How to judge the quality of industrial washing machines

Preface

Eating and dressing are two major aspects of life, both indispensable. In terms of diet, our ancestors created a brilliant culinary culture; no country's feast can compare to a full Manchu-Han banquet. Dressing is also dazzling; from the exquisite ancient costumes we can see today, each piece is embroidered with dragons and phoenixes, symbolizing auspiciousness, which gives a glimpse of their splendor. Related to dressing is washing. In ancient times, only the royal family or military camps had laundry facilities, but washing was mainly done by hand, and mechanical washing was limited to pounding and beating with sticks. Li Bai's Tang Dynasty poem "Midnight Autumn Song" says: "A piece of moon over Chang'an, the sound of ten thousand households pounding clothes. The autumn wind never ceases, always carrying the feelings of Yuguan. When will the barbarians be pacified, so the good men can end their distant expeditions?"
Using machines to wash clothes and bedding is only a matter of the past century. Our country started relatively late; it was not until the early 1970s that Jiangsu Haishi Machinery Group developed China's first fully automatic industrial washing and dehydration machine, which has been over 40 years now. For China to move from a large washing country to a strong washing country, it requires the state or industry associations to formulate authoritative standards; otherwise, our washing equipment going abroad is just empty talk.
 
1. Safety standards are the primary lifeline of washing machines
What is a standard? A standard is a contractual document formulated by the state or industry to protect the interests of both users and enterprises. Therefore, a standard is a measure, a balance; the clauses of the standard are the laws of the industry, and all newcomers must comply. Nowadays, there are many types of industrial washing machines on the market; how to judge their quality? This requires relevant testing centers to test according to the clauses of the relevant standards. Products that meet or exceed the standards are considered high-quality; otherwise, they are inferior. There are many clauses in the standards; any clause related to safety standards that fails to meet the requirements means the product is not allowed to be released or sold. Currently, our industry has not fully achieved this, especially for those that may cause personal safety risks or equipment damage hazards. These must be taken seriously, with administrative intervention to prevent such products from entering the market. Those who do not heed warnings and cause accidents must be held criminally responsible. Without this, we cannot establish a proper business conduct in our industry.

