Bags

Bags

The most common element for transporting merchandise, both for the private individual and companies, is the bag. We have been manufacturing all types of bag for over 25 years covering the requirements of the most demanding of customers. With the passing of time and in line with our commitment to the environment, we have switched to the production of biodegradable or compostable bags.

The eco-friendly mindset is not a fad but something that all of us need to bear in mind. Currently one of the most requested bags, due to the need for safety and protection in the COVID-19 pandemic are water-soluble bags which are vital for the hospital, care homes and health-centre sectors.

For the retail sector, we have a large number of different models and types which are customisable depending on the size of the order and which in many cases are available from stock. Our team of advisors will be delighted to solve any doubts about the types of bags we manufacture and to advise you on the best choice according to the use and requirements of your business or company.

Preguntas frecuentes

Before buying any bag, the first thing to be clear about is the use you are going to give it. It is not a matter of wasting money on a thick bag when what you really need is a thinner or smaller bag and, therefore, wasting extra material.

You may need a strong, tear-resistant bag, or it may be that what you need is one that can stretch under a heavy load. This factor will determine the thickness. For example, if you are going to buy a kitchen garbage bag and you are going to put milk cartons, leftovers... a thickness of 40 microns will do just fine. However if you need a bag that can withstand punctures and tears from plaster, broken glass, nails, old paints... things change, and a bag of 75 or 100 microns or even thicker is more suitable.

Another factor to consider is color. Bags can be purchased in a rainbow of colors. White is a common choice because it blends in nicely with its surroundings and is non-intrusive. Black bags help hide what's in the bag. But it's important to keep the brand entity in mind to reinforce our message and be able to match the bag to our brand.

To help you find the perfect bag, we will explain the different materials and how they are manufactured, as well as the different types of zippers and handles. We'll also explain their ecological characteristics and the advantages of using low-polluting materials in their manufacture.

It is a flexible, lightweight and affordable material. For billions of people, plastic bags are an efficient and inexpensive way to transport goods.

Plastic bag manufacturing

Most single-use plastic bags are made from a few structural chains of the polyethylene molecule. This polyethylene is obtained from refined petroleum or cracked natural gas. This oil, or gas, is superheated, and pressurized, to isolate the pure polyethylene chains which can be combined (polymerized) to form pure plastic resin granules.

To begin the manufacturing process, known as plastic film extrusion, the raw HDPE, LDPE or LLPDE plastic pellets are again superheated and pressurized to form a uniform molten liquid, into which air is pumped from below, producing a long, thin glob of flexible plastic film that passes through a tall vertical passageway.

This plastic "bubble" cools as it expands upward, and multiple rollers stretch the plastic into thin sheets that form the walls of the bag. These sheets are then rolled into two separate flat parts and sent to the printing machine. The two printed sheets are pressed together at the edges to form the sides of the bag. The plastic can be rolled and then cut to the desired shape and size, depending on the bag design.

If the product is a grocery bag, for example, different amounts of heat and pressure will be applied to create plastic resin granules of different densities. They are usually made of a high-density plastic (HDPE) that has a higher tensile strength compared to plastic films that are made of low-density plastic (LDPE or LLDPE). Let's explain a little more about its characteristics:

  • High density polyethylene (HDPE) Moderate opacity, a propensity to wrinkle, a higher degree of strength than other plastic films and a lack of stretchability. They tear easily, but because of their strength, they are well suited for use as grocery bags or air cushions for packaging, for example.
  • Medium density polyethylene (MDPE) Less opaque than high density polyethylene, but not as clear as low density polyethylene. Generally do not stretch well and are not associated with a high degree of strength. It is used in consumer packaging for paper products, such as toilet paper.
  • Low density polyethylene (LDPE) Used to make bags with moderate stretch and strength properties. It has a high degree of clarity and is commonly used in consumer packaging such as bags for sliced bread.
  • Linear Low Density Polyethylene (LLDPE) Slightly thinner and is characterized by its elastic consistency. These films are usually tacky and have a moderate degree of clarity. Generally used for the manufacture of thin bags.

