As more and more brands emerge in the food, beverage, and consumer goods space, there has become a greater need for packaging to use new high-quality ink formulations to differentiate brands from one another. Flexible packaging is one area where inks play a pivotal role in the package’s visual appearance and perceived quality. Eastman cellulose esters are the tools necessary for ink formulators to produce top-quality inks for the rapidly expanding flexible packaging market.
What Are Eastman Cellulose Esters?
Eastman cellulose esters encompass cellulose acetate (CA), cellulose acetate butyrate (CAB), and cellulose acetate propionate (CAP) polymers. These polymers are naturally derived organic esters of cellulose that originate from sustainably managed forests. These cellulose esters are soluble in a wide variety of organic solvents and are commonly used as additives, resins, or coresins in coating, ink, and adhesive formulations.
CAB polymers are effective binders in formulations that require excellent color strength and good chemical, weathering, and abrasion resistance. They may also be used as additives to increase flow and leveling properties, promote faster drying of solvents, and reduce blocking. CAP polymers provide many of the same benefits as CABs and are preferred in formulations that require low odor. With these facts in mind, it is clear that Eastman cellulose esters are critical components in printing ink formulations.
Why Should You Use Eastman Cellulose Esters? The Difference Is Clear.
- Better ink adhesion to packaging films
- Excellent cold-crack and heat resistance
- Resistance to grease and chemicals
- Outstanding flow, leveling, and wetting
- Fewer surface defects
- Improved gloss
- Better UV resistance (nonyellowing)
- Excellent pigment orientation
- Faster printing speeds due to quicker solvent release
- Improved blocking performance
- Better intercoat adhesion
Improved Performance
Enhanced Appearance
Increased Productivity
Formulating with Eastman™ Cellulose Esters
Eastman CAB and CAP can be used in inks for a variety of printing technologies, including gravure, flexographic, offset, UV-cure, and inkjet. They are compatible with most common solvents as well as acrylic monomers and provide a much safer option for a let-down vehicle, a coresin, or an additive than traditional nitrocellulose. Many grades of Eastman CAB and CAP comply with the Swiss Ordinance on Materials and Articles in Contact with Food (SR 817.023.21). See the table below for the grades recommended for food-safe printing inks.
| Product | Acetyl Content (wt%) | Butyryl Content (wt%) | Propionyl Content (wt%) | Hydroxyl Content (wt%) | Tg (°C) | Molecular Weight (g/mol) |
|---|---|---|---|---|---|---|
| CAB-381-0.1 | 0.6 | 37.0 | - | 1.3 | 123 | 20,000 |
| CAB-381-0.5 | 13.0 | 38.0 | - | 1.3 | 130 | 30,000 |
| CAB-381-2 | 13.5 | 38.0 | - | 1.3 | 133 | 40,000 |
| CAB-551-0.01 | 13.5 | 53.0 | - | 1.5 | 85 | 16,000 |
| CAB-551-0.2 | 2.0 | 52.0 | - | 1.8 | 101 | 30,000 |
| CAP-482-0.5 | 2.0 | - | 45.0 | 2.6 | 142 | 25,000 |
| CAP-504-0.2 | 2.5 |
-
|
42.5 | 5 | 159 | 15,000 |
Summary
Eastman cellulose esters are necessary components in many high-quality, solvent-based packaging ink formulations. They are a great source for adding sustainably sourced bio-content into inks and provide a host of performance benefits that make printing processes more efficient. CAB and CAP polymers may be used as binders or additives to increase adhesion, leveling, drying time, and resistance to yellowing, chemicals, and abrasion. Click below to request a sample to formulate into your ink system today.
