Galvanized 3d Anti Climb Fence
Anti climb fence is a type of security fence designed to prevent unauthorized access and climbing over the fence. These fences are commonly used in high-security areas such as prisons, military bases, and government facilities.
Anti-climb security fences are designed to prevent unauthorized access to a property or area by making it difficult for intruders to climb over the fence.
Anti-climb security fences are commonly used in high-security areas such as military bases, prisons, and government buildings. They are also used in commercial and residential properties to provide an added layer of security.
Starch adhesives were applied to corrugated cardboard from Japan in the early 1950s and were quickly promoted worldwide. The raw material source of starch binders is corn, wheat and potato, which has a wide planting area, high yield, easy processing, convenient transportation and low price. It provides solid and reliable raw material resources for the processing, application and popularization of starch binders.
In recent years, many packaging science and technology workers in China have been devoted to the development and practical application of starch adhesives. In the mid-1980s, the National Foreign Economic and Trade Commission and other departments proposed that when making corrugated cartons for export goods packaging, starch adhesives or adhesives with the same effect must be used. By the end of the 1980s, it had been strengthened. In the inspection of export goods packaging, the advantages of the use of starch adhesives and the good adhesive strength and resistance to moisture that are exhibited after application have been reflected in the advantages of cold storage and no secondary pollution.
The formulation and production process of starch binders (mature gums) used in single units in the country is generally a mixture of starch, water, sodium hydroxide, oxidants and terminators. The specific operation process is to successively input the prescribed proportions of materials and sufficient stirring to finally make the finished adhesive product. Some of them use starch to make mature gum first and then finish the process one by one. Some of them heat the water to a certain temperature and then put them into the above-mentioned raw materials of a certain ratio and in turn, while maintaining a suitable temperature, and finally produce a finished product adhesive. The corrugated paperboard production line has always been based on the two-step process of Starbucks in the United States. However, the actual choice of materials, ratios, production processes, etc. are not the same. Instead, according to the local environmental factors, the quality of raw and auxiliary materials, and the actual application, a variety of finished starch adhesives with different raw and auxiliary materials, different ratios, different quantitative amounts, and different process methods were produced.
Styrofoam's two-step process for preparing starch binders is currently widely used in the carrier (the first container) to mix a certain amount of water and sodium hydroxide and stir the starch in the sodium hydroxide solution. Fully gelatinized under the action (known as the cooked pulp), and at the same time, a certain amount of starch and water are put into the main body (the second container) to be fully stirred and mixed (called as raw slurry); under constant constant stirring, the carrier The inside of the cooked slurry is slowly prevented from entering the main body, and after the raw and cooked slurry is sufficiently mixed, the production process and method for forming a finished starch binder in the storage tank (third container) are performed. In order to prevent starch granules from swelling sufficiently (but not soluble in water) after they interact with water at room temperature, sedimentation will occur once stirring is stopped. Therefore, after raw and cooked pulp are mixed into the storage tank, they must be constantly stirred at a constant speed.
China has a vast territory, and the climate, environment, and temperature and humidity vary greatly. Starch adhesives in addition to the above factors in practical applications will also have many subjectively uncontrollable problems due to the quality of the raw materials used and the different proportions and manufacturing processes. The quality of the adhesive directly affects the quality of corrugated cardboard and corrugated boxes. In order to solve the specific quality problems of starch adhesives in practical applications, many experts dedicated to the development of the packaging and decorating industry have put forward various aspects to improve the adhesive strength, drying speed, and reduction of starch adhesives on the premise of conscientiously summing up experience. The cost of preparation methods. The common goal is to improve the bonding quality of the adhesive, reduce the manufacturing cost and increase its operating speed in the production process.
The above description is a synthesis of many excellent processes of starch adhesives and appropriate improvements to make a suitable for a single unit, a low cost, simple to manufacture, suitable for corrugated board production line, and adhesive strength to corrugated board after use. , Thickness and other physical and chemical performance indicators have improved the formulation and production process of frozen high-strength quick-drying starch adhesive. The raw and auxiliary material ratio of the adhesive used by a single unit and the manufacturing process, the high ratio of the raw and auxiliary materials of the quick-drying starch adhesive used in a single unit, and the manufacturing process are advantages in absorbing existing adhesives. Based on the above, it provides a cold high-strength quick-drying adhesive with a simple production process, no heating, no influence of the four seasons, short reaction time, stable product quality, a shelf life of more than six months, fast drying speed, and strong adhesion. And its method of manufacture.
