Lapol was founded in 2007 to meet the need of enabling PLA to be utilized in as many applications as possible. The shortcomings of the PLA polymer are that it is inherently brittle and has a low use of temperature, thereby limiting its breadth of applications. As such, we developed Lapol, a renewable biopolymer resin technology company and innovator of the revolutionary US patented Lapol bioplasticizer and the patented Lapol® HDT-P, or heat deflection temperature additive. Lapol sells its resins to polymer compounding and converter companies to enable the use of all bioplastics. We also can provide guidance for application specific compounded resins to end user converting companies that seek biodegradable/compostable and renewable/sustainable polymer applications for products such as: containers, food service disposables, electronic components, credit cards, toys and a variety of other products that are injection molded, thermoformed, blow molded, extrusion coated or extrusion cast films.
Product and Technology
The Lapol patented technologies are based on the unique polymerization of lactic acid and other monomers to specifically blend with poly lactic acid (PLA) and traditional petroleum derived polyolefins. Polymerization of Lapol® 108 uses like polymers thereby negating the need for additional costly compatibilizers. The resulting products have increased pliability while maintaining modulus (stiffness) and only slight reductions in Tg. The Lapol® HDT-P grade was developed to enable PLA to have both flexibility and toughness with higher end use temperatures so that it can be shipped worldwide in hot climates and meet the elevated use temperature requirements for food service and durable goods applications such as automotive and electronics. Both Lapol® 108 and HDT-P have been designed to be biodegradable and compostable, renewable and sustainable, high performing and cost-competitive. The performance of Lapol® HDT-P is unmatched in the marketplace wherein there is neither distortion nor deflection at use temperatures exceeding 125 ºC.
Marketplace
When biopolymers were first introduced to the marketplace in the mid-90's, the raw materials costs for petroleum-based polymers were as low as $0.25-$0.50/lb. and biopolymers were in their infancy with costs ranging from $2.50-$10.00/lb. Since the middle 90's, the biopolymer industry has steadily grown 20-30% each year and the resins have been further commercialized and brought to market at more reasonable costs ranging from $0.75-$2.50/lb., while oil prices have surged and plunged and are likely to surge again the traditional petroleum-based polymers have ranged from $0.40-$1.25/lb. With this change in cost structure and appropriate cost reduction minerals, the biopolymers have become more competitive and economical to traditional petroleum-based non-degradable polymers.
Although biopolymers have become more cost effective, they typically do not perform well on their own; rather, they must be modified and compounded with plasticizers to reach sufficient fitness for use properties to compete with both neat and compounded petroleum-based resins. Polylactic acid (PLA) has high rigidity and is unsuitable for applications that require high heat deflection, flexibility and toughness. The most common technique to make PLA flexible is to add a plasticizer or to compound in more flexible polymers. Secondly, the temperature profiles are limited and usually only slightly increased with the use of minerals for moderate improvements of about 5 ºC. Rather, Lapol forumulated compounds using the Lapol® HDT-P additive, the use temperature improvements are increased by an order of magnitude to a 50ºC improvement. When PLA is crystallized, these temperature improvements can also be realized, yet the parts distort and are not usable. With the addtion of Lapol® HDT-P, the parts do not warp or distort and will maintain their form stability with sufficient toughness and flexibility.
The current global capacity of the major producers of PLA is 150,000-300,000 tons in the United States and other companies in Asia and Europe. The PLA from these plants need to be modified for heat deflection temperature and toughness to be able to be used and shipped in a variety of applications, such applications include:
Injection Molding: cups, plates, bowls, trays, cutlery, straws, bottles, electronics and automotive components, toys, etc.
Extrusion coated paper: cold cups, hot cups, food wraps, deli paper, butcher paper, etc.
Thermoforming and Blow Molding: packaging products, bottles, trays, plates, bowls and other shallow draw products
Extrusion and cast film: bags and agricultural films.
Each of the products listed above require different loadings of Lapol to achieve certain properties that can range from 5% - 20% loading of Lapol® HDT-P (of the PLA fraction only, not the entire compound).
Lapol® HDT-P Properties
Lapol® HDT-P is a thermoplastic resin that increases the heat distortion temperature and improves the crystallization rate of PLA-based resins. NatureWorks Ingeo™ Biopolymer 2000, 3000, 4000, and 6000 series all show improved heat distortion temperatures with the addition of Lapol® HDT-P.
Table 1 shows some of the physical properties of Lapol® HDT-P. Drying prior to processing is essential. The polymer is stable in the molten state, with very little to no out-gassing, provided that the drying procedures and extrusion procedures are followed. The resinis available as a white pellet.
