Introduction
We have intended to dedicate a section of our website to the most frequently asked questions. Answers are necessarily brief and make no pretence of being exhaustive, though they can explain how to use scrubber-dryers properly, solve one's cleaning problems obtaining, at the same time, the best possible result with the goal of preserving the machine in the best conditions and over time.
All this, which is the most important thing, in full compliance with all the safety regulations.

Click on one of the above topics to go to the specific question

The underlined words are sensitive and represent a link to the question concerning that specific topic.

1) What is a scrubber-dryer and how does it work?

A scrubber-dryer is a combined automatic machine which can be either pushed, self-moving or ride-on. It has a front scrubbing unit and a rear drying unit and it cleans the floors by means of the mechanical abrasive action of one or more rotating brushes and the emulsifying action of a water-detergent solution. It is fitted with a tank for solution water with a varying detergent percentage according to the type of dirt or of product to be used. When moving forward the machine drips the solution onto the brushes which, thanks to their mechanical rotating action, scrub the surface thoroughly and remove all dirt. At the same time, at the back of the machine, a squeegee has the task of collecting the water-detergent solution together with the dirt and conveying them, by means of a suction system, into a proper tank, which is separated from the fresh water tank, and is called recovery tank. Water used for scrubbing is usually at room temperature or lukewarm. The machine cannot be filled with water which is too hot.
 

2) How many types of scrubber-dryers are there on the market?

On the market there are two main types of scrubber-dryers: the walk-behind, that is pushed by the operator, and the ride-on, where the operator rides on them and they are more suitable for medium-large surfaces. There are other differences regarding the scrubbing system, the supply system and the type of traction. In the following there's a list of the features you can find on both categories of machine:

Walk behind
- working width from 35 cm up to approximately 100 cm;
- power supply with cable or 24/36 Volt battery;
- mechanical drive or with electrical traction;
- separated tanks, with membrane or with dividing filter (the latter are less common);
- scrubbing unit with disk brush/brushes (1 to 3) or pad/pads / sweeping-scrubbing unit
  with brush/brushes;

Ride-on
- working width from 65 cm up to approximately 150 cm;
- power supply with 24/36 Volt battery, diesel or gasoline fuel;
- drive with electrical/electronic traction;
- separated tanks, with membrane or with recycling system (these last two are less
  common);
- scrubbing unit with disk brushes (2 or 3)/ sweeping-scrubbing unit with cylindrical
  brush/brushes (1 or 2) / sweeping unit with cylindrical brush/brushes (1 or 2) on the
  back of the scrubbing unit / pre-sweeping unit with cylindrical brush/brushes (1 or 2)
  on the front of the scrubbing unit (these last two are less common)
 

3) What are the main applications of a scrubber-dryer?

A really valuable machine with great power and versatility, scrubber-dryers are suitable for cleaning any type of paved floor, indoors as well as outdoors:
  - ceramic;
  - marble;
  - cement;
  - linoleum;
  - bolted;
  - porcelain-effect gres;
and every type of dirt.
It can be used every day - in which case the use and purchase of a professional model is recommended - or less frequently.
In case of especially "stubborn" and tough dirt (turnery dirt), sludge, grease, vehicle tread marks, solid work residues, etc.) special equipment is recommended: from tynex brushes, to the sweeping-scrubbing unit, cylindrical brushes or specific squeegee rubbers.
Nowadays, scrubber-dryers are of exclusive importance among floor-cleaning machines: they are in fact used in every sector, in public as well as private environments such as:
- industrial sites;
- communities and schools, offices, religious buildings, hospitals, public buildings,
  airports, harbours;
- shopping centres, logistics centres;
- cleaning contractors and multi-service firms.
 

4) What are the components and the main features of scrubber-dryers?

The main components of the scrubber-dryers are:
- the scrubbing unit, with a motor for brush and pad rotation, whose work performance
  depends on how large the working path is;
- the tanks, usually two: one for fresh water - which is called solution tank - and the
  other for dirty water - called recovery tank - whose holding capacity directly influences
  the performance autonomy and consumption rate. Some machine models you can find
  on the market have a single tank, both for solution water and dirty water, that are
  fitted with a dividing membrane; others suggest optional water recycling systems in
  order to increase working autonomy and reduce times for water filling;
- the drying unit, consisting of a squeegee, whose shape is of basic importance, and of a
  suction motor, which influences the work performance and quality;
- the type of power supply, usually with 24 to 36 Volt batteries or with 220 - 230 Volt
  mains supply, which influences the autonomy of operation, the work performance, the
  number of possible cleaning procedures during the machine life and, therefore,
  maintenance;
- the traction motor on automatic models, influences the work performance.
 

