), product-to-product collision, product and abrasive abrasion, product and shot blasting impact, then the thin burrs will be broken, and then fall off, and finally reached the edge trim Purpose, and the product will then restore its original performance at room temperature. This method has high production efficiency, but it has a poor effect on the inner edge.