Zwick is concentrating its activities in the plastics field through its own competence center. The “Plastics Testing Initiative” has been underway for two years, and the range of products for testing plastics is being systematically expanded within the framework of this initiative.
The Mflow from Zwick used for MFR determination.
Helmut Fahrenholz, who heads the competence center, is expecting the plastics market to continue its strong development. “The particular material characteristics, numerous design possibilities, and cost-effective processing continually allow new product innovations which are not possible using other materials. Material characterization plays an important role in development as well as quality assurance. Examples of promising markets are the construction industry, electronics, automotive, packaging, and medical technology.”
As Zwick is already strongly established in the plastics industry with its static testing systems, the goal of the initiative is to further expand the product range. Zwick will now cover the measurement of mechanical characteristics as well as thermal and rheological characteristics in accordance with the basic values stored in CAMPUS®. Testers will carry out static, creep, pendulum impact, drop impact, and high speed tests, as well as extrusion and hardness testers and HDT/Vicat machines.
As the world market leader in robotic material and component testing, Zwick has more than 20 years of experience in developing solutions for customers around the world.
Determination of the Melt Index Value
The Mflow (Modular Flow) is a plastometer which in its basic version covers all tests in accordance with process A (MFR determination) of the ISO and ASTM standards. By adding a displacement sensor, the Mflow can be upgraded to measure the MFR in accordance with process B. An optional weight lift unit allows the machine to be operated entirely automatically. A significant advantage of the machine is the constant temperature in the extrusion barrel, which meets the requirements of the draft ISO/CD 1133-2 standard (moisture sensitive and time-dependent materials). The Adaptive Parameter Configuration (APC) system is a unique innovation which enables the tester to automatically select test parameters to optimize measurement precision. The automatic detection and elimination of the effects of air bubbles in the material guarantees reliable and meaningful results.
Determining MFR
The Cflow is based on the Mflow concept, but is designed solely for the simple determination of the MFR. It is designed to be cost effective but cannot be upgraded to the same degree as the Mflow. The temperature control system meets the high requirements of the current draft for ISO/CD 1133-2. An automatic cutting unit for the extrudate improves the precision when measuring higher MFR values, and a laboratory scale is required to calculate the result.
The latest developments in Pendulum Impact Testers
Zwick introduced new HIT series of pendulum impact testers in 2005 and 2006 with impact energy ranges of 5.5 Joule, 25 Joule, and 50 Joule, and has already been very successful in the global market. A new compact 5 Joule ISO machine with an extremely compact construction has been developed for Charpy and impact tensile testing. This is achieved by using short ISO pendulum hammers and restricting the measurement range. The tester possesses the same advantages as the larger machines, and uses the low-vibration, double-rod carbon pendulum, which features very high rigidity in the impact direction and a high concentration of the mass at the point of impact. The automatic pendulum recognition (APR) system means that the test results are traceable even if different pendulums are used. Additional advantages are the slip-proof tool fixtures with dovetail guides and a convenient USB interface for connecting to the testXpert® II software.
The larger pendulum impact testers were also improved and Zwick has added a new motorized pendulum lifting unit together with a new CE-conforming protective shielding. This increases the operating convenience significantly especially for the large 25 or 50 Joule pendulum hammers. In addition, the motorization is an important precondition for the automation of the impact tests.
Drop Impact Tester
Zwick recently introduced its new HIT230F instrumented drop impact tester for multi-axis penetration tests and compression-after-impact tests.
This machine is optimized especially for the requirements of penetration tests, e.g., in accordance with ISO6603-2 and ASTM D3763. The drop impact tester is equipped with a low-noise characteristic piezo force sensor. The sensor is located very close to the impact point to minimize the effects of the mechanical vibrations found in other instruments. An innovative pneumatic specimen gripping system allows the insertion and impacting of specimens in less than 5 seconds, and in many applications it is possible to avoid the installation of an expensive temperature chamber. The testing area is outside of the protective shielding and is easily accessible by the operator - but still optimally secured. An optional spring pre-load is available for additional acceleration to increase the impact speed.
The drop impact tester can also be used to initiate mechanical damage to long fiber-reinforced composites for the compression-after-impact (CAI) test. Additional tooling is available for this purpose. The compression test for determining the influence of the damage on the compressive strength is then performed on a static testing machine.