How can the rubber sealing ring be free from burrs?

Among all PET Self wrap braided sleeve, besides tires, the most common one is O-ring, which has the basic characteristics of shock absorption, sealing and wear resistance. Depending on the material, it can also have characteristics such as oil resistance and chemical resistance, often used in excavators, automobiles, instrumentation, construction machinery and other fields, and the most basic requirement to measure the quality of the sealing ring is: whether there are burrs (flash), because only zero burrs can ensure the tightness of the O-ring, Today we are going to talk about how the burr is produced and how to achieve zero burr O-ring.

Burrs often occur during molding and vulcanization. At this time, the PET Self Wrap Braided Sleeve will fill the cavity of the entire mold, and since the filled Pet Self Wrap Braided Sleeve must have a sufficient amount, the excess PET Self Wrap Braided Sleeve flow along the parting surface, resulting in edges of different thickness on the ID and OD, which are referred to as "burrs".
1. Manual trimming: This method is the most primitive and traditional, that is, manually use a tool 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 workers, and the efficiency is low, and the scrap rate is high, so It is only suitable for the processing of small batches of zero-burr O-rings.
2. There are two types of mechanical trimming: grinding wheel edging, and low-temperature freezing to remove edges:
① Grinding wheel edging: Compared with manual edging, grinding wheel edging with sandpaper has a corresponding improvement in efficiency and quality. The specific method is to wrap the vulcanized O-ring on a sand rod or nylon rod with the same inner diameter , using a motor to drive it to rotate at a high speed, and then rubbing the outer circle of the O-ring with sandpaper or a grinding wheel to achieve trimming, but the precision is not high, and the rough grinding surface is the shortcoming of this trimming method.
②Low-temperature freezing and edge removal: This method originated from Japan, and it is also a kind of mechanical edge trimming. The difference is that it works in a freezing environment, and it can be used in five ways: vibration, swing or shake, drum, brush grinding, and shot blasting. Different forms to achieve zero flash O-rings.
The specific working principle is: in a low-temperature freezing environment, the thin burr of the O-ring changes from an elastic state to a glass state (hardening and brittle) due to freezing, but the product itself still has a certain degree of elasticity, and then moves with the vibration (or The other five forms), the collision between the product and the product, the abrasion between the product and the abrasive, the impact between the product and the shot blasting, at this time the thin burrs will be broken, and then fall off, and finally the trimming is achieved The purpose of the product, and the product will restore its original performance at room temperature. This method has high production efficiency, but the effect on the edge removal of the inner ring is poor.