Shredding
Type of materials for which the shredder was originally designed.
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Leaves only. In this case, we mean shredders designed for all types of “soft” and wet garden waste: leaves themselves, thick stems of herbaceous plants, freshly cut branches of small thickness, etc. Typically, these models use a knife or line chopping system (see below). Many units for this purpose can cope with coarser dry waste, but this mode of operation is still not recommended, because. it increases the wear of cutting elements, leading to rapid blunting and failure.
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Branches only. Shredders designed to work with coarse materials — primarily large dry branches with a thickness of several tens of millimetres (for more details, see "Maximum diameter of shredded material"). Usually, roller chopping systems are used for such work (see below). Aggregates of this type without much difficulty "eat" and medium-sized soft debris, however, the quality of its processing is much lower than in specialized models for leaves. Therefore, it hardly makes sense to use this type of shredders for "non-native" material.
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Branches and leaves. Models that process both types of garbage described above with equal efficiency — both soft (leaves, freshly cut thin branches) and hard (dry thick branches). Some models have separate modes of operation for both, while others have separate holes for hard
...and soft materials (see Features). Anyway, such shredders are the most versatile, however, their cost is higher than that of specialized ones.Max. shredded material diameter
The largest thickness of debris that the shredder can handle normally. This parameter will allow you to evaluate how a particular device is suitable for a particular situation.
Note that the maximum diameter of the crushed material is important for models that allow working with branches (see "Chipping"). But in specialized aggregates for leaves, it is usually not indicated at all: the thickness of the garbage processed in such grinders is, by definition, small, and creating a design that works normally with any “soft” materials is usually not a problem.
Material throughput
The maximum amount of material that the shredder can process per hour. Note that in this case, the possibilities for perfect conditions are usually indicated: homogeneous garbage fed evenly, no interruptions in work, maximum speed (see “Adjusting the speed of the shredder”), etc. In addition, for universal models (see "Crushing"), the throughput is usually indicated for the most "convenient" material — leaves. Nevertheless, this parameter quite clearly characterizes the performance of the grinder.
It is worth choosing a model for throughput taking into account the volume of the proposed work. At the same time, it does not fit to take a certain margin, but it should not be too large — after all, high performance requires appropriate power, which, in turn, affects the dimensions, weight, price and "voracity" of the unit. Specific recommendations on optimal performance values for different situations can be found in special sources.
Shredder speed
The speed of rotation of the cutting tool of the chopper (see "Crushing system"). Variable speed models (see below) usually have a maximum RPM value.
In general, the general pattern is as follows: with equal engine power, the higher the speed, the lower the torque (see below), and vice versa. In addition, high speed improves performance (see "Bandwidth"). At the same time, this parameter in most cases is more of a reference value than a practically significant one: manufacturers select the rotation speed in such a way that it provides the claimed throughput and at the same time maintains the torque at a sufficient level for efficient processing of materials that were originally calculated design. Therefore, in some models, revolutions may not be indicated at all, and when choosing, it is worth focus on moments that are closer to practice.
Torque
The maximum torque provided by the chopper motor. This parameter can be described as the force applied to the working tool. The higher this force, the easier it is for the unit to cope with complex materials, primarily hard and thick branches, the larger, usually, the maximum diameter of the crushed material (see above). However to ensure high torque and power, you need the appropriate one. Therefore, this indicator is selected by manufacturers taking into account the specialization of the chopper: for example, a model for leaves simply does not need the same high effort as a professional unit for branches.
Waste container capacity
The capacity of the garbage collector provided in the design or delivery set of the grinder.
The larger the container, the more recycled material the collector can hold and the less often it will have to be emptied. On the other hand, it is not always convenient to carry a large amount of material, and a large container takes up a lot of space — and if for soft bags (see "Type of collection") the latter is relevant only when fully loaded, then rigid containers are bulky by definition. Therefore, when choosing, you should proceed from the optimal compromise between capacity and convenience.
Noise level
The maximum noise level produced by the grinder during normal operation. The comfort of using the unit primarily depends on this indicator: strong noise can be very unpleasant, and at high volume it may even require the use of protective headphones.
Shredders are a rather “loud” type of modern technology, even in the quietest models the noise level is about 83 – 85 dB — this is comparable to the sound background on a busy city street. Note that the decibel is a non-linear quantity, so it is best to use comparison tables to estimate specific noise levels. Here are some guideline values:
- 90 dB — freight car at a distance of 7 – 10 m;
- 95 dB — subway car (inside), perforator;
- 100 dB — symphony orchestra, demolition hammer;
- 105 dB — home theater at maximum volume;
- 110 dB — indoor rock concert.
Weight
The total weight of the grinder. Usually, in this case, only the weight of the unit itself is indicated — i.e. with an empty collector (for models equipped with standard tanks, see "Type of collector"), without fuel in the tank (for internal combustion engines, see "Engine type"), etc.