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How to choose the online weighing and rejecting method?

2022-12-28 10:10:04

With the increasing development of production and technology, the manual sampling inspection method can no longer meet the needs of the internal quality control of the enterprise. The automatic online checkweigher gradually replaces the manual sampling inspection method, which can realise product inspection and significantly reduce the scrap rate. Reduce labour costs, reduce the intensity of manual work and the impact on production due to manual misoperation.
Automatic checkweighers have a wide range of applications, the products to be inspected of different shapes, and the efficiency of the production line varies, so there is a particular emphasis on the selection of the check weighing and rejecting mechanism.

The checkweigher and online weighing products our company produce are used in all walks of life. Now we will explain the various elimination methods for your use. Currently, the main rejecting methods of the checkweigher are blowing type, double blowing type, pull-down type, push rod type, lever type, rising type, etc., and there are corresponding devices for each.


1. Air-blowing type

Applicable products: light packaging products with a weight less than or equal to 300g, small size and a certain height.
The blowing and rejecting response time is fast, which can meet the processing and rejecting speed of more than 400 pieces/min.

1. Air-blowing type
1. Air-blowing type

2. Pull-down type

Applicable products: lighter and thinner products.
The pull-down reject adopts the cylinder as the actuator, which can realize the up and down movement within a specific stroke range. For the characteristics that thin products are easy to get stuck, the pull-down reject can solve the above shortcomings. Moreover, the pull-down belt can be connected to the unqualified product collection device, which can transition smoothly and have no essential damage to the rejected products. However, since the actuator is operated by a cylinder, it takes time to eliminate the round trip, so it is unsuitable for high efficiency production lines.


3. Push rod type

Applicable products: boxed, cartoned, or thickly packaged products, products with low production line efficiency.
When the push rod type rejects in regular operation, the push rod is stretched outwards. Once unqualified products appear, the push rod immediately pushes the unqualified products into the recovery device from the outside to the inside. The push rod type rejection method is generally suitable for boxed and boxed products and products with a certain height. The push rod type rejects the unqualified products from the outside to the inside with a push rod, the unqualified products fall into the recycling device, and the qualified products normally enter the next production stage. It is to let the products to be rejected slide down to the ground or storage device or another production line through a panel with a particular slope. Because the slide will generate a specific power, and there will be a more incredible momentum when it falls into the device or production line, the products rejected by the slide are generally lighter and thinner.

3. Push rod type
3. Push rod type

4. Lever type

Applicable products: barrel-shaped, boxed or thicker products.
The lever-type rejecting device has two levers, left and right, and generally, the two are in a parallel state. When unqualified products enter the relevant position, the two levers intercept and reject them from inside to outside. The lever-type rejection method is generally suitable for products in boxes or thick packages.


5. Rising type

Applicable products: thinner products that are not afraid of damage.
The principle of ascending rejection is the same as that of pull-down rejection. The ascending rejection is when the products are conveyed to the rejecting section to rise, and the rejected products fall freely. It is more suitable for thin parts and products not afraid of damage.

In addition to the above rejection methods, according to product characteristics and production line requirements, there will be more non-standard rejection methods, such as swing tail type, guide type, etc.

If you have doubts or are interested in learning about more check weighing equipment and rejection methods, you are welcome to contact us at any time, we are your reliable partner!