SPECIAL BELTS FOR PACKAGING INDUSTRY

Drawdown belts are used in the packaging industry when something is filled into a folia or paper bag. Drawdown belt is also called haul off or bagger belt, coated belt, vacuum belt, or VFFS belt. The later term is an abbreviation from Vertical Fill Form and Seal Machine, one type of packaging machine where the draw-down belt hauls off the folia to form a bag.

The drawn-down belt consists of a basic toothed belt and a cover. The basic belt is around 90 ShA while the cover should be much softer ranging from 35-55 ShA to sti SPECIAL BELTS FOR PACKAGING INDUSTRYck to the folia or paper they draw for packaging the product into a bag.

For the basic belt manufacturers can use either Polyurethane (PU) or Neoprene timing belt. A lifetime of PU is longer. If you prefer a longer life you should buy PU basic while if the price is a preference you should buy Neoprene. However, if you consider stopovers/ change periods and maintenance cost no question PU is more economic.

Neoprene basic is much cheaper especially when we talk about H, L, XL, and MXL pitches.  Interesting to note that the most popular sizes on this market are T10 920 and T10 630. Drawdown belt can be with or without vacuum wholes

Coating & covers:

Glued Cover. In this case, you can choose from hot rubber, linatex, or silicon if you want to avoid overlap. Manufacturers can buy the basic belt on the market in case the belt is without vacuum holes and then glue a layer on it. Quality dawn down belts have no overlap, they are seamless have not been cut. With a continuous backing, having no overlap joint, belts can run in either direction, with no risk of delamination. The major cause of premature belt failure is absent-minded operators running belts in the wrong direction after cleaning. Continuous backing stops this problem.

If you want to manufacture a drawn-down belt with vacuum whole you cannot use PU basic belt available on the market. If you punch a normal PU T10 belt with Kevlar or Steel cord reinforcement and punch it, the cord sticks out at the vacuum hole. For a vacuum belt, you can use all Neoprene belts because they are reinforced by a glass cord and you can punch it without sticking out the cord at the vacuum hole.

 What cover to choose in case of glued layer?

In Europe, Linatex is one of the most popular covers. The product looks good. However that our customers say it is porous and as a consequence wearing resistance is not the best. In the case of using a vacuum belt with linatex covers, there is more false air compared with using pure rubber or silicon covers.

A lot of the customers don’t use the linatex cover because it is expensive and because they don’t want a cut. A lot of market player’s offers linatex covered timing belts with a cut. Others prefer linatex because it is a brand and they trust it.

Customers whose preference is price issue buy the hot rubber construction because the price is so much cheaper. The wearing resistance of pure rubber is not the best but it is not porous and keeps the vacuum value properly. Has excellent wet abrasion resistance.

The silicon is fairly expensive but customers highly appreciate it. Silicon cover has a lot of advantages: Lifetime is long. The grip is good. Silicon cover is food grade and friendly to the environment. In freezers, silicon cover is unbeatable because silicon has a long lifetime under minus centigrade versus hot rubber and linatex. Silicon has good wear, abrasion, release, and temperature resistance properties.

Good OEMs in Europe prefer to buy this construction. Silicon Glued to a PU basic has the longest lifetime according to our customers.

If you prefer a vulcanized cover solution PU foam is the most popular for PU basic timing belt, while for the Neoprene basic they vulcanize hot rubber.

In the case of PU basic and vulcanized PU foam manufacturers need expensive tooling for the process which shows in the price. The other disadvantage is that PU foam is not environmentally friendly and is not food grade. As these belts are mainly used in the food and pharmaceutical industry one might worry that a piece of the PU foam might drop into the food and that can cause a health problem.

The Neoprene basic belt with the vulcanized cover is manufactured in sleeves and afterward, they are cut into pieces and processed. It is the cheapest solution but if we consider a shorter lifetime and greater maintenance cost it is not recommended, also to note that hot rubber is not food grade.

In the US a lot of OEMs prefer using double mold construction which means they mold a softer layer to the PU basic belt. In this case, you need a special mold for all sizes and profiles.   That makes the belt more expensive. When we talk about drawdown belts sizes and profiles there are many hundreds of variations.

Finally, there is a construction when they spray PU foam to the basic belt but it is not popular and not recommended as this construction is extremely porous and as a consequence small parts easily come off and can drop into the food they pack.

 Conclusion:

Our opinion is that the best solution is the PU basic with glued silicon cover. The PU has a long life while the grip is excellent it is environmentally friendly and can be used under minus degrees centigrade.   Silicon has good wear, abrasion, release, and temperature resistance properties.

Heat resistant timing belts

 

Our endless heat-resistant timing belts are available in Polyurethane and Silicone. To transmit power we recommend the Polyurethane belt produced with hardness 90 ShA and it is heat resistant until 110 °C. Belts made of Silicone are less loadable can be used for transporting but heat resistance is up to 200 °C.

Silicon Belt Up To 200 °C

Mechanical and Chemical Properties:

·       Heat resistance on operating temperature 200°C (on short run-up to 230°C)

·        Very good resistance to hydrolysis

·        Good resistance to oil, solvents, hydrocarbons

·        Free maintenance

·        Silent operations

Applications: Ceramic Industry & Tobacco Industry

Heat Resistant PU Timing Belt With Silicon Cover Up To 100 °C

Mechanical and Chemical Properties:

·   
·        Available with several tension member
·        Hardness of the teeth side is 90 ShA, while the back side is 35 ShA.
·        Good resistance to hydrolysis
·        High abrasion resistance
·        Good resistance to chemicals (hydrocarbons, oils, solvents..)
·        Wide range of standard sizes

Applications: Chemical, Ceramic Industry & Tobacco Industry

Heat Resistant PU Timing Belt

Mechanical and Chemical Properties:

·
·        Good resistance to abrasion
·        Very good dynamic properties
·        Good resistance to hydrolysis
·        Good resistance to chemicals (hydrocarbons, oils, solvents..)
·        Free maintenance
·        Silent operations
·        High Strength and High speed