20 questions about cutting

1. What is steel cutting?

Steel plate cutting is a process where a part of the plate is separated from the rest. There are two distinct methods: thermal (hot) and mechanical (cold).
The most common cutting methods used for steel plate are:

Thermal:

Shengmao are exported all over the world and different industries with quality first. Our belief is to provide our customers with more and better high value-added products. Let's create a better future together.

• Oxy-fuel (or flame)
• Plasma
• Laser

Cold:

• Waterjet (AWJ)
• Shearing
• Sawing
• Punching
• Machining

2. How to cut steel

There are many ways and methods of steel cutting. They can basically be divided into two methods: Thermal cutting and Cold cutting. Thermal cutting methods use thermal energy obtained by combustion reaction, electric arc or light rays. Cold cutting methods use mechanical energy for cutting. Typical examples of thermal cutting methods are oxy-fuel (or flame) cutting, plasma cutting and laser cutting. Typical examples of cold cutting methods are waterjet cutting, shearing, sawing, punching and machining.

3. What are the types of thermal cutting of steel?

The most common thermal cutting methods used for steel plate are: Oxy-fuel (or flame), plasma and laser cutting.

6. What is oxy-fuel steel cutting?

Oxy-fuel cutting is the oldest and most commonly used steel cutting method. It is used for cutting materials 3-300 mm thick. A burning gas jet or flame (acetylene or propane) is used to heat the steel to its ignition temperature (approx. 900°C). Oxygen is mixed into the fuel flame to enhance the melting and burning process. The gas jet oxidizes and blows away the liquid steel and oxidation products, producing a hole. The flame motion at a proper speed forms a continuous gap between the plate parts to be separated.

7. What is plasma steel cutting?

Plasma cutting is a thermal cutting process where an electrical arc ionizes a gas jet to form a plasma at temperatures exceeding 20 000°C. The steel is melted, oxidized and blown away. The tool is moved along the intended cutting line at a proper speed forming a gap line between the plate parts to be separated.

8. What is laser steel cutting?

Laser cutting is a thermal process where a high-power laser beam is used to cut, melt or burn a hole in a steel sheet or plate. The beam motion will produce a line gap, separating the sheet or plate into two.

9. What is waterjet steel cutting?

Waterjet or abrasive waterjet (AWJ) cutting is a cutting method where a high-pressure water jet carrying a fine-grained abrasive erodes a hole in the steel. The waterjet motion will produce a line gap, separating the steel plate into two.

11. What is preheating of steel?

Preheating steel before cutting increases the temperature in the vicinity of the cut during the actual process. This will reduce the risk for hydrogen-induced cracking in particular for high-strength/hard steel. The maximum temperature allowed greatly depends on the steel grade. Too high temperature may destroy the steel properties.

13. What is post-heating of steel?

Postheating can be applied directly after thermal cutting in particular for high-strength and hard steels. The purpose is to reduce residual stresses and to make hydrogen diffuse out of the cut pieces, thereby reducing the risk for hydrogen-induced cracking. A furnace or a gas flame can be used for post-heating. Using a flame calls for careful temperature control to prevent undesired changes in steel properties.

14. How do I choose cutting speed?

The single most important factor controlling cutting speed is plate thickness. SSAB steel grades can be cut as any commercial steel grade. The cutting machine suppliers give proper recommendations.

15. What are hydrogen-induced cracks in steel?

A hydrogen-induced crack is a delayed crack phenomena that might occur during cutting of steel using thermal methods. The cutting process will contribute with some hydrogen, with temperatures stimulating diffusion of hydrogen and residual tensile stresses. The concentration of hydrogen in the steel, close to the cut, will increase. In hard steel in particular, the conditions necessary for hydrogen-induced cracking are now present. Since diffusion of hydrogen in the steel needs some time, cracking can be delayed for some days.

