Stock and Custom Plastic Packaging

Custom Molding

6 Steps Take Your Idea from Art to Part

Custom MoldsWhen companies embark on a custom packaging project, the brand managers and creative team are often focused on the art and aesthetics of the finished package; the company molding the new bottle, however, is probably more focused on the science and engineering. Both elements are equally important in creating a successful package that meets requirements for appearance, performance, cost and availability. That’s why it is critical for brand owners and bottle manufacturers to work in partnership to ensure a custom bottle meets all the criteria necessary for success.

The process starts with a list of questions.

Oftentimes, the brand’s creative team has a fairly defined vision of what they want a bottle to look like. Sometimes, they even have a sample they are trying to simulate or directly duplicate. But the success of the bottle is much more than whether we can make the bottle look like someone’s vision. As the manufacturer responsible for making a bottle that can be filled, decorated, shipped and used reliably by the consumer, we ask a wide variety of questions to guide our design and engineering process.

Perhaps most importantly, what is going into the bottle? Is it watery, oily or viscous? How will it be dispensed, and has a specific closure been selected? Does the bottle need to be squeezable, or should it be rigid enough to withstand the downward pressure of a pump dispenser? And are the contents colored or clear? A dark product can impact the color of the filled container, even if the container is opaque, so knowing that upfront can help us guide the color selection process for the bottle or jar.

Regarding the closure system, if the dispensing closure needs to face a particular direction to align with the front label panel, that fact may determine which blow molding process we use. Knowing how a container will be decorated is also critical. Will it be pressure-sensitive labeled, silkscreened, or printed in some other manner? Does the bottle need decoration lugs – small indentations on the base of the bottle that allow the decorator to orient the bottle on the decoration line? Knowing what processes the bottle will be subject to enables us to determine the correct wall distribution, as well as any forms of surface treatment that may be recommended.

While the list of questions may seem tedious to the brand manager who is excited about launching a new product in a flashy new package, getting the right questions answered upfront can mean the difference between having a prototype approved in weeks, or going back to the drawing board to address issues that weren’t identified in the early stages of design.

Saving time and money using existing root tools

Once the customer-driven parameters of the new package have been defined with the customer, it becomes Alpha’s job to define the best manufacturing options for creating it. At Alpha, we not only have a variety of plastics that we can blow mold, but we also have different blow molding processes that we can use for those materials.

If we’re designing a PET bottle, we will almost always start with our existing library of preforms, to evaluate whether or not an existing preform can be used to blow the bottle. The preform is essentially a “test-tube” shaped plastic component that can be reheated and blown into a variety of shapes and sizes. We use both single stage and 2-stage PET blow molding processes, but both processes require a preform. (With single-stage blow molding, the preform is made in the machine during the blow molding process, instead of beforehand in a separate machine.) If we can use an existing preform, we can save the brand owner over $100,000 in mold costs, and also dramatically shorten the development process. The preform dictates the neck finish that the bottle will have, as well as its gram weight, and may lend itself to certain bottle shapes more than others. However, with nearly 100 preforms in our PET library, Alpha often has an existing preform from which to make a custom bottle or jar.

If an appropriate preform does not exist – for example, if the customer needs a special neck on the bottle, or a heavier or lighter bottle than normal – we work closely with the customer to create a custom preform that is optimized for their new bottle. Again, all the upfront questions we ask will help ensure this preform development process goes smoothly.

For HDPE bottles, the blow molding process we use (extrusion or injection) also affects the cost of the mold, so we take all factors into consideration while determining which process to use. The anticipated annual volume, closure requirements and decorating process are just a few of the criteria we’ll consider prior to selecting a platform and building a new mold.