Precautions for buying high quality carton adhesives

In the packaging industry, adhesives are a very widely used material. In the corrugated boxes, folding boxes, paper pallets, paper tubes, and paper protection corners, adhesives are used, and the scope of use of the adhesives is also covered. From the papermaking to corrugated processing, paper or paperboard layer bonding, veneering, film and adhesive molding and other multiple processes. Therefore, for the packaging industry, its importance is naturally self-evident.

For a long time, due to the small proportion of the cost of the adhesive in the packaging products, it has not been given sufficient attention, so many packaging companies lack sufficient understanding of the adhesive. For this reason, this article will briefly analyze the market conditions, purchase methods and quality requirements of adhesives, in order to provide some reference for the purchasing personnel of packaging companies. Only by purchasing high-quality adhesives, can we ensure the bonding quality of the carton.

Current market analysis of the adhesive market According to statistics, the current domestic adhesive market for packaging has reached an annual growth rate of 8% to 10%. From the perspective of the development trend of the packaging industry in China, this growth rate may continue. As the competition in the packaging industry continues to increase, packaging companies gradually move towards rationality and maturity in the procurement of adhesives, and the use of adhesives has become diversified, environmentally friendly, and low-cost.

Corrugated board processing is one of the most used adhesives in the packaging industry. Most of the adhesives currently used are self-made heat-curing starch adhesives, and a few manufacturers have insufficient equipment capacity or use cold-formed corrugating technology to use synthetic resins or Oxidized starch binders. Heat-curable starch adhesives are made by cardboard manufacturers using starch, caustic soda, and borax, and they are used to glue the adhesive to glue the cardboard.

The amount of binder used for the surface coating is only inferior to that of the corrugating process. At present, there are three types of brewing alkali, synthetic resin and starch binder on the market. The silicate is also called water glass, its adhesive strength is still acceptable, but there is a major shortage of synthetic resin binders such as slow drying speed, easy efflorescence, moisture absorption, and damage to carton properties. , Made of polyvinyl acetate emulsion. Due to the scarcity of materials, high costs, and high energy consumption, its market share is rapidly declining. In stark contrast to this, starch adhesives quickly occupied the market due to its many advantages such as fast initial adhesion, firm bonding, good water resistance, low cost, and environmental protection. It can be foreseen that in the next few decades, unless newer materials emerge, the water glass will completely withdraw from the market, and the starch adhesive will occupy most of the market share. Synthetic resin will only be used as a supplement to become a market for adhesive coverings. The inevitable trend.

In the past, due to limitations in drying speed and adhesive strength, the bonding of ordinary cartons, paper tubes, paper cards, and paper pallets basically used synthetic resin adhesives. With the continuous development of starch adhesive technology, many starch adhesives newly released on the market have the same drying speed and adhesive strength as synthetic resin adhesives, and the cost is much lower than that of synthetic resin adhesives.

At present, most of the adhesive products used in the market are solvent-based polyurethane adhesives. In view of the harmful effects of solvents on human bodies, there are potential fire hazards during use. Some manufacturers have developed environmentally friendly, non-flammable, non-toxic, and widely adaptable waterborne environments. Polyurethane adhesives. However, its adhesive strength is lower than that of the solvent type, the drying speed is slow, the energy consumption and the cost are high, and the development prospect is not optimistic. Recently, foreign companies have also produced solvent-free polyurethane adhesive products. Solvent-free polyurethanes are environmentally friendly products in the true sense of the word. They have strong peeling power, low energy consumption, and a wide range of applications. Therefore, they must be rapidly promoted in the market.

In addition, some cartons whose surface has been coated with a film or treated with UV have a particularly high requirement for the permeability of the adhesive, and some of them are used.

I. Precautions for Adhesive Purchase

1. The necessity of using starch adhesive

The use of starch binders instead of synthetic resin binders will benefit cost savings. The starch adhesive has excellent characteristics such as fast drying, strong adhesive force, no pollution to the environment, and very low cost. In adhesive, ordinary carton bonding, paper tube bonding and paper pallet bonding, starch adhesives can completely replace synthetic resin adhesives.

2. Advantages of hot melt adhesives

In many adhesives, the hot-melt adhesives have the shortest drying time, and hot-melt adhesives should be used for the adhesive molding processes that require instantaneous drying and curing. Hot melt adhesives are very suitable for the bonding process between plastic foams or EPE materials and paper. They not only dry quickly but also have a very strong bond. It should also be noted that although hot melt adhesives are the most widely used adhesives, they are not suitable for bonding of paper products that have been exposed to UV varnish.

3, adhesive coated products with UV varnish

Paper products with UV varnish on the surface require special attention for adhesion. At present, there are three commonly used bonding methods, one of which is to use base oil first, followed by UV polishing, and then use a special UV box to glue the box glue; the second is to use local UV method to combine The parts are protected from UV varnish and then bonded with white latex. Third, the bonded parts are ground before bonding, and then coated with white latex. After the surface of the coated paper products, it is best to use a dedicated box glue sticky box glue.

4, according to the mode of operation to choose adhesives

It is also very important to choose a binder with a suitable drying time depending on the mode of operation. The drying time of the adhesive can be divided into two aspects: the initial dry time and the dry time. The initial dry time is the time that the adhesive force generated after the adhesive is coated is sufficient to destroy the adherend. The initial drying time should be matched with the bonding process and bonding equipment, otherwise it will affect the bonding quality. Drying time refers to the time after a long time of drying to enter the next process. The thorough time directly affects the product delivery cycle.

(to be continued)