What are T-shirt bags made of? Types and sizes of plastic bags

Many customers are wondering what type of bags to choose: packable, T-shirt, with a die-cut handle or with a loop handle? Everything, of course, depends on the goals that the customer sets for himself. So, in order:

1. Packaging bags

They are not intended for carrying products from stores, as they do not have handles, but only for storage and transportation. Most often they can be found in grocery stores. Popular manufacturing materials: LDPE, HDPE, polypropylene. The minimum size is 6x6 cm. The maximum size depends on several parameters. It is possible to additionally make a closing valve (including with an adhesive strip) and a Euroslot. The bags are printed using the flexography method. Minimum circulation - 5,000 pieces.

2. T-shirt packages

Most often, it makes sense to order them for stores that sell inexpensive and, at the same time, heavy or bulky goods. For example, grocery stores, hypermarkets, auto parts stores. These bags are cheap, spacious and durable. Minimum size: 24x40 cm, maximum - 40x85 cm, load capacity - up to 25 kg. (more is risky, as the bottom seam may not withstand). They are mainly made from HDPE (rustling polyethylene). Their only drawback is that they do not look as attractive as other types of cellophane bags. But the advantages are quite significant, so T-shirt packages are in considerable demand. They are printed only using flexography. Minimum circulation - 10,000 pieces.

3. Bags with die-cut handles

A favorite option for most stores and companies that want to emphasize their status. Indeed, they look more attractive than T-shirts. It can be manufactured from LDPE, HDPE, PSD or COEX (multilayer polyethylene). The handle can be either reinforced or non-reinforced. Often such bags are equipped with a bottom fold. Dimensions vary from 20x25 cm to 85x60 cm. Load capacity - up to 30 kg. Minimum circulation - 500 pcs. (when printing by silk-screen printing) and 5,000 pcs. - for flexo printing.

4. Loop handle bags

When visiting any store, T-shirt bags are offered to make it easier to carry purchases. This is the most common type of packaging products used in various retail outlets. They are inexpensive, but durable and roomy, and they got their name “t-shirt” for the original look of the handles.

Package types

There are two main types of packages:

• from low polyethylene (LDPE);
• made of high pressure polyethylene (LDPE).

Low-cost T-shirt bags with a thickness of up to 25 microns are usually produced from HDPE. Although they are small in thickness, they can withstand heavy weight - up to 15 kg. Such bags stretch less, so they can be used to carry heavy items. To increase the volume of packaging, side folds are used - folds.

HDPE packaging is distinguished by its high tensile strength, but it quickly loses its shape and has low impact resistance - if punctured, it can tear severely. Great for single use. The bags are opaque, usually white, black or colored, rough to the touch, and rustle when touched. They are most often used in grocery stores.

T-shirt bags are also made from LDPE. They look much more beautiful: smoother and shiny. However, they are made thicker, since their strength is much lower, which may increase the manufacturing price. In order for such packaging to withstand a load of up to 5 kg, the film thickness must be at least 50 microns. To withstand a load of up to 8 kg, the thickness must be greater - up to 90 microns.

The LDPE package is less susceptible to deformation and is more frost-resistant, so this packaging is suitable for reusable use. Such films are more durable, resistant to impacts, stretching, compression, and waterproof.

Raw materials for polyethylene production

The main raw material for film production is. They come in two types: low-density polyethylene (LDPE) and high-pressure polyethylene (HDPE).

HDPE granules are obtained from a special solution. The process takes place at a high temperature of +2500 degrees, but low pressure. After a complex transformation, polyethylene is obtained, which is steamed with water steam and then dried. It is stored in powder form or granulated.

To obtain LDPE, a special reactor is used. First, ethylene is heated to a temperature of +1800 degrees, then it polymerizes at high pressure and a temperature of +300 degrees. Ethylene that has not undergone a chemical reaction is removed, and the resulting product is granulated, then dried and packaged.

When T-shirt bags are made, various dyes are also used, which usually make up no more than 3% of the total weight of the product.

Stages of making bags

First you need to produce. For production, special equipment is used - an extruder. Granules are poured into it, there they melt, then the molten material is pushed through heads with special holes of very small sizes - from thousandths of a millimeter.

