Bioplastics and Biodegradable Materials in Injection Molding - Guide 2025

Introduction to bioplastics in injection molding

Bioplastics represent a revolutionary solution in the plastics processing industry, enabling the production of ecological components through injection molding technology. In the era of growing environmental awareness and strict environmental regulations, biodegradable materials are gaining increasing popularity among manufacturers seeking sustainable alternatives to traditional plastics.

In this guide, we will present comprehensive information about injection molding bioplastics, their types, technical properties and applications in modern production. Whether you're just starting your adventure with sustainable materials or looking for advanced solutions for the bio-packaging industry, this article will provide you with essential knowledge about the future of injection molding.

What are bioplastics and biodegradable materials?

Bioplastics are advanced polymer materials that serve as an alternative to traditional petroleum-based plastics. Depending on their origin and properties, they can be divided into three main categories: bio-based, biodegradable and compostable, although often these materials combine several of these properties.

The technology of injection molding bioplastics is characterized by specific process requirements related to the thermal sensitivity of materials and the need to preserve their biological properties. Modern injection machines for bioplastics are equipped with advanced temperature and humidity control systems that ensure optimal processing conditions and maximum quality of final products.

History of bioplastics development

The history of bioplastics dates back to the beginning of the 20th century and is closely tied to the development of the chemical industry and growing environmental problems. Below we present key moments in the evolution of this technology:

• 1920-1940s - Discovery of polylactide (PLA) by Wallace Carothers in DuPont laboratories, forming the basis for future bioplastics
• 1950-1960s - First attempts at commercialization of biodegradable materials based on cellulose and starch
• 1970-1980s - Development of fermentation technologies for lactic acid production for PLA
• 1990-2000s - Commercialization of PLA by Cargill and introduction of the first bioplastics to the market
• 2000-2010s - Development of biodegradation standards (EN 13432) and growing popularity of bio-packaging
• 2010-2020s - Investments in PHA and TPS technologies, development of the bioplastics market worth $2.11 billion
• Currently - Integration with Industry 4.0 technologies, development of intelligent materials and market growth to $6.3 billion by 2025

Types of bioplastics and biodegradable materials

The modern market offers various types of injection molding bioplastics, differing in mechanical properties, production costs and degree of biodegradability. The choice of the appropriate type depends on the specifics of the application, environmental requirements and production costs.

Bio-based bioplastics

Bio-based bioplastics use plant or animal-derived raw materials to produce polymers that can be both biodegradable and durable. These are the most commonly used materials in industry, especially in applications requiring high mechanical strength.

Advantages of bio-based bioplastics:

• Reduction of CO2 emissions - using renewable raw materials reduces carbon footprint by 50-70%
• Independence from oil prices - stable raw material prices independent of oil market fluctuations
• High surface quality - excellent optical and mechanical properties
• Compatibility with existing machines - possibility to use standard injection machines
• Wide range of applications - from packaging to technical components
• Recycling possibility - some bio-based materials can be reprocessed multiple times

Disadvantages of bio-based bioplastics:

• High production costs - price 20-50% higher than traditional plastics
• Limited raw material availability - dependence on weather conditions and cultivation areas
• Moisture sensitivity - need for special storage and drying
• Property variability - differences in quality depending on batch of raw materials

Biodegradable bioplastics

Biodegradable bioplastics are materials that decompose under the influence of microorganisms in the natural environment. The decomposition process can take from several weeks to several years, depending on environmental conditions and material type.

Advantages of biodegradable bioplastics:

• Complete environmental decomposition - no toxic residues after biodegradation
• Reduction of plastic waste - solution to environmental pollution problems
• Possibility of home composting - some materials decompose under home conditions
• Compliance with environmental regulations - meeting EU Directive 2019/904 requirements
• High barrier properties - some materials provide excellent product protection
• Thermoplasticity - possibility of multiple reprocessing

Disadvantages of biodegradable bioplastics:

• Sensitivity to environmental conditions - biodegradation requires specific conditions
• Higher costs - price 30-80% higher than conventional materials
• Limited durability - shorter shelf life of products
• Identification problem - difficulties in waste sorting

Compostable bioplastics

Compostable bioplastics combine biodegradation properties with the possibility of composting in industrial or home conditions. These are the most ecological materials that completely decompose into organic substances.

