Dear Angela,
Thanks for your kind reply. I visited COCO-LATEX around 2001 and it doesn’t surprise me they burned down. Microwave (ata that time they use it for drying) is a dangerous tool, if you don’t know how to control it.
Some basics on the subject of DUNLOP vs. TALALAY (from another text of mine):
There were times when there were clear differences between these foams. This was based on the different manufacturing processes, in particular the 2 additional and one modified step in the TALALAY process. Firstly, these are pumping out the remaining air after (partially) filling the mold in order to fill it completely and secondly, the subsequent freezing of the foam with the mold to around minus 22 degrees Celsius. The third and modified step concerns the gelling, which is carried out in TALALAY foam by introducing carbon dioxide into the frozen foam. In DUNLOP foam, a gelling agent is mixed in immediately before the molds are filled.
DUNLOP foam (in the past) was used to be produced in batches with large HOBART mixers. The uniformity in terms of density was a matter of luck and/or the task of the responsible employee. The foam structure was inhomogeneous, there were many large bubbles that naturally wanted to come to the surface. The dispersions were produced using ball mills, the particle size was correspondingly large, which led to an increased need for vulcanization chemicals to ensure complete vulcanization.
In my opinion, both of the points mentioned above led to the myth of the different hardness in DUNLOP foams being created.
Nowadays, the DUNLOP process uses modern high-tech mixers that continuously produce an exact density with the same qualities and the same good and fine foam structure.
The statement “The TALALAY process enables lighter densities” is just as misleading. This is demonstrably false. With modern mixers, the DUNLOP process can produce foams with 55 grams per litre (dry) or less.
I bet that most of the so-called experts would not be able to tell the difference between a (modern) DUNLOP foam and a TALALAY foam (in a finished mattress) in a blind test.
The vulcanization itself in both processes is the same. The foam is vulcanized (heated up) through the detour from steam to metal mould surface from there through the pins into the foam”. The pin design (length and diameter) may differ, the process itself is the same SLOW one. With high pressure steam you may shorten it a bit, but in turn that needs additional expensive technical upgrade.
To my knowledge, in both cases a King Size mattress needs one hour to vulcanize, with RF only 5 minutes.
I hope this helps.
Best regards,
Jens