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How to make stainless steel sinks

Prior to understanding how to make a stainless steel sink, we should observe briefly a sink made of stainless steels.

This type of sinks emerged in the USA and Europe for the first time. Such sinks produced by China showed up in Taiwan. At the beginning of 1990s these sinks were imported by Taiwan traders. The first brands were Mntangchun and Molin.

Stainless steel apears the stock substance for a sink made of this material. The fundamental frame is formed through draw and weld processes, which are followed by surface finishing.

A sink made out of stainless steel serves as integral equipment in up-to date kitchens to do the washing-up.

Here are the necessary facilities to make this type of sink:

  • Two kits of hydraulic draw presses (400T&500T)
  • A hydraulic press
  • An electric press
  • Four kits of molds.

The 400 T draw presses are required to realise draw process. The 500 T presses are applied to perform formation. A 200 T hydraulic press is required to trim edges and power presses are commonly meant to punch holes. Four kits of molds include draw, formation, trim and punch dies.

These are the necessary items to make a stainless steel sink.

Now let us go into the fabrication processes.

1. Purchase of stock materials (from 0.8 to 1.5 mm sheets).

Sink factories purchase sheets of a number of breadth and thickness in accordance with the sink producing claims. Mostly 0.8 and 1.5 mm thick sheets are applicable in the sink fabrication.

Sheets are expected to be brought to sink factories in reels. The utmost breadth of non-cut steels can be 1220 mm, and they might be unlimitedly long.

2. Lamination.

Steel sheets are limitedly ductile. So, steel sheets need lamination films at primary stages to prevent cracks and damage while realising drawing. The cot should cover just one of the sheet sides. The coated face touches the mold in successive draw steps. You may coat the sheet prior to cutting or after it.

3. How to cut sheet metals.

Steel sheets get sheared in sections via sheet shearing machines in various lengths depending on the sink designs to corespond to the sizes of the blank.

It is shown in the figure given beneath that film coat is accomplished through controlling the rolling relay by making the protection coating and sheet get through the roll area meanwhile.

After coating the sheet goes across the guillotine, the switch of which gets pressed by the operator thus cutting the sheet to gain the necessary span.

4. Notch of corners.

When cut the sheets have rectangular shapes. To fit the sink shapes the sheet corners have to be notched through shear machines. 

In the aftemath of notch process sheets apear multangular and arch-edged.

5. Greasing.

When cut and coated sheets need to be smeared with grease on ech side, as this reduces the risk of beaing cracked extending the service period of molds or presses. 

6. Initial drawing.

Place the steel upon the draw machine workdesk. The top and bottom sides of the laminate plate work bench have got holes. (See the figure beneath)

When the engine switch is pressed the machine top plate lowers sinking the whole workdesk. When the workdesk is sunk, the mould keeps its lateral location forcinging the steel sheet upward to accomplish draw shaping. The initial draw deepness should be over 80 percent of the complete estimated deepness.

7. Clean-up.

Remove the primarly shaped sink and wipe the work bench from draw grease contaminations.

In the aftermath of initial draw process send the basin to clean stations so that the coating can be peeled off. Remove the remnants of draw grease to anneal the sheet for further.

8. Annealing.

Why should sheets be annealed? 

On condition that the estimated basin deepness does not surrpass 160 mm, it is possible to gain the intended deepness through single draw process. If the sink is 180-250 mm deep, there is a risk of rupturing when drawing is carried out through one step.

So, to gain the necassary depth the stainless steel should be annealed and exposed to double draw processing. When annealed, the sheets become more durable and rupture-resistant to bear proper drawing.

The aneal rail has got 20-meter length leading to a stove, where the heat is nearly 1150 C◦. There is an enterance and exit on each side. The basin is placed on the aneal line through a conveyer band. The rail has a capacity of processing 30 basins meanwhile. Through anealing the sheets get demagnetized as well, which ensures the elimination of magnet features of steels owing to the draw process.

If basin factories happen not to have aneal lines, they might turn to aneal shops to deal with the matter.

Otherwise, plants fabricating sinks use aneal furnaces to replace the function in accordance with their demands.

9. Secondary draw treatment.

Here you can see double-drawn steel sinks. The drawing treatment is carried out by means of mplds and hydraulic presses.

10. Trim processing.

Upon being drawn for the second time, sinks need to be trimmed at edges. This is required to take away the excesses inorder to accomplish processing. While trimming, take into consideration the setting location of stiffener ribs over the sink.

11. Punching of holes.

Certain molds of punch machines punch drain and repletion holes. Based on the specifications of a punch machine and sheets, barbs might have to be removed from the punched planes.

12. Welding.

In case of double-tank rolling weld basins, the top part of the water plate needs welding when holes have been punched. Rolling weld is mostly carried out through CNC weld, yet, it can be done manually by a worker. In case of butt weld, each side of the basin should be soldered. The main featuring specification of butt weld is the welding seam in the midst of the sink both sides.

13. Spotting weld.

Weld the edges through laser spot welding. Every dot welding creates three welding seams according to the equipment tuning. Edges of stiffeners demand manifold solder at various positions. The sink ribs may be glued if the client requires.

14. Surface processing.

Coni transparent treatment is a special processing method of C-range sinks. Present-day surface processing includes these 4 steps:

  1. Sand/draw technique
  2. Sandblast technique or electrolysis
  3. Polish technique
  4. Emboss technique.

Sanding is realised specially. Polishing is carried out through up to 4 operations. It depends upon the differences of sinks and machines. The base of sinks has to be polished first, next come the basin walls.

As two adjoining surfaces do not get ground in the same direction, rambling creases might appear near ridges, at the texture meeting areas.

The creases at the joints can be removed with polishing wheels. The top surface needs complete polishing to eleminate weld spots, creases on the sink.

15. Unclosing holes. 

Holes for water tap can be opened at any location in accordance with ordering party requirement.

Hole openning can be realised prior to any operation in the aftermath of welding.

16. Mark processing.

This process implies laser marking and emboss marking.

Embossing mark

The basin must be pushed wholly in the spit location to make proper printing possible.

Laser marking

This process implies marking by laser engraving. Besides automatic laser mark processing, hand marking is possible as well. Set the half-transparent coat bearing logos of barnds upon the defined mark area. Perform marking through manual laser emitters. Laser penetrates into the half-transparent coating to gain moxibustion upon steels.

17. Restoring.

Slight faults occuring during fabrication stages should be restored manually prior to spray processing.

18. Spraying.

Here are the aims to realise spary treatment:

  1. To enable slim and lightweight sinks to take heft.
  2. To hide the burnt signs of anneal processing. 
  3. To make the steel resistant against condensation within kitchen setting.

In reality, many basin fabrications perform spray processing by just painting, which provides no condensation resistance. Besides spray treatment, burnt signs get removed through pickling.

19. Clean-up and packaging.

Clean-up operation implies cleaning the remnants of draw grease, dust, spray, fingerprint spots, scrapes of polishing wheels from sinks.

Sinks may be packed in a bracket, box, retailing package depending on the requirements of clients.

20. Reservation.

Products can be placed in a storehouse before being delivered to the defined destination.

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