Seed Packaging and Handling
After processing and treating are completed seeds are packaged into containers of specified new weight. Packaging or bagging is essentially the last operation in which seeds are handled in bulk flow; the packaging consists of the following operations:
1. Filling of seed bags to an exact weight.
2. Placing leaflets in the seed bags regarding improved cultivation practises.
3. Attaching labels, certification tags on the seed bags, and sewing of the bags.
4. Storage / shipment of seed bags.
Equipment Used for Packaging of Seeds:
The Bagger Weigher:
These are small machines which, when properly mounted beneath a bin, will fill and weight a bag accurately in a single operation. Operational steps include:
a) The empty bag is suspended on the bagger weigher by a bag clamp.
b) Seed flow into the bag is begun, usually by a trip lever.
c) As seed flows into the suspended bag, a scale –type counter –balance mechanism is actuated, so that when the proper weight of seed is in the bag, the seed flow lever is tripped and seed flow is automatically stopped.
d) The bag now filled with the exact weight of seed is removed from the bagger weigher and is closed.
Bagger weigher and bagging scales, used in seed packaging may be manual, semi- automatic or automatic.
This type of scale, usually a portable plant form is considered inefficient for volume weighing operations because of high labour requirements and relatively low capacity, in terms of bags filled per minute. With this scale, bags are filled to approximate weight, placed on the scale and then ‘even weighed with a hand scoop. These scales are useful in following conditions.
a) Weighing bags of non-free flowing seeds.
b) A bagging bin is not available.
c) Labour costs are minimal.
Semi-automatic. This is the most widely used scale. The scale is attached to the bottom of a bagging bin, and the bag is clamped to the bottom of the scale. The feed gate is opened manually and may be closed either manually or automatically when the proper weight is attained. The scales have a capacity to weight four to eight bags of 50 kg per minute, depending upon the seed being packaged and the skill of the operators.
When selecting a scale of this type, the circumference and composition of bags or containers must be considered. The office, or the bag clamp, must be smaller than the open end of the bag, however; too small an orifices and clamp will result in seed spilling around the edge of the bag. The bag clamps hold bag material of specific finish and thickness, therefore, the composition of the bagging material, that is, jute, cloth, plastic, paper, etc. should be stated when ordering the scale.
Automatic scales: Scales of this type are used primarily for small packages, E .g vegetable and lawn seeds. In these machines the entire weighing and filling process is done automatically. Installation is similar to the semi-automatic bagger. Some completely automated systems pick up the empty bag, place if on a bagger, fill the bag and release the filled bag which then moves by conveyer to a bag closer.
Regardless of the types of scales used, they should be checked regularly to determine their accuracy, particularly if they are portable. Frequent and careful cleaning of the weighing mechanism will decrease the number of inaccurate weighings and extend the life of the scale.
Bag sewing machine. After an open- mouth bag is filled, the bag top must be sewed with a bag sewing machine. Bag sewing machines are precision, high speed machines and must be operated and maintained properly to prevent frequent break.