Screw blackening agent 

We do not add thickener, really super concentrated, liquid ratio = stoste: water =1:9 - 15

     Screw black in general after the heat treatment, screw heat treatment tempering temperature is low, the workpiece itself is relatively small, the stored heat is relatively small, so the heating temperature to heighten a proposal, colleagues with low temperature blackening agent, improve concentration.

    1, DS-1018 type blackening agent workpiece into the liquid temperature not lower than 200℃. In short, the better the higher the temperature effect, the maximum not more than 400℃, the workpiece heated to a predetermined temperature after thermal insulation for a period of time (small workpiece insulation for more than 30 minutes), which is heated evenly to ensure adhesion of blackening film and substrate.         
    2, the workpiece from the working fluid should be put forward after drying, the drying temperature is 100-150℃, after drying and oiling.

    The steel blackening agent of Delishin Brand employs the principle of high polymer organic polymerization and uses the afterheat of tempering process within the heat treatment to form a film and blacken. The formulated working solution can be recycled and is easy to operate, being a kind of new environment-friendly, energy-saving and water conservative steel surface treatment material and the best solution to reduce the production costs. It is widely used in the surface blackening of all kinds of iron and steel parts such as standard parts, fasteners, screws, nuts, chains, gears, springs, elastic pads, bicycle parts and accessories, auto parts, machine parts, hydraulic parts, engineering machinery parts and railway equipment which are made of iron and steel materials as carbon constructional steel, alloy constructional steel, cast iron and powder metallurgy etc.

    I Advantages
       1.Water-soluble emulsion which is environment-friendly and safty;
       2.Being manufactured with the heat treatment mesh belt furnace, which is efficient and energy-saving;
       3.The continuous operation of heat treatment technology which can make the tempering and blackening be  performed at one time;
       4.The blackened work piece is lustrous, corrosion resistant and rust-preventing;
       5.It can reduce the labor intensity and improve the production environment;
       6.It can save energy, reduce cost and improve productivity;
       7.No acid cleaning before blackening, no washing after blackening and free from the discharge of waste water, gas and residue;
       8.The blackened work piece has no hydrogen embrittlement pinholes and burrs;
       9.It can perfectly substitute the traditional alkali boiling blackening, which can eliminate pollution;
       10.The blackening agent of Delishin Brand can greatly reduce the part processing costs. 

    II Drawing of the application of blackening process flow on the mesh belt furnace:

1

2

     III Using Instructions
       1. Formulation of blackening solution
          A. Formulation of the working solution of blackening agent: fully shake or evenly mix the stock solution, determine the concentration of the solution and choose the model of blackening agent according to the size and temperature of the work piece. The general blackening agent as a percentage of water is 5-15% (namely 1:6~1:18); the using principle is that: if the size of the work piece is large, the solution concentration should be low, if the size of the work piece is small, the solution concentration should be high; if the temperature of the work piece is low, the solution concentration should be high, if the temperature of the work piece is high, the solution concentration should be low.
          B. Adding of the working solution of blackening agent: when adding the working solution of blackening agent during the operation, the working solution should be diluted before adding, and the stock solution can not be added.
          C. The temperature control of working solution: the working solution tank should be equipped with a cooling and circulating device to keep the temperature at 35℃±5℃ , the maximum temperature shall not exceed 50℃.

       2. Treatment of the blackening work piece
In the assembly line work, the work piece can not bring in other chemical substances.When the work pieces enter into the working solutions successively, the solution-entering temperature of the work piece shall not be lower than 200℃. In a word, the higher the temperature is, the better the performance is, but the maximum temperature shall not exceed 560℃. The heat of the work piece should be preserved for some time after it is heated to the specified temperature in order to keep the work piece being heated evenly and assure the binding force between the blackening films and the matrix. The work piece should be dried after been taken out from the working solutions, the dry temperature should be 100-150℃. If the result of one blackening is not satisfied, a second blackening can be performed.

       3. Analysis & adjustment of the concentration of the working solution
The formulated working solution will be dipped by the hot work piece continuously during use. In the working solution, the film-forming substances will be deposited onto the surface of work piece continuously, with the consumption of solutions, the components in the solutions will be changed gradually, thus, the solution concentration should be tested and analyzed periodically and the blackening agent should be refilled regularly combining with the production quantity. Water should be refilled when too much water is evaporated to keep the working solution within the specified concentration range.

Part of the application of the picture：