Specifying conveyor belts

Manufacturing and material handling equipment designed for the medical and pharmaceutical industries must be heavily regulated for safety purposes. This means any automated conveyor system used in these operations must be completely sanitary, easy to clean, and resistant to corrosion. Forget rubber or plastic – stainless steel conveyor belts fit the bill for these requirements.

From the production and distribution of DNA test kits and COVID-19 test swabs, to the creation of robotic operating equipment, metal conveyor belts play an important role in medical manufacturing. PureSteel metal belts from Belt Technologies Inc., are custom designed and fabricated for this use.

Why metal belts?

Metal belts offer advantages over belts made of other materials. When specifically applied to medical and pharmaceutical production, stainless steel belts provide superior precision control, hygiene, and customization options.

In many cases, stainless steel is preferable to other materials (such as rubber and fiberglass) because metal won’t stretch and variations in surface speed are minimized. Metal belts offer unlimited travel lengths and are available in a variety of alloys. When compared with other power transmission or motion control components (linear actuators, lead screws, chains), metal belts are often preferred due to their high strength-to-weight ratio, durability, and precise positioning.

Additionally, metal belts can be stacked in multiple layers consisting of several bands ranging in thickness from 0.003" to 0.005". This arrangement combines the strength of all layers while retaining the reduced bending stress of each individual layer, increasing the modulus of elasticity and helping resist backlash. The stacked configuration also improves belt strength without sacrificing precision or flexibility in tight spaces – an ideal scenario for robotic surgery applications.

Hygiene

Although popular, polymer, plastic, and metal mesh conveyors are limited in hygienic capabilities and may increase the risk of contamination. It’s not a coincidence that equipment coming into contact with medical products is often made with austenitic stainless steel 304L or 316L because it has a smooth, impermeable surface offering no opportunity for the invasion of microbes or bacteria. The complete lack of gaps, recesses, and crevices also makes it easier to clean than traditional materials. Stainless steel is also resistant to corrosion so it can be sanitized by high-pressure steam, high-pressure wash, or chemical cleaning.

Products from Belt Technologies also don’t require dust-generating lubricant that could introduce foreign substances into cleanroom environments. Their sterilization process can be performed in an autoclave, so unlike materials that call for the belts to be removed from the conveyor for regular cleaning (which interrupts production), metal belts can be cleaned in place.

Customization

For customization, the most important element is a belt’s pitch profile – the space between individual perforations, timing pins, or other such features on a conveyor. Perforations are created by mechanical and laser cutting, die-and-cut presses, and rotary-pinned perforation rollers. While custom pitch profiles vary by manufacturer, Belt Technologies can create perforations in stainless steel belts as thin as 0.002", as narrow as 0.040", and as wide as 36".

Other customization options include a large array of metal alloys, belt width and thickness combinations, perforation patterns, coatings, and attachments.

custom assembly systems for high-volume disposable medical device production (syringes, pen needles, and pipettes) found success with Belt Technologies’ conveyors. The automated machinery producer needed to move small needles for automated assembly of a medical device, so a precisely designed custom belt was needed. The required solution also had to excel in a cleanroom environment while offering repeatability and the personalization of a custom pitch.

Repeatable accuracy was also critical to the belt design; the product had to be capable of holding tight tolerance on the pitch. This was possible because metal belts don’t exhibit pulsation – enabling precise transmission of the control system’s motion profile. To ensure the most accurate and reliable motion possible, PureSteel metal belts are manufactured to dimensions with very tight tolerances. This allows Belt to fabricate metal belts with a pitch accuracy of ±0.0005", which is valuable in designing, indexing, positioning, or processing bulk medical devices.

About the author: Denis Gagnon, BA, MBA is CEO of Belt Technologies Inc. based in Agawam, Massachusetts. He can be reached at dgagnon@belttechnologies.com or 413.786.9922.

Belt Technologies Inc. https://www.belttechnologies.com