Setting Up for a New Part

To manufacture a new plastic container, the manufacturer of any new part starts with the mold, but even once we have it there is still plenty of work to do. Apex Plastics has the experience, and technicalities to manufacture high quality plastic containers. Creating parts that meet specifications for wall thicknesses, consistency, and weight requires precision, experience, and trial and error. Here’s a quick look at some of the steps we take when setting up to make a new product.

First we have to create a parison, the piece of plastic that we will blow air into. The parison for every part is different. To make a parison, we have to select the proper head tooling. The size and shape of the head tooling is directly related to the weight distribution, or wall thickness, of the final product. Matching the tooling shape to the desired part is essential – it has to be right for the product to be a success. So how do we get it exactly right? First, we estimate. We need to consider both length and weight when we manufacture a new plastic container.

Length

It is safer to overestimate than underestimate. A short shot will make an incomplete, unusable part, but a long shot will result in an imperfect part we can learn from and refine to your calculations. We’ve been in the business a long time. The first thing we will do is study similar parts we have made to establish an approximation of what we will need. Then, we consider:

•     The length of the mold we are using
•     The distance from the start to top of the mold
•     The “lay-flat” of the parison (its size when laid on a surface)

Weight

We will use our experience with similar parts to make our first attempt at achieving the targeted weight. The thickness of the base and walls of the product, the amount of flash needed on the top, bottom, and sides, and the overall size will all be considered. At Apex, we have an extensive collection of head tooling available. If we do not already have what we need, we will have it built at the same time as the mold so the project can move ahead.

First Runs

With an educated estimate on the proper parison size, we will run a part and see how we did. Length can be refined by examining the amount of excess plastic left at the top and bottom after the part is molded. The piece is weighed and examined for wall thicknesses and consistency. With the problem areas identified, the process of refinement begins.

Profile Programming

Refining the process is done through profile programming. This automation tells the machine how fast to form the parison at different moments during the blow-molding process to achieve specific thicknesses throughout the part. We will test making automation set-points until the finished pieces are perfect and uniform. Once we are happy with the result, production can begin!