ISO/TR 21275:2017 pdf download – Rubber — Comprehensive review of the composition and nature of process fumes in the rubber industry.
4 Overview of the rubber industry 4.1 General This clause is intended to give the reader a brief overview of rubber technology in order to provide some essential background information that will support and inform non-technical readers of the literature review. The overview is broken down into four specific areas (see 4.2 to 4.5) as detailed below, and encompasses the full spectrum of the rubber industry, with the fifth part (see 4.6) covering the effect of elevated temperature on the base polymers and rubber additives. — Rubber component production processes — Generic rubber types — Rubber chemicals and additives — Mechanistic chemistry of rubber vulcanization — Effect of elevated temperature on rubbery polymers and rubber additives 4.2 Rubber component production processes The wide diversity of rubber components in the market is highlighted in the Introduction. The rubber product manufacturing industry can be divided into four groups: 1) vehicle tyres, 2) engineering and industrial products, 3) latex products and 4) other miscellaneous rubber products. The manufacturing processes involved in these industries have many similarities but there are also many differences. The differences relate to the raw material (whether using NR or synthetic rubber), the types of chemical additives used in the rubber formulations and the type of curing methods employed.
The main processing stages for the majority of rubber components manufactured involve the following: — Mixing: The first stage of the rubber manufacturing process involves the production of a rubber formulation, (also known as a “mix” or “compound”). Mixing is of crucial and fundamental importance to the rubber industry. The base rubbers have to be extended with a variety of essential ingredients including plasticizers, reinforced with particulate fillers and important additives such as accelerators, curatives and protective agents, which all need to be thoroughly dispersed and distributed before the resultant compound can be shaped and vulcanized to give an end product with adequate properties. All these cannot be achieved without effective mixing. Rubber formulations vary significantly in their composition depending upon the desired characteristics of the product. As many as 15 to 20 different ingredients may be used in a single compound depending upon the polymer type and application fumes. The mixing equipment used to produce the rubber compounds includes internal batch mixers, mixing mills, continuous internal mixers and mixing extruders. The appropriate compounding ingredients for the formulation are normally weighed out in a compounding area or “drug” room before being loaded into the mixer at predetermined stages. However, it is also a practice, especially in the tyre manufacturing industry, for ingredients to be supplied preweighed by the supplier and added directly into the mixer.