How to Grind up PLLA into Powder?
If you grind PLLA material like other solid material, can you get the small powder in the end?
Anyone can grind PLLA polymer, either manual or use equipment. But not everyone can create one that people need?
In this post, you’ll learn how to grind up PLLA material into small powder and the main issue in the processing.
Table of Contents
Why Do You Need PLLA Powder?
Polylactic acid (PLLA) is an L-lactide of the word-famous degradable polymer derived from lactic acid — PLLA. It’s made of renewable, organic resources, like corn, sugar, beets, and similar products that are rich in starch.
The interesting thing about PLLA is that it has superior material properties that outperform even some petroleum-based products. Some important characteristics include:
- Compatible with a variety of coatings, inks, and adhesives.
- Effective flavor and aroma barrier.
- Good weight-to-strength ratio.
- Environment friendly waste material, if disposed of correctly.
- Suitable for a variety of applications.
- Comes with multiple composite and color options.
- Can be solvent welded.
- Has a high molecular weight and crystallinity.
PLLA is a promising material that can be used for healthcare purposes, such as regenerative medicine or cell engineering. It’s used for cardiovascular implants and dental niches as well due to its ability to degrade under physiological conditions.
Some pharmaceutical manufacturers utilize PLLA as the material for drug carriers. Cosmetology companies involve PLLA in the production of the injectable agents are used for noninvasive facial enhancement.
PLLA may be used for food purposes, such as bio-degradable containers for products that do not require lengthy transporting and storing. It’s also suitable for food and beverage primary, sustainable packaging.
PLLA often comes in the form of powder or in blocks of varying sizes. But most users love to grind sub-quality parts to powder with precise particle sizes themselves. For example, to dispose of components. Or to mix PLLA with other biodegradable polymers to get a material with a unique combination of properties.
Issue with Grind with PLLA Material
Grinding PLLA is nothing like turning any other material into powder. The reason is a low glass transition temperature (about 60°C) that doesn’t allow for high-end grinding with mechanical methods. The friction of the material with the cutter simply makes PLLA melt, which is completely unsuitable for high-end grinding.
In most cases, it’s possible to obtain the PLLA pellets from sub-quality PLLA parts. Yet, pellets are unsuitable for mixing with other filaments. Chemical methods for dissolving PLLA and drying the solution till the powder is obtained are also not quite a solution.
How to Grind up PLLA Polymer?
The way to grind PLLA polymer is called low-temperature grinding. Its working principle is cutting the materials under lowered temperatures. This prevents PLLA from melting in the process.
The approach here is complex. First, you should start with pre-cooling and even pre-freezing PLLA-based parts or pellets. Vary the conditions depending on the size of the components and the particle size needed. In the best-case scenario, the temperature of about 5°C of a grounded sample is enough for a process to be executed successfully.
However, you may want to freeze your components below zero, but only if the supplier of your PLLA claims that the raw material will restore its characteristics after temperature stabilizing.
Another good tip is to use cold water to cool your cutter down during the grinding. You may need to stop grinding and cool the cutter down multiple times for the best outcomes.
An unusual but highly effective way to safely cool your PLLA-based parts down and grind them is to add dry ice to the container in which you grind your components. This way helps to lower the temperature of grinding pretty much without any fuss or undesired consequences. Dry ice doesn’t turn into liquid and just vaporizes. It should not affect the characteristics of your parts much.
Yet, you should be aware that dry ice is toxic to a certain extent. Don’t use PLLA powder obtained with the help of it for the production of food containers or similar items.
PLLA is a convenient, biodegradable material that has excellent properties. It suits medical, food, cosmetology, dental, and manufacturing purposes well. However, it’s quite an issue to grind PLLA into powder because of its low melting point.
Yet, you may utilize low temperature grinding techniques to turn sub-quality PLLA parts or pellets into powder with any fraction you desire. Stick with pre-cooling, freezing, water-cooling, or mixing PLLA with dry ice to get high-quality PLLA powder.
As the manufacturer of PLLA, PDLLA material, we have cooperated with many grinding companies. Feel free to contact us if you need PLLA grinding service.