Advantages of compostable bioplastics:

• Closed material cycle - materials return to the organic cycle
• Rapid biodegradation - decomposition in 3-6 months under appropriate conditions
• Environmental safety - no toxic decomposition products
• Organic recycling possibility - use as fertilizer or substrate
• Certification - compliance with EN 13432 and ASTM D6400 standards

Structure and main elements of bioplastics

Each bioplastic consists of polymer chains of specific molecular structure, functional additives and stabilizers that ensure appropriate processing properties and end-use characteristics. Understanding the structure and function of individual elements is key to the effective use of biodegradable materials.

Molecular structure

The molecular structure is responsible for the basic properties of bioplastics and determines the processing conditions. It consists of the following elements:

• Polymer chains - basic structure built from monomers of natural origin
• Functional groups - responsible for biological and degradation properties
• Hydrogen bonds - influence mechanical and thermal properties
• Biodegradation additives - accelerate the decomposition process in the environment
• Thermal stabilizers - protect against thermal degradation during processing

The process in bioplastics proceeds in stages: water absorption, bond hydrolysis, microorganism metabolism, and then mineralization to CO2 and water.

Physical and mechanical properties

Physical and mechanical properties of bioplastics determine their behavior during injection molding and end use. The main elements include:

• Density - affects material costs and product properties (1.2-1.4 g/cm³)
• Melting temperature - determines processing conditions (150-200°C)
• Young's modulus - material stiffness (2-4 GPa)
• Tensile strength - mechanical resistance (40-70 MPa)
• Impact strength - resistance to damage
• Water vapor permeability - barrier properties

Key technical parameters of bioplastics

When choosing bioplastics, one should pay attention to several key technical parameters:

1. Processing temperature (°C)

This is the range of temperatures in which the material can be safely processed. Typically from 160°C to 220°C. The temperature must be adapted to the polymer type and avoid thermal degradation that could reduce the biological properties of the material.

2. Material moisture (%)

The maximum permissible moisture before processing. Should be lower than 0.05% for most bioplastics. Excessive moisture causes surface quality problems and mechanical properties.

3. Drying time (hours)

The time necessary to remove moisture before processing. Typically 4-6 hours at 80-100°C. Improper drying can lead to material degradation and quality problems.

4. Injection speed (cm³/s)

The optimal injection speed for a given material. Depends on melt viscosity and mold geometry. Too high speed may cause thermal degradation.

5. Injection pressure (MPa)

The maximum pressure needed to fill the mold. Typically 80-120 MPa for bioplastics. Higher pressure may be necessary for materials with high viscosity.

6. Mold temperature (°C)

The mold temperature affecting crystallization and surface properties. Typically 40-80°C. Appropriate temperature ensures good surface quality and minimizes internal stresses.

7. Cycle time (seconds)

The total time of one production cycle. Depends on wall thickness and cooling conditions. Shorter cycle time increases production efficiency.

Applications of bioplastics in industry

Injection molding bioplastics find application in virtually every branch of modern industry. Their versatility and ecological properties make them indispensable for sustainable production.

Packaging and bio-packaging

In the packaging industry, bioplastics are used for the production of disposable ecological packaging. Requirements: high barrier properties, aesthetic appearance, thermal properties. Typical products: cups, plates, cutlery, stretch films.

Agriculture and horticulture

The agricultural sector requires materials resistant to weather conditions and biodegradable. Injection molding bioplastics are used in the production of pots, mulch, plant covers. Key aspects: mechanical strength, UV resistance, rapid biodegradability.

Medical and pharmaceutical

The medical industry requires the highest purity and safety of materials. Biodegradable bioplastics are used in the production of surgical sutures, temporary implants, pharmaceutical packaging. Special requirements: biocompatibility, sterility, medical certifications.

