Food is made up of many different chemical can components or parts, including vitamins, minerals, sugars, fibres, water, lipids, proteins and starches.

In addition to these main nutrient components, many foods contain smaller amounts of biologically active chemicals. In plants, these are referred to as phytochemicals. Scientists can separate out all of these different components of foods.

Why separate food into its component parts?

There are many reasons why scientists might want to separate out the component parts of food. For example, the nutrigenomics project investigated why different people respond differently to different foods. It seems that sometimes these variations arise because of differences in our genes. This is because our genes can affect the way that our bodies deal with the chemical components that make up a particular food. As a result, some food can components might be particularly good for some people, and cause problems for others!

The aim of the nutrigenomics project is to work out which specific food compounds are most helpful (or most harmful) to people with particular food-related diseases, like Crohn’s disease.

How can different food components be separated?

A range of different methods can be used to separate specific molecules out of foods using a range of different methods. These methods include: Differential solubility, ion exchange chromatography, size exclusion chromatography, and selective adsorption chromatography.

Differential solubility

Some molecules dissolve easily in water; other molecules will dissolve in hexane but not in water. This is because some molecules are more polar than others. Polar molecules dissolve in polar solvents, like water. Non-polar molecules dissolve in non-polar solvents, like hexane. Molecules like sugar are polar, whereas fat molecules are non-polar.

Ion exchange chromatography

Molecules have different charges (positive and negative). This property can be used as the basis of separation. The food sample (as a solution) is passed through a column containing beads that are charged. If the beads have a positive charge, negatively charged molecules in the food will attach but positively charged molecules will run easily through the column and can be collected.

Size exclusion chromatography

This has a sieving effect. Because molecules have different sizes, they move through a size exclusion chromatography column at different rates. Larger molecules are collected first, smaller molecules are collected last.

Selective adsorption chromatography

Because different molecules have different chemical properties, they are more or less able to adsorb (or stick) to materials such as silica gel. This means that they can be separated based on their polarity (degree of surface charge). For example, hydrocarbons (molecules with lots of carbon and hydrogen atoms) have no affinity for silica, whereas alcohols have strong affinity.

How is the use of easy peel-off end in food packaging?

The Easy peel off ends(lids), is a metal packaging form with high sealing and certain pressure resistance,is used in food canned packaging. The base material is made of tinplate or aluminum,after punching, drawing and curling, it can be safely opened after opening.

It is covered with a metal composite membrane or a composite plastic membrane resistant to ultra-high temperature sterilization,with embossed processing, beautiful and easy to open.

At metal sheet left by the punching process of the base lids can be recycled and reused,the food-grade composite membrane covered is small in thickness and quality, saving natural resources,after the consumer opens the end, will not cause environmental pollution in case being discarded.

The peel off end, is widely used, widely used in the packaging of infant milk powder cans with high safety level,nowadays, meat、fruits、vegetables、coffee、tea and other packaging are gradually used.

The peel off end varieties are currently used for dry powde、high-temperature sterilization,、with one-way valve ventilation, and also individualized transparent、 printed 、various sizes of large and small, inner ring is 0-shape Or D-shaped, the outer ring is round or square, etc., China uses a lot of two-dimensional code information technology, now has gradually become popular.

Common types are as follows:

Peel off end for dry powder packaging does not have high-temperature sterilization technology, is used in canned foods such as milk powder and snack foods, is more common in market.

Retort peel off end has the characteristics of high temperature sterilization resistance. It can be used in canned foods such as meat, and consumers can easily cook food.

Peel off end with valve embedded in lid is a one-way pressure relief valve, used in the packaging of fermented foods, such as in canned coffee, to effectively preserve the quality of coffee for a long time.

Transparent peel off end, consumers can see the food they are tempted, have the characteristics of resistance to ultra-high temperature sterilization, UV resistance, water barrier、oxygen barrier, etc.，in recent years, a company in China named Zhejiang Bosun New Material & Tech Co., Ltd. in major technological breakthroughs ,is very novel form of packaging , is well received by consumers.

Tea leaves in tea packaging are peel off end, in recent years by means of business and gatherings,deducting Chinese tea culture into another social culture with exquisite and noble love.

The demand of the market has also led to the development of various types of production equipment. From material suppliers to CNC press machines, peel off end making machine, visual inspection machine, stamping box machine, filling and sealing machine, etc., complete supply chain has been formed and technology is more mature.

