Vulcanisation Systems For The Production of Latex Foam
Due to its properties, natural, organic latex has been an ideal material e.g. for mattresses for decades. In terms of sustainability, this is quite a ‘modern’ and a renewable raw material: elasticity, respiratory activity, body adaptation, durability as well as homogeneity are its outstanding characteristics. Similar properties are also offered by newer systems based on synthetic latex. Customized vulcanisation systems allow for a good processing of both raw materials
A basic formulation consists of latex (synthetic and / or natural latex), foam auxiliaries and stabilizers, the vulcanisation system itself (consisting of sulphur, zinc oxide, accelerators and aging inhibitors) and any necessary filler. This compound is mechanically mixed with air, put into moulds or applied to a carrier and ’vulcanized’ in the oven.
The chains of the latex molecules are linked via sulphur bridges. The reaction time, temperature and the required amount of sulphur can be significantly reduced by the targeted use of auxiliaries (so-called accelerators). Nowadays, guanidine derivatives (DPG), dithiocarbamates (ZDEC / ZBEC) and 2-mercaptobenzthiazole derivatives (ZMBEC) are used preferably either individually or in combination.
Solutions From The Specialists
Weserland has been a specialist in the manufacture of tailor-made vulcanisation systems for the latex processing industry for many years. Suprotex UGB is a proven system for synthetic latex based formulations. This product contains all the additives necessary for vulcanisation (sulphur, zinc oxide, accelerator and anti-aging agent) in a coordinated composition and is added directly to the synthetic latex compound.
If the formulation is predominantly based on natural latex, a complete dosing of the vulcanisation system is not possible since zinc oxide and DPG lead to stability problems of the compound. For this kind of application, Weserland has divided Suprotex UGB into two components:
- Suprotex L N566-1, consisting of sulphur, accelerator and aging protection, is added to the compound before ’ripening’, whilst
- Suprotex L N566-2, consisting of zinc oxide and DPG, is injected into the mixing head during foaming.
Both Suprotex UGB and the split system Suprotex L 566-1 / -2 form the basis for a successful production of latex foam. As a producer for special solutions, it is possible for Weserland to modify the configuration of these systems in wide areas in order to meet specific customer requirements.
Photo: limco72
