Renprene ® TPE K300-Z is a series of grades developed by Meite for EPDM sealing tape joints. eliminates defects that material in corner area is easily compressed and small edge is not firmly bonded, and maintains stability of adhesive strength.
More materials are now being used in corners of EPDM sealing tape. One is German company A and other is Japanese company J. The specific comparison data between Mete and them is as follows:
Import a specific A
Import a specific J
ASTM D 2240
The strength of connection
No cracks, no bleaching
No cracks, no bleaching
Without cracks and whiteness
Note. The above data is from Meite Lab, excluding climate change data.
Based on data above, shrinkage data of K365B-Z is very close to imported material A, but in actual use by customer, it is found that shrinkage grade of K365B-Z is better than that of material. imported material A. The customer has used imported material in past. For a certain A, a certain proportion of foam masterbatch must also be mixed outside.
How can Meite's research engineers reduce shrinkage? How about higher bond strength?
In injection molding process, it is necessary to melt thermoplastic elastomer material at high temperature, and then screw of injection molding machine injects thermoplastic elastomer melt into mold cavity under a certain pressure, and then cools and molds it for a period of time. During this process In process of cooling, thermoplastic elastomer material shrinks, which is an inherent characteristic of material. Our method is to reduce shrinkage rate of material. The usual solution is to reduce amount of filling oil and increase filler, but reducing filler will increase hardness, and increasing filler will increase hardness. Adhesion strength decreases , so this is a tricky moment, and usually only balance can be achieved.
However, by optimizing two-loop structure of TPE-S, Meite R&D engineers have increased entanglement of molecules, which reduces ability of molecules to move freely throughout system. Thus, shrinkage rate of material is reduced without affecting bond strength. As a rule, shrinkage ratio of K300-Z is 50% of shrinkage of domestic counterparts. If corner position is not very thick, it is usually no longer necessary to mix external foaming masterbatch to reduce shrinkage marks.
The improvement in bond strength depends on whether continuous phase of system is compatible with thermosetting EPDM molecules on one hand, and on other hand depends on whether continuous phase of system can penetrate thermosetting EPDM PoeMeite R&D engineers The viscosity builder/lubrication system is optimized to ensure that K300-Z is fully impregnated with EPDM.
As for adhesion strength and stability of small edge of sealing tape, it is related to rheological properties and uniformity of material, which is related to main raw material polyolefin, styrene elastomer, paraffin oil. Quality as well as dispersion and distribution capabilities of a twin screw extruder.
Meite implements strict quality control in terms of raw material characteristics. Even world's leading material suppliers conduct lab tests on batches to determine if they can be used. In mixing modification process, process stability (temperature, host speed, feed rate) is ensured, and twin screw screw combination is optimized to meet high dispersion and distribution requirements.
Hope that Meite's K300-Z series innovative gusset material can provide our partners with more reliable quality to win respect of OEM customers!