We may not see it with our eyes every day, but polyvinyl alcohol is used in so many forms and applications. Essentially, polyvinyl alcohol is a synthetic polymer that is soluble in water. It is white in colour and odourless as well. When polyvinyl alcohol suppliers send it across for use it is done so in the form of beads or mixed with water.
What makes polyvinyl alcohol different from other polymers is the process in which it is created. Polyvinyl alcohol manufacture involves a process called hydrolysis. In this process, polyvinyl acetate is dissolved in alcohol (methanol) and then treated with sodium hydroxide which is an alkaline catalyst. What results from hydrolysis is a polymer that is highly soluble in water but which is insoluble in all organic solvents.
The uses of polyvinyl alcohol
There are two industries that are primarily catered to by polyvinyl alcohol suppliers: the textiles industry and the paper-making industry.
The textiles industry
In the textiles industry, polyvinyl alcohol is used to strengthen textile yarns. The process is called sizing of yarn. What sizing does is to reduce the chance of breakage while the yarn is on the weaving machine. This abrasion-resistance will enhance the strength of the yarn and also decrease its hairiness. Sizing in the textile industry is done either by hand or by suing machines.
The paper industry
In the paper industry, polyvinyl alcohol is used to make the paper more resistant to both grease and oil, thus making it more stable for use. It also adds surface gloss and smoothness to the treated paper.
Other uses of polyvinyl alcohol
Apart from being used in the paper and textile industries polyvinyl alcohol has other uses as well.
- The most known use of polyvinyl alcohol is in freshwater sport fishing. During this sport, dry or oil-based bait is placed in polyvinyl alcohol bags. These bags are then either cast into the water or placed in front of the fishing hook. When the bag hits water it dissolves and thereby releases the bait into the water to attract fish swimming close to it.
- Polyvinyl alcohol also finds many uses in the printing sector. It is used as a support structure during 3D printing which will eventually dissolve away leaving no trace.
- Because polyvinyl alcohol is non-toxic, it is used in eye drops that treat conditions such as dry eyes. It is also hard contact lens solutions. The polyvinyl alcohol in this case as a lubricant in the solution.
- There are other medicinal uses of polyvinyl alcohol as well. It is used to make protective gloves that are resistant to chemicals, as an embolization agent in many medical procedures and also as a fixative for the collection of specimens for testing such as stool samples.
- Polyvinyl alcohol is also used to manufacture water-soluble bags to store liquid detergent in pouches or ‘cleaning pods’ that offer ease-of-access and use to the end-consumer.
The simple reason why polyvinyl alcohol finds so many uses is that it is non-toxic. Moreover, it is biodegradable, strong and odourless as well.