The first plastic-type bag was created in the mid-nineteenth century, but using organic cellulose from starch. And although it is called plastic, because of its similarity in finish and use, its composition is not the same. It is based on cellulose from cereals such as wheat or corn cobs, sugar cane or tubers such as potatoes or cassava, instead of a carbon source of fossil origin. It is manufactured by fermentation into molecules that, when heated and mixed with additives such as glycerin, form sheets. These sheets can be heated and molded in the same way as conventional plastic bags. Composting is a great way to reduce food waste and the contribution to greenhouse gas emissions. But what is compost? It's simply decomposed organic matter. When you mix a bunch of these elements in a compost pile, they break down naturally and become a nutrient-rich fertilizer.

You can compost any vegetable or fruit scraps, but also stale bread and cereals. Coffee grounds and filters, tea leaves, herbs, spices and nuts. But animal products cannot be composted. Neither meat, fish, butter, yogurt, cheese, nor milk.

When the food in your garbage goes to a landfill, it emits methane, a greenhouse gas that contributes to climate change. Composting is one way to minimize those methane emissions. But in addition, because compost is used as a fertilizer, it reduces the need for chemical options. According to the EPA, compost is also capable of capturing and removing 99.6% of volatile organic compounds, or VOCs, from the air. These vapors and gases can have a harmful impact on health, with side effects ranging from nausea to throat irritation. Studies also show that compost can contribute to carbon sequestration, because when applied to soil, compost functions as a "carbon sink," trapping and holding the element in the soil. And if the carbon is in the soil, it is not in our atmosphere.

Some cities collect compost through garbage and recycling services, in a designated garbage can. And compostable bags are designed for this use, as they degrade naturally and can be part of the composting process.

Water-soluble bags are made of a plastic-like material that dissolves effectively in water, with no harmful residues. Consumer trends are changing and our environmental awareness is growing.

More alternatives to plastic are being developed for companies of all sizes to consider. It becomes an ideal option for brands looking to reduce their reliance on plastic packaging. A water-soluble package means it can dissolve in cold water and hot water (at least 60º). They are made from a bio-based material that is sustainable and earth-friendly.

The main ingredient in this bio-based material is polyvinyl alcohol, or PVA for short, which is a synthetic polymer created without heavy toxic metals that are harmful to the planet. It is also odorless, biodegradable and, as mentioned above, water-soluble. Like the wrapper found on a dishwasher or washing machine tablet, the packaging dissolves on contact with hot water.

Las primeras telas no tejidas comenzaron a utilizarse en la industria manufacturera en 1942 con la entretela. La entretela es el tejido que se encuentra en el interior de las costuras de las camisas y otras partes de prendas de ropa. Se utiliza para aportar una mayor resistencia y estructura.

Las telas no tejidas no contienen hebras entrelazadas, pero tienen una estructura interna organizada. El fieltro es uno de los ejemplos más comunes de tela no tejida. Se fabrica agitando fibras en una solución hasta que se entrelazan formando un tejido denso.

Se fabrican colocando fibras juntas y, a continuación, se utiliza un material cohesivo para combinarlas y crear un material similar a un tejido. Estos son los principales métodos utilizados para la unión de fibras:

  • La unión mecánica: enredo de fibras.
  • La unión química: las fibras se unen con compuestos parecidos al pegamento.
  • La unión térmica: se usa el calor para fundir las fibras entre sí.

Las telas no tejidas son más ligeras y frágiles que las telas tejidas o de punto. La mayoría de los TST se utilizan para una aplicación de un solo uso. Tienen una gran versatilidad y bajos costes de producción. Además su producción es realmente rápida.

Tiene una gran variedad de texturas, y su peso oscila entre 15 hasta 1000 gramos el metro. Esto significa que hay opciones para todo tipo de necesidades. Las telas resultantes no tienen mucho en común, aparte de ser clasificadas como no tejidas. Depende de la selección de las fibras, el encolado y las técnicas de acabado, por lo que los resultados son muy variados. Se fabrican con distintos grados de resistencia, suavidad, absorción y capacidad de filtración.

