PLA, short for Polylactic Acid,is one of the biodegradable materials. It has received the most attention from both domestic and foreign research institutes. Polylactic Acid is popular in the areas of medical, packaging and fiber. Natural lactic acid is the main raw material of PLA. It has good properties of biodegradability and biocompatibility. PLA gives much lower pressure on environment than polymers from petroleum. It is well known as the most promising green packaging material. PLA manufacturing machine has a close working process of PP non woven machine.
Is Polylactic Acid Filament Biodegradable
PLA is a biodegradable material. It can be degraded into low molecular substances by microorganisms under certain conditions. Polylactic acid completely decomposes into carbon acid and water when discarded.
Polylactic Acid Properties
PLA is water resistance and biocompatibility. It’s recyclable and pollution-free to environment.
PLA also has good mechanical properties. It performs well in strength, flexibility and permeability.
Polylactic Acid has a service life of 2 to 3 years. It has good transparency, mildew resistance and antibacterial.
Polylactic Acid Use in Food Package Film
Air permeability is important for package materials. It determines the application filed of this material. Some products need enough oxygen to keep fresh. So the packaging materials require oxygen permeability. Some products must stay away from oxygen. The package material should have the property of oxygen barrier. Fox example, in order to inhibit the growth of mold,drink bottle must keep oxygen far away. PLA is a good food package film because of its transparency, barrier and antibacterial.
PLA has good transparency and gloss, which is almost same as cellophane and PET. Other degradable plastics usually can’t reach this level. It is 3 times of ordinary PP film. This makes PLA package film look beautiful in appearance. Most candies in the market are packed by PLA material. It’s close to traditional package in appearance and usage performance. But PLA material has a better barrier, which preserves the scent of candies well.
PLA can be made into film packages. It has high transparency, good barrier and excellent processability. So it is a good package material for fruits and vegetables.
- PLA package film creates a suitable storage environment for fruits and vegetables.
- It maintains the life activities of fruits and vegetables, delaying aging.
- PLA package film maintains fruits and vegetables’color, fragrance, taste and appearance.
However, food package material has a higher request. Some modifications are very necessary when applied in food packaging. For example, people have found that composite films are better than pure films. Here is an experiment. A scientist packed broccoli with pure PLA film and PLA composite film respectively. Then stored broccoli at (22±3)℃. He regularly tested the changes of broccoli in various physiological and biochemical aspects.
The result shows that PLA composite film has a better preservation effect on broccoli storage. It forms a suitable humidity level for broccoli. This effectively maintains the appearance and quality. The flavor and taste are also well preserved. It extends the life of broccoliat room temperature by 23 days.
PLA creates a weakly acidic environment on the surface of product. It is the basis of antibacterial and anti-mildew. The rate of antibacterial achieves as high as 90% with other agents. So PLA can be used for antibacterial packaging. The scientist took mushroom for example to study the fresh-keeping effect with the PLA composite film. The result shows it effectively delays the decrease the vitamin C in mushroom..
PLA is the main raw material of disposable tableware in the market. PLA performs well in normal temperature. But it degrades quickly in the environment of high temperature, acid-base and microbial. PLA is also poor on shock resistance. So it’s often unable to meet the requirements of circulation in harsh environments. PLA should make an improvement.
How to Improve Thermal Stability
The thermal stability of PLA material is almost same as PVC. But it’s lower than PP, PE and PS. The processing temperature generally comes between 170-230 ℃. This is suitable for common processes such as injection, stretching, extrusion and blow molding. However, the crystallization rate of PLA is relatively slow in the actual process. Heat distortion happens at a relatively low temperature. It limits the application in packages of hot tins and heat sterilization products. We usually need to modify the chemical performance.
The main modification method is to mix PLA with natural fibers. The scientist made an experiment to mix bamboo fiber with PLA. He found bending strength and broken elongation increased by 19.3% and 30.1%, respectively.
PLA has a great prospect in the market as a new type of bio-based material. More and more people will choose to use PLA in future. It is of good physical properties and friendly to environment. However, we must make improvements when applied in package. We also have to decrease polylactic acid price. It’s much higher than PP. We are a professional nonwoven machine manufacturer. We not only sell PLA production lines but also PLA fabric. Contact me for a free quote. I assure you the competitive price and high quality.