Silicone Rubber Bellows & Boots

Silicone Bellows, also known as Rubber Bellows and Boots, Rubber Expansion Joint, Silicone Bellows Hose, Automotive Rubber Bellows, Rubber Boots, which are essential parts of many different industrial systems. Silicone Rubber Bellows are designed to protect against dust, water, oil, grease, acids, bleaches, spatter and other environment elements, according to the different application, we can choose corresponding material for production like solid silicone, liquid silicone or rubber (EPDM, CR, NBR, etc.) And for molding way, there are also some options, compression molded bellows, LSR injection molded bellows, transfer molded bellows.

Silicone Compression molded bellow is the process of placing a given amount of uncured solid silicone rubber material into a mold cavity, which is then closed and heated. When the parts have cured, they are removed from the mold. Silicone Compression molding has been used to mold silicone rubber parts since the beginning of the rubber manufacturing industry. It is one of the oldest methods still used to mold silicone rubber parts. Compression molded bellow is the most cost economic way, and the compression molding process of bellows is quite simple when compared to injection molding.

Transfer molded bellow begins by measuring the molding material and placing this uncured silicone rubber in a “pot” that is a part of the mold. The mold is then closed and a plunger compresses the material (Normally, it is 3-plates mold tool, but it doesn’t ends at 3-plate, can be 4 or 5). As heat is applied, pressure forces or “transfers” the uncured rubber through sprues into the mold’s cavities, giving this molding process its name. Transfer Molded Bellows have shorter production cycle times compared to traditional compression molding witht Tighter dimensional tolerance, while the mold cost will also be higher than compression molding.

LSR Injection Molded Bellows is high precision with good quality. Building a production mold entails a combination of CNC milling and EDM (electrical-discharge machining) and uses the highest quality hardened stainless steel. It takes time and a high degree of accuracy to build a production mold capable of withstanding the LSR molding process. In the silicone rubber molding process, the production tooling can be the lengthiest step and requires the largest capital investment. However, LSR's ability to flow into very thin cross-sections, tight radii, and thick/thin features make the mold design a simpler task.  Once the curing or vulcanization and solidification phase is completed, the LSR molded part is removed from the mold without concern for distortion or damage.