5) What are the main accessories of scrubber-dryers?

The accessories are extremely important since they have been specially designed to meet the most exacting needs of customer-users and to make use of all the scrubber-dryer's applications in the best possible way.
The main accessories available on the market are listed in the following:
- brushes of different types, are in nylon, with bristles of different sizes, in tynex, in
  natural fibre, in steel and they are disk-shaped or cylindrical according to the type of
  dirt and of surface;
- pad holders and pads, as an alternative to brushes, with variable hardness and
  abrasive power according to the surface;
- squeegee rubbers with variable hardness according to the type of floor and in case oil
  is present;
- interchangeable scrubbing and sweeping-scrubbing units;
- a recycling system, which allows you to re-use water by means of a filtering systems
  (rarely used);
- headlights to work at night time or in dark environments.
 

6) What types of brushes are available on the market and what application do they have?

Here follows a list of the main types of brushes and related applications.

PPL BRUSH
It is used on every type of floor and it has a high wear and hot water resistance (no more than 60°C). PPL is not hygroscopic and therefore it preserves its properties even when working on wet floors.

NYLON BRUSH
It is used on every type of floor and it has an excellent wear and hot water resistance (no more than 60°C). Nylon is hygroscopic and so, when working on wet floors, it tends to lose its properties over time.

TYNEX BRUSH
The bristles of this type of brush are impregnated with extremely aggressive abrasives. It is used to clean very dirty floors. To prevent any damage to the floor the use of the minimum required pressure is recommended.

STEEL BRUSH
They have wire or flat bristles, which may be either steel or mixed, that is with steel and synthetic fibres. The steel wire brush is used to de-scale very uneven floors or with wide joints; the one with steel flat bristles (more rigid) are used to scrape away dirt that is more difficult to get rid of.

NATURAL FIBRE BRUSH
These bristles of vegetal origin are especially suitable for very delicate or treated floors since they are extremely thin. They last less than nylon bristles and should be used with non-aggressive detergents.

BRISTLE THICKNESS
The thicker bristles are more rigid and so they are suitable for smooth floors with narrow joints.
On uneven floors or with irregularities or deep joints, softer bristles are recommended which penetrate more easily in depth.
It should be remembered that as the brush bristles wear out, that is as they are too short, they become stiff and cannot penetrate nor clean in depth any longer also due to the fact that, as it is the case with too thick bristles, the brush tends to bounce.

PAD HOLDER
The pad holder is recommended for polished surfaces.
There are two types of pad holder:
1. The traditional pad holder is fitted with a series of anchor-shaped tips thanks to which
    they hold and drag the abrasive disk during cleaning.
2. CENTER LOCK pad holders are not only fitted with anchor-shaped tips but have also a
    centre snap-lock system in plastic which allows to centre the abrasive disk perfectly
    and to hold it coupled without any risk of detachment. This type of holder is especially
    suitable for machines with several brushes where centring the abrasive disks is
    rather difficult.
 

7) Which detergents are suitable for scrubber-dryers?

All the products that are recommended for scrubber-dryers need to be specifically approved to be used with automatic machines. Basically, they have an alkaline base with low foam agents (in fact there shouldn't be too much foam otherwise the suction motor could get damaged). No acids nor corrosives should be used, not even inflammable substances. The percentage depends on the type of product. For very dirty floors or with stubborn dirt, pre-washing is recommended: it takes longer but it is more effective. The procedure involves washing the surface twice: in the first wash the machine simply scrubs the floor while the suction motor is off and the squeegee is lifted up; in the second one the detergent solution which was put on the floor in the first wash, is sucked up so that a visible cleaning effect is obtained.
 

8) What are the main problems encountered when using professional scrubber-dryers?

If the machine you use is appropriate for the work environment it is used in and is properly used, the main problems you may encounter when using a professional scrubber-dryer are usually simple and easy to solve. Not infrequently, in fact, machines are used improperly to clean surfaces that are much larger than the machine's technical capacity or the equipment used is absolutely inappropriate for the type of task.
Here follows a list of examples of problems you may have with the related recommendations for safe and effective cleaning.