These machines produce films of varying thicknesses. When using extruders, the best raw materials are spherical granules with a diameter of 3 to 5 mm. Granules of other shapes are also used in production: cylindrical and cubic. The performance of the device depends on the shape of the granules. If you use cubic granules instead of spherical ones, the extruder productivity is reduced by 10%. If you use cylindrical ones, productivity may decrease even more.

When a T-shirt bag is produced on extruder equipment, the end result is a polyethylene sleeve. Next, it is sent to a cutting and soldering machine, which processes it in accordance with the specified parameters.

The sleeve is cut into pieces of the required length, then the workpiece is sealed. The bags, sealed on both sides, go to the cutting press, which is needed to cut out handles. The press can cut out different types of holes. The “throat” of the “T-shirts” is cut out. Now the T-shirt bag is ready.

Logos, company symbols, and various advertising information can be applied to the finished package. This requires a special printing press. It can be used to apply any image using quick-drying paints. As a result, it is quite inexpensive to place effective advertising on the packaging.

A package is a type of packaging for a product, material, things or food, made of plastic (polymer). Plastic bags for packaging are used in all areas of human activity. Due to their ease of use, low cost, reliability, practicality, and versatility, they have replaced fabric, paper, glass and cardboard. We will look at the different types of packages based on material, shape and purpose in this article.

Types of bags by material of manufacture

About 85% of goods are packed in plastic bag. Therefore, manufacturers try to make products from different materials so that they can be used under any circumstances. Types of packaging bags by composition:

• polypropylene;
• polyethylene LDPE and HDPE;
• paper;
• PET (vacuum);
• BOPP.

Polypropylene bags (PP)

This is a frequently used, cheap and convenient package. The material is odorless, colorless, and can be easily painted to the desired shade using pigments or dyes. Able to withstand up to 7 kg of weight, as it has the strength of welds, as well as resistance to damage. Has a thickness of up to 45 microns. Available with or without valve.

Polypropylene bag with a valve (density up to 60 microns) - designed so that one side is larger than the other - for lightness and ease of opening. Scope of application: packaging of food, electronic equipment, textile or household products.

Polypropylene bag without valve (density up to 30 microns) - produced in the form of packaging without a handle, with a fold for the bottom, and an air hole. Scope of application: food and household goods.

Plastic bags

This is the most famous and widespread type of packaging and packaging. Polyethylene is resistant to stretching, damage, alkaline or acidic environments, and decomposition. Retains its properties at temperatures down to -60°C. Does not allow gases and water to pass through, non-toxic.

Considering that plastic packaging melts at temperatures above 80°C, it is not recommended to store hot foods in it.

According to quality indicators, plastic bags for packaging are divided into LDPE and HDPE packaging.

LDPE bags

LDPE stands for high-density polyethylene.

LDPE bags

High-pressure PE is smooth, dense, and aesthetically appealing. Load capacity is up to 20 kg. This indicator is achieved through the use of a special substrate on plastic bags, called “reuter”. The dimensions of LDPE bags and the increase in volume due to the bottom fold allow you to place a large number of items inside.

Technical characteristics: smoothness, density, transparency, high extensibility, wrinkle resistance, elasticity, softness. Thickness – up to 100 microns.

The famous bag with pimples is made from LDPE, which is designed for transporting fragile objects, and at the same time calming the nerves.

HDPE packages

HDPE stands for low pressure polyethylene.

HDPE packages

Low-pressure PE is a cheap and convenient material used for the production of packaging plastic bags, T-shirts, and other packaging. Less stretchable than high pressure PE. Due to the absence of additional elements that strengthen the handle, the product can withstand loads of up to 7 kg. To give the container an attractive appearance, printing is applied to the plastic surface.

Interesting: what are plastic bags made of? Made from a thin polymer combined with CnH 2n (ethylene hydrocarbon gas).

Gardeners widely use bags for seedlings made of black film. They protect plants and seedlings from direct sunlight, take up little space, give good results, and are easy to transport.

Despite the fact that plastic bags are the undoubted leader in the packaging materials market, the composition of a bag made from paper is more environmentally friendly. Other advantages include ease of disposal, recycling, and versatility.