Household appliances

The household appliances sector uses bioplastics for the production of ecological components. Examples: toothbrushes, battery packaging, toys for children. Trend: growing popularity of "green" products.

Electronics and technical components

In electronics, bioplastics are used for the production of device housings, battery packaging, assembly components. Requirements: electrical insulation properties, dimensional stability, ease of processing.

How to choose the right bioplastics?

Choosing the right bioplastic requires analysis of many factors. Below we present key criteria that will help you make the optimal decision:

1. Environmental requirements

• Degree of biodegradability required by the target market
• Environmental certificates (EN 13432, ASTM D6400)
• Possibility of recycling or composting
• Carbon footprint throughout the life cycle

2. Production costs

• Material price compared to traditional plastics
• Processing costs (drying, special equipment)
• Production efficiency and cycle time
• Waste disposal costs

3. Technical properties

• Mechanical requirements (strength, stiffness)
• Thermal properties (operating temperature range)
• Optical properties (transparency, color)
• Chemical resistance and barrier properties

4. Certificates and standards

• Compliance with EU regulations (REACH, RoHS)
• Food safety certificates (FDA, EFSA)
• Biodegradation and compostability standards
• Sustainable development certificates

5. Availability and support

• Material availability in the Polish market
• Technical support from the supplier
• Availability of processing documentation
• Possibility of testing and samples

Maintenance and servicing when working with bioplastics

Proper maintenance when working with bioplastics is key to ensuring long machine life, production reliability and optimal product quality. The specifics of biodegradable materials require special attention during cleaning and maintenance.

Daily activities:

• Control of material moisture before processing (recommended <0.05%)
• Checking injection machine thermal parameters (cylinder temperature, mold)
• Control of drying system (temperature, cycle time)
• Cleaning the injection nozzle of material residues
• Verification of safety system operation

Weekly:

• Control of screw and cylinder condition for degradation signs
• Cleaning of air filters and ventilation systems
• Checking calibration of temperature and pressure sensors
• Testing alarm systems and safety
• Cleaning the work area of dust and contaminants

Monthly:

• Replacing filters in the granulate drying system
• Control of hydraulic connections and seals
• Calibration of all measurement systems
• Testing cooling system performance
• Updating control software (if available)
• Control of safety system efficiency

Annual (major inspection):

• Complete replacement of hydraulic oil (approx. 200l)
• Control of all heating elements condition
• Replacement of all main seals and gaskets
• Recalibration of all measurement systems
• Safety control by authorized personnel
• Inspection and modernization of control systems
• Replacement of filters and consumable elements

Consumable parts requiring regular replacement:

• Dryer filters - every 3-6 months or after 500 operating hours
• Injection machine screw - every 2000-5000 hours depending on material
• Heating cylinders - every 12 months or upon efficiency drop
• Seals and rings - every 6-12 months
• Hydraulic filters - every 3 months

Summary

Bioplastics constitute a fundamental technology in sustainable plastics processing industry, enabling the production of ecological components through injection molding. From bio-packaging to medical components, biodegradable materials play a key role in modern environmentally-friendly production.

Key conclusions from the guide:

• Market development - growth of bioplastics market value to $6.3 billion by 2025
• Three categories - bio-based, biodegradable and compostable - each with unique properties
• Condition sensitivity - need for strict moisture and temperature control
• Universal applications - from packaging to technical and medical components
• Technical challenges - higher costs and processing requirements
• Environmental regulations - compliance with EU directives and biodegradation standards
• Sustainable future - bioplastics as a response to the ecological crisis

The bioplastics market is developing dynamically, driven by growing environmental awareness of consumers and strict environmental regulations. The choice of appropriate materials and processing technologies becomes a key element of business strategy in the plastics industry.

If you are looking for solutions in the field of injection molding bioplastics or want to modernize your production towards sustainability, contact TEDESolutions experts. As an authorized Tederic partner, we offer comprehensive technical consulting, the latest machines and full service support.

See also our articles on sustainable production and ecology, plastics processing guide and engineering materials selection guide.