Magnet for injection moulding machine hopper (temperature resistance up to 80 °C) dia. 250 mm

The hopper magnet (sometimes also referred to as a magnetic grate) is designed exclusively for industrial use, it will ensure perfect cleaning of your dry mixes from ferromagnetic impurities (by ferromagnetic impurities we mean fully magnetic metals such as iron, nickel, cobalt and alloys containing iron not paramagnetic, very finely magnetic materials). It is designed to be used in circular hoppers to perfectly follow the inlet of the downstream process equipment.

For proper operation, the mixture to be purified (the material you pour over the magnetic grid) must be:

·         homogeneous,

·         dry with good spreading properties to prevent clogging (congestion), see below.

The hopper magnet (magnetic grate) is only suitable for use in non-continuous operations (during its manual cleaning, the flow of material to be cleaned must be stopped). It is installed only in vertical hoppers, the tube must be horizontal (in case vertical installation is not possible do not use this product and contact us to find another hopper magnet or another magnetic separator or to confirm its suitability for use) e.g. in the food, chemical, plastics, agriculture, waste processing industry in the building materials industry see list of suitable materials below.

The hopper magnet is used as a pre-stage to protect the technology so that metal ferromagnetic impurities do not get into the equipment that they could damage, such as mill knives, crushers, regranulation and granulation line nozzles, injection molding nozzles, extrusion benches, press benches, scrapping equipment, fine screens, ceramic press benches, glass presses, etc. Wherever material is collected in a hopper prior to technology. It can also be used to purify the mixture to the highest possible cleanliness, where the grate is placed at the end of the production process just before packaging, dispatching, so that there is no more contamination with metallic ferromagnetic material during further operations in the production plant (for example, during manual packaging of products through auxiliary hoppers). In this case, it is expected that the purified material will be immediately enclosed in resealable containers or in other resealable containers. Due to the perfectly designed magnetic circuit and the sieving labyrinth created by the expanding circular steel, a high capture of ferromagnetic impurities is achieved (please read in detail below the description of what ferromagnetic metallic impurities can be captured by this magnetic grid).

The grain size (fraction, size) of the material to be cleaned may be up to a maximum of 3 mm (3x3x3 mm) in diameter, regular in shape, the material must be well flowable, dry, non-sticky and free of lumps to avoid clogging (blocking) of the magnetic grid with material. It must have a low moisture content and minimal adhesion between particles and surfaces. It shall not have the properties of arching (clumping together into uniform units), retaining itself and preventing free flow through the magnet into the hopper. Examples of such materials (which do not flow well) are wet, oily materials, but also materials which are dry at first sight, seemingly looking like they are well-flowing, but their natural property is that they do not flow well. Examples of this are smooth, very finely ground flour or various very finely ground starches. The materials that we recommend and that, in our professional opinion and experience, are suitable for feeding (purification) through this magnet into the hopper (magnetic grate) are listed below (please note the maximum permissible fraction/grain size mentioned above). If the material from which you require to separate metallic ferromagnetic impurities (material to be purified) is not found in the listing below, do not use this product and contact us for further clarification and possible recommendation of another magnetic separator/grid or agreement that this type is also suitable for use for magnetic separation from your material.

Listing of suitable materials for magnetic separation using a magnetic grid:

- sugar crystal

- powdered sugar (be careful not to overload the material here, we recommend spreading it more slowly and evenly over the entire surface of the grid)

- cereals, various types

- lens (in case of frequent use for large amounts of lens there is a risk of abrasion, please note the possible faster wear of the cover tubes)

- crushed cocoa beans

- Crushed PET bottles (beware of overcrowding here, we recommend spreading more slowly and evenly over the entire surface of the grate, rather suitable for smaller capacity quantities)

- rubber regranulate

- rubber crumb

- chilli seeds

- animal feeds, well friable, similar in character to flour up to coarser fractions but max. grain size 3 mm (must not be abrasive)

- coconut flour

- cocoa

- flour (be careful not to overcrowd the material here, it is recommended to spread it more slowly and evenly over the whole surface)

- poppy seeds (only poppy seeds not whole poppy seeds)

- ground maize

- meat and bone meal

- matcha powder

- pudding (risk of arching and clogging with material, spread slowly and evenly over the entire area)

- plastic granulate and regranulate

- plastic grit (well crushed without residual fibres)

- ash (not hot but cooled to the working temperature of the magnetic grid)

- food grade bulk non-abrasive mixtures

- milk powder

- dried chocolate

- dried coconut

- dried herbs

- dried spices (finely ground or very finely crushed)