Paper packages can come in various shapes and sizes. They are usually classified as follows:

• vertical;
• horizontal;
• under the bottle.

Coated paper has an average density of 170-200 g/m2, which makes it easy to withstand food and clothing.

PET (vacuum) bag

It is made of cheap, sustainable plastic - lavsan (polyester) with a thickness of 12 microns and LDPE. It does not allow water and gas vapors to pass through, but is not resistant to oxygen. Products with a shelf life of more than a week cannot be stored in it at temperatures above -15°C. But it preserves frozen products well for more than six months at temperatures above -15°C to -20°C.

The higher the percentage of LDPE in the composition, the greater the stability and density of the product. It will not tear or puncture soon.

This is one of the most popular materials, characterized by resistance to elevated temperatures, reliability and flexibility. The composition of the bag is non-toxic, does not interact with chemical reactions, and is designed for repeated use without damaging the surface. Area of ​​application: food, textile, printing, souvenir industries.

BOPP bags are produced with a valve and tape or with a Velcro valve and a hanger. In the first case (thickness up to 45 microns), sticky, reusable glue is applied to the long side. Used for storing textile, household and haberdashery products. In the second case (thickness up to 45 microns), a hole is made at the bottom for a hanger or the bottom is reinforced with a cardboard insert. It is used in stores (on stands, showcases) for general display of promotional products.

What types of packages are there?

Depending on the appearance and design features, the following types of plastic packaging are distinguished:

Interesting: in such plastic packaging you can strengthen the handle and thereby increase the load capacity to 20 kg. Reinforcement occurs using hot welding, cold gluing, bottom turning, integration;

A special feature of the packaging is handles, which can be made in the form of:

• polyethylene strips;
• plastic devices connected to the base through additional reinforcement;
• ropes threaded through holes and tied at the ends.

The most durable are plastic ones, since additional reinforced fasteners are provided in the area where the handles are attached to the bag. This increases resistance to stress;

• ziplock bags. Plastic bags with a zip lock are convenient and practical. They are manufactured with a thickness of up to 40 mm based on LDPE. The packaging does not have handles, but there is a special lock that is difficult to open from the inside, but closes tightly from the outside. This creates a vacuum, which allows you to store liquids and bulk materials. The contents of the plastic bag do not contain moisture, air or dust. Therefore, you can pack food, household goods, parts and accessories from household appliances, as well as other small, valuable things there. The product has gained popularity in the last ten years.

Types of plastic bags by purpose

Depending on their purpose, plastic packaging is divided into consumer packaging (issued at retail outlets) and used for business purposes. The main types are packaging products, garbage and branded products.

1. Packing. Thickness – up to 20 microns. Load capacity – up to 5 kg. They are not intended for transporting goods. Their purpose is to protect the contents of the plastic bag from moisture and dirt. The transparent cellophane bag is designed for one-time use. Feature: low cost and compliance with hygiene standards.
2. Garbage. They are made on the basis of LDPE, HDPE or a combination of two types of polyethylene with dyes. Available without handles, with handles, with a tightening tape. For ease of use, there are tightening straps at the top that need to be pulled out so that the contents do not fall out while moving to the trash cans. The products are sold in rolls, with a corresponding label indicating the displacement. Facilitate the collection and transportation of household waste. Large plastic bags have been created for construction waste.
3. Branded with logo. Developed for advertising products, organizations, events. An image is applied to a plastic surface using flexo printing. This enhances resistance to moisture and dust.

Dimensions and thickness of bags

A wide selection of LDPE bag sizes allows you to select the plastic packaging that suits a particular product. The most optimal sizes are from 25x45 cm to 45x60 cm. Bags with a die-cut HDPE handle are available up to 100×130 cm. If you compare the thickness, dimensions and load-carrying capacity of the bags, the data can be combined into one table.

Types of packaging bags	Density, microns	Dimensions, cm
plastic bags T-shirt	14-20	28 x 50 30 x 60 38 x 60
with cut-out handle

Plastic bags were first introduced to consumers about 50-60 years ago. However, the specialists who produce them continue to work on improving the shape of the finished products and improving the quality characteristics of the bags.

