Rice

Rice is dense, abrasive and merciless to weak seals: a single grain caught in the seal jaw opens the pack, and the leak is usually found in the warehouse rather than on the line. Rice flows fast and free, so the product column drops the instant the doser releases it and grains reach the sealing area while the jaws are already closing. The same free-flowing behaviour that makes rice easy to dose makes it hard to seal cleanly. Abrasion is the second problem: dry long grain and parboiled rice wear contact parts, dosing cups and forming shoulders, and a worn part changes the dose long before anyone inspects it. Grain deflection before sealing and wear-resistant contact parts are therefore not options on a rice line; they define it. Rice belongs to the free flowing granules group, and for that group volumetric cup dosing is the correct method. Bulk density is consistent enough for a cup to fill repeatably, and the cup releases the whole charge in one drop, which is what a rice filling machine needs in order to hold speed. Auger dosing belongs to powders that will not flow on their own; rice does not need it. High-speed volumetric dosing keeps accuracy at kilogram scale, with the cup volume set for the rice type, since basmati, long grain and parboiled do not share the same bulk density. The working format is the VFFS pillow bag, formed from film strong enough to survive filling shock, stacking and palletising; 1 kg, 2.5 kg and 5 kg packs are the retail and food service standard. At the lower end of the range, 500 g portion packs and sachets serve single households, hotel and catering portions and private label programmes — a rice sachet packaging machine at that weight is the same VFFS platform running a shorter bag. Stick packs belong to powders and single-serve doses and are not a rice format at these weights. The dosing range on these lines is 500 to 5000 g and the cycle speed is 35 to 50 bags per minute. Because this is a single-tube vertical VFFS machine, the cycle count is directly the bag count: there is no lane multiplication as on multi-lane sachet machines. Where a given job sits inside that band depends on bag width and length, dose volume, film and seal time — a 500 g pack runs near the upper end, a 5 kg pack near the lower end. Mentpack runs rice on the VB series: VB-Q, VB-PLUS, VB-MINI and VB. The choice follows bag size, required output and how much automation the plant carries. Typical users of a rice packaging machine are rice mills, grain and pulse packers, dry food processors, private label packers and exporters filling retail and food service weights on a single platform.