2. Revising the current washing machine safety standards is imperative
First, our current national or industry standards have been in place for many years; some clauses urgently need revision. These standards represent only the average advanced level domestically or internationally; as long as enterprises do not produce shoddy products, they can achieve these standards through effort.
Second, the formulation of standards, especially safety-related clauses, must not be careless or relaxed, but also should not be overly harsh. With the development of washing equipment, the related safety requirements vary. For example, fully automatic washing and dehydration machines have very high electrical safety requirements, among which the leakage current of the equipment is a very important indicator. The US UL standard stipulates that leakage current must not exceed 5 milliamps, while China's national standard GB17202 stipulates 3.5 milliamps. GB17202 is basically a translation of the UL standard, but for some reason, the UL standard's 5 milliamps was changed to 3.8 milliamps. This change is not trivial and has caused huge trouble for enterprises. We tried several imported frequency converters on washing machines, all exceeding 3.5 milliamps leakage current, meaning they did not meet our national standard and thus could not be released. Eventually, we found a frequency converter from a certain country that met the requirements and improved the insulation seat's safety level. We believe that the 5 milliamps stipulated by others has been proven safe and reliable over decades of use; we do not necessarily have to reduce the value. Reducing it only increases enterprise workload and costs unnecessarily.
Third, the insulation resistance between live parts and exposed non-live metal parts in washing machines, the electrical strength between live parts and exposed non-live metal parts must not flashover or break down; grounding protection resistance, short-circuit protection devices, and overload and overheating protection devices must not be omitted and must undergo comprehensive safety testing before release. These aspects also need to be fully considered in the revision of standards.
Fourth, for tetrachloroethylene dry cleaning machines, besides electrical safety requirements, leakage of the cleaning solvent is another safety issue. This problem must receive sufficient awareness and attention from relevant parties. It is known that chlorine gas can be obtained by electrolyzing salt. Then chlorine combines with carbon to form carbon-chlorine compounds. In 1821, Faraday decomposed hexachloroethane to produce tetrachloroethylene. Its molecular formula is C2Cl4, and it has a strong ability to extract oils and fats. Later, countries like the UK, US, and Germany used tetrachloroethylene as a dry cleaning solvent. However, tetrachloroethylene is a toxic liquid; if a person works long-term in high concentrations of this gas, inhaling too much can anesthetize the central nervous system, causing mild symptoms such as breathing difficulties, headaches, dizziness, vomiting, and fatigue, and severe cases may lead to unconsciousness or death. A greater aftereffect is that it can cause cancer. Therefore, controlling the leakage amount of tetrachloroethylene in dry cleaning machines must be very strict. The QB/T2326-2004 standard still includes testing clauses for open-type dry cleaning machines. I believe that all clauses related to open-type dry cleaning machines in this standard should be deleted; open-type washing machines should be immediately scrapped and not produced.
Fifth, Beijing local government DB11/501 stipulates the tetrachloroethylene emission standard as 20g/kg. That is, 20 grams of tetrachloroethylene is allowed per kilogram of laundry. In terms of single-machine input ratio, the emission is not high; however, considering how many tetrachloroethylene dry cleaning machines there are in Beijing, the total emissions are staggering. Therefore, I believe this allowable emission standard value is too high and needs further scientific verification and revision. Washing is to create civilization for society; we cannot do so at the cost of damaging people's health or even lives. The Beijing government’s decision to abolish open-type tetrachloroethylene dry cleaning machines is welcome. This is a measure to benefit the people, and I hope other cities will act quickly to restore a clear sky for the public.
Sixth, the QB/T2639-2004 petroleum dry cleaning machine standard should add a clause limiting leakage current to 5mA, include fire and explosion prevention measures, and pressure vessels should also meet relevant standard requirements. I especially remind those involved in drafting standards to add clauses to limit or eliminate static electricity, because petroleum has a low ignition point, and a single spark can cause a fire.
In addition, the BW series sanitary isolated washing machines are mainly used in sanitary systems, especially infectious disease hospitals. The washing concept of this machine is to designate the laundry room as two independently operated zones: a clean zone and a non-clean zone. Laundry to be washed is loaded through the door on the non-clean side, and after washing, it is taken out from the door on the clean side to prevent cross-contamination caused by loading and unloading from the non-clean zone. However, the current testing uses the QB/T2323-24004 "Industrial Washing Machines" standard, meaning that the testing standard for this model is currently blank. Since it is a double-door machine with laundry entering and exiting separately as dirty and clean, we have no testing for the content of coliform bacteria and other pathogens before washing, nor have we tested the post-wash condition. Without methods to detect pathogens, what is the use of having two doors? Therefore, I say, revising the standard is an urgent task.

3. Participants in the drafting and revision of washing machine standards should be representative.
I believe that in addition to experts from testing units participating in drafting standards, experts and technical supervisors from relevant universities and grassroots enterprises should be invited. Such a team would be more comprehensive, combining theoretical guidance, grassroots practical experience, and expert oversight. Furthermore, reference should be made to the US UL standards, EU CE standards, and international IEC standards, etc., to make the standard revision more scientific and reasonable.
I believe that safety standards should become the primary criterion for judging the quality of washing machines.

4. Other criteria for judging the quality of machines.
Besides safety standards, other criteria for judging the quality of washing machines mainly involve evaluating the consumption of the three energies: water, electricity, and steam. It goes without saying that lower energy consumption is better, and higher consumption is worse.
A machine only meets the conditions to discuss the third criterion, cleanliness, if it meets the standards for safety and energy reduction. In fact, industry insiders can roughly tell by looking at the machine. For example, some manufacturers produce washing and dehydration machines with nameplates indicating a washing capacity of 100 kilograms. By carefully measuring the diameter of the inner drum and calculating, one can estimate its approximate washing capacity. If the actual washing capacity is less than the indicated amount, forcing 100 kilograms of laundry into the machine cannot result in clean washing. This is because the washing principle relies on the laundry falling and rubbing inside the drum. Without enough space, how can the laundry fall sufficiently and be cleaned properly? Therefore, the standards (both national and industry) stipulate that the "volume load ratio" must be greater than 10, meaning that washing 1 kilogram of dry fabric requires a washing space of no less than 10 liters in volume. Of course, to accurately know cleanliness, testing with contaminated fabric washing is necessary.
Secondly, the machine's vibration condition, noise decibel (dB) level, mechanical strength, rigidity, paint and coating quality and lifespan, as well as mechanical aesthetics (appearance design), cost performance, etc., are also comprehensive criteria for judging the quality of washing machines, but they are ranked after safety and low consumption criteria.