9) What should you do to maintain a scrubber-dryer over time?

The accurate ordinary maintenance of the machine is of basic importance to preserve a professional machine. This type of machine, working with water, requires in fact some simple care-taking daily or, anyway, at the end of each cleaning task.
For instance, it is necessary to:
- empty and clean the recovery tank. During operation the machine collects water
  mixed with solid dirt which deposits very rapidly and may become rotten and
  foul-smelling. It is therefore important to rinse it with running water;
- empty the fresh water tank, especially if cleaning is not a daily task because stagnant
  water can become unpleasant and be a source for bacteria;
- clean the suction filter; sometimes there is deposits build-up and drying performance
  could be impaired. Rinse with running water.
- check that the squeegee is always clean; if necessary, use a jet of water to clean the
  rubbers and the suction inlet;
- check weekly brush and squeegee wear; if floors are extremely abrasive, a strong
  pressure onto the floor could damage these accessories or cause them to wear out
  quickly. In normal conditions, the brushes should be replaced after 50 working hours,
  whereas the rubbers should be replaced or turned, if re-usable on the four edges, after
  30 working hours;
- inspect the solution filter regularly, if any; the filter could sometimes get clogged due
  to tiny water impurities and could affect the regular outflow during cleaning tasks;
- clean regularly the suction hose which is connected to the squeegee; even a partial
  obstruction may impair the suction performance.
 

10) Which important safety regulations should always be considered when using
        scrubber-dryers?

- Read the labels on the machine carefully, never cover them and replace them
  immediately if damaged.

- The machine should only be used by authorised and specially trained personnel.

- During machine operation pay attention to the other people around and especially to
  children.

- Never mix different types of detergent in order to prevent formation of harmful gases.

- Never put containers with liquid onto the machine.

- The machine is supposed to scrub and dry at the same time.
  If otherwise, such operations should be carried out in restricted areas where
  non-authorised personnel is not admitted.
  Areas with wet floors should be clearly marked by means of appropriate signs.

- If parts need to be replaced, ask for original spare parts.

- Prior to any maintenance procedure, disconnect the machine from the mains power
  supply.

- Never remove coverings requiring tools to be removed.

- Do not wash the machine with direct jets of water, with water under pressure nor with
  corrosive substances.

- Every 200 hours, have the machine checked by a service centre.

- In order to avoid fouling of the solution tank filter, do not fill in the detergent solution
  many hours prior to machine use.

- Before using the machine, check that all doors and coverings are properly positioned
  according to the instructions given in the operator's manual.

- Prior to removing the recovery tank make sure it is empty.

- Take care to dispose of consumable materials in strict compliance with the applicable
  regulations.

- At the end of the machine's working life, take care to dispose of its components
  properly, especially of oils, batteries and electronic components bearing in mind the
  fact that, in any case, the machine has been manufactured with fully recyclable
  materials.
 

11) What should first be considered prior to purchasing a scrubber-dryer?