Las telas no tejidas se utilizan ampliamente en diferentes industrias. Para crear bolsas ecológicas, batas quirúrgicas, ropa de aislamiento y protección, ropa de trabajo industrial, trajes de defensa química, mascarillas...

Aunque el inventor de la bolsa de papel se ha perdido en el olvido, la invención del diseño de fondo cuadrado de la bolsa está documentada en 1870 y su autoría corresponde a Luther Childs Crowell de Wellfleet en Estados Unidos. Pero fue Francis Wolle, maestro de escuela estadounidense, quien inventó la primera máquina para producir en masa estas bolsas ya en la década de 1850. Wolle y su hermano patentaron la máquina y fundaron la Union Paper Bag Company.

Las bolsas se fabrican a partir de pulpa de papel, que se prensa en hojas planas o rollos de papel. Estos rollos de papel se cortan a medida, estas hojas cortadas se doblan y los dos lados abiertos paralelos se pegan. Así se obtiene una sencilla bolsa plana de papel.

Para hacer un diseño de fondo plano más complejo, como las bolsas planas con fuelle, se sigue un proceso similar. Sólo que hay pliegues más complejos en la parte inferior de la bolsa, de modo que la bolsa terminada es cuadrada u oblonga con la parte superior abierta. Y para las bolsas con asas, las asas separadas se fijan con cola adhesiva.

Las bolsas marrones estándar se fabrican con papel Kraft, pero se pueden hacer con todo tipo de papel y en cualquier color. Las bolsas kraft también pueden fabricarse con papel laminado, el cual tiene un revestimiento de plástico en el interior para proteger la bolsa de la humedad de los productos que contiene o para mantener la humedad fuera.

También pueden diseñarse en cualquier color y con cualquier gramaje de papel kraft (normalmente 60 g/m2) y se presentan en una gran variedad de tamaños. Las bolsas de papel son una forma barata, fácil y sostenible de almacenar y entregar todo tipo de objetos, siempre que no estén mojados o sean muy pesados. Además se pueden personalizar tanto en colores como con los logotipos.

A continuación se presenta una rápida introducción a los tipos de cierre de bolsas y asas, para que pueda escoger la más adecuada a sus necesidades.

Bolsas autocierre (cierre hermético) o también llamadas bolsas de cierre a presión o cierre Zip. Son muy comunes y populares, se sella la bolsa sencillamente presionando con los dedos para un cierre seguro. Permite abrirlas y cerrarlas constantemente.

Bolsas con cierre deslizante o de cremallera. Este cierre es muy similar al anterior, pero en vez de presionar se utiliza un mecanismo deslizante unido a la apertura de la bolsa. Son especialmente fáciles de utilizar con las manos enguantadas. Se utilizan habitualmente en el transporte y almacenamiento general de alimentos.

Bolsas con cierre de solapa y cinta adhesiva. La solapa de un lado de la bolsa tiene una cinta adhesiva que cuando se dobla en el otro lado, cierra. Las bolsas Courier se caracterizan por su opacidad y su cierre auto-adhesivo de seguridad.

Bolsas con cierre de cordón. Muy fácil de atar y dejar cerrada la bolsa, tan solo con tirar del cordón y hacer un nudo.

Bolsas con asa camiseta. Denominadas así por su parecido razonable a una camiseta de tirantes. Suelen tener una solapa en la parte superior con un agujero centrado para poder colgarse.

Bolsas con asa troquelada. Se crea una bolsa perforada para facilitar el desgarro. Son el tipo de bolsa que encontramos en las tiendas de comestibles. También hacen referencia a aquellas que el asa se hace mediante una perforación, no es añadida a la bolsa sino que forma parte de ella.

Bolsas con asa lazo. Su asa está soldada en el interior, lo que la convierte en muy cómoda para transportar y muy reutilizable dada su resistencia. Bolsas con asa rígida. Su asa también está soldada a la bolsa, la diferencia con la anterior es que esta asa es más rígida, por lo que no se arruga.