Under the development trend of food safety and environmental protection, the material suppliers and the peel off end making machine are technically difficult. At present, Amcor Limited Company and China's one named Huzhou Jinjie Industry Co., Ltd. Is supplier of coating materials. Peel off end making machine, the previous technology is in the hands of SOUDRONIC AG in Switzerland,.Now, Hangzhou Sunking machinery Co., Ltd. Since 2006, after years of hard work, independent research and development, has mastered the technology of peel off end making machine and become a famous Chinese company in international metal packaging industry.

Metal pails and drums are two storage containers that are similar in function, but vary in capacity and the pail drum components used to make them. Notice that pails hold only 7 gallons or less, while steel drums can hold far more. Also, the higher the gauge size of the material, the thinner it is. Pails are made up of 22-24 gauge metal while steel drums are composed of 20 gauge and under making them stronger. Pails typically have bails or handles attached to them for ease of carrying while drums do not.

Many components that make up a steel drum, which is a much more complex design. Items such as fittings are indeed part of each item, though not labeled on both illustrations. These are the openings of the containers, which make it possible to pour out the contents of the container, and typically come in 3/4", 1-1/2“ & 2" sizes in both the Rieke and Tri-Sure brands. Other components include ears, which are attached to can or pail to hold bails/handles; beads (rolling hoops), which are rounded depressions on the surface of a container to improve its performance and the chime, which is a sort of “lip” on the top or bottom of the pail or drum.

Manufacturing

All metal containers must meet certain standards. The most important of these is compliance with UN Regulations. Such regulations mandate that steel pails and drums used in the U.S. need to comply with Department of Transportation standards if they are to be used in the transport of hazardous materials (Hazardous Materials Regulations Performance-Oriented Packaging Standards).

To manufacture steel drums, plants complete the process during a formation phase. To start, the sheet metal to be used in making each drum enters an edge grinder, a machine that rids sheets of jagged edges, smoothing them instead. The steel sheets then enter a bender, which has a cylindrical mold, proceeding to curve and bend the metal.

Next, various welding processes are employed. Once the metal is bent, it is fed by a worker into a spot welding machine, which begins to connect the two ends of the metal sheet into a tube by welding several points along the edge. After this, the two somewhat connected ends are seamed together completely by entering a seam welding machine, welding up and down the entire joint of sheet ends.

Once the basic body of the drum has been created, it undergoes a rigorous manipulation process. The flanging operation includes feeding the drum into flange insertion machine to create rim indentations and edges on the top and bottom of the container. Following the creation of these edges, drums enter a bead expander, a machine that takes the drum horizontally and expands beads or rolling hoops around the circumference of the container. These hoops are created by cranking rods around the inside of the drum and serve to strengthen the body of the item. These outward facing hoops or beads are combined with inward facing circumferential indentations along both the top and bottom of each drum. The indentations are corrugated and are created with a corrugating machine.

Now that the body has been created to the above specifications, the bottom piece of the container must be created and then connected. Drum bottoms first go through a cutting and embossing process. The bottoms are stamped down and cut in a pressing machine using special dies/molds. Once the container bottoms have been made, they enter a pre curler, a machine which smoothes the edges of each bottom piece to prepare it for seaming to the drum body. Ready to be added to containers, bottom pieces enter a seaming machine along with a drum body which rotates and presses the two pieces together. The now-seamed item prevents leakage of materials that the container will eventually hold.

A freestanding container now formed, it’s time to add a top piece to the drum. Drum tops are formed in a similar manner as bottoms. Once created, drum tops must be punched via a machine which will punch out holes in specific sizes and positions. These holes will hold flanges to be inserted next. The flange insertion process involves bending the insides of metal rings within a flange fitting die set/mold machine and inserting them into the drum openings/holes. These openings will later be the point at which drum contents are poured into or out of the container. When all is said and done, the top, now complete with flanged openings, is seamed to the body in a process not unlike that for bottom seaming to create a functional container. This completes the basic steel drum.

Optional processes are employed, however, in steel drum production, depending on preference and end usage. Each drum may enter a paint booth machine, in which the drums are fed horizontally and rotated while the machine sprays and coats the drum exterior with paint. To complete the paint process, the containers are cooked in an oven to help dry and bring the paint to the correct shade.

Much goes into understanding how metal containers work and how they are made. As these items are fairly large storage containers, both pails and drums do get most of their use in industrial settings such as holding chemicals, paints, coatings and petroleum products. Metal containers afford us many benefits as well, including capacity and strength.