Discuss the development trend of biodegradable hanger
I. Definition and classification of degradable plastics
Plastic degradation refers to the environmental conditions (temperature, humidity, moisture, oxygen, etc.), its structure has significant changes, performance loss process.
The degradation process is affected by many environmental factors.According to its degradation mechanism, degradable plastics can be divided into photodegradable plastics, biodegradable plastics, photobiodegradable plastics and chemical degradable plastics.Biodegradable plastics can be divided into complete biodegradable plastics and incomplete biodestructive plastics.
1. Photodegradable plastics
Photodegradable plastic refers to the plastic material in sunlight cracking decomposition reaction, so that the material in sunlight after a period of time to lose mechanical strength, become powder, some can be further microbial decomposition, into the natural ecological cycle.In other words, after the molecular chain of photodegradable plastic is destroyed by the photochemical method, the plastic will lose its own strength and embrittlement, and then become powder through the corrosion of nature, enter the soil, and re-enter the biological cycle under the action of microorganisms.
2. Biodegradable plastics
Biodegradation is generally defined as: biodegradation refers to the process of chemical transformation of compounds through the action of biological enzymes or chemical degradation produced by microorganisms. In this process, photodegradation, hydrolysis, oxidative degradation and other reactions may also occur.
Biodegradable plastic mechanism is: by bacteria or hydrolase polymer material into carbon dioxide, methane, water, mineralized inorganic salts and new plastics.In other words, biodegradable plastics are plastics that degrade by the action of naturally occurring microorganisms such as bacteria, molds (fungi) and algae.
The ideal biodegradable plastic is a kind of polymer material with excellent performance, which can be completely decomposed by environmental microorganisms and finally become a part of the carbon cycle in nature.That is, the decomposition into the next level of molecules can be further decomposed or absorbed by natural bacteria, etc.
The principle of biodegradation is divided into two classes: first, there is a biophysical degradation, when microbial attack after erosion of polymer materials, due to the biological growth thin made polymer components hydrolysis, ionization or protons and split into pieces of oligomer, the molecular structure of the polymer is changeless, the polymer biophysical function of the degradation process.The second type is biochemical degradation, due to the direct action of microorganisms or enzymes, the polymer decomposition or oxidative degradation into small molecules, until the final decomposition of carbon dioxide and water, this degradation mode belongs to biochemical degradation mode.
3, biodestructive degradation of plastic
Biodestructive degradable plastics, also known as collapse plastics, are a composite system of biodegradable polymers and general plastics, such as starch and polyolefin, which are combined in a certain form and are not completely degraded in the natural environment and may cause secondary pollution.
4. Completely biodegradable plastics
According to their sources, there are three types of fully biodegradable plastics: polymer and its derivatives, microbial synthetic polymer and chemical synthetic polymer.At present, starch plastic is the most widely used compound flexible packaging.
5, natural biodegradable plastics
Natural biodegradable plastics refer to natural polymer plastics, which are biodegradable materials prepared from natural polymer materials such as starch, cellulose, chitin and protein.This kind of material comes from various sources, can be completely biodegradable, and the product is safe and non-toxic.
Based on the degradation of different ways, as well as in different parts of the request, now we need the client identity of biodegradable materials is completely degradation, degradation and landfill or compost, require existing plastic material degradation for materials such as carbon dioxide, water and mineralized inorganic salts, can easily be absorbed by nature or recycle again by nature.
Two, the characteristics of degradable plastics
1. The material is natural and non-toxic.
2, the use of any waste treatment method (such as composting, burial, etc.) can control the impact on the environment to the minimum.
3. It can replace the traditional plastic based on petroleum, and has the material properties of the same kind of traditional plastic products. It does not need much change in the way of use.
4, after being abandoned, after composting or burial treatment, can be cracked into the next level of molecules in a short period of time, can be harmless absorption by nature or become mineralized inorganic salts.
Common misconceptions about biodegradable plastics
1, the biological based plastic equivalent to biodegradable plastics
According to relevant definitions, bio-based plastics refer to plastics produced by microorganisms based on natural substances such as starch.Biomass for bioplastics synthesis can come from corn, sugar cane or cellulose.And biodegradable plastic, refers to the natural conditions (such as soil, sand and sea water, etc.) or specific conditions (such as composting, anaerobic digestion conditions or water culture, etc.), by the microbial action (such as bacteria, mold, fungi and algae, etc.) cause degradation, and eventually decomposed into carbon dioxide, methane, water, mineralized inorganic salt and new material of plastic.Bio-based plastics are defined and classified based on the source of material composition;Biodegradable plastics, on the other hand, are classified from an end-of-life perspective.In other words, 100% of biodegradable plastics may not be biodegradable, while some traditional petroleum-based plastics, such as butylene terephthalate (PBAT) and polycaprolactone (PCL), can be.
