Plastic is an organic material derived from crude oil. It has a very heavy molecular weight as each polymer molecule is comprised of hundreds of monomers (the basic substance). Plastic is used in the modern industrial world to manufacture tools, cloth, types of packaging and more. Numerous and varied types of plastic are sold, differing in their flexibility, transparency and rigidity. During the production process, the plastic is poured into moulds of varying shapes and sizes, and as the plastic hardens, it maintains the shape of the mould. Plastics are used as an alternative to wood (furniture, for example), glass (greenhouse coverings, for example), and cotton (in the textile industry).
Our modern world is filled with plastic materials. We use them all day long, for almost everything we do, and sometimes, they are even life saving. Plastics are light weight, strong and durable. They can be recycled and are inexpensive in comparison to other materials. Most plastics are made from synthetic materials – they are man-made. As a result, we can plan and arrange their properties to our heart’s desire. We can make them strong or flexible, transparent or colorful, and can choose from a long of list of properties that might be useful or necessary for the specific design of the item. This is the primary explanation for the significant and central place that plastic holds in our modern world.
At Grofit Plastics we manufacture polyethylene and polypropylene packaging, as well as packaging comprised of more than one type of plastic (laminates).
The basic principle behind the design of the product is the unique relationship between strength and light weight. The characteristic density of plastic is one gram per cubic centimeter. Plastic toy blocks weight almost eight times less than iron blocks of the same size. Glass blocks are two and half times heavier than plastic ones. Plastic is weaker than both iron and glass, but by combining the right materials and the proper engineering design, a strong and durable product can be produced without the need for large amounts of material. A thin polyethylene bag can hold a heavy load for a long period of time without ripping or being damaged and without any harm to the usefulness of the product.
There is another advantage to the light weight of plastic: New technologies enable the manufacture of light weight products that serve as alternatives to products made from heavier materials. Even manufacturers of automobiles, trucks and airplanes make use of advanced plastic materials. With lighter weights, less fuel is required for long distances.
But even though its light weight is advantageous, the volume of plastic is the crucial element. When plastic is thrown away it becomes a tremendous environmental hazard. One kilogram of discarded plastic takes up the same amount of space as eight kilograms of metal rubbish. The use of plastic packaging has greatly increased in our consumer culture and modern way of life. Plastics comprise a high percentage of the average household’s daily garbage. In the past, plastic garbage was burned in order to solve the problem of volume. Although burning plastic can reduce the volume of garbage piles by 90%, and the weight of the pile by 70%, the problem is the toxic gases that are expelled into the air.
Most plastic products can be recycled and processed for re-use by a simple procedure of heating and melting. At Grofit Plastics we recycle all of the plastic rubbish that can be recycled. In recent years, with the increased awareness of environmental matters and the possibilities for recycling, an increase has been noted in the amount of recycled plastic. About one-third of these products return to the production line for re-use.
The processing of plastic materials involves heating and cooling: therefore, energy is required. The temperature for processing plastic materials is much lower than the temperature required for processing glass or metal. Most of the processing is done at temperatures that are available to everyone, in a regular, kitchen oven. Energy costs money, but lower temperatures are significantly more economical.
Another property of plastic that has made it an inseparable part of our lives is the safety factor, even when it comes into contact with food or the human body. This is due to the molecular nature of the substance: the molecules are very large and unlike other molecules, are not capable of penetrating into the human body. But, additives are often added to plastic during the processing stages to improve or introduce certain unique properties to the material. These molecules are usually low in weight and there is a chance that they might penetrate into the body. Therefore, there are strict, international standards regarding the use of additives. Abiding by these standards ensures a safe product. Grofit Plastics abides by all Israeli and international standards regarding contact with food products.
The plastic industry, responsible for developing products that facilitate our daily lives, also strives to offer solutions to enable us to live longer. The industry of medical transplants, for example, has joined the campaign against plastic’s bad reputation and is conducting numerous research studies geared towards finding new types of plastic materials derived from nature. After using the biodegradable products, they can be returned to nature as part of a complete recycling process.
