Plastic

Plastic, also known as synthetic material, is a collective term for a group of synthetic or semi-synthetic materials consisting of polymers. Polymers are large molecules made up of repeating structural units known as monomers. These monomers are bonded together through chemical reactions known as polymerization.

Properties of plastic

Advantages

Diversity: Plastics can be used in a variety of forms and applications, from hard and rigid materials to soft and flexible ones.
Lightweight: Plastics are generally lighter than many other materials such as metal or glass.
Water resistance: Most plastics are water-repellent and do not corrode.
Chemical resistance: Many plastics are resistant to chemicals that could damage other materials.
Electrical insulation: Plastics are often good insulators and are used in many electrical and electronic applications.
Moldability: Plastics can easily be cast, extruded or molded into different shapes and sizes.

Main types of plastics

Chemical observation

Thermoplastics: These plastics can be melted and repeatedly molded when heated. Examples include polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC) and polystyrene (PS).
Thermosets: These plastics are molded once during production and cannot be melted afterwards. Examples include epoxy resins, phenolic resins and melamine resins.
Elastomers: These plastics are elastic and can return to their original shape after being stretched or deformed. Examples are rubber and silicones.

Applications of plastics

Areas of application

Packaging: Bags, bottles, packaging films
Construction: Pipes, insulating materials, window frames
Automotive industry: Bumpers, dashboards, seat covers
Electronics: Housing of devices, cable insulation
Medicine: Syringes, containers, implants
Everyday objects: Toys, household appliances, furniture

Stress cracks

The challenge

Stress cracks in plastics are an important topic in materials science and engineering. They are caused by various factors and can significantly impair the integrity and performance of plastic components. Here are some important points about stress cracking in plastics:

Causes of stress cracks

Mechanical stresses: Excessive mechanical loads that exceed the tensile strength of the material can cause cracks.
Temperature changes: Fluctuations in temperature can lead to thermal stresses that weaken the material.
Chemical influences: Contact with chemicals, such as solvents or oils, can attack the material and lead to cracking.
Moisture absorption: Some plastics tend to absorb moisture, which can affect their mechanical properties.

Types of stress cracks

Crater cracks: These cracks occur on the surface and are often the result of surface defects or damage.
Internal cracks: They form within the material and can be more difficult to recognise. These cracks can spread through the entire cross-section.

Avoidance and control

Choice of material: The selection of suitable plastics that are resistant to stress cracking is crucial. Polypropylene (PP) and polyethylene (PE) are often resistant to stress cracking.
Processing: The right processing techniques (e.g. tempering, suitable cooling rates) can help to minimise stresses in the material.
Surface treatment: Coatings or surface treatments can increase resistance to chemical influences and reduce stress cracks.

Testing and inspection

Visual inspection: Regular visual inspections can help to recognise early signs of stress cracks.
Non-destructive test methods: Methods such as ultrasound or X-rays can be used to identify internal cracks.

Economic impact

Stress cracks can lead to failures in the application, resulting in high costs for maintenance, repair or replacement of components. It is therefore important to consider the risks of stress cracks when designing and manufacturing plastic parts.

Plastics industry

Description

The plastics industry is known worldwide for its technological excellence, innovative strength and sustainability efforts. The use of software in production plays a crucial role in optimizing processes while integrating new technologies that increase efficiency, reduce environmental impact and cut costs.

The requirements in plastics processing are as diverse as the product range. In this respect, planning, control, logistics and production pose a major challenge. tetys has developed a competent solution that provides you with a high level of transparency at all times regarding resources used, deadlines, customer and quality requirements.

Production of plastic

Efficiency through the use of software

The manufacture of plastics requires precise process control and smooth production. Production software - such as our tetys MES - enables companies to monitor, control and optimize every step of the manufacturing process. From material procurement to final production, the software enables seamless integration and automation, leading to increased efficiency, reduced production costs and improved product quality.

Examples from practice

Some of our customers come to us with similar challenges, such as "just-in-time" reporting and documentation of all departments in production with a focus on complete coverage of all processes:

Downtimes, rejects, feedback of order data to SAP, real-time reporting of machines and work areas, traceability of process data, bottleneck analysis of personnel, material and tools and BOM resolution with automatic scheduling - our software can handle all of this. With the help of the tetys system, including the PEP, CAQ and TPM modules, we provide a running system that allows customers to plan their orders in the system on a daily basis, reports all relevant order data back to SAP and generates automatic quality reports and reports for management.

Environmental aspects

Plastics are problematic when it comes to the environment due to their durability and resistance to degradation. They contribute significantly to pollution, especially in the form of microplastics in the oceans and landfills. However, there are increasing efforts to develop recyclable plastics and improve recycling rates, as well as to promote bio-based plastics that are biodegradable.

Shaping the future

Increasing product complexity and decreasing batch sizes mean that all companies need increasing transparency. In the processing of plastics, the high degree of automation and ever thinner staffing levels are forcing digital processes and solutions. Digital orders, paperless production, fully integrated quality assurance and centralized settings data management create completely transparent production. And are the next steps towards highly efficient production.

The company tetys supplies a Manufacturing Execution System (MES) software solution for analysing and optimizing injection moulding processes. The individual processes are mapped and optimized in the tetys software.

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