Hygienic, transparent and from a single mold
Why timing belts produced by injection molding are ideally suited for use on packaging machines for food and pharmaceutical products
Hygienic, transparent and from a single mold -
Why timing belts produced by injection molding are ideally suited for use on packaging machines for food and pharmaceutical products
Timing belts used in the food industry must meet high standards. Among other things, these include ease of handling, insensitivity to certain cleaning agents, few surfaces for dirt to accumulate, and various legal requirements.
Together with a manufacturer of food packaging machines, Alphabelt has developed a belt that not only meets the highest hygiene standards, but also offers several other advantages.
Initial situation and hygiene-optimized belt design
Conventional timing belts have so-called winding noses - small grooves in the tooth base that make the belt more flexible. The disadvantage is that the tension cords are exposed and unprotected at these points. Moisture and cleaning agents can penetrate and attack the material. Particles can be dislodged and come into contact with food. In addition, impurities accumulate more easily in the fine grooves.
In order to merely avoid corrosion, it would theoretically be possible to use tension cords made of stainless steel. However, this is not only much more expensive, but also does not solve the problem of dirt accumulation. We therefore rely on a hygiene-optimized belt design, i.e. surfaces that are as smooth and closed as possible to facilitate cleaning and prevent dirt from accumulating.
Development of a special transport belt for food packaging machines
A manufacturer of production equipment in the food sector asked us for a special timing belt that could be used on its packaging machines. With the help of these machines, thermoformed packs are to be filled and sealed fully automatically. For example, fresh meat, sausage, fish, poultry, cheese, snacks, baked goods, fruit and vegetables are packaged.
ADue to the modular design of this manufacturer's equipment, it is also possible to connect automatic inspection systems to the packaging unit. These can be metal detectors, for example, or optical inspection systems for counting applications or quality assurance tasks.
The new timing belt therefore had to meet the following requirements:
- Hygienic, easy to clean
- Insensitive to moisture and cleaning agents
- Transparent / translucent
- No deflection with magnetic fields (metal detectors)
Based on an already proven timing belt with a hygiene-optimized surface design, the idea for a completely new design was developed through consistent further development.
Production by injection molding
The base material selected for the timing belt already has sufficient tensile strength itself for the desired application, so that tension cords could be dispensed with completely here. This offers the advantage that the belt (when using a translucent material) can be optically shone through, for example in camera applications. Since no metallic components are used, the belt can also be used on metal detectors without any problems.
Due to the completely homogeneous belt structure, this timing belt can be manufactured by injection molding, which significantly simplifies and accelerates the manufacturing process. A special mold must first be made for the desired pitch and length of the belt. The belt material can then later be injected directly into this mold. There are two possibilities when designing the mold: Either the mold is already manufactured with the belt width required later, so that exactly one belt is produced per casting process. Or (similar to timing belts made of cast molded rolls) a wide "sleeve" is cast, from which the desired belt widths can then be cut off as required.
In any case, the belt produced is endless, i.e. manufactured without a splice. This eliminates potential weak points, and the tensile strength is constant over the entire belt length.
Other options of the injection molding process
The injection molding process offers a number of options for imparting certain properties to the timing belt directly during the injection process: For example, surface structures (spikes, lamellae, lengthwise contours, etc.) can already be incorporated into the mold. If wear protection is required on the tooth side, an appropriate PA fabric can be inserted into the mold and incorporated during the injection molding process. A FDA-grade PU coating can likewise be finished in the same operation. Depending on the belt material, various colors and degrees of hardness are also available.
The features at a glance
Here again is an overview of all the characteristics for our timing belts produced by injection molding:
- Homogeneous belt structure
- Manufactured without splices
- Hygiene-optimized design without winding noses
- Without tension cord, therefore limited tensile strength
- Suitable for optical applications (transparent)
- No metallic components (suitable for use in magnetic fields, metal detectors, etc.)
- Different surface structures possible
- Different colors possible (blue and transparent, other colors on request)
- PAZ coating possible
- PU coating in FDA quality possible
- Different degrees of hardness possible (60, 83, 95 Shore A)
- Any pitch possible
- Max. length 950 mm
- Max. width 150 mm
Application examples for timing belts produced by injection molding
As described above, our timing belts produced by injection molding are already successfully used as conveyor belts in packaging systems for foodstuffs. Due to their special properties, they are suitable here not only for the packaging process itself, but also for the subsequent optical or ferromagnetic processes for quality assurance.
A very similar belt, but much slimmer and shorter, is now used in a pharmaceutical plant on which tablets are packed into blister packs. Thanks to its hygiene-optimized design, the belt easily meets the increased cleanliness and purity requirements that apply here.
A completely different application example, which is particularly intended to illustrate the versatility of injection-molded belts, relates to the brake belt for a printing press: Here, an 8 mm wide and 230 mm long belt was produced by injection molding and has since been proven in use.
Alphabelt - Your partner for innovative solutions
Do you also have a special task that you're still looking for the perfect belt for? Just contact us - together we will develop a solution tailored exactly to your application!
Contact