The choice of materials plays a central role, even a small mistake can lead to increased costs or failure of the component and the equipment.
The material selection should bring following benefits:
- know-how acquisition
- more reliability
- more safety
- longer working life
- cut incidental damages
- lower cost of the component
- less maintenance
- weight loss
- less maintenance
and should also avoid:
- greater workload
- dealing with new materials
- redesign due to new materials (tools, injection moulding tools, production planning, etc.).
To best schematise the concepts to be considered in a proper material selection, we have decided to make use of a chart, classifying in 7 levels / procedures (from 0 to 6) how the material selection can be done, specifying what are the disadvantages of one rather than the advantages of the other.
The points found in this table are first attributed on basis of the selected parameters and then added together, thus indicating the minimum level of choice required for the material selection.
Obviously, the indicated values are to be understood as an example. These values are subject to variations in relation to companies, industrial fields, etc.. Each company should adapt the values to its own needs.
Although this method have allowed us to travel a long & successful way to the present days, it does not have the presumption to solve all the problems or to indicate the most correct way to go. This method only wants to indicate the steps, which according to our point of view, are to be followed in the material selection and / or in the design of the component.
Description of the individual material selection levels
Classic example, unfortunately still very popular, I try and then I see what happen. If we analyse the time used and the final price of the parts, it can be noted that it is not worth proceeding following this method.
If we analyse the topicality of knowledge and the improvements obtained, we see respectively that the first criterion is very old and the second one does not lead to any improvement.
If we analyse this level, we can see that it is really possible to obtain a high quality solution but in most cases the reference example cannot be used and the final price of the parts, added to the time needed and the costs incurred are very high.
The risk of failure is high and there is a risk of not considering the values of the materials that are truly important for the specific application.
From this level onwards we begin to have the first advantages. The risk of failure starts to drop and at the same time there is a saving on the final price of the parts.
The risk of failure and the final price of the parts is further lowered and at the same time a high price optimisation and efficiency are obtained.
It is the highest level of material selection. Optimal price and efficiency optimisation of the parts is obtained, reducing the final price of the parts. The customer’s time investment is reduced to a minimum since corporate Wolf will perform all the estimates required for the correct selection.
Example for plastic materials
If the sum is > 6 then the suggested minimum level of the material selection is 6.
For the material selection are available various options:
Send us a sampling request
Here you will find some application examples of the ZEDEX® materials sorted by application.
Relative material comparison
The chart will give you an overview of the properties of ZEDEX® materials in comparison to standard materials.
Specific material comparison
Compare the material properties in terms of stress, deformation, flexural modulus, permissible PV value, expansion coefficient, impact strength, wear and friction.
Consults from our experts
With us you have a contact person for all cases.
We have developed questionnaires for certain applications. Please consider: The more precise your information is, the better our proposal.
Relative material comparison
For material selection and comparing ZEDEX® engineering & high-performance polymers with standard polymers. The highest number means the best quality, the lowest the worst. (1 = bad, 10 = very good)
Thermal limits of use
All polymers react to changes in temperature with strong changes in properties. The property changes are relatively small up to the glass transition temperature.
If polymers are used above their glass transition temperature, the changes in properties must be taken into account when selecting the material. If the glass transition temperature is exceeded by 20%, the properties can reduced by 80%. The properties of the material determined at 20°C therefore lose their validity.
… may be allowed for a short time, but is likely to start changing properties. The duration depends on the operating conditions (e.g. atmosphere) and can vary from 3 to max. 100 hours.
Continuous use temperature
… or according to UL 476B Relative Temperature Index (RTI) represents a material property. It depends on the thermo-oxidative stability of the plastic. If exceeded for a long time, the plastic reacts with strong changes in properties, e.g. colour change, embrittlement up to complete destruction.
This also happens without the influence of external factors such as surface pressure, friction, chemicals etc.
Glass transition temperature
… is the temperature at which the amorphous structural areas of the polymer lose their strength. The mechanical properties of amorphous polymers drop sharply. In the case of semi-crystalline polymers, only the crystalline part of the structure forms a bond. If the temperature increases further, the crystalline areas also lose their firm bond and the properties decrease drastically.
Core properties overview
Quick material selection can also be based on the core properties of the material. However, this table has been published to give a general overview of the ZEDEX® materials and to allow a skimming upstream of the materials that are not suitable for the application studied.
It is advisable to continue the selection of the appropriate material with the other tools described on this webpage.
|~||applies to a limited extent (FOOD: test on going)|
|–||does not apply|
|N/A||FOOD: not been tested yet|