Spooling of tapes and fibres is an historic art going back many centuries. Many products...
ALPHA Converting believe that its approach to understanding their customer requirements has led to some unique machine developments for a wide range of products but more importantly satisfied customers appreciate the quality of the equipment and with the correct machine for their requirements are happy to place orders for repeat machines.
In any process there ends up being compromises and it is our role to fully understand the priorities of our customers in order to supply the best solution for their requirements. As machinery manufacturers we cannot normally influence the quality of the materials in terms of gauge and length variations, surface friction and extensibility. What we can do is to make sure that we offer the most suitable machine.
The ALPHATWIN slitter rewinder has many features for high-quality winding of general packaging films and laminates. Every machine is fitted with closed loop unwind tension control and this will be selected from a choice of load cell or dancer control depending on the roll sizes and material types to be used in the machine. Good unwind tension control is important because it effects not only the actual hardness of the rewind roll for many webs, but also the tracking of the web through the machine and wrinkling of lighter webs.
The layout of the slitting section can also have a major influence on the side wall quality of the rewind rolls: the best solution would almost always be to pass over a full stacked slitting shaft providing support across the full width of the web, but this is expensive and very inefficient when changing slitting patterns. Because the ALPHATWIN is used for slitting a wide range of webs it has the flexibility for wrap slitting (the web wraps the female knife shaft or grooved roll) or tangential slitting (the web is slit as it passed straight through a pair of slitting knives or razor blades) . If precise wrap slitting is required the female knives can be easily exchanged without handling of the knife shaft and restacked with spacers.
Most webs do not require full support and the automatic knife setting system has a series of algorithms to optimise the web support on every slitting width including the edge trims. And then there is rewinding, which is the end process in a slitting machine. Here the ALPHATWIN has a full recipe system providing full control of both winding tensions and layon roll pressures across the full range of conditions.
These not only control the roll hardness but can also affect the side wall quality and look of the finished roll. Once these have been set for a particular product the conditions are stored in the recipe system which is backed up automatically on to a data card in case of system failures, to ensure that the investment into optimising the conditions for each product are not lost.
Whilst the ALPHATWIN produces high-quality rolls for a wide range of products it is often necessary to use a different type of machine for specific products and sometimes to create a new machine specifically for a new product. The ALPHAWIND individual arm machine is normally used for high-quality film winding and features improved tension control on each individual roll, a constant short web path from the slitting station to the rewinds and a very precise contact layon roll system. In narrow slitting applications the threading of the web and controlling the tracking of the web are normally the major issues so the correct layout of the machine with short web paths and good tension control between path rollers are key.
The key thing for ALPHA Converting is to understand what their customer wants to achieve with their slitting and rewinding.
"No machine is the same. This can be difficult for a machinery supplier but it is vital to fully understand customer requirements before specifying a machine. When specifying a machine we never start with one of our standard machines but always with a full understanding of the customer requirements."
Everyone wants the fastest machine with quick size changes and automatic setting but economics and reliability of the total process is very important. The right machine may be completely different for two customers each converting identical products. The main facts that we start with would be:
- Material types
- Web widths
- Diameter of unwind and rewind rolls
- Shift patterns and local labour costs
- Frequency of size changes
- Special labelling and wrapping requirements
- Existing handling equipment for supply of unwind rolls and removal of finished rolls
From the initial specifications received we like to enter into a dialogue with any potential customer of the different options. Customers have their own experiences and it is only through discussion that we can offer a machine that is both right for the customer and one that we feel right to offer. In this second phase we build up the machine specification and where possible will offer a number of options. Even an unwind has many choices:
- Shafted or shaftless system
- Fixed height for loading by forklift or overhead crane or pick up from the floor
- Driven or braked tension delivery
- Load cell tension measuring roll or lightweight dancing roll for closed loop tension control
- Edge guiding or line guiding on printed webs, or no web guiding at all
- Use of hydraulics or clean line machine with
- Splicing on the roll or splice table; straight splice or angled splice; splice in register or simple alignment
Automation is perhaps the more interesting section of any machine specification. Alpha Converting can offer fully automatic machines complete with core labelling, roll transfer, roll closure and wrapping, removing many of the time consuming operator tasks and delivering machine dependent cycle rates down to 20 seconds. The automatic slitting knives, rewind arms or laser positioning systems can offer virtually instant size changes. Yet when there are a wide range of requirements there is little that can compare with a pair of human hands; again the right machine has to be specified for each customer.
Alpha Converting prides itself not just being another machine manufacturer but like to see it’s self as an engineering solutions partner to your business.