What is paraffin wax
Paraffin wax, also known as crystalline wax, is a hydrocarbon mixture of about 18 to 30 carbon atoms, the main group is divided into straight chain alkanes (about 80% to 95%), and a small number of alkanes with individual branch chains and single ring cycloalkanes with long side chains (the combined content of both is less than 20%). Paraffin wax is a flake or acicular crystal obtained from the distillation of crude oil by solvent refining, solvent dewaxing or frozen crystallization of wax, press dewaxing, and then deoiling, and supplemented by refining. According to the different degree of processing and refining, it can be divided into three kinds: fully refined paraffin, semi-refined paraffin and crude paraffin.
Each type of wax is divided into different varieties according to the melting point, generally every 2 ° C, such as 52,54,56,58 and other brands. Crude paraffin wax has a high oil content and is mainly used in the manufacture of matches, fiberboard, canvas and so on. Fully refined paraffin wax and semi-refined paraffin wax are widely used, mainly used as food, oral drugs and some commodities (such as waxed paper, crayons, candles, carbon paper) components and packaging materials, baking containers for dressing, for fruit preservation, electrical components insulation, improve rubber anti-aging and increase flexibility. It can also be used for oxidation to produce synthetic fatty acids.
Second, what are the classifications of paraffin wax
1. Microcrystalline wax
Microcrystalline wax is mainly composed of textual-chain hydrocarbons, cycloalkane and some straight-chain hydrocarbons, and the molecular weight range is about 500-1000. This is a relatively small crystal, soluble in non-polar solvents, insoluble in polar solvents.
2, liquid paraffin
There are many types of liquid paraffin, and their lubrication effects are also different. In the extrusion process, the initial lubrication effect is good, and the thermal stability is also good. However, due to poor compatibility, the product is easy to be sticky when the amount is too much.
3, polyethylene wax (ACPE)
Polyethylene wax refers to low molecular weight polyethylene with a molecular weight of 1500-25000 or partially oxidized low molecular weight polyethylene. It is granular, white powder, block and milky waxy. It has excellent fluidity, electrical property and demoulding property.
4, semi-refined paraffin
It is a granular white solid whose relative density increases as the melting point rises. The product has good chemical stability, moderate oil content, good moisture resistance and insulation properties, and good plasticity. Semi-refined paraffin wax produces candles with concentrated flame, smokeless, and no tears. Used to make candles, crayons, wax paper, general telecommunications equipment and short circuit and light industry, chemical raw materials.
5. Chlorinated paraffins
Chlorinated paraffin is a golden yellow or amber thick liquid, non-flammable, non-explosive, very volatile. Soluble in most organic solvents, insoluble in water and ethanol. Heating to more than 120 ° C slowly decompose, can release hydrogen chloride gas, iron, zinc and other metal oxides will promote its decomposition. Chlorinated paraffin is the auxiliary plasticizer of polyvinyl chloride. Low volatility, non-flammable, odorless, non-toxic. This product replaces part of the main plasticizer, can reduce product cost, and reduce flammability. Mainly used in PVC cable material and water pipe, floor material, film, artificial leather and so on.
Third, what is the use of paraffin
Crude paraffin is mainly used in the manufacture of matches, fiberboard, canvas and so on because of its large oil content. After adding polyolefin additives to paraffin wax, its melting point is increased, its adhesion and flexibility are increased, and it is widely used in moisture-proof and waterproof wrapping paper, cardboard, the surface coating of some textiles and the production of candles.
After the paper is immersed in paraffin wax, a variety of waxed paper with good waterproof performance can be prepared, which can be used in food, medicine and other packaging, metal rust prevention and printing industry; When paraffin is added to cotton yarn, the textile can be soft, smooth and elastic. Paraffin wax can also be produced detergent, emulsifier, dispersant, plasticizer, grease and so on.
Fully refined paraffin wax and semi-refined paraffin wax are widely used, mainly used as food, oral drugs and some commodities (such as waxed paper, crayons, candles, carbon paper) components and packaging materials, baking containers for dressing, for fruit preservation, electrical components insulation, improve rubber anti-aging and increase flexibility. It can also be used for oxidation to produce synthetic fatty acids.
As a latent heat storage material, paraffin has the advantages of large latent heat of phase transformation, small volume change during solid-liquid phase transformation, good thermal stability, no supercooling phenomenon, and low price. And the development of aviation, aerospace, microelectronics and optoelectronics technology, often requires that a large amount of dissipative heat generated when high-power components work can only be dissipated in a limited heat dissipation area and a very short time, and low-melting phase change materials can quickly reach the melting point compared to high-melting phase change materials, and make full use of latent heat to achieve temperature control. The thermal response time is relatively short, so that paraffin wax has many advantages in aviation, aerospace, microelectronics and other high-tech systems, as well as house energy saving and other fields have been widely used.
GB2760-96 allows the use of gum sugar base agent, limited to 50.0g/kg. Foreign countries are also used for sticky rice paper production, the amount of 6g/kg. In addition, it is also widely used for moisture-proof, stickproof and oil-proof food packaging materials. It is suitable for food gum, bubble gum and pharmaceutical gold oil and other components, as well as wax (made from waxy fractions of petroleum or shale oil by cold pressing and other methods) that are in direct contact with food and medicine, such as hot carrier, release mold, tablet pressing, polishing, etc.