Filter Aid Combo Bags Our Filter Aid Combo Bags are now used in more than six countries. A special brown finish has been well accepted as it imparts a very stiff shape to the bag. Launder Socks, Channel Bags, Mini Channels, etc. are also available as per international specifications. URJA PRODUCTS now supplies the above products to leading Smelters and Cast houses in several parts of the word. The aluminium industry is well covered by Urja.