Metal tubes do have some advantages over plastic tubes. They stay coiled up from the bottom better, and because of this, they are less likely to draw air back inside because the paste stays put at the top opening. This is because metal tubes did not have the “memory” that plastic tubes have. Memory is a characteristic of materials that is related to resilience. A material with memory will, after stress has been relieved, tend to restore itself to a configuration the material was in before the stress was applied. A plastic tube if coiled will tend to uncoil; a metal foil tube will much more readily remain coiled.
For reasons of economy, many people prefer to exhaust the supply of toothpaste in a tube before discarding it. Removing the toothpaste from a plastic tube is, to some extent, much easier than removing the toothpaste from a metal foil tube because the plastic tube can be subjected to squeezing without concern for perforations and tearing. But after squeezing the tube from the bottom end to the cap, the tube should be coiled to prevent the toothpaste from migrating away from the cap end of the tube. However, the tendency of a plastic tube to uncoil and straighten enables the toothpaste to migrate; a straightened tube encourages some people to squeeze the tube from the middle or top, near the cap, rather than from the bottom where they should if they want to force the toothpaste in the tube toward the cap.
Metal tubes are still commonly used for oil paint and certain gels containing pharmaceutical products and supplements, to keep air from getting in at the top. Air can dry out the product, or it can cause oxidation that may result in some degradation.
Metal tubes do have some advantages over plastic tubes. They stay coiled up from the bottom better, and because of this, they are less likely to draw air back inside because the paste stays put at the top opening. This is because metal tubes did not have the “memory” that plastic tubes have. Memory is a characteristic of materials that is related to resilience. A material with memory will, after stress has been relieved, tend to restore itself to a configuration the material was in before the stress was applied. A plastic tube if coiled will tend to uncoil; a metal foil tube will much more readily remain coiled.For reasons of economy, many people prefer to exhaust the supply of toothpaste in a tube before discarding it. Removing the toothpaste from a plastic tube is, to some extent, much easier than removing the toothpaste from a metal foil tube because the plastic tube can be subjected to squeezing without concern for perforations and tearing. But after squeezing the tube from the bottom end to the cap, the tube should be coiled to prevent the toothpaste from migrating away from the cap end of the tube. However, the tendency of a plastic tube to uncoil and straighten enables the toothpaste to migrate; a straightened tube encourages some people to squeeze the tube from the middle or top, near the cap, rather than from the bottom where they should if they want to force the toothpaste in the tube toward the cap.Metal tubes are still commonly used for oil paint and certain gels containing pharmaceutical products and supplements, to keep air from getting in at the top. Air can dry out the product, or it can cause oxidation that may result in some degradation.
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