Spent plastic processing will emit unpleasant odor, in order to eliminate these odors in the future to meet the needs of the environment, waste plastic processors have long been committed to eliminating or reducing these odors.
This article briefly summarizes ways to reduce plastic odor.
1, Add adsorbent
In plastic, a small amount of zeolite, an aluminosilicate adsorbent, can be used to remove odors from the material.The zeolites have a large number of crystallographic voids that trap small gas molecules that smell.
Molecular adsorbents have been successfully used in polyolefin extrusion tubing, injection and extrusion blow molded containers, barrier packaging, extrusion molded overwrap materials and sealing polymers. Molecularly adsorbed powders can also be incorporated into plastics as hygroscopic agents In order to remove water vapor, these water vapor can also contribute to the smell of plastic products.
2, Antibacterial agent
Adding antibacterial agents to plastics not only reduces the odors they emit, but also delays the appearance of aging, discoloration and embrittlement on the surface of the product. The most commonly used antibacterial agents are OBPA, trihydroxyl Triclosan, OIT, Pyrithione Organometallic compounds containing tin and silver are sometimes also used as antibacterial agents.
3, Use desorption method
Another way to deodorize plastic is to place the plastic in an odor adsorbent, such as activated carbon and high surface area silicates. Vacuum treatment can speed up the desorption process.
Treating plastic granules with a special detergent solution can also help to remove odors, which are generally aqueous or alkaline solutions containing surfactants that can effectively remove vinyl chloride monomer, styrene, Acrylic acid ester, acrylic acid monomer, unsaturated hydrocarbon and the like.
4, Add fragrance
The addition of aromatics to plastics does not eliminate the unpleasant odor, but can cover these odors, which in many cases suffices for the purpose. This method can be applied to polyethylene, polypropylene and polyolefin thermoplastic elastomers by Injection molding, extrusion or blow molding.
The retention time of the fragrance does not necessarily equate to the life of the molded part. The retention time depends on the degree of agglomeration, the volume to surface area ratio, whether it is exposed to a heated or humid environment, and whether the molded part is packed with airtight air-tightness or the like. Fragrances are generally used in toys, household products, cosmetic containers, household appliances and gardening equipment.
5, Waste plastic odor treatment methods
Waste plastics tend to produce unpleasant odors. Most recycled plastics, such as HDPE, PP, PVC and PET, are cleaned with an aqueous solution to remove contaminants, but the odor trapped inside the plastic remains. Organic Solvent Extraction The method helps to remove odor-producing compounds The latest solvent extraction method also uses supercritical carbon dioxide as a solvent.
This technology has been applied to HDPE and PET, which can remove odorous contaminants in oil containers, pesticide containers and other discarded devices.Carbon dioxide extractant has the advantage that it will not bring the trouble of organic solvents solving issues.
Odor removal device is an integral part of the waste plastic pellet extruder, it can effectively remove some of the smell of strong volatile compounds.
Anhui cleaning Environmental Protection Technology Co., Ltd. joint Fujian Normal University developed a plastic extruder high temperature exhaust gas recycling equipment can be used for different types of plastic materials and waste production of waste gas treatment, can achieve ultra-low emissions requirements.
6, Plastic odor scale
Smell is a subjective problem that varies from person to person, so it is difficult to develop a system that scales the smell. The first step in objectively confirming the smell is to allow a group of people to discern whether it is pleasing to divide the smell they smell Or not happy.
The latest plastic odor detector is a device that becomes an "electronic nose," which relies on electronic probe lattice and pattern recognition technology to work with volatile odor that can be classified as pleasant, neutral, unpleasant, Or in the form of intensity and molecular aggregation.
The birth of plastic is a kind of big blessing, but its processing and production of environmental issues have been controversial, how to make plastic processing and recycling of the entire industrial chain more environmentally friendly, we also look forward to more new technologies Solve the environmentally friendly plastic, such as plastic odor sharing today to deal with technology.