If a company wishes to remain competitive, it must work with its laboratory technicians to ensure it maintains the highest of quality control through precise testing. One way of doing so is to employ the melt flow index tester. A relatively simple test, it nevertheless performs its intended function efficiently and effectively. Only the sophistication of the method has changed since its introduction in the 1950s. Automation and computerization of the process has decreased the reliance on operators exclusively. The result is an improvement in both the accuracy and repeatability of the results.
First Choice for Certain Industries
When it comes to outfitting the lab with the proper and most effective instrumentation, those in the plastic industry are likely to consider a melt indexer among the top of their selection list. This is true when the plastics involved are compounders, extruders and/or molders. This device is actually an extrusion plastometer. Its purpose is simple: to determine the mass or melt-flow rate (MFR) of thermoplastic resins. The resins may be a compound or virgin form.
Discovering the MFR is important for several reasons. It:
- Evaluates material as it enters the plant
- Tests finished products
- Helps companies with quality control by allowing direct comparison between materials
Just as important, the use of MFR testing indicates the company’s willingness to meet ISO 9000 standards concerning quality management
Melt Flow Test Quality Standards
The melt flow index tester helps with the implementation of quality control. In its ability to aid a company in this aspect, it puts the company’s production in line with the quality standards of the industry specified in ASTM D1238 and ISO 1133 standards. These detailed and provide specifications indicate how to comply. They note the need to measure one point of the viscosity (thickness) curve under the designated standard conditions.
The multi flow index (MFI) tester does specifically measure the melt flow viscosity (flow resistance). It takes these measurements of the polymer at a specific shear stress and temperature. It helps clearly distinguish between short length polymers of simple geometry and long chain ones of high molecular weight easily.
Common Materials Tested
The most common type of material tested using the MFI for analysis for their melt flow rate (MFR) and melt volume rate are the following thermoplastics:
- Nylon (Polyamide)
- Polycarbonate
- Polyester
- Polyethylene
- Polypropylene
- Polystyrene
These are the ones most commonly subjected to an MFI test.
The Melt Flow Index Tester
The MFR serves several purposes. Its most common application is as a means of determining whether a material meets the specifications for a product or component. However, it is also capable of delivering information helpful in other related areas. As a means of ensuring quality control and providing an accurate comparison between similar resins from diverse vendors, it is hard to argue against the accurate findings of the melt flow index tester.