Pumping any type of PUR (polyurethane reactive) adhesive requires a hot melt drum unloader, as the material is solid at room temperature and must be heated to convert it to liquid form.KLEIBERIT HotCoating® materials deliver unique performance advantages, but also create challenges for the drum unloader.  This document provides information on HotCoating® and on the drum unloader needed to pump it.  A Case Study at the end illustrates how Versatrim Inc. was able to obtain huge cost savings by choosing a Uniflow® Hot Melt Drum Unloader for their HotCoating® application – over $100,000 annually!


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Why use KLEIBERIT HotCoating® materials?

HotCoating is the process in which KLEIBERIT PUR HC 717 is applied to a surface.  The chemical crosslinking of the PUR material achieves a high surface quality, which is exceptionally shock and wear resistant.  The PUR material also has very high UV stability and chemical resistance.

Direct application of a UV hardening topcoat ensures precise setting of the desired gloss level and allows for variations in coloring.

Uses for KLEIBERIT HotCoating®:

  • Flooring – KLEIBERIT HotCoating® offers significant savings over the traditional lacquering process used on flooring because it eliminates multiple application steps.  There is no micro-cracking, and the high wear resistance of the material guarantees long life for the flooring.
  • Furniture Surfaces and Doors – Real wood surfaces are protected by water-resistant, shock-resistant HotCoating®, plus the warmth and natural structure of the wood is emphasized.
  • Decorative Surfaces / Direct Print / Digital Print – The strong bonding properties of PUR HC 717 to paper, print colors, and lacquer systems make this a great sealer.  HotCoating is applied with a roller application system and it replaces an expensive multi-layered under layer buildup process.

How the Drum Unloader Works

All 55-gallon (200 liter) hot melt drum unloaders work with the same principles.  A heated aluminum platen is lowered into the top of a drum of hot melt material.  Air cylinders are used to apply downward pressure on the platen to maintain contact with the material.  When a melt pool is created, a pump is activated.  The pump pulls molten material through the platen and pushes it into a heated hose.  The hose is connected to the customer’s manufacturing process.  This might be a roll coater, a tank, an application device, or many other things.

What Challenge does HotCoating® Create for a Drum Unloader?

KLEIBERIT’s PUR HC 717 achieves its wear resistance property by adding fine particles to the material.  Ironically, these particles cause the pump on a drum unloader to wear out fast.  Drum Unloader manufacturers initially tried pumping HC 717 with a gear pump, but the pump failed in one day. A piston pump was tried next, and it did not last much longer.  Eventually, one manufacturer developed a piston pump with ceramic seals that would last for about 100 drums.  With the custom pump selling for $14,000 to $18,000, that is an expensive wear item!

How does a Uniflow® ® Hot Melt Drum Unloader Save Money?

Industrial Machine Manufacturing (IMMCO) has been manufacturing Uniflow® Hot Melt Drum Unloaders since 1975.  The Uniflow® brand was well known for handling the most challenging applications – very high viscosities and/or very high pump rates.  However, it was also well known for high prices.  That changed in 2017 with the introduction of the Uniflow® Model 4230.  This machine has many of the features of high-performance Uniflow®  machines, but has a price point that compares well to other brands.

All Uniflow® machines use a machined platen that has almost twice the heat transfer area of any competing platen.  This gives Uniflow® a higher melt rate. The performance of the Model 4230 is so good that IMMCO guarantees a 40% higher pump rate than any other drum unloader.

The high pump rate is helpful, but that’s not the only way Uniflow® saves money.  Every drum unloader leaves some material in the bottom of each drum … sometimes lots of material.  In fact, competing machines routinely leave 1.5” to 3” of material in a drum, or about 22 to 45 pounds.  Since PUR adhesive cures by moisture, the leftover material cannot be salvaged and has to be thrown away.  In the case of HotCoating®, this amounts to $200 to $400+ in waste per drum! The Uniflow®, due to its unique platen, only leaves 1/8” (2 pounds) of material in each drum, saving customers up to $400 per drum! If a customer is running one drum per day, that is a savings of $100,000 per year.

Uniflow® machines also save customers money on maintenance costs.  The Uniflow® gear pump is half the price of the piston pump used on competing machines, and it lasts longer.  In addition, IMMCO offers a pump replacement program that guarantees a low operating cost for customers. When using HC 717, this can offer customers additional savings up to $35,000 annually when running one drum per day.

Uniflow® in Action at Versatrim

Versatrim Inc. is a leading manufacturer of floor moldings, located in Henderson, NC.  The company provides flooring manufacturers, retailers, distributors, installers, and the end consumer with high quality transition moldings at reasonable prices.  They make coordinating laminate decors for all of the big brand names and they offer a variety of solutions including vinyl moldings, LVT moldings, SPC moldings, WPC moldings, and laminate moldings. Versatrim’s list of profiles include three PVC moldings for LVT floors, Slim Trim, VersaEdge, Slim Cap, and their standard laminate T-moldings, Reducer, End Cap (Square Nose), Stair Nose (Bull Nose), Wall Base (Baseboard), Colonial Base, Quarter Round, Base Shoe (Shoe Mold) profiles. In short, Versatrim has achieved rapid growth because they make it easy to find transition moldings and trim that coordinate with any floor.

Versatrim bought their first Uniflow® Model 4230 Hot Melt Drum Unloader in 2018.  They were using a 5-gallon pail unloader to pump PUR adhesive to one of their profile wrapping lines, but as their production increased, they wanted a 55-gallon drum unloader to give them higher pump rates and less down time for drum changes. They chose Uniflow® because it was easy to use, it offered a great value for the price, and the lead time was unbeatable – less than two weeks.  Markus Schalkamp, Executive VP and COO, said “The installation of the Uniflow® was seamless.  The machine was installed and running in a few hours, and IMMCO engineering worked with us to provide the automatic speed control and integration to our wrapping lines that we needed.  The machine has now been in operation for 1-1/2 years and it has worked great.”

When Schalkamp wanted to add a drum unloader in 2019 to pump KLEIBERIT HotCoating® to a finishing line, he turned to IMMCO for another Uniflow®. He cautioned that HotCoating® was highly abrasive, and he was right.  The standard Uniflow® pump only lasted for 3 drums, but IMMCO had a second pump, specifically designed for abrasive material, ready to put in.  So far, that unit has pumped nearly 100 drums of material, and still works well.  Even better, the Uniflow® leaves very little material at the bottom of each drum.  “We were concerned about material waste,” said Schalkamp, “so we weighed the amount of material left in each drum and found it was only about 2-5 pounds.  That was a great relief, because we were told that other drum unloaders leave 20 to 45 pounds of material. The low material waste from the Uniflow® is saving us about $200 to $400 per drum!”


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