There are several important factors to be considered when purchasing a scrubber-dryer. The first thing to consider concerns anyway the actual requirements and cleaning problem to be solved.
When purchasing a scrubber-dryer, and its specific equipment, several elements should be considered, such as the environment in which it should be employed and its size, the type of dirt, any the obstacles that may be present, cleaning times and the level of quality required.
To choose the most suitable model of machine, the product's features which best meet the customers needs should be considered. The higher the requirements and the frequency of use, the more professional should the product be that you choose.
Basically the following should be considered:
- machine yield, resulting from the working width (i.e. how large the scrubbing path is)
  working speed considering any obstacles or possible downtimes. It is usually advisable
  to carry out the cleaning task for an hour so that the actual hour performance can be
  assessed;
- quality of performance, which is mainly related to the type of scrubbing unit, the
  pressure on the floor, the type of brush, the brushes rpm, the suction system and,
  finally, to the type of detergent;
- strength and reliability, which ensure long life to the machine, for instance of the type
  of structure and of the materials used for the bodywork, the frame, the scrubbing unit,
  the reliability and quality of the motors and of the other components, of electrical
  installations and mechanical as well as electronic services;
- manoeuvrability and ergonomics, which affect the use of the machine, its drive, which
  should be assisted, agile, extremely accessible to the operator so that he/she can work
  in the best conditions with good visibility in any type of environment and in any
  conditions. Machine shape and size are important, working visibility must be
  guaranteed and basic operations and controls should be easy to understand and to
  perform
- safety, is governed by precise rules, it is an essential feature since the machine very
  often has to perform tasks in environments that are at risk and the operator has to use
  it in crowded areas. The use of the machine should, then, comply with some basic
  requirements, including electromagnetic compatibility and low noise emissions
  according to the European applicable regulations; EC construction conformity and
  conformity with the related technical regulations; all visible parts should comply with
  the construction rules and be shaped so as to be in no way harmful to the operator and
  to other people; the machine should be used with caution and exclusively by trained
  personnel; specific detergents are to be used and product mixtures avoided,
  explosion-risk environments should be avoided; suction of flammable liquids or
  dangerous powders is absolutely forbidden; finally, the machine should not be
  operated on surfaces that slope too steeply;
- operating costs are related to detergent consumption, energy consumption - if the
  machine is electrically operated - water consumption, and, besides, they are also
  related to the necessary maintenance procedures and to the wear of consumable
  accessories, such as brushes or pads and squeegee rubbers. What is important is that
  the machine is provided with all the devices which take such aspects into
  consideration.
  For instance, the machine could be provided with an electromagnetic valve to check
  detergent solution outflow; large motors resit absorption better; adjusting the brush
  contact pressure makes it possible to modulate mechanical strength according to
  actual needs; The basic adjustment procedures and ordinary maintenance should be
  practical and simple; the electronic equipment installed on the machine should be as
  simple as possible in order to avoid complex machine downtimes which would imply
  high recovery costs.
- offered services, which can make all the difference, such as the advice of experts in
  the sector, user training , guarantee, qualified service, availability of spare parts,
  planned maintenance packages, courtesy machines, hire service.
 

12) What is the added value of a Comac machine?

There are so many reasons that make all Comac scrubber-dryers extremely competitive in several respects.
The Comac machines are manufactured in a big company which constantly looks at the future and at innovation and tries to combine all the decisive factors for success, in the best possible way, with its wide range of models at each stage: from production to trading and post-sale customer service.
The BRAND NAME Comac, well-known all over the world, is a sure guarantee of quality and of professionalism.
The Comac scrubber-dryer is then a synthesis of:
- consolidated tradition, thirty years of efficiency
- experience and innovation: Comac is always a step ahead in launching innovative
  machines
- strength and reliability: Comac machines have always been tireless working partners
  for the largest cleaning contractors and multi-service firms all over the world
- guarantee of quality, the greatest care is taken in certifying the machines: each
  machine, prior to leaving the factory, undergoes strict checks which verify the working
  of the machine, its quality and safety
- user-friendliness and utmost safety: the machines have been specially designed to be
  used without any special training and in compliance with all criteria regarding
  materials, operator safety and third party safety;
- fully equipped: all Comac battery-operated models are fitted with electromagnetic
  valve to control water outflow, with anti-skid wheels and large motors which allow
  continued daily use for several hours.
- wide range of accessories: different types of brushes and of pad holders, different
  types of squeegee rubbers and sweeping-scrubbing units;
- professional service at each stage: Comac authorized dealers' workshops are highly
  specialized to be able to take the right measures in case of any technical trouble;
- extremely easy maintenance: the machines are such as to make every ordinary or
  extraordinary maintenance procedure extremely simple;
- large distribution network: Comac has been operating for over thirty years with a
  network of authorized dealers that are present in all five continents and are
  particularly widespread throughout Italy
- excellent quality-price ratio: Comac's products rank at medium-high level on the
  professional market with a good competitive advantage over their multinational
  competitors on the various markets world-wide;
- comprehensive services which have been designed to always be ready to provide
  post-sale services to the customer, such as: advice, assistance, training, hire services
  etc.
 

13) Where can I buy a Comac machine and whom do I have to refer to for assistance

Comac machines are distributed by authorized dealers that are experts in professional and industrial cleaning in general and can provide a high-level training and post-sale services. To find the address of the dealer nearest to you please look in the yellow pages, our website under the section "distribution network" or contact us directly at:

Comac spa
Via Cà Nova Zampieri 5
37057 San Giovanni Lupatoto (Vr)
tel. 045 8774222
fax 045 8750303
e mail: com@comac.it