How to choose hot melt adhesive particles for sealing large household appliance cardboard boxes? Experience of a home appliance factory reducing the unboxing rate to one thousandth

The problem starts with the logistics return order

A home appliance factory in Foshan that produces heaters and small refrigerators experienced concentrated complaints during the peak winter season last year: nearly 2% of the cardboard box covers of goods shipped to the north were lifted or even completely cracked after arriving at the warehouse. The product itself is not damaged, but as soon as the box is opened, the distributor rejects it as “outer packaging damaged”, with round-trip shipping costs and labor for repackaging, consuming less than 100000 yuan per month.

Investigation: It’s not that the glue is insufficient, it’s that three conditions are stacked together

The first reaction in the factory was to increase the amount of glue used, resulting in a 30% increase in glue usage and a decrease in the unboxing rate to only 1.5%. The technicians squatted on site for two days before finally piecing together the reasons:

• The box is heavy.The gross weight of a single box is 18-25 kilograms, with five layers of corrugated boxes. The elastic force of the box cover itself is strong, and the adhesive needs to withstand continuous peeling force, rather than just sticking two layers of paper together.
• Crispy at low temperatures.The truck ran to North China, and the temperature inside the carriage often dropped to minus ten degrees Celsius. The universal sealing rubber particles used before were obviously brittle at low temperatures, and they would collapse along the rubber points when bumped.
• The cardboard box contains a lot of recycled materials.In order to control costs, we replaced the recycled cowhide surface paper, which has low surface adhesion and powder loss. The adhesive dots look full, but in reality, only one layer of paper powder is stuck.

Adjustment plan: Change the type of glue and change the glue application method at the same time

The plan is divided into two steps. Replace the rubber with high initial adhesion and low temperature resistant EVA sealing particles, with a brittleness temperature below -25 ℃, and sufficient initial adhesion to bite the paper surface before the box cover rebounds. The gluing method is no longer to pull a long line along the middle seam of the box cover, but to change it to a “dense at both ends and dotted in the middle” arrangement – the position where the box cover is most stressed is at both ends, and concentrating the amount of glue is more effective than covering the entire process.

result

After changing the glue, the first full container was sent out. 600 boxes were randomly inspected at the northern warehouse, and only one box had a slight raised corner. The consumption of glue per box has actually decreased from 1.6 grams to 1.1 grams, with a monthly production of 120000 boxes. This saves tens of thousands of yuan per year on glue alone, and the hidden costs of returns and secondary packaging are directly eliminated.

Three experiences in selecting adhesive for sealing large household appliances

• First, look at the transportation temperature range. When transporting across regions in winter, it is important to ask about the embrittlement temperature, not just the softening point.
• After changing suppliers or using recycled materials for cardboard boxes, the adhesive should be re validated and old parameters should not be used.
• The arrangement of adhesive points is more critical than the amount of adhesive, and increasing the stress location is often more cost-effective than increasing the overall amount.

FAQ

Q: Will low-temperature resistant adhesive particles become sticky again in summer?
Answer: The formal formula achieves low temperature resistance by adjusting the toughness of the base material, not simply lowering the softening point. It will not stick back when stored at room temperature in summer, but the warehouse should still avoid direct sunlight exposure.

Q: Can we use a glue to seal and paste boxes?
Answer: Small batches can be accommodated, and it is recommended to separate them for large-scale production. The pasting line speed is fast and requires fast curing, while the sealing requires high initial adhesion and anti peeling, with different emphasis on indicators.

Guangzhou Sunlife TradingSunlifehot melt adhesiveOn the packaging and sealing line, different grades are classified according to box weight, transportation temperature zone, and carton material. We support sending samples for trial runs on the customer’s production line to confirm that the unpacking rate and adhesive consumption meet the standards before supplying in bulk. When encountering winter cross regional transportation orders, it is recommended to conduct low-temperature verification one month in advance, so as not to wait for peak season shipments to discover the problem.