摘要 |
<p>The invention provides novel integral man-made vitreous fibre batt products having a core section in which the concentration of an additive material is greater than the concentration in each of the face sections. Three novel processes are provided which can be used to produce such a product. One in particular comprises forming a primary web of product, applying additive to the centre region of the primary web and cross-lapping the web to form a secondary web so that the centre region to which additive has been applied mainly forms the core section of the product.</p> |