- dried instant soups

- whey powder (be careful not to overcrowd the material here, we recommend spreading it more slowly and evenly over the whole area)

- sesame seeds

- enamel or fibreglass (note the increased abrasion and increased risk of penetration of the cover tubes)

- Salt (please note the possible reduced service life due to the material used, depending on the frequency of use)

- bulk starches e.g. corn starch

- building materials (good flowable and non-abrasive)

- tapioca pearls

Again, we emphasize that the materials must be dry, well-friable (must not have arching properties), non-abrasive in maximum regular granulometry up to a diameter of 3 mm (3x3x3 mm). The permeability capacity varies depending on the material from which you require ferromagnetic impurities to be separated, it cannot be clearly determined, it varies for each type of material. In case you are not sure of the permeation capacity, do not use this magnet in the hopper, contact our sales and technical department to recommend another type of magnetic separator or to approve the use of this type.

Please note that the wall thickness of the cover tube is very small due to the high magnetic induction (magnetic force) and breakaway force on its surface. Therefore, please also consider the height from which you will pour the material onto the magnet in the hopper (impact height). The height from which the material is poured onto the magnet in the hopper must not exceed 1 m. However, this is individual for each type of material. It is not possible to determine and prescribe exactly which material should be poured from which height. In the case of pouring from a great height, the cover tubes may be bent or punctured and the whole product may be damaged. If the height from which your material is to be poured onto the magnet hopper is higher than 1 m, do not use this product and contact our sales and technical department to recommend another type of magnetic separator or to approve the use of this type.

This magnet picks up (separates) metallic ferromagnetic particles from 1 µm and smaller (characteristically ferromagnetic, immeasurable, magnetic dust) up to a size of 3 mm (3x3x3 mm), which is the maximum fraction (size) of material that can fall on the magnet into the hopper and that can be poured over it. In rare cases, this magnet can also trap larger metal objects up to 5 mm (5x5x5 mm) in the hopper. However, it is assumed that these impurities will occur randomly up to a maximum of 1% of the total hourly capacity of the material to be screened (it is assumed that the magnetic grate is cleaned of ferromagnetic impurities regularly, this is not meant to imply that the entire 1% of larger, ferromagnetic impurities may remain on the hopper magnet for the entire time the hourly capacity of the material to be screened is being screened). The content of these larger ferromagnetic impurities must not be higher. If the presence of these larger ferromagnetic impurities in your material is higher, do not use this hopper magnet and contact our sales and technical department for expert advice.

The magnet must not be hit by objects larger than we specify (max. diameter 3 mm, 3x3x3 mm) except for ferromagnetic impurities, which we describe above in random amounts. In case you are concerned about the presence of larger ferromagnetic or other impurities, it is necessary to pre-set the sieve with a mesh size of max. 3 mm, so that these larger, unwanted objects are caught before entering the magnet into the hopper (after installing the sieve, it is necessary to consider reducing the capacity load, permeability, of the magnet into the hopper). The sieve is not included in the delivery of the hopper magnet. Please also note that your material may contain large amounts of fine metallic impurities (very fine metallic magnetic dust less than 1 µm in size), which can coat the magnetic tubes and make the hopper magnet impassable (the fine magnetic particles also pack up the hopper material and overwhelm the entire system). At the same time, the magnetic force/efficiency of the magnet into the hopper is greatly reduced. In case your magnetic tubes immediately after you start passing the material through the hopper magnet become coated and "hide" entirely in iron dust this is not a defect of the hopper magnet, but you need to strengthen the magnetic separation with another magnetic separator or clean the hopper magnet more often, your material probably contains a very large amount of ferromagnetic particles.

If you are unable to provide:

- absence of particles in your material larger than 3 mm (3x3x3 mm) in diameter

- less than 1% of larger ferromagnetic particles (up to 5 mm) in hourly capacity

- minimal metallic fine dust in your material

do not use this magnetic grid and contact our sales and technical department to recommend a different type of magnetic separator or to approve the use of this type. 

The hopper magnet is designed to capture as much ferromagnetic metallic contaminants as possible. However, it all depends on the amount of these ferromagnetic impurities present in your material. It is not possible to guarantee the capture of all ferromagnetic impurities. The specific technology and capacities must always be considered. If necessary, other types of magnetic separation/magnetic grids/magnets should be preassigned or added to the hopper. Please do not rely solely on this one hopper magnet. If you are unsure, do not use this type of hopper magnet and contact our magnetic separation experts at any time.