The starch binder used by a single unit can be achieved by adding quantitative water to the reactor, adding starch to mix well, adding the strong catalyst to the reactor, stirring evenly, and adding sodium hypochlorite and hydrogen peroxide or potassium permanganate. 5-20 minutes; dissolve the caustic soda with cold water, add it into the reactor and stir for 20-40 minutes; then dissolve the borax with hot water, add it to the reactor, stir for 3-5 minutes, and finally add a suitable amount of defoamer, stir 2-3 minutes Serve.
The content of each component is by weight: unit: Kg starch: 150-250 caustic soda (95% above content 018-26 strong catalyst: 6-10 borax 4-7 defoamer: suitable amount of sodium hypochlorite (10% content) 40-55 Water: 1000 (Industrial Hydrogen Peroxide: 27.5% Content: 6-9) (Potassium Permanganate: 3-5) The specific processing process is as follows:
a. Add water to the reactor and stir the starch evenly.
b, the strong catalyst is added to the reactor and stirred evenly;
c. Add sodium hypochlorite or hydrogen peroxide or potassium permanganate to the reactor and stir for 5-20 minutes;
d, the caustic soda dissolved with 3-5 times cold water, added to the reactor, stirring 20-40 minutes;
e, the borax with 5-10 times boiling water dissolved into the reactor, stirring 3-5 minutes;
f. Finally, add an appropriate amount of defoamer and stir for 2-3 minutes.
The starch adhesive produced by this formula and process is simple in process and does not require heating. It takes only 30-60 minutes from the feeding to the finished product. The adhesive carton is fast drying, high strength, no running, no moisture absorption, No flooding, no alkaline, after testing, the initial viscosity of 1-1.5 minutes, the full viscosity of 5-10 minutes, the destruction of fiber 30-50 seconds, its physical and chemical indicators are better than the basal foam and other formulations and processes Starch binders. It can be widely used in corrugated cartons for export goods packaging, corrugated cartons for food packaging, corrugated cartons for fruit and vegetable packaging, and corrugated cartons for high-end products.
The analysis of technical indicators related to the adhesives and common starch binders and scolated alkalis is as follows:
Category/Test Results and Requirements/Cold Name High Strength and Rapid Drying Adhesive (Test Results) Common Starch Adhesives Requirements Alkali (NaOH) % 1.13 ≤1.8 10.16 Viscosity (25°C) - 4 cups) S 41.4 40-50 30 Specific gravity (g/ml) 1.074 1.04-1.1 1.4 Application amount (g/m2) 80-100 80-100 150-190 Adhesion rate Initial viscosity 1.5 minutes 5-8 minutes 30 minutes full adhesion 10 minutes 15-20 minutes destruction of fiber 45 seconds 3-5 minutes bond strength N/cm2 6543-6548 7.88 ≥5.88 Unfavorable side pressure strength N/m2 GB6543-6548 7150 ≥6860 Unqualified raw materials and formulations :
1. Corn starch (wheat starch, potato starch or potato starch): The quality of the binder is related to the starch quality and dosage. The fineness, protein and fat content of the starch all affect its performance. If the content of protein and fat in starch is too high and the fineness is less than 98 mesh (100 mesh pass rate), even if the oxidation degree is high during production, the viscosity at the time of discharge is only 20 seconds (measured with a 4 cup viscometer. ) However, the adhesive will naturally thicken, lose its fluidity, and become jelly-like after being stored for 5 to 7 days. When used, the foam is also large, directly affecting the bonding quality. The use of qualified starch, as long as the appropriate degree of oxidation and gelatinization, the finished adhesive viscosity of 40 ± 10 seconds, the viscosity of the storage period will not have much change. Only the color is deep, but the viscosity does not change. The amount of corn starch varies depending on the specific requirements of the bonded object, such as:
(1) Single-faced corrugated paperboard and fine corrugated boxboard are surface-reinforcing with the adhesive. The requirements for adhesives are relatively low. The amount of starch is: 150-170kg/ton of water.
(2) High-strength corrugated paper on both sides of sizing and cardboard and cardboard composite processing cartons. Slightly higher adhesive requirements, starch dosage: 170-180Kg/ton water.
