Two roll rubber mill and operations

Operation

To produce rubber for tires, hoses, shoes, and many other applications the rubber must first be produced using a two-roll rubber mill. The rubber mill consists of two horizontally opposite stainless steel rollers that rotate in opposite directions at different speeds.The rollers spin toward each other, one faster than the other.The distance between the two rollers can also be adjusted by the operator. Opposing directions of rotation and different speeds create combined shear and compression forces on the materials being mixed on the mill.For open mills, the operator may also be responsible for adding ingredients to the rubber while mixing on the rubber. Compounds typically heat up due to chemical reactions that occur during compounding.To help keep the rubber compound cool, usually one of the rolls is hollow and can be connected to a cooling water line, and cold water is then run over the roll, cooling the metal roll and thus the rubber.Although the process of operating a rubber mill sounds simple, it is very dangerous, so many precautions are added to ensure the safety of the operator.

Operators and safety personnel must undergo extensive training to be qualified to operate rubber mills.Since the two rollers of the mill roll inwards, human hands are easily sucked into the mill. Not only can this crush the hand, but if the person removes the hand quickly,it can cause the glove to come off.Safety features include an emergency stop lever located 40 inches vertically above the rolls which can be pulled at any time to stop the mill from rolling.Pressure-sensitive body bars are also at knee height so the operator can stop the machine by tapping the bar with his knee.Protective equipment such as safety glasses was also worn.In addition to the main operator there is usually a safety operator who is also trained to use the rubber mill and what to do in an emergency.

Rubber compounding

Mixed rubber refers to adding rubber components to the rubber mixture to make it evenly dispersed.This rubber mixture is called mixed rubber.The mill facilitates the two main steps in rubber processing mastication and mixing.Plastication is when the original polymer is sheared and broken down to create easier flow.This allows for better bonding of materials when other materials of the compound are added, resulting in mixed compositions.To produce a rubber compound on a mill, you first need a raw or base polymer.Polymers can be a variety of substances including natural rubber such as SMR CV, SMR 20, SMR L or various synthetic rubbers such as Nitrile Butadiene (NBR), Ethylene Propylene Diene (EPDM), Butyl, Polychlorinated Butadiene (CR) ), Polyisoprene (IR) etc.After the raw rubber has been masticated, usually for natural rubber, the other ingredients need to be mixed into the raw polymer on a Banbury kneader or other rubber mixer, then dispersed and tableted by a two-roll mill, The compound used is suitable for molding dimensions. Rubber mixing can also add ingredients in turn on the two-roller mixer, and fold, cut, roll and mix the rubber.This process produces rubber that can be used to make products.The ingredients added to make a rubber compound include oils, fillers and accelerators, often including sulfur or peroxides, and possibly metal oxides as activators, such as zinc oxide, in some cases as fillers and activators. After mixing, the compound is removed from the mill in large flakes and molded into the desired product.