2. Biodegradable is considered to be biodegradable
Plastic degradation refers to the environmental conditions (temperature, humidity, moisture, oxygen, etc.) under the effect of significant changes in structure, performance loss process.It can be divided into mechanical degradation, biodegradation, photodegradation, thermo-oxygen degradation and photooxygen degradation.Whether a plastic will fully biodegrade depends on a number of factors, including crystallinity, additives, microorganisms, temperature, ambient pH and time.In the absence of appropriate conditions, many degradable plastics are not only unable to biodegrade completely, but may also have negative effects on the environment and human health.Such as part of the oxygen degradation of plastic additives, only the rupture of the material, degradation into invisible plastic particles.
3. Consider the biodegradation under the condition of industrial composting as biodegradation in the natural environment
Compostable plastics are treated as biodegradable plastics.You can't exactly draw an equal sign between the two.Compostable plastics belong to the category of biodegradable plastics.Biodegradable plastics also include plastics that are biodegradable in an anaerobic manner.Compostable plastic refers to the plastic in composting conditions, through the action of microorganisms, in a certain period of time into carbon dioxide, water and the mineralized inorganic salts and new substances contained in the elements, and finally formed compost heavy metal content, toxicity test, residual debris should meet the provisions of the relevant standards.Compostable plastics can be further divided into industrial compost and garden compost.Compostable plastics on the market are basically biodegradable plastics under the condition of industrial composting.Because under the condition of compost plastic belongs to the biodegradable, so, if discarded compostable plastic (such as water, soil) in the natural environment, the plastic degradation in the natural environment is very slow, can not completely degraded in a short time, such as carbon dioxide and water of its bad effects on environment and the traditional plastic, there is no substantial difference.In addition, it has been pointed out that biodegradable plastics, when mixed with other recyclable plastics, can reduce the properties and performance of recycled materials.For example, starch in polylactic acid may lead to holes and spots in the film made from recycled plastic.
Fourthly, the present situation and pain point of flexible packaging application of degradable plastics
At present, there are some flexible packaging enterprises trying to use degradable plastic packaging production, the main problems are:
1, few varieties, small yield, can not meet the requirements of mass production
If base for degradation of materials, fabrics, of course, also need to fully biodegradable material, otherwise, the base can be degraded completely, we can't take petroleum base of PET, NY, BOPP as fabric to match the material of PLA composite, so the meaning is almost zero, and is likely to be worse, even the possibility of recycling will be indelible.But at present, there are very few fabrics that can be used for composite flexible packaging, and the supply chain is very scarce, and it is not easy to find, and the production capacity is very short.Therefore, it is a difficult problem to find biodegradable fabrics that can adapt to soft package printing.
2. Functional development of the underlying degradable materials
For composite flexible packaging, the degradable material that can be used for the bottom is particularly important, because many packaging functions are entrusted to the bottom material to achieve.But at present can be applied to the composite soft packaging bottom degradable materials, domestic production can be few and far between.And even if some of the bottom film can be found, some of its key physical properties such as tensile, puncture resistance, transparency, heat sealing strength, etc., whether it can match the existing packaging needs is still a relatively obscure unknown.There are related health indicators, barriers, but also to study whether to meet the packaging requirements.
3. Whether the auxiliary materials can be degraded
When fabrics and substrates can be found, we also need to consider accessories, such as ink and glue, whether they can be matched with the substrate and whether they can be completely degraded.There's a lot of debate about this.Some people think that the ink itself is a particle, and the amount is very small, the proportion of glue is also very small, can be ignored.However, according to the above definition of completely degradable, strictly speaking, as long as the material has not been completely decomposed into easily absorbed by nature, and can be recycled in nature, it is not considered to be truly completely degradable.
4. Production process
At present, most manufacturers, the use of degradable materials, there are a lot of problems to be solved.No matter in the printing process, or in the compounding or bagging, finished product storage process, we need to find out how different this kind of degradable packaging is from the existing petroleum-based composite packaging, or what we need to pay attention to.At present, there is no more perfect control system or standard suitable for popular reference.
Shenzhen Mengcai Paper Products Co., Ltd. is a professional printing and packaging enterprise of environmentally friendly paper hangers for high-end clothing. It is a production-oriented enterprise integrating design, production, sales and development. Professional manufacturers customize paper hangers, paper shoe hooks, paper photo frames, paper silk towel holders, paper sock holders and other environmentally friendly paper products, which are environmentally friendly and 100% recyclable.