(3) Both ordinary corrugated paper and straw pulp corrugated paper have relatively high adhesive requirements for sizing. The amount of starch used is 180-250 kg/ton water.
(4) The automatic veneer machine and the glue for the paper tube have special requirements for the adhesive. In addition to fast drying, it also requires good adhesion and high strength.
The amount of starch is: 190-240Kg/ton water.
Physical and chemical indicators of corn starch (2)
Item Standard color, white, odor, no odor, taste, no grit, moisture (%) 174 acidity (OT) (%) ≤ 20 ash (%) ≤ 0.2 protein 0.5 spot (pieces/m2) 1 fineness (100 mesh pass rate )(%) 98 Fat (%) 0.15 SO2(mg/Kg) 30
2. Strong catalyst (abbreviation as desiccant): The main factor that distinguishes cold high-strength and fast-drying starch adhesives from other adhesives is the selection of a strong catalyst. The strong catalyst is formed by polymerization of several salts and organic-inorganic compounds. In the adhesive and production process, as long as it is suitable for use, it not only accelerates the reaction speed, but also chemically reacts with oxygen in the air after the sizing. The flocculation crystallizes quickly, accelerates the speed of the adhesive conjunctiva, shortens the drying time of the carton, and improves the strength of the cardboard. Therefore, the adhesion speed of the adhesive (first-viscosity, full-stick, and fiber-breaking) is several times higher than that of the conventional starch glue. And cardboard, high hardness, stiffness, number of strong catalyst in the binder per ton of water less than 5Kg less than the effect, the amount of water per ton is higher than 13Kg, adhesive film is too fast, medical cardboard degumming phenomenon. So we must strictly control the proportion of placement. The normal dosage standard is 6 ~ 12Kg/ton water.
3. Oxidizers: Among the starch binders, the commonly used oxidants include hydrogen peroxide (hydrogen peroxide), sodium hypochlorite, and potassium permanganate. Potassium permanganate is used as an oxidizing agent, and the amount is easy to grasp. The finished starch binder has a stable product quality, but the color of the produced starch binder is dark brown or brownish black. The sodium hypochlorite-made starch adhesive is unstable in quality during use, and easily decomposes chlorine gas, causing the operator to feel eye discomfort. Starch adhesives made from hydrogen peroxide often generate a lot of foam in use, and need to put anti-foaming agent. In addition, sodium hypochlorite is easy to oxidize and decompose under sunlight or high temperature, and its secondary chlorine content is reduced. In application, it is necessary to grasp its exact content and moderately increase the dosage. From the use of analysis, the use of hydrogen peroxide as an oxidizing agent for starch adhesives, stable quality, small amount, low cost, fast response, is the ideal material for use as oxidants.
When making two high-strength and quick-drying starch adhesives, the oxidation reaction plays a key role (40-minute viscosity is 60-80 seconds), the starch solubility is improved, the film-forming ability is good, and the adhesive force is strong. If the oxidation is not enough, macromolecules Less degradation, its nature and the same nature of starch, after adding caustic soda, it will not be a long time thin, even stir phenomenon (add caustic alkali reaction more than 40 minutes than the viscosity of more than 100 seconds), so add oxidants for secondary oxidation, If the oxidation is excessive, the starch ring structure is opened, the viscosity is too low, and even the bonding ability is lost (the viscosity is less than 40 seconds after the addition of caustic soda for 20 minutes). Therefore, special attention should be paid to the use of oxidant content and ratio.
Oxidation also plays a role in the temperature, the higher the temperature, the faster the oxidation, the general oxidation reaction in summer 5-10 minutes, the spring oxidation reaction 10-15 minutes, the winter oxidation reaction is about 20 minutes, the oxidation reaction time is extended, the oxidation is complete, the viscosity is reduced Product quality is stable, and taking too long a time can affect the production cycle.
The specific amount of oxidizing agent changed with starch, the amount of starch was small, the amount of oxidizing agent was small, the amount of sodium hypochlorite (10%) was about 28% of starch, the content of hydrogen peroxide (27.5%) was about 4% of starch, and the amount of potassium permanganate was used. About 2% of starch.
The method for judging whether the oxidation is appropriate is: after adding caustic soda, the reaction is stirred for 20-40 minutes and the viscosity is measured to be about 60 seconds. such
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