Corrosion in plastics
Olive oil is a natural product sensitive to light and oxygen. Oxidation occurs mainly in two ways: auto-oxidation and photo-oxidation. Oxygen from the air, which dissolves in the AEVO, is not in itself very destructive; the presence of oxygen TOGETHER with light, on the other hand, is a lousy combination as it causes destructive oxidation reactions.PET bottles must therefore necessarily be colored with an additive that reduces the amount of light able to pass through the bottle walls. The use of oxygen scanvengers reduces the permeability of oxygen through the bottle and consequently of the AEVO. The use of UV light blocking additives is also advisable.
Development objectivesThe development objective is to design a plastic container with high aesthetic characteristics, comparable to glass, able to offer good performance in terms of mechanical resistance and barrier to light and oxygen, to achieve an optimal shelf-life.
Table of chemical resistance of plastics
This is usually one of the first questions asked by those new to the world of aromatherapy, and it really pays to know what to do and what not to do about it. Why? The way essential oils are handled affects their longevity, so we should learn a thing or two about that. Proper storage is definitely the key to getting the most out of your oils. Both essential and vegetable oils don’t like extreme temperatures and sudden changes. So we must make sure that they do not lose their therapeutic qualities.
First of all, essential oils should preferably be bottled in dark amber or cobalt blue glass containers, whose characteristics protect the oils from the attack of ultraviolet rays. Oils should never be left in direct sunlight.
Essential oils should be stored in cool, dry places, totally protected from light and heat, in tightly closed and sealed bottles in which air does not enter. The storage place must be properly ventilated.
Chlorine damages plastic
Science has always stated emphatically that oil and water repel each other and cannot mix. The answer lies in two basic properties of liquids: density and polarity. However, recent research seems to have found a way to mix them.
Oil and water can be made to mix by adding an emulsifier. This creates a stable mixture of water with oil droplets spread through it, or oil with water droplets spread through it. No sedimentation occurs in this mixture.
Oil floats on water because it is less dense (a tablespoon of oil weighs less than a tablespoon of water). Salt is denser than water: it weighs the oil and causes it to sink. Once the salt dissolves in the water, the oil floats back to the surface of the water. In its practical application, the properties of water and oil and how they relate to each other is very beneficial to some species of animals.
Having an oily coat or oily feathers helps animals that live in rivers or the sea to stay warm in cold water, because the oil keeps the water away from their skin. Oil and water not mixing also means that crude oil spills from tankers remain on the sea surface. This makes the oil accessible for disposal, but it also means that marine animals and birds get trapped in the oil, which weighs down their feathers and fur and is poisonous if they swallow it when they try to clean up.
Plastic corrodes easily
The extreme result that can occur in service is hydrolysis, a chemical reaction with water. Hydrolysis is a slow process at room temperature but can be rapid at high service temperatures. This reaction causes a loss of molecular weight, breakage of molecular chains, loss of molecular weight and therefore loss of polymer properties, especially toughness.
This process is irreversible. Drying the plastic material will not restore the molecular weight or the initial properties. Hydrolyzed parts cannot be shredded and reused because their properties are not recoverable.water exposure of the plastic in the molten state.at melt temperature different reactions of the polymer to water or moisture can occur.plasticization of the mass causes an increase in fluidity. This will be reversible if the polymer is dried and reprocessed.
Hydrolysis occurring at melting temperatures is a rapid and severe process. It is not reversible, there is a loss of molecular weight and properties as well as a drastic reduction in the viscosity of the polymer, thus a substantial increase in flowability. This effect is not reversible. This effect at melting temperature does not require a large amount of water and is a fast process.