The very popular Rhinestones experience a boom as jewellery and fashion accessories. In addition, many textiles are decorated with stick-on stones (hotfix or hot glue rhinestones).
For the retailer, the exact dosage of these stones is quite difficult. The smallest stones may have dimensions of a few 1/10 mm and a weight of only a few milligrams. The weight of Hotfix stones varies due to tolerances in the amount of adhesive. The commonly practiced determination of a number of pieces based on the weight therefore leads – especially for small and hotfix stones – inevitably to incorrect values. Complaints from customers, inventory discrepancies or missing sales margins for the dealer are the result.
In an actual case, a customer has decided to count its stones with a PC controlled elmor C3 counting system. The elmor counters were originally developed to count plant seeds. Increasingly, the seed counters are also used for counting smallest mechanical parts – as well as rhinestones.
The elmor C3 can exactly detect small parts in the range of 1/10mm to more than 10mm. The control software allows to count total amounts or a predetermined number of pieces accurately and repetitively, for example 50 times 100 parts.
The small parts are an important sector of the customer’s product range. They can be processed with the standard conveyor bowl. Since very flat stones are present among these parts (thickness only a few 1/10 mm) the feeder bowl was equipped with the sorting element FS3. The FS3 is continuously adjustable in height and width. Thus stones next to each other as well as superposed stones can be eliminated from escaping so that only one stone after another leaves the vibrating bowl and is precisely detected by the highly sensitive sensor.
Caused by the vibrations of the conveyor bowl stones with small dimensions tend to charge electrostatically, which could lead to errors. With an ionizer the charges can be neutralized.
For large stones there is a risk that the cut edges being damaged during the conveying process. For this reason a conveyor bowl with polyurethane coating is used for stones larger than about 5 mm in diameter.
The data of all counting operations can be stored and exported for further use.