Introduction the basic knowledge of plastic lubricant.-Iota

Products

News

Office Address:	Sunmoon Science Park, 985 Xingzhong Road, High-Tech Zone, Bengbu, China
Factory Address:	Mohekou Industrial Park, Huaishang District, Bengbu, Anhui, China
Contact:	Nathan Zhang
Phone:	0086-552-19805521900
FAX:	0086-552-3822922
Mobile:	19805521900/18119733779
WebSite:	www.siliconeoil.cn www.siliconeoil.net
Email:
QQ:	729118868

Service > Introduction the basic knowledge of plastic lubricant.

Introduction the basic knowledge of plastic lubricant.

After the molten polymers generally have a higher viscosity, in the process, the molten polymer in through the narrow, gates and other flow channel, the polymer melt bound to cause friction and surface processing machinery, some friction on the processing of the polymer is very negative, which reduces friction melt flow, while serious friction causes the film surface becomes rough, lack luster or appear rhyolite. To do this, we need to be added in order to improve lubricity, reduce friction, for the purpose of reducing interfacial adhesion performance additives. This is the lubricant. Lubricants In addition to improving liquidity, but also can play a molten accelerators, anti-blocking and anti-static agents, slip agents role.
Lubricants can be divided into two kinds of external lubricant lubricant inside and outside friction lubricant role is mainly to improve polymer melt processing equipment with hot metal surfaces. It is less compatible with the polymer, migrate out easily from the melt, so the lubrication can be formed in the plastic sheet with the metal melt interface. Internal lubricants and polymers have good compatibility, which serve to reduce the role of cohesion between the polymer molecules within the polymer, thereby improving the internal friction of the plastic melt heat and melt flow. Commonly used lubricants are stearic acid and its salts outer; the lubricant is a low molecular weight polymer. There are other uses for some lubricant. Each lubricant has actually can achieve some claim the role of internal and external lubrication always together, but in a way more prominent. With a lubricant at different polymers or different processing conditions exhibit different lubrication, such as high temperature, high pressure, internal lubricant is squeezed out and become external lubricant.
In the production of plastic film, we will encounter some adhesion phenomena, such as plastic film production, not easy to separate the two films, which bring difficulties to the automatic high-speed packaging. To overcome it, the resin can be increased by adding a small amount of surface lubricity additives to increase the external lubrication, generally referred to as anti-blocking agent or a slip agent. The molecular structure of the lubricant in general, there will be a long chain of non-polar and polar group in two parts, they are compatible on different polymers are not the same, thus showing the effect of different internal and external lubrication. According to the chemical composition, conventional lubricants can be divided into the following categories: fatty acids and their esters, fatty acid amides, metal soaps, hydrocarbon, an organic silicon compound.
Efficacy in a variety of lubricants with the actual processing of plastics, for example kneading, rolling processing time, the polymer can be prevented from sticking barrel, suppressing friction and heat, is reduced and the kneading torque load, thereby preventing the polymer material thermal deterioration. In the extrusion molding, can improve mobility, improve polymer materials and the barrel and die adhesion to prevent and reduce the retentate. Also it can improve the film appearance and gloss.
From processing machinery perspective, mixing, rolling, slush molding, etc., the external lubricant has an important role, in extrusion, injection molding, internal lubricants are more effective.
The amount of lubricant is generally in the 0.5% to 1%, the choice should pay attention to:
1. The flow properties of the polymer molding process needs have been met, the main considerations of the role of lubrication in order to ensure internal and external balance;
2. The external lubrication is valid, whether it should be in the molding temperature, the plastic surface of the liquid film to form a complete prevail, and therefore should be close to the melting point of the lubricant outside the molding temperature, but a difference of 10 ℃ ~ 30 ℃ in order to form a complete film;
3. Do not reduce the mechanical strength and other physical properties of the polymer.
When selecting a lubricant in production, should be made to achieve the following requirements:
4. Lubricate high efficiency and long-lasting;
5. compatibility with the resin of moderate size, internal, external lubricating balance; do not spray frost and difficult to scale;
6. The surface gravity is small, a small viscosity, at the interface scalability, easy to form an interface layer;
7. Try not to reduce the excellent properties of the polymer, it does not affect the secondary processing properties of plastics;
8. itself excellent in heat resistance and chemical stability, does not decompose during processing, non-volatile;
9. The non-corrosive, non-pollution film, not toxic.
However, the simple use of a lubricant is often difficult to achieve the purpose, to be used in combination of several lubricants, lubricating compound developed rapidly in recent years, the choice can be multi-angle to look at the role of the lubricant.
Commonly used lubricants are stearic acid, butyl stearate, oleamide, ethylene bis stearamide and the like.
Many substances can be used as a lubricant of paraffin, such as natural paraffin, liquid paraffin (white oil), microcrystalline wax, etc., but the effect was mixed. Natural waxes do more with external lubrication can be used as a variety of plastic lubricants, release agents, the general amount of 0.2 ~ 1phr, but its compatibility, thermal stability and dispersion is not very good, the amount is not too large, the best and within the lubricant and use; and shortening much used PVC, PS of internal lubricant, good lubricating properties, good thermal stability, the general amount 0.5phr. They are drug-free, can be used for food packaging. Another kind of microcrystalline wax: in plastic processing is also used as a lubricant, the amount of 1 ~ 2Phr, thermal stability and lubricity better than regular paraffin.
Low molecular weight polymers are widely used as lubricants, such as polyethylene wax, low molecular weight polypropylene, its internal and external lubrication are good, and non-toxic. Polyethylene wax and other materials suitable for PVC extrusion, rolling processing, the amount is generally 0.1 ~ 1phr, can improve processing efficiency, prevent the film adhesion, improve the dispersion of fillers or pigments, compatibility and transparency is not very good; irregular low molecular weight polypropylene structure as rigid PVC, PE lubricant, excellent performance, can improve the dispersion of other additives, the amount of the 0.05 ~ 0.5phr.

Feedback to "Iota Silicone Oil (Anhui) Co., Ltd."