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.
Collector type
The type of container for the collection of processed mass, provided in the design or delivery set of the grinder.
— Hard. Capacity in the form of a rigid container. Such collectors are very reliable, they carry any kind of debris without any problems — from soft crushed leaves to sharp hard pieces of wood that could pierce soft tissue; in addition, they are more convenient to unload than soft bags. On the other hand, hard boxes are bulky and take up quite a lot of space; in some models, this drawback can be partially compensated by various technical solutions (for example, using a container as a transport case for the upper part of the unit), but this does not change the essence of the problem.
— Soft. Capacity in the form of a soft bag, fabric or polymer. Such collections are extremely convenient in storage and transportation — a rolled bag takes up very little space, moreover, it is usually lighter than a rigid container of the same capacity. On the other hand, soft containers tolerate contact with large sharp particles worse, they are less convenient for unloading, and in many cases it is more convenient to use disposable garbage bags instead of reusable bags (see below for more details).
— Is absent. Absence of any collection in the chopper design/set. This option involves the use of external containers — most often, such models are designed for garbage bags, however, some units are more convenient to use with hard boxes, buckets, etc. On th...e one hand, the absence of a collection implies additional efforts to find it; on the other hand, finding a suitable capacity is usually not a problem, moreover, the user can choose it himself, depending on the specifics of the situation. For example, for recycled leaves, you can take an inexpensive garbage bag, and for wood chips left after thick branches, a box made of solid material is better; for large volumes of work, collections of the corresponding volume are usually required; if the crushed material is intended for export, you can immediately pour it into packaging for transportation (for example, bags), etc.
Overload protection
Availability
of protection against an overload in a design of a grinder.
Overload is a critical increase in the load on the working mechanism and, accordingly, the engine of the device. Such a situation may arise, for example, when too large or solid debris (or too many “regular” materials) enters the unit; at best, its consequences are limited to increased wear, at worst, an accident can occur. The protection system prevents such troubles by shutting down the motor (or the drive to the grinding system) in the event of an overload. Of course, you can also turn off the unit manually — however, automation is more reliable, since it constantly monitors the status of the device and reacts almost instantly.
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.
