Propylene glycol manufacturers _ Wei Connaught Chemical (certified) _ Wei Changzhi glycol provided by Qingdao Sino Chemical Co. Qingdao Wei Connaught Chemical Co. (www.qdweinuo.com) is specialized in the "phenol, aniline, ethylene, n-butanol, isobutanol, n-propanol, isopropanol, methanol," the business, the company adhering to the "integrity management, service intentions, "the idea, to provide you with the highest quality products and services. Welcome to inquire! Contact: Feng Zhongying. Propylene glycol is an unsaturated polyester, an important raw material propylene glycol epoxy resins, polyurethane resins, the amount of this area accounts for about 45% of the total consumption of propylene glycol, which is used extensively for unsaturated polyester surface coatings and reinforced plastics. The viscosity and moisture absorption of propylene glycol, and non-toxic, and thus in the food, pharmaceutical and cosmetic industry is widely used as a hygroscopic agent, antifreeze agents, lubricants and solvents. In the food industry, propylene glycol and propylene glycol fatty acid esters of fatty acids produced by the reaction, mainly for food emulsifier; Propylene glycol is an excellent solvent seasoning and coloring. Propylene glycol in the pharmaceutical industry for manufacturing various types of commonly used ointments, salves solvent, softener and excipients and the like, due to propylene glycol with various spices have good mutual solubility, and thus the solvent and the softening agent for cosmetics and the like. Propylene glycol is also used tobacco moisturizing agents, preservatives propylene glycol manufacturers, food processing equipment, lubricants and food marking ink solvents. An aqueous solution of propylene glycol is effective cryoprotectant. Propylene glycol: Production Method Editor glycol supply because of different varieties, but basically include condensation and mixing steps. Condensation methods are: ① melt polycondensation. Acid and alcohol direct melt polycondensation, without adding other ingredients. The use of alcohol, water boiling range difference, so that the water of reaction is separated by the separation column. This method is simple equipment, short production cycle, widely used. ② solvent azeotropic dehydration. Add toluene or xylene (solvent) in the polycondensation process, the use of toluene and water azeotropic point lower than the boiling point of water, the water of reaction out quickly, promoting polycondensation reaction. The advantage is that the reaction method is relatively stable, easy to grasp, the product color is better, but requires a watershed reflux device, use toluene reaction, condensation section to be explosion-proof. ③ decompression. Shrink in the condensation of propylene glycol in effect amounted to 2/3 3/4, taking the time to meet the requirements until the acid value. ④ pressure method. Pressure can accelerate the reaction, shortening the reaction cycle, to increase productivity. Blended mix and wet premixed intervention points. Intervention is to mix the reactive solid prepolymer, the solid-state cross-linking agent, glass fiber, catalyst, pigment mixed into a molded plastic; wet premixed with styrene as the crosslinking agent, the liquid unsaturated polyester, glass fibers, catalysts, lubricants, pigments, etc., after mixing kneader, dough made of polyester molding compounds.