17. How can I improve steel cutting quality?

Oxy-fuel cutting: Make sure the relation between cutting speed and cutting oxygen pressure is correct. A high speed requires a high pressure and vice versa. To obtain satisfactory cut edge quality, the cutting speed must be maintained within a certain range. Check the recommended cutting speed provided by the manufacturer.

Plasma cutting: The recommended speed provided by the manufacturer often works well with new consumables, when the consumables get more worn, it often helps to reduce the cutting speed slightly. The voltage during plasma cutting will affect the shape of the kerf. If the kerf is very narrow at the bottom and wide at the top, the voltage should be decreased. The same situation will occur if the travel speed is to high. If the kerf is very wide at the bottom, the voltage could be increased.

Laser cutting: The most important factors for a good cut edge quality during laser cutting is surface cleanliness and temperature of the material. Remove paint or corrosion prior to laser cutting, try to nest the cutting sequence so the heat is distributed over the entire plate.

Waterjet cutting: A low cutting speed will result in a better cut edge quality, make sure that the nozzle is in good condition when high quality is required.

18. How does the surface quality effect the cut edge quality?

A dirty, painted or corroded plate surface is detrimental for the cut edge quality, although this depends on the method.
For oxy-fuel and plasma cutting, the surface condition has a limited influence, during oxy-fuel cutting the speed might need to be reduced slightly if the surface is painted or corroded.
For laser cutting, surface quality is very important and a very clean (naked) plate surface near the intended cutting line is needed. 

19. What is the Heat Affected Zone (HAZ) of steel?

The Heat Affected Zone (HAZ) is the area of base material which is not melted but has had its microstructure and properties altered by the intensive heat of cutting operations.

20. How large is the Heat Affected Zone (HAZ) caused by cutting steel?

The size of the HAZ depends on steel grade, the plate thickness and heat input. Higher heat input will provide wider HAZ. According to that wider HAZ will be when cutting with Oxy-fuel cutting method comparing to laser cutting which will provide narrower HAZ.

Category and tags

img]:inline [.inverted_&:hover]:text-[--txt-content-interactive-inv]">Contact Technical support

When surgery patients go home, they sometimes look like Freddy Krueger visited them in their anesthetic dreams.

Veterinarians rarely pay much attention to clipping and clippers, but they should, because poor technique and cleaning actually could affect the outcome of the surgery.

Clipping patients actually goes well beyond surgery. We reach for clippers during wound management, before ultrasounds, to place IV catheters and to perform intradermal allergy testing.

As ubiquitous as they are, the humble clippers are a common source of frustration. A classic comment is "our clippers suck." To be fair, clippers are abused, poorly cleaned and dropped regularly.

The company is the world’s best Clipping Machine supplier. We are your one-stop shop for all needs. Our staff are highly-specialized and will help you find the product you need.

Here are 10 questions and answers about the proper use and management of clippers.

1. What's the Big Deal About Cuts and Abrasions?

The most obvious reason is that they hurt. Just think of the last paper cut you had.

In addition, skin trauma can encourage patients to lick at their surgical site. At worst, it can lead to dehiscence of the incision.

When clippers cause abrasions or "clipper burn," the damaged tissue can result in bacterial colonization or infection. Nosocomial infections are a growing concern in our profession. Appropriate clipping and cleaning techniques are important to reduce these risks.

2. What Bacteria Can Be Involved? 

Clipper blades have been shown to harbor several types of Staphylococcus, Pseudomonas and Actinomyces, as well as E. coli.

Pseudomonas spp. has been shown to survive up to 16 months on inanimate objects. This is the reason why cuts and abrasions should not be taken lightly. They are not just a pain; they can lead to infection.

3. How Clean Should Clippers Be?

Appropriate cleaning and care of blades and clippers is important for adequate surgical preparation. . Ideally, they should be cleaned after each use.

They definitely should be cleaned thoroughly after clipping hair around infected sites, the anus, the feet and any body part that is oozing. Cleaning clipper blades soon after they've been used simplifies debris removal.