If you are placing the hopper magnet in its own structure (box, hopper, chute...), please note that such structures must not be made of metallic (magnetic) material. There is a risk of injury and a significant reduction in magnetic force. All structures in which the magnet is placed in the hopper must be made of non-magnetic materials. The minimum distance of metal (magnetic) structures from the magnet to the hopper is 200 mm.

Do not use a hopper magnet to separate stainless steel (generally referred to as stainless), even if it appears to be magnetic/paramagnetic (such as after passing through various crushers or other forms of deformation, just as these paramagnetic stainless steels can be used to make various sieves).

The hopper magnet is not intended for the magnetic separation of non-magnetic non-ferromagnetic metals nor for the magnetic separation of parts or parts containing ferromagnetic metals (e.g. plastic parts with pressed-in metal parts, crushed window frames with leftover metal strips, wooden pellets with pressed-in fine wires...). In case you need to separate such ferromagnetic impurities, do not use this magnet in the hopper and contact our magnetic separation experts who will advise you which other magnetic separator to use or which type to add to your separation set-up.

Please note that pressurized water cannot be used or the magnet cores soaked during the cleaning of the hopper magnet. Only a dry cloth may be used for cleaning or well-dried pressurized air to blow off residual metallic contaminants and separated material.

Use extreme caution when cleaning the hopper magnet, the magnetic cores are very strong and attaching them to metal objects can cause pinching, pressure-squeezing injuries. Do not place on anything magnetic (tables, ponks, staircases, floors...).

This hopper magnet is not intended for use in any environment that is classified as an explosive atmosphere (ATEX).

The hopper magnet is for internal use only. Do not install outdoors.

Magnetic induction measurement procedure

The measurements are made with a standard gaussmeter with a 0.75 mm probe at the location with the highest magnetic induction - the location of the pole extensions or the lowest point of the magnetic circuit arc. Repeat the test 3 times, always at a different point of the magnetic circuit, and calculate the average magnetic induction.

Procedure for measuring the breakaway force

Measure with a polished steel standard with a diameter of 10 mm and a height of 20 mm. The measurements are taken at the point with the highest breakaway force - at the point of the pole extensions or at the lowest point of the arc of the magnetic circuit. Record the force at which the etalon was torn off. Repeat the test 3 times and calculate the average breakaway force.

For your information 10 N = approx. 1 kg.

As a confirmation of the measurement and guarantee of the measured values, we issue and include in the delivery of each piece of magnetic separator an original measurement report issued just for your specific hopper magnet (we indicate the stock and serial number on the report).

Operating temperature:

-20 °C to +80 °C (-4 to +176 °F)

The hopper magnet is equipped with magnets with a temperature resistance of 80 °C. It can therefore only be used at this maximum working temperature. Please note that in this case the entire hopper magnet construction will heat up to this high temperature. In this case, the hopper magnet cannot be handled with ordinary work gloves, but must be handled with heat resistant gloves.

Exceeding the operating temperature is possible in certain cases, but it is important to note that this can lead to impaired functionality or shortened equipment life. In this case, consultation with the manufacturer is necessary to clarify the extent to which the equipment can be exposed to higher temperatures without damage and maintain safe operation.

WARNING:

The resulting breakaway force and magnetic induction depend on many factors - e.g. the dimensions of the standard, the air gap between the standard and the magnetic circuit under test, the thickness of the measuring probe, surface contamination, surface treatment of the standard, etc. The reported values of the breakaway force and magnetic induction were measured under ideal conditions given by the test environment. However, these values may vary depending on the specific type of environment, where e.g. operating conditions and subsequent wear may affect the effectiveness of the product, the measurement results. The values quoted are therefore to be regarded as indicative and any variation cannot be considered as a defect. In order to determine the exact value of the magnetic induction and breakaway force in a particular case, actual measurements must be made. If the values of the breakaway force are not sufficient for you, because they do not correspond to the stated values, you can take advantage of the guaranteed return option within 30 days under the conditions stated in the terms and conditions and purchase another type of magnetic separator. These 30 days are just for testing the goods, after which the seller may refuse the return.

Copyright:

We do not agree, do not wish and do not hereby grant anyone any consent to copy individual parts or the whole text. It is also forbidden to alter the text by using identical phrases with the resulting similarity of meaning and correspondence to our text. We do not wish and do not agree to any placement of our text anywhere on other websites, in professional journals, studies, theses in secondary schools and universities without prior permission of Magsy. If you wish to use our text or parts of it, please contact us at any time.