With the costs for labor and workmen's compensation continuing to spiral upward, more and more companies are moving toward bulk material handling to reduce labor content and eliminate manual handling as much as possible. For pharmaceutical manufacturers, reusable plastic hoppers provide one of the most economical solutions.
At first glance, the process of choosing a hopper for collecting, storing and transporting tablets, granulations and powders manufactured in your pharmaceutical manufacturing operation may appear to be quite simple. But in order to maximize operational efficiencies in your handling system, you should conduct a thorough analysis of your needs so you can select or design a hopper that offers the greatest positive impact on your bottom line.
Use the following checklist to make an informed decision about the pharmaceutical hopper that best meets your bulk material handling needs. Before you make a final selection, however, it's best to review your options with a qualified container consultant.
What's In Your Hopper?
Are you handling tablets, caplets, capsules or granular materials? What are the physical properties of your product? Is it fragile or robust? What is the bulk density in pounds per cubic foot or kilograms per cubic meter? Knowing critical information about the contents the hopper will contain will have an important bearing on your choice.
Start With the Basics
Naturally, the hopper you select should be constructed of FDA-approved polyethylene. Additives such as pigments and anti-static agents, for example, must also meet FDA standards. Most polyethylene materials have traces of animal derivatives and you should determine if this condition is acceptable for your products. If not, make sure your supplier is aware of your requirements and uses an animal-derivative-free polyethylene.
Make A Good Fit
It's a good practice to walk through all the areas of your plant where hoppers will be used and note all space restrictions.
Ask yourself: "Do the filling and discharge stations limit the size of the hopper?" "Does the hopper need to fit under a coating pan?" "Is there adequate ceiling height to place the hopper over a feed station?" "Will the hopper need to be specifically positioned?" "Does orientation matter?" "Is the hopper compatible with existing equipment?" "Where will the hoppers be stacked?" "Will the sprinkler system provide adequate protection?"
The answers to these questions will help to simplify your selection process and make sure the hopper is a good fit for your operation.
The Plastic Advantage
Plastic hoppers are a lightweight, cost-effective alternative to stainless steel and can be stacked or racked to make efficient use of floor space. What's more, they are gentler on expensive flooring materials found in most pharmaceutical facilities, and are much quieter than metal containers. Reusable and durable, plastic hoppers offer an environmentally-friendly solution that can help to eliminate waste generated by small, single-use cardboard boxes and fiber drums.
The Capacity Is Right
Batch size drives container volume, which means selecting the right capacity for your hoppers is essential. For handling and validation purposes, it makes sense to specify a capacity that matches the smallest processing equipment on your line. Sizes generally range from 13 to 45 cubic-foot capacities. Larger or smaller capacities, however, can be produced to meet specific requirements.
Do you use an automatic or manual cleaning process? Lightweight polyethylene hoppers that detach from their bases are easier to handle, clean and sanitize than heavy metal containers. Plastic hoppers with smooth, seamless interior surfaces are ideal for complete, rapid cleaning.
What's Your Angle?
Identifying the proper slope for the hopper's interior cone is critical for complete discharge of contents. The size, weight, coating and shape of the tablet – or the consistency of the powder or granular ingredients that are being processed – will determine how "steep" the slope needs to be.
Typically, a 20- to 30-degree slope angle is sufficient for most tablets to flow freely in a gravity feed from the hopper. Powders, however, may require a 45- or 60-degree angle in order to avoid getting "hung up" in the cone.
Minimizing the slope allows for a much more compact container and increases overall space efficiency and safety, because stacks of hoppers are shorter and easier for a forklift driver to build or take apart. Conduct a few simple in-plant tests with your tablets and powders to determine the optimal angle for your hoppers.
What's the friability or compression strength of your tablets? If tablets break or crumble easily, you may want to consider a "shallow" hopper that serves two purposes. First, the tablets will have a shorter distance to fall into the container, greatly reducing impact energy. And second, the tablets on the bottom will not be crushed by the weight of the tablets on top of them.
See the Light
If the ingredients in the tablets and powders processed at your plant are sensitive to light, be sure to specify an opaque pigment for the hopper. This can best be accomplished by having the pigment melt compounded into the polyethylene. The thickness of the hopper wall will play a minor role in opacity and the minimum required thickness will vary depending on whether you choose single- or double-walled containers.
Control Moisture and Dust
Do you manufacture a hygroscopic product? If so, hopper openings should be designed to prevent moisture absorption. Lids with a variety of gasketed closures, for instance, would meet this requirement. Since slidegate and butterfly discharge valves are not moisture-tight, specify an iris valve. If product dust poses a hazard to your employees, make sure that all material transfer operations are fully enclosed and vented. Hoppers can be designed and developed to accommodate these specific requirements.
Hoppers – also referred to as intermediate bulk containers – are used to move materials to and from compression, imprinting, coating and packaging lines. It's a good idea to compile a list of lift trucks, pallet jacks, automated guided vehicles (AGVs), conveyors, and column lifts that may be used to transport hoppers and check to ensure compatibility. Your equipment should be able to securely lift the hopper without damaging the bottom discharge valve.
If your operation employs an automated storage and retrieval systems (AS/RS), compatibility is a critical issue. Also, consider the physical layout of your plant. Depending on factors such as aisle width, staging area dimensions and orientation, hoppers may require two-way or four-way access for lift trucks or pallet jacks.
Need A Sample?
Will you need to sample a product while it's in storage? Is it permissible to open the main lid or valve? A hopper that features a convenient sampling port provides easy access to contents for testing and inspection purposes.
What Color Is Your Hopper?
Plastic hoppers are available in a wide range in colors. Color-coded hoppers and bases provide a quick visual method for sorting material and managing inventory more easily. Color-coding can also help to identify different brands of pharmaceutical products and prevent cross-contamination concerns.
Put a Trace On It
Traceability is always an important consideration, so make sure hoppers can be equipped with labeling areas for bar codes, card holders, or RFID tags for more precise tracking within your plant or during transit.
Hoppers provide the greatest efficiency in bulk material handling for pharmaceutical operations. Containers such as small totes and boxes are less expensive and less efficient than hoppers. The ergonomic advantages of hoppers over labor-intensive totes or hard-to-handle drums may be a significant factor to consider in terms of injuries and workers' compensation issues.
Custom Designed Hoppers
Depending on your circumstances, it may be more economical to make a mold and produce custom engineered plastic hoppers than to fabricate stainless steel hoppers. What's more, it may not be necessary to order a large quantity of custom hoppers to justify the expense.
Whether you need hoppers for a brand new or an existing line, custom engineered hoppers can be designed to meet your specific in-line manufacturing requirements. Size, color, discharge valves, tamper-resistant lids and compatibility with auxiliary equipment are just a few of the options that can be customized to save time, streamline production and make your operation more efficient.
In fact, a growing number of pharmaceutical manufacturers are starting from scratch and specifying hoppers that are completely customized to their plant environment and products. There are cases where 25 plastic units were more economical than stainless because the required tooling is relatively inexpensive.
To be sure, there are a number of points to consider when selecting pharmaceutical hoppers. Be smart. Do your homework. Get all the facts. Talk to knowledgeable container consultants who understand your bulk material handling concerns. Knowing all the available options is the first step in making a smart equipment decision that will benefit your operation and your bottom line for years to come.