4. How Should Blades Be Cleaned?

Here is a step-by-step protocol:

1. Unplug the clippers.
2. Remove the clipper blade.
3. Brush hair from the clippers.
4. Turn the blade facedown.
5. Use a stiff brush, such as a toothbrush, to remove the hair from the blade using an upward motion. Gently slide the cutting blade to each side, and remove debris between the cutting blade and the guide blade.
6. Place the blade back on the clipper, and dip the running clipper teeth of the blade into blade wash for 10 seconds.
7. Turn the clippers off.
8. Remove the blade and gently dry it with a towel.
9. Apply clipper oil to the teeth. Slide the cutting blade to one side and place thin strip of oil at the bottom of the guide teeth and the upper and lower running rails.
10. Slide the cutting blade to the other side and apply oil in the same manner.
11. Wipe excess oil off the blade.
12. Run the clipper for 10 seconds before use.

5. What Type of Blade Is Better?

For the closest surgical preparation, a number 40 or 50 blade should be used. Most clinics use stainless steel blades. Have you heard of ceramic blades? They remain 75 percent cooler than steel blades, so they can be used for longer periods.

Multiple blades should be available in case they get dirty or hot. Always check the blade's temperature on your wrist. If it's hot, please change blades for your patient's sake.

6. What Is the Best Way to Clip?

Before you even think of clipping, inspect the blade. If it has broken or missing teeth, throw it away because it cannot be repaired. Rust, however, often can be removed by refurbishing. Any blade that cuts poorly, pulls hair or vibrates excessively should be serviced.

It's amazing to see how many people clip incorrectly. The most common mistake is holding the blade at a steep angle or even perpendicular to the skin. Keep the blade parallel to the skin to ensure the cleanest, closest trim.

First, clip fur in the same direction as the hair growth to remove the bulk of the fur. Then clip it in the opposite direction to obtain the closest shave.

7. Cordless or Electric?

Surely, cordless clippers are more convenient, but electric clippers won't die mid-use. Keep all cordless clippers clean and charged at all times in case of an emergency situation, such as a patient in shock who needs an IV catheter. To be safe, consider keeping both types of clippers at hand.

8. What Are the Best Ways to Disinfect Clipper Blades?

Studies show that certain disinfectants can decrease bacterial growth substantially, while others don't do a very good job.

Multiple products—sprays, solutions, alcohol, disinfectants, lube, etc.—can be used to clean clippers. Which ones are acceptable?

The following methods were found to be unsuccessful at inhibiting growth for 48 to 120 hours:

• No soaking
• Saline soak (20 minutes)
• Isopropanol and phenylphenol (10 minutes)
• Ethanol/dimethyl benzyl ammonium chloride/o-phenylphenol spray (10 minutes)

9. What Are the Best Products for Disinfecting Blades?

The following products were found to be the most successful at inhibiting bacterial growth for 48 to 120 hours:

• Ethanol and phenylphenol based spray (moist for 10 minutes)
• 70 percent alcohol (20 minutes)
• 2 percent chlorhexidine solution (20 minutes)

10. How Short Should Hair Be Before Surgery?

The best way I can summarize the answer: I would rather see very short hair on a surgical patient's skin than clipper burn, cuts and abrasions.

When all is said and done, we do not want to put our patients at risk over something as routine as clipping. Proper technique makes a significant impact on the patient's well-being. Be sure to appropriately maintain and clean all clippers to prevent irritation, abrasion and infection. The end result is happier clients and healthier patients.

Contact us to discuss your requirements of heavy duty meat grinder. Our experienced sales team can help you identify the options that best suit your needs.

References

1. Ley B. "Evaluation of Commonly Used Products for Disinfecting Clipper Blades in Veterinary Practices: A Pilot Study." JAAHA. 52(5):277-280, .
2. Mount R et al. "Evaluation of Bacterial Contamination of Clipper Blades in Small Animal Private Practice." JAAHA. 52(2):95–101, .