New sources from cornfields, sugarcane and even weeds will soon become the plastic materials of tomorrow. They will have properties very similar to those of today’s plastics, but will be biodegradable. When thrown away, these new plastics will decompose into components such as water and carbon dioxide, which are not at all harmful to the environment. In the near future we expect to see a significant change in the plastic raw material market. Biodegradable substances and materials from renewable sources, derived from sources other than petroleum, will become a reality. Then plastic will be able to join the many substances recognized as having a “green” nature.
Experiments with innovative and “green” raw materials are constantly being conducted at Grofit Plastics. Some of the above mentioned materials are already being used to manufacture simple packaging and we hope to serve as the spearhead of packaging production from renewable raw materials.
The Plastic Packaging Production Process at Grofit Plastics
The plastic production plant at Grofit manufactures polyethylene packaging by a film inflating method. The production process is as follows:
The raw materials are conveyed into a machine for preparation of the mixture. Raw materials for plastic in general, and for polyethylene in particular, usually come in flakes. These flakes are stored in a silo (a huge container) and sucked into a mixing device. The flakes are mixed together with other substances (new raw material, recycled raw material, flakes of color) into a uniform mixture. Actually, the raw material is “colorless” (it has a milky-semitransparent shade). In order to reach the desired shade, a “pigment” must be added to the mixture. The precise composition of the mixture is one of our professional secrets. The prepared mixture is then vacuumed sucked into the machine’s feeder.
The Production of Polyethylene Film – The prepared mixture is fed into the “snail” or the “screw” (extruder). This is a spiral conveyer belt (in the shape of a screw) that operates within an iron encasement (“barrel”). The material is compressed by the revolving spiral and heats up. When it reaches the level of desired viscosity, it is pushed upwards through “the head” and a sleeve of melted plastic is expelled. The sleeve cools on its way upwards and is folded into its final shape at the top section of the extruder. It is then sent for continued processing.
Printing on the Film – After the film is produced, it is sent to the printing machine. At Grofit Plastics, we use the Flexo printing method. The film sheets are stretched onto a large drum surrounded by six stations, each with a different color of ink. A stencil is placed at each station, in accordance with the selected color. Special rollers are used for transferring the ink from the station onto the stencil and consequently, onto the film. The film is then dried by a heating process in order to permanently affix the printed graphics.
Cutting and Sealing the Bags – The printed film, still in the form of a roll, is transferred to the sealing machine. This machine cuts and heat-seals the bags according to the desired size. Additional features are added, as per client requests: carrying handles, ventilation holes, closures for repeated sealing of the bags and a bottom fold for creating larger volumes.
The Unique Types of Packaging Manufactured at Grofit Plastics – At Grofit Plastics, we excel in offering packaging solutions suited to each and every client and emphasize the high quality of our products. Grofit Plastics’ unique products include:
Bags with closures for repeated use – Bags that can be opened and closed repeatedly allow for repeated use of the bag for long periods of time.
Anti-static packaging – Packaging for use in the electronic industry that prevents the occurrence of static electricity while packaging sensitive electronic components.
Anti-corrosion VCI Packaging – Contains a substance that prevents the formation of rust on the packaged product. It is used primarily by weapon and automobile industries.
Bio-fresh Packaging to Maintain Freshness – These smart bags limit the transmission of gases and thus delay the formation of mold and decay on fruit and vegetables. The bags are intended for long-term use by the fruit and vegetable industries (shipping by ocean freight, for example).
This part of the process is comprised of two primary stages: The first is conducted primarily by the intended client and includes the defining of his specific needs. The second is conducted in cooperation with the Engineering and Development Department at Grofit Plastics. It includes developing and coordinating theoretical, technical solutions suited to the client’s needs (as defined by the client) and building the tools required to produce (perforators, sealers, etc.), to store (method of packaging) and to ship the goods.
Defining the Client’s Needs
At first, it this would seem to a trivial stage – the client knows what he wants . . . But, in reality, clients often voice a type of request such as: “I need a bag like the one X has, but a bit wider and with the handle a little bit higher. Can you make me something like it?”
The answer is “Yes, and in order to do so we need more details, like: the purpose of the packaging, the shelf-life of the product, other special requirements, etc.” In short, the stage of defining the client’s needs is not complicated, but it is vitally important to conduct this stage in an organized and efficient manner in order to ensure that you, the client, receive precisely what you want (and need). For your convenience, we have enclosed a list of questions to help you focus on the important aspects and to assist us in planning the most suitable product for your specific needs.