Today, representatives of the NikaPlast company will tell our readers about what types of plastic bags exist.

Main types of polyethylene bags

Now many manufacturers of plastic bags decorate their products with bright colors and print advertising from their partners on their surface.

Most often, consumers are offered polyethylene bags in 5 different versions:

• "T-shirts";
• with loop handle;
• packaging bags;
• With a cut handle (“banana”);
• products with logos.

Each of these types has its own characteristics.

With loop handles

Bags with die-cut (loop) handles are made from high, medium or low pressure polyethylene. They are characterized by a density of 40 microns, have a rectangular shape and allow advertising logos and high-quality printing to be applied to the outer surface of polyethylene.

Some manufacturers even combine several types of films. The product made using this technology is highly durable, has a presentable appearance and often serves as an effective basis for applying an advertising logo. Loop handle bags are becoming a profitable option for advertisers. They belong to the fashion category, and their main feature is the handles, which are presented in 3 types:

• made from a polyethylene strip, which is fixed on the inner surface of the product using a special machine;
• molded from plastic and characterized by a special type of fastening (with additional reinforcement in the fastening area, which increases the load-carrying capacity of the package);
• rope, at the ends of which knots are tied and pulled into holes made in the upper part of the product, and then reinforced with special pistons.

Banana bags with cut-out handle

Banana bags are made from low- or high-density polyethylene, have a rectangular shape and a hole in the upper part, which acts as a handle.

Depending on the production features, this type of bag may have a double fold at the bottom or on the sides. The thickness of the product varies between 35-100 microns.

A banana-type plastic bag has a high density and is therefore attractive to advertisers. Complex designs and logos can be applied to its surface using several different types of inks and flexo printing technology. The design on these products looks more beautiful than on T-shirts. “Bananas” are ideal for packaging small gifts, price lists, advertising and presentation materials. And if this type of package is equipped with side tabs, then you can even put large purchases in it.

"T-shirt"

For the manufacture of T-shirt bags, smooth high- or low-density polyethylene is used. Even representatives of small businesses can set up the production of such products, since the process does not require large material costs. A wide selection of “T-shirts” is determined by their different colors, sizes and shapes. Many consumers prefer this type of package because they are easy to use and inexpensive. "T-shirts" have a load capacity of 5-35 kg. The main disadvantage of this type of bag is its deformation when it is very full. If an advertising image is applied to its surface, then in a situation with deformation it will blur and become unreadable.

Packaging bags may not be very strong and durable, because their main purpose is to protect the packaged goods from dirt, dust and moisture. For the production of packaging products, low-density polyethylene (the cheapest raw material) is used, and they are thin-walled and inexpensive. They are focused on transporting elements with low weight, and therefore have a small thickness and density in the range of 6-13 microns. The load capacity of packaging bags varies in the range of 2-7 kg.

A little about how to apply a logo to a package

There are special types of polyethylene bags that not only serve as an assistant in carrying food or heavy items, but are also an effective means of advertising.

Advertising information is applied to the surface of plastic bags using a variety of techniques. The quality of the picture will depend on which advertising display method is chosen. This parameter is also affected by the characteristics of the plastic bag itself.

The cheapest technology for printing images on polyethylene is line printing. However, in the production of polyethylene products, there are more advanced image printing techniques. The following types of printing on plastic bags are very popular among manufacturers:

• flexography;
• silkscreen printing.

Screen printing is suitable for designing small batches of bags ranging from 100 to 5000 pieces. The work is carried out using inexpensive printed matrices, which, nevertheless, allow you to obtain a bright, colorful and durable design.

Flexographic printing involves the use of expensive stamps (and an individual cliche is used for each type of paint). The flexo printing technique is suitable for applying images to bags that are produced in large quantities, when large expenses will be justified and recouped.

When ordering logo printing on plastic bags, take into account the designer’s opinion regarding the combination of color solutions. If the selection of shades is done correctly, then the effectiveness of the products increases and becomes longer lasting (both for the consumer, for whom the practical properties of the package are important, and for the advertiser, who wants to convey his advertising to potential buyers and clients). This article was written with the support of Nika Plast.