Table 1. Physical Properties of Lapol® HDT-P
Properties
Lapol® HDT-P
Color
White to off white
Density
1.20 - 1.30 g/cc
Physical State
Pellet
Melting Point
110 – 125 °C
170 - 180 °C
Compounding
Lapol® HDT-P resin processes on conventional plastics compounding equipment with minimal modifications. The resin is stable and processes at medium speeds. Drying procedures must be followed to ensure proper processing and plasticity of the polymer. The following recommended processing temperatures may be adjusted for certain processes, but processing above 220 °C (428 °F) will likely result in degradation and will compromise properties. Process optimization in specific equipment may require technical support from Lapol, LLC.
Note: The chart shown below is for a 20% Lapol® HDT-P and 80% NatureWorks 3001D PLA compound run on a twin-screw extruder. Temperatures are provided as a guideline and may need to be adjusted according to the specific equipment and Lapol® HDT-P loading percentage.
Table 2. Compounding Parameters of Lapol® HDT-P
Processing Parameters
Settings
Feed Throat
145° - 155 °C / 293° - 311 °F
Feed Temperature
155° – 165°C / 311° – 329 °F
Melt Temperature
160° - 195°C / 320° – 383 °F
Die
165° – 180°C / 329° – 356 °F
Screw Speed
30 – 150 rpm
Back Pressure
No higher than 700 psi
Injection Molding
Lapol® HDT-P resin processes on conventional injection molding equipment with minimal modifications. The resin is stable and processes at medium speeds. Drying procedures must be followed to ensure proper processing and plasticity of the polymer. The following recommended processing temperatures may be adjusted for certain processes, but processing above 220 °C (428 °F) will likely result in degradation and will compromise properties. Process optimization in specific equipment may require technical support from Lapol, LLC.
Note: It is important not to allow the blends to remain in the barrel of the for extended periods of time. The chart shown below is for a 20% Lapol® HDT-P and 80% NatureWorks 3001D PLA dry blend; processing parameters and results may differ with pre-compounded Lapol® HDT-P and PLA. Temperatures are provided as a guideline and may need to be adjusted according to the specific equipment and Lapol® HDT-P loading percentage.
Table 3. Injection Molding Parameters of Lapol® HDT-P
Processing Parameters
Settings
Melt Temperature
170° - 180 °C / 338° - 356 °F
Mold Temperature
50° – 110 °C / 122° – 230°F
Mold Residence Time
5-30
Back Pressure
No higher than 400 psi
Screw Speed
Moderate
Thermoforming
Lapol® HDT-P resin processes on conventional thermoforming equipment with minimal modifications. The resin is stable and processes at medium speeds. Drying procedures must be followed to ensure proper processing and plasticity of the polymer. The following recommended processing temperatures may be adjusted for certain processes, but processing above 220 °C (428 °F) will likely result in degradation and will compromise properties. Process optimization in specific equipment may require technical support from Lapol, LLC.
Note: It is important not to allow the blends to remain in the extruder for extended periods of time. When processing Lapol® HDT the sheet temperature should be 80 - 120 °C, otherwise, follow the guidelines for processing INGEO™ PLA polymers. Processing parameters and results may differ with pre-compounded Lapol® HDT-P and PLA prior to thermoforming. Temperatures are provided as a guideline and may need to be adjusted according to the specific equipment and Lapol® HDT-P loading percentage.
The Lapol® 108 bioplasticizer is principally sold based on the following properties:
Biodegradability/Compostability (ASTM D6400, EN 13432 & ISO 17088 compliance)
Renewability/Sustainability (predominantly derived from plant sources)
Compatibility and miscible (no need for additional compatibilizers during compounding)
Flexibility without compromising stiffness
Clarity (little clarity reduction of PLA)
Maintains melt strength for high mineral content loading in PLA
Typical Physical Properties of Compounded Lapol® 108 in PLA
Lapol® 108 resin compounded into NatureWorks 4042D
(biaxially oriented film – general purpose grade) polylactic acid at 0.5 mm thick films.
Physical Property
ASTM Test
5% Lapol in PLA
10% Lapol in PLA
Elongation @ Break
D 638
60%-100%
80%-160%
Tensile Stress @ Yield MPa
D 638
77-84
57-59
Tensile Modulus MPa
D 638
2160-2313
1700-1786
Specific Gravity
D 1505
1.25 g/cc
1.25/g/cc
Melt Flow Index @ 190⁰C at 2.15kg
D 1238
3-4 g/10 min.
9-11 g/10 min.
It is recommended that Lapol® 108 be added according to the properties that are desired for the particular application. Typical applications require between 5% and 10% Lapol® 108 bioplasticizer. Note that 50%-75% less Lapol® 108 is required to achieve >100% elongation when compared to 100% petroleum based aliphatic aromatic copolyesters.
Intellectual Property
Lapol has a two United States granted patents and two United States patents pending for Lapol® 108 bioplasticizer, Lapol® HDT-